Registration Dossier

Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information

In the preliminary multiple generationstudy (supporting study in IUCLID), glufosinate ammonium was administered continuously in the feed to Wistar rats (10 animals/dose/sex) at nominal dietary concentrations of 0, 50, 500, 2500 and 5000 ppm. All test diets (including control) were available forad libitumconsumption; the homogeneity and stability of glufosinate ammonium as a dietary admixture was confirmed. Body weight and food consumption determinations and detailed clinical examinations of each animal were conducted weekly throughout the study, as well as, an evaluation of multiple reproductive parameters. All animals placed on study were subject to a postmortem examination, which included documenting and saving all gross lesions and weighing designated organs. Because of a total post-implantation loss in the females of groups 4 and 5, a supplementary study was initiated to clarify if the effects on fertility were caused by the parent males or by the parent females. For this reason, the 9-week continuously-treated males of groups 1, 3, 4 and 5 were paired over night with untreated mature females. Effects attributed to exposure to glufosinate ammonium were as follows: During the pre-pairing period, decreased food consumption was observed at 2500 and 5000 ppm. Implantation rate was decreased at 2500 and 5000 ppm with increased pre-implantation losses and total post-implantation losses. Increased post-implantation losses were also observed at 500 ppm. In pups a slight increase in body weight on LD21 and organ weights (liver, kidneys and spleen) was seen at 50 and 500 ppm, but mainly due to a slight decrease in mean pups per litter compared to control group.

The NOEL for parental toxicity was considered to be 50 ppm (approximately 4.3 mg/kg/day) based on

decreased food consumption during pre-pairing from 2500 ppm and increased kidney weights in males

from 2500 ppm, reprotoxic effects from 500 ppm, decreased body weight gain at 500 ppm and body

weight loss from 2500 ppm during gestation. The NOEL for reproduction toxicity was 50 ppm

(equating to 4.5 mg/kg bw/day) based on increased post-implantation losses at 500 ppm. The NOAEL

for pup toxicity was 500 ppm (equating to 74 mg/kg bw/day) based on increased body weight and

organ weights and no pups being delivered at 2500 and 5000 ppm.

Based on the results from the supplementary study, the reproductive effects seen in this study are due

to the toxicity of glufosinate ammonium on the females and not the males. The males treated at

5000 ppm were not affected in their reproductive capacity.

 

The principal objective ofthe definitive reproduction study(key study), was to assess the effects of glufosinate ammonium on the growth and reproduction of multiple generations in rats. In this study, glufosinate ammonium was administered continuously in the feed to the Wistar rat (30 animals/dose/sex, F0 parents and 26/sex/group, F1 parents) at nominal dietary concentrations of 0, 40, 120 and 360 ppm. Both generations were paired twice to rear two litters (F1A and F1B, F2A and F2B). Body weight and food consumption (parents only) determinations and detailed clinical examinations of each animal were conducted weekly throughout the study, as well as, an evaluation of multiple reproductive parameters. All animals placed on study were subject to a postmortem examination, which included documenting and saving all gross lesions and weighing designated organs. The findings observed in this study were decreased food consumption in the females during lactation at 360 ppm which correlated with a decrease litter size, increased kidney weights in both males and females from 120 ppm and no significant findings in the pups up to the highest dose.

The NOEL for reproduction was 120 ppm (equating to 7.7 and 9.6 mg/kg/day in males and females, respectively) based on reduced litter size at 360 ppm. The NOEL for offspring was higher than 360 ppm equating to 19 mg/kg/day from the lactation period.

Link to relevant study records

Referenceopen allclose all

Endpoint:
multi-generation reproductive toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Mar 1984 - May 1985
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Qualifier:
according to guideline
Guideline:
other: US EPA 163.83-4
Version / remarks:
1978
Principles of method if other than guideline:
To assess the effect of the test substance upon the growth and reproduction of multiple generations in the rat, it was mixed with granulated feed, pelleted and administered orally to the F0 generation of Wistar / HAN rats during an 80-day prepairing and also during the pairing, gestation and lactation periods for breeding of the F1A and F1B litters. Following the weaning of the F1B litters on day 21 post partum, the pups were reared for a further seven days on the test diet. Selection of the F1 parents and actual treatment of the F1 generation was considered to have commenced when they were approximately four weeks of age. The test article was administered during a 101-day prepairing period and also during the pairing, gestation and lactation periods for breeding of the F2A and F2B litters. The control group received the same diet without the test article.
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Remarks:
HAN, outbred, SPF quality
Details on species / strain selection:
This system has been selected as standard rodent species (according to guidelines) and is internationally recognized for this type of investigation.
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: KFM, Kleintierfarm Madoerin AG, CH 4414 Fuellinsdorf / Switzerland
- Age at study initiation: 7 weeks
- Weight at study initiation: 130 - 177 g (males), 112 - 149 g (females)
- Housing: individually
- Diet (e.g. ad libitum): pelleted standard Kliba 343, rat / mouse maintenance diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 10 days under test conditions, after veterinary examination

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2 °C
- Humidity (%): 55 +/- 10 %
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 h / 12 h
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): at least every 2 weeks
- Mixing appropriate amounts with (Type of food): standard Kliba 343, rat / mouse maintenance diet
- Storage temperature of food: room temperature
Details on mating procedure:
- M/F ratio per cage: 1/1
- Length of cohabitation: max. 9 days
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged (how): individually
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analyses of the test article, its content, homogeneity and stability in the food pellets were performed before starting the test, content and homogeneity at the start of pairing and at the end of gestation / start of lactation periods for breeding of F1A, F2A and F2B generations. The analyses were performed in the Analytical Laboratories of RCC according to an analytical method supplied by the sponsor.
Duration of treatment / exposure:
- F0 parent animals: The test article was administered during an 80-day prepairing- and also during pairing-, gestation- and lactation periods for breeding the F1A and F1B litters / pups.
- F1 parent animals (originated from F1B litters / pups): Following weaning on day 21 and the removal of the dams, the F1B pups were reared for a further seven days on the test diet. At this date, 26 male and 26 female pups were randomly selected to form the F1 parent animals. Actual treatment (food consumption) of the F1 males and females was considered to have commenced when they were approximately four weeks of age. The test article was administered during a 101-day prepairing period and also during pairing, gestation- and lactation periods for breeding of the F2A and F2B litters / pups.
Frequency of treatment:
daily
Details on study schedule:
- Selection of parents from F1 generation when pups were 21 days of age.
- Age at mating of the mated animals in the study: 18 weeks
Dose / conc.:
0 ppm
Dose / conc.:
40 ppm
Dose / conc.:
120 ppm
Dose / conc.:
360 ppm
No. of animals per sex per dose:
F0 generation: 30
F1 generation: 26
Control animals:
yes, plain diet
Details on study design:
- Dose selection rationale: The dosages were based upon the results of the preliminary study, in which 500 ppm in the diet caused a high postimplantation loss of 43.3 %, which was shown to be related only to effects in the females, was considered to be excessively high for use in a multiple generation study.
Parental animals: Observations and examinations:
MORTALITY / VIABILITY: Yes
- Time schedule: at least twice daily

CLINICAL OBSERVATIONS: Yes
- Time schedule: at keast twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Time schedule: weekly
- The food conversion ratios and consumption of the test article (in mg/kg bw/day) were calculated.
Sperm parameters (parental animals):
Parameters examined in F0 male parental generations:
testis weight, prostate weight and seminal vesicles weight
Litter observations:
PARAMETERS EXAMINED
The following parameters were examined in F1 & F2 offspring:
number and sex of pups, stillbirths, live births, presence of gross anomalies

GROSS EXAMINATION OF DEAD PUPS:
yes
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals shortly after the F1B pups were weaned
- Maternal animals: All surviving animals shortly after the F1B pups were weaned

GROSS NECROPSY
- Gross necropsy consisted of [external and internal examinations

HISTOPATHOLOGY / ORGAN WEIGHTS
The following tissues were prepared for microscopic examination: all gross lesions, aorta, adrenals, bone (with marrow, vertebra), brain (cerebrum, cerebellum, brainstem), eyes and the contiguous Harderian glands, heart, intestinal tract (esophagus, stomach, small intestine (duodenum, jejunum), large intestine (cecum, colon)), kidneys, liver (with at least two lobes), lung (with mainstream bronchi), lymph nodes (cervical, mesenteric), mammary gland, ovaries, pancreas, pituitary, porstate and accessory glands, salivary gland (submaxillary), seminal vesicles, sciatic nerve, skeletal muscle, skin, spinal cord (two levels), spleen, stomach, testes with epididymides, thymus in pups or where present, thyroids (with parathyroids if possible), tongue, trachea, urinary bladder, uterus (corpus and cervix), nasal cavity / turbinates, macroscopical changes
Postmortem examinations (offspring):
SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at 21 days of age.

GROSS NECROPSY
- Gross necropsy consisted of: brain (including entire brain stem), adrenals, spleen, uterus, pituitary, thymus, testes or ovaries, heart, kidneys, liver

HISTOPATHOLOGY / ORGAN WEIGTHS
The tissues were prepared for microscopic examination: all gross lesions, aorta, adrenals, bone (with marrow, vertebra), brain (cerebrum, cerebellum, brainstem), eyes and the contiguous Harderian glands, heart, intestinal tract (esophagus, stomach, small intestine (duodenum, jejunum), large intestine (cecum, colon)), kidneys, liver (with at least two lobes), lung (with mainstream bronchi), lymph nodes (cervical, mesenteric), mammary gland, ovaries, pancreas, pituitary, porstate and accessory glands, salivary gland (submaxillary), seminal vesicles, sciatic nerve, skeletal muscle, skin, spinal cord (two levels), spleen, stomach, testes with epididymides, thymus in pups or where present, thyroids (with parathyroids if possible), tongue, trachea, urinary bladder, uterus (corpus and cervix), nasal cavity / turbinates, macroscopical changes
Statistics:
The following statistical methods were used to analyze the body weights, food consumption, organ weights and reproduction data:
- Univariate one-way analysis of variance was used to assess the significance of intergroup differences.
- If the variables could be assumed to follow a normal distribution, the Dunnett-test (many to one t-test) based on a pooled variance estimate was applied for the comparison between the treated groups and the control groups.
- The Steel-test (many-one rank test) was applied when the data could not be assumed to follow a normal distribution.
For the overall spontaneous mortality data, the Fisher's exact test for 2 x 2 tables was applied.
Group means were calculated for continuous data and medians were calculated for discrete data (scores) in the summary tables.
Individual values, means, standard deviations and statistics were rounded off before printing. For example, test statistics were calculated on the basis of exact values for means and pooled variances and then rounded off to two decimal places. Therefore, two groups may display the same printed means for a given parameter, yet display different test statistics values.
Clinical signs:
no effects observed
Description (incidence and severity):
No test article-related signs of toxicity or clinical symptoms were evident in any animal of any dose group in any generation.
The isolated deviations and variations in behavioral and appearance noted in a few animals were considered to be spontaneous in origin and common in rats of this strain and age.
Mortality:
mortality observed, non-treatment-related
Description (incidence):
Throughout this multiple generation reproduction study on the test substance, no test article-related deaths occurred in the parent animals of either generation.
One group 3 (120 ppm) male lost body weight rapidly and died on day 8 after the pairing period for breeding of F1B litters. Additionally, female of group 2 (40 ppm) died during parturition of its F1B litter. These exceptions were considered to be incidental and within the normal mortality-range for animals of this strain and age.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Males
Before pairing for bredding of F1A litters, the mean body weights of all groups at the beginning of treatment were similar. At the end of the prepairing period of 80 days, no significant differences between the control group and any dose group were evident. After pairing for breeding of F1A litters until pairing for breeding of F1B litters, no test article- or dose-related differences were noted. The body weight gain in all groups was similar. After pairing for breeding of F1B litters until necropsy, the mean body weight gain and the mean body weights on the day of necropsy were similar in all groups. No test article-related or statistically significant differences were evident.

Females
Before pairing for breeding of F1A litters, no test article- or dose-related differences between the dose groups and the control group were noted. The calculation of the body weight gain for hte 80-day prepairing period resulted in similar values of all groups. During the gestation period for breeding of F1A litters, similar mean body weight gain of dams was noted in all groups. During the lactation period for breeding of F1A litters, no test article- or dose-related differences between any dose group and the control group were found. During the gestation period for breeding of F1B litters, no statistically significant differences in the mean body weight gain of dams in all groups were evident. During the lactation period for breeding of F1B litters, no test article-related differences between the dose groups and the control group were noted.
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
Males
Before pairing for breeding of F1A litters, the mean food consumption of all test article-treated groups was similar when compared to that of the control group. No treatment-related differences were noted during this prepairing period of 80 days. After pairing for breeding F1A litters until pairing for breeding F1B litters, no treatment-related difference in the mean food consumption of any group was evident. After pairing for breeding F1B litters until necropsy, the mean food consumption of all groups was similar.
Food Conversion of males: The food conversion ratios corresponded to the food consumption and body weights. The food conversion of both generations was similar during all periods.
The nominal dosage levels (test article consumption) of both generations were similar during the entire study.

Females
Before pairing for breeding of F1A litters, no test article-related or statistically significant differences between the control group and any dose group were evident during the prepairing period of 80 days. During the gestation period for breeding of F1A litters, no test article-related or statistically significant differences in the mean food consumption of dams of all groups were evident. During the lactation period for breeding of F1A litters, the comparison of the mean food consumption of dams until day 14 of the lactation period yielded no test article-related or statistically significant differences between the low- and mid-dose group and the control group. The statistically significant reduced food consumption of dams noted in group 4 was due to reduced litter size (number of pups per dam) in this group. During the gestation period for breeding of F1B litters, the mean food consumption of dams of all dose groups was comparable with the values of the controls. During the lactation period for breeding of F1B litters, no test article-related or statistically significant changes in food consumption of the dams of the low- and mid-dose group were evident. The statistically significant reduced food consumption noted of dams of group 4 was considered to be related to the reduced litter size (number of pups per dam) in this group.
Food conversion: The food conversion ratios corresponded to the food consumption and body weights. The food conversion of both generations during all periods was similar. The reduced values noted in the group 4 dams of both generations during the lactation periods was caused by the reduced litter size (number of pups per dam) of these animals.
The nominal dosage levels (test article consumption) of both generations were similar during the entire study. The amount of test article consumed during the different perios varied according to the corresponding food conversion.
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Reproductive performance:
no effects observed
Description (incidence and severity):
All parameters recorded yielded no evidence of adverse effects on mating performance and fertility except the number of the progeny of group 4 (360 ppm). The mean precoital time, percentage of mating, fertility index, conception rate and gestation index were similar.
No test article-related or statistically significant difference between any group was evident for the following observations: The number of females paired, mated, pregnant, bearing and rearing the pups and also the breeding loss. The number of living pups per dam in group 4 (360 ppm) was significantly reduced when compared with the other dose groups and the controls. This finding was considered to be test article-related.
The mean duration of gestation of groups 1, 2, 3, and 4 was similar.
The behavior of the dams of groups 1, 2, 3, and 4 during parturition and nursing was similar.
One dead pup was found at the first litter check after parturition in groups 2 and 3 and in the control group, respectively. In group 4, four dead pups were found. This findings were considered to be incidental and not treatment-related.
The total and mean number of pups in group 4 were significantly reduced when compared with the other dose groups and the controls. This finding was considered to be test article-related.
No test article-related differences were noted in any dose groups when compared to that of the control group concerning breeding loss.
Dose descriptor:
NOEL
Effect level:
120 ppm
Based on:
test mat.
Sex:
female
Basis for effect level:
other: reduced litter size at 360 ppm
Remarks on result:
other: Reproduction
Critical effects observed:
not specified
Clinical signs:
no effects observed
Description (incidence and severity):
No test article-related signs of toxicity or clinical symptoms were evident in any animal of any dose group in any generation.
The isolated deviations and variations in behavioral and appearance noted in a few animals were considered to be spontaneous in origin and common in rats of this strain and age.
Mortality:
no mortality observed
Description (incidence):
Throughout this multiple generation reproduction study on the test substance, no test article-related deaths occurred in the parent animals of either generation.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Males
Before pairing for breeding F2A litters, the mean body weights of all groups at initiation of the prepairing period were similar. At the end of the 101-day prepairing period, no significant differences between any group were evident. After pairing for breeding F2A litters until pairing for breeding F2B litters, comparable mean body weights were noted in all groups at start and end of this period. After pairing for breeding F2B litters until necropsy, the mean body weight gain amounted 12 to 17 grams during this period. No statistically significant difference was noted between any group.

Females
Before pairing for breeding of F2A litters, no test article-related or statistically significant differences between the dose groups and the control group were evident during the 101-day prepairing period. During the gestation, lactation period for breeding of F2A and F2B litters, no test article- or dose-related differences in the dose groups were noted when compared to that of the control group. The mean body weight gain in the dams of all groups were similar.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
Males
Before pairing for breeding F2A litters, the mean food consumption of all treated groups was similar and comparable with the controls. No test article-related changes were noted during the 101-day prepairing period. After pairing for breeding F2A litters, no treatment-related differences in the mean food consumption of any group was evident. After pairing for breeding F2B litters until necropsy, no significant differences were noted between the mean food consumption of the dose groups and the control group.
Food Conversion of males: The food conversion ratios corresponded to the food consumption and body weights. The food conversion of both generations was similar during all periods.
The nominal dosage levels (test article consumption) of both generations were similar during the entire study.

Females
Before pairing for breeding of F2A litters, no test article- or dose-related differences in the mean food consumption of groups 2, 3 or 4 were noted when compared with that of the controls. During the gestation period for breeding of F2A litters, the mean food consumption of dams during the gestation period was similar in all groups. During the lactation period for breeding of F2A litters, no test article-related changes in mean food consumption between the dose groups was noted. During the lactation period for breeding of F2A litters, the significantly reduced mean food consumption values noted in the dams of group 4 was related to the reduced litter size (number of pups per dam) in this group. During the gestation period for breeding of F2B litters, the mean food consumption of the dams of all groups during the gestation period was similar. During the lactation period for breeding of F2B litters, no test article-related change was noted. The statistically significant reduced mean food consumption of the group 4 animals was related to reduced litter size (number of pups per dam) observed in this group.
Food conversion: The food conversion ratios corresponded to the food consumption and body weights. The food conversion of both generations during all periods was similar. The reduced values noted in the group 4 dams of both generations during the lactation periods was caused by the reduced litter size (number of pups per dam) of these animals.
The nominal dosage levels (test article consumption) of both generations were similar during the entire study. The amount of test article consumed during the different perios varied according to the corresponding food conversion.
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
Statistically significant weight changes were noted for the kidneys. These were manifested by increased absolute kidney weights in group 3 (120 ppm) and 4 (360 ppm) males in F0 and F1 parents and group 4 (360 ppm) females (F1), increased kidney to body weight ratios which were recorded in groups 3 and 4 males (F1) and females (F0).
Increased organ to brain weight ratios of groups 3 and 4 males (F0 and F1) and group 4 females (F0 and F1) were also noted. No evidence of macroscopical correlation to these findings and no dose-relationship existed.
Other statistically significant absolute and relative organ weight changes were noted, but were considered to be random occurrences.
In the males of the F0 and F1 generations which failed to induce pregnancy in the second mating, no treatment-related changes were noted for seminal vesicles and prostate weights.
Reproductive performance:
no effects observed
Description (incidence and severity):
All parameters recorded yielded no evidence of adverse effects on mating performace and fertility except the number of the progeny of group 4 (360 ppm). The percentage mating, fertility index, conception rate and gestation index were similar in all groups.
With the exception of reduced litter size noted in group 4 (360 ppm), no test article-related or statistically significant differences between the control group and any dose group were evident. The number of females paired, mated, pregnant, bearing and rearing the pups and also the breeding loss were similar in all groups.
The mean duration of gestation of the dams of groups 1, 2, 3, and 4 was similar.
The behavior of the dams of groups 1, 2, 3, and 4 during parturition and nursing was similar.
No dead pups were found at the first litter check after parturition in any group.
No differences in the total and mean number of pups in the dose groups 2 and 3 were evident when compared with the control group. In group 4 (360 ppm), the total number of pups and the mean number of pups per dam was reduced. This finding, although not statistically insignificant, was considered to be related to the treatment with the test article.
No test article-related losses were noted in any dose group.
Dose descriptor:
NOAEL
Effect level:
120 ppm
Based on:
test mat.
Sex:
female
Basis for effect level:
other: reduced litter size
Remarks on result:
other: Reproduction
Dose descriptor:
NOAEL
Effect level:
360 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: absence of adverse effects
Remarks on result:
other: systemic toxicity
Critical effects observed:
not specified
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Similar body weights and body weight gain were noted in the pups of all dose groups of all generations. There were no significant or treatment-related changes observed.
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
No statistically significant changes in absolute or relative organ weights were noted in F1A and F2A male and female pups.
In F1B and F2B male and female pups, several organs of the group 4 (360 ppm) pups showed slightly but statistically significant increased absolute weights and in some cases, resulting increased relative organ weights. These changes were considered to be related to the increased body weights of the pups of this group.
Similar sex ratios in all groups were noted. No statistically significant differences between the sex ratios of groups 2, 3 and 4 were evident when compared with the respective control group.
The physical development, health conditions, viability and appearance of the pups of all groups were similar; no test article-related differences were noted.
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
360 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: absence of adverse effects
Remarks on result:
other: systemic toxicity
Critical effects observed:
no
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Similar body weights and body weight gain were noted in the pups of all dose groups of all generations. There were no significant or treatment-related changes observed.
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
No statistically significant changes in absolute or relative organ weights were noted in F1A and F2A male and female pups.
In F1B and F2B male and female pups, several organs of the group 4 (360 ppm) pups showed slightly but statistically significant increased absolute weights and in some cases, resulting increased relative organ weights. These changes were considered to be related to the increased body weights of the pups of this group.
Similar sex ratios in all groups were noted. No statistically significant differences between the sex ratios of groups 2, 3 and 4 were evident when compared with the respective control group.
The physical development, health conditions, viability and appearance of the pups of all groups were similar; no test article-related differences were noted.
Dose descriptor:
NOAEL
Generation:
F2
Effect level:
360 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: absence of adverse effects
Remarks on result:
other: systemic
Critical effects observed:
no
Reproductive effects observed:
yes
Lowest effective dose / conc.:
360 ppm
Treatment related:
not specified
Relation to other toxic effects:
reproductive effects in the absence of other toxic effects
Dose response relationship:
not specified
Relevant for humans:
not specified
Endpoint:
multi-generation reproductive toxicity
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
Sep 1983 - Dec 1983
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Remarks:
preliminary dose range finding study
Qualifier:
no guideline followed
Principles of method if other than guideline:
To determine the maximum tolerated dietary concentration of the test article for a subsequent multigeneration study, the test substance was mixed with repelleted feed and administered orally to Wistar / HAN rats at dose levels of 50, 500, 2500 and 5000 ppm during a three-week premating period and continued throughout the mating-, gestation- and lactation period. A control group received similar feed without the test article.

Supplementary x-fostering study:
Because of a total postimplantation loss in the females of groups 4 and 5, a supplimentary study was initiated to clarify if the effects on fertility were caused by the parent males or by the parent females. For this reason, the 9-week continously-treated males of groups 1, 3, 4 and 5 were paired over night with untreated mature females. During the pairing period, the males were administered with the corresponding diet only during the day. The females received feed continously without the test article also only during the day. After established mating, each animal was
housed individually and maintained on its respective diet until necropsy.
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Remarks:
HAN, outbred, SPF quality
Details on species / strain selection:
This system has been selected as standard rodent species (according to guidelines) and is internationally recognized for this type of investigation.
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: KFM, Kleintierfarm Madoerin AG, CH 4414 Fuellinsdorf / Switzerland
- Age at study initiation: between 8 and 9 weeks
- Weight at study initiation: 200 - 241 g (males), 157 - 185 g (females)
- Housing: individually
- Diet (e.g. ad libitum): pelleted standard Kliba 343, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 10 days under test conditions, after veterinary examination

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2 °C
- Humidity (%): 55 +/- 10 %
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 h / 12 h
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): at least every 2 weeks
- Mixing appropriate amounts with (Type of food): standard Kliba 343 maintenance diet
- Storage temperature of food: room temperature
Details on mating procedure:
- M/F ratio per cage: 1 / 1
- Proof of pregnancy: vaginal plug and / or sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged (how): individually
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analysis of the test article, its content, homogeneity and stability in the food pellets were performed before starting the test; content and homogeneity at start of mating and at the end of gestation / start of lactation periods. The analyses were performed in the Analytical Laboratories of RCC according to an analytical method supplied by the sponsor.
Duration of treatment / exposure:
- F0 generation parent animals: The test article was administered during a 3-week prepairing-, and also during pairing-, gestation- and lactation period.
- F1 generation pups: Following weaning on day 21 and the removal of the dams, pups were reared for a further seven days.
Frequency of treatment:
daily
Dose / conc.:
0 ppm
Dose / conc.:
50 ppm
Dose / conc.:
500 ppm
Dose / conc.:
2 500 ppm
Dose / conc.:
5 000 ppm
No. of animals per sex per dose:
10
Control animals:
yes, plain diet
Parental animals: Observations and examinations:
MORTALITY: Yes
- Time schedule: at least twice daily

CLINICAL OBSERVATIONS: Yes
- Time schedule: at least twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Time schedule: weekly
- The food conversion ratios in mg/kg bw/day consumption of the test article were calculated.
Litter observations:
PARAMETERS EXAMINED
The following parameters were examined in F1 offspring: litter size, live birth, stillbirth and any gross anomalies, sex ratio, body weights, behavior

GROSS EXAMINATION OF DEAD PUPS: yes
Postmortem examinations (parental animals):
GROSS NECROPSY
- Gross necropsy consisted of counting of corpora lutea and implantation sites; uteri of apparently non-pregnant females were placed into a solution of ammonium sulfide to visualize possible hemorrhagic alterations of implantation sites

HISTOPATHOLOGY / ORGAN WEIGHTS
The following tissues were prepared for microscopic examination and weighed, respectively: testes, prostate, seminal vesicles, spleen, liver, kidneys, ovaries
Postmortem examinations (offspring):
HISTOPATHOLOGY / ORGAN WEIGTHS
The following tissues were prepared for microscopic examination and weighed, respectively: spleen, liver, kidneys, ovaries
Statistics:
The following statistical methods were used to analyze the body weights, food consumption and organ weights:
- Univariate one-way analysis of variance was used to assess the significance of intergroup differences.
- If the variable could be assumed to follow a normal distribution, the Dunnett-test (many to one t-test) based on a pooled variance estimate was applied for the comparison between the treated groups and the control groups.
- The Steel-test (many-one rank test) was applied when the data could not be assumed to follow a normal distribution.
For the overall spontaneous mortality data, the Fisher's exact test for 2 x 2 tables was applied.
Group means were calculated for continuous data and medians were calculated for discrete data (scores) in the summary tables.
Individual values, means, standard deviations and statistics were rounded off before printing. For example, test statistics were calculated on the basis of exact values for means and pooled variances and then rounded off to two decimal places. Therefore, two groups may display the same printed means for a given parameter, yet display different test statistics values.
Clinical signs:
no effects observed
Description (incidence and severity):
No sign of toxicity or clinical symptom was noted in any animal of any group.
Mortality:
no mortality observed
Description (incidence):
No death occurred in any animal of any group during this preliminary study.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Males
- Prepairing period: Similar mean body weight gain was noted in groups 1, 2, 3, and 4. In group 5 (5000 ppm), the calculations of body weight gain during the entire prepairing period resulted in a slight, statistically insignificant reduction in comparison to that of the control group. The body weight gain amounted to 39.9 % in group 1 (control) and 32.6 % in group 5 (5000 ppm).
- After pairing for breeding F1 litters: After the pairing period, the mean body weight gain of all groups was similar. No statistically significant or test article-related differences were evident.

Females
- Prepairing period: No statistically significant or test article-related differences between the mean body weight gain of the dosed groups and that of the control group were noted.
- Gestation period for breeding F1 litters: The mean body weight gain during the gestation period was similar in groups 1 (control) and 2 (50 ppm). In group 3 (500 ppm), the calculations of the body weight gain during the entire gestation period resulted in a slight, statistically insignificant reduction in comparison to that of the control group. The body weight gain amounted to 56.7 % in group 1 (control) and 43.8 % in group 3 (500 ppm). This finding was considered to be indirectly test article-related because it was an effect of the reduced mean number of 6.4 pups per dam in group 3 compared to 12.7 pups per dam in group 1 (control). Females of groups 4 and 5 did not have fetuses / pups and were therefore not considered for the evaluations of body weights during the gestation period.
- Lactation period for breeding F1 litters: No test article-related difference between groups 1, 2, and 3 was evident. The deviations observed were considered to be caused by the different mean number of pups per dam. Females of groups 4 and 5 did not have pups and were therefore not considered for the evaluations of body weights during the lactation period.
Food consumption and compound intake (if feeding study):
effects observed, non-treatment-related
Description (incidence and severity):
Males
- Prepairing period: Similar mean food consumption was noted in groups 1, 2, and 3. The mean food consumption was dose-related significantly reduced in groups 4 (2500 ppm) and 5 (5000 ppm) during the first and second week of the prepairing period. During the third week of the prepairing period the mean food consumption of groups 1, 2, 3, and 4 were similar. In group 5, the mean food consumption remained slight and statistically insignificantly reduced whencompared to that of the control group.
- After pairing for breeding F1 litters: After pairing for breeding F1 litters, the mean food consumption of all groups was similar. No statistically significant or test article-related differences were noted.

Females
- Prepairing period: In groups 1, 2, and 3 the mean food consumption was similar. The mean food consumption was dose-related reduced in groups 4 (2500 ppm) and 5 (5000 ppm) during the first and second week of the prepairing period. The reduction was slight in group 4, but statistically significant in group 5. During the third week of treatment, the mean food consumption values of all groups were found to be similar.
- Gestation period for breeding F1 litters: The mean food consumption of groups 1, 2, and 3 was similar during the gestation period. The food consumption of groups 4 and 5 was not evaluated: no pups were born to the dams of these groups.
- Lactation period for breeding F1 litters: During the lactation period, similar mean food consumption was noted in groups 1 and 2. The mean food consumption of the dams in group 3 (500 ppm) was significantly reduced. This finding was not considered to be related to treatment with the test article, but referred to the reduced number of pups per dam in group 3, when compared to that of the group 1 dams. Females of groups 4 and 5 did not deliver pups and were therefore not considered for the evaluations of body weights during the lactation period.
Organ weight findings including organ / body weight ratios:
no effects observed
- Mating performance: No dose-related difference between any group was noted. The majority of all females were mated by the fourth day of the pairing period. The females of group 1 showed the longest mean precoital time.
- Pregnancy rate: No dose-related difference between any group was evident. All females of all groups treated with the test article were mated and found to be pregnant. The females of groups 4 and 5 delivered no pups, although implantation sited were noted.
- Duration of gestation: The mean duration of gestation in groups 1 and 2 were found to be similar. In group 3, the mean duration of gestation was 0.9 of a day longer than that of the control group. This was considered to be caused by the reduced number of pups per dam in group 3 and therefore only indirectly related to treatment with the test article. The females of groups 4 and 5 delivered no pups.
- Parturition and nursing: The behavior of group 1, 2 and 3 dams during parturition and lactation was similar. In each group, one dam did not rear its litter.
- Number of pups per dam after parturition: No test article-related differences between the total and the mean number of pups in groups 1 (control) and 2 (50 ppm) were noted. The differences noted were within the normal range of deviations for animals of this strain and age. In group 3 (500 ppm), the mean number of pups (6.4 per dam) was test article-related significantly reduced in comparison to that of the control group (12.7 pups per dam).
- Postnatal losses: No test article-related postnatal losses were noted. Only one pup was lost during the lactation period in groups 1 and 3, respectively, and no pup was lost in group 2.
- Implantation rate: In groups 4 (2500 ppm) and 5 (5000 ppm) the mean number of implantations was 26.7 % and 38.9 % less, respectively, when compared with that of group 1 (control). These statistically significant reductions were considered to be test article related. The mean number of implantations in groups 2 (50 ppm) and 3 (500 ppm) showed no dose-related redcution when compared to that of group 1.
- Preimplantation losses: The preimplantation losses of groups 4 (2500 ppm) and 5 (5000 ppm) were considered to be test article-related significantly increased compared to that of group 1 (control), indicated by the distinctly reduced mean number of implantations per dam. No statistically significant or dose-related differences in the mean number of implantations per dam of groups 2 (50 ppm) and 3 (500 ppm) and the control group were noted.
- Postimplantation loss: No treatment-related difference between groups 1 (control) and 2 (50 ppm) was evident. The mean postimplantation loss of group 3 (500 ppm) was 43.4 %, while groups 4 (2500 ppm) and 5 (5000 ppm) had postimplantation losses of 100 %, respectively.
Dose descriptor:
NOEL
Effect level:
50 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: decreased bw gain during gestation at 500 ppm
Remarks on result:
other: decrease in bw gain copared to control animals due to reduced litter size
Critical effects observed:
not specified
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
slight increase in bw on LD21 was seen at 50 and 500 ppm, but mainly due to a slight decrease in mean pups per litter compared to control.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
The mean food consumption of groups 1, 2, and 3 were similar.
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Slightly, but statistically significant increased liver weights in the male pups of group 2 (50 ppm), increased weights of liver, kidneys and spleen in the male pups of group 3 (500 ppm), increased absolute and relative weights of liver, kidneys and spleen in the female pups of group 2 and increased absolute and relative weights of liver and kidneys in the female pups of group 3.
These findings were considered to be the result of the increased body weights of pups caused by the reduced litter size (number of pups per dam) and not a specific effect of the test article.
Gross pathological findings:
no effects observed
Description (incidence and severity):
No treatment-related macroscopic findings were observed in any rat of the F1 generation.
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
No treatment-related differences were observed between groups 1, 2, and 3.
- External inspections for malformations and / or anomalies: No findings were noted in any group.
- Sex ratio: The sex ratio of groups 2 and 3 was similar to that of group 1. No significant differences were noted.
- Losses of pups during the lactation period: No treatment-related differences between groups 1, 2, or 3 were evident. No losses were noted after day 4 p.p. (identical with postnatal losses).
Dose descriptor:
NOAEL
Effect level:
50 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: increased postimplantation loss at 500 ppm
Critical effects observed:
not specified
Reproductive effects observed:
yes
Lowest effective dose / conc.:
500 ppm
Treatment related:
yes
Dose response relationship:
yes

The overall NOAEL for reproductive effects has been set at 50 ppm based on increased post-implantation losses at 500 ppm.

It could be shown that the pre- and postimplantation losses were caused by effects on the parent females as ascertained by the results of the supplementary study in which the untreated females mated by treated males showed no significant differences in the pre- and postimplantation losses in comparison to that of the control group.

Effect on fertility: via oral route
Endpoint conclusion:
adverse effect observed
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available

Effects on developmental toxicity

Description of key information

In the first rat developmental toxicity study, glufosinate ammonium was administered daily by gavage from gestation day (GD) 7 to 16 to groups of 20 pregnant Wistar female rats per dose-group. The doses given were 0, 10, 50 and 250 mg/kg/day dissolved in water.

Clinical observations were recorded daily and body weights were recorded for all females on GD 0, 7,

14, 17 and 21. Food consumption was also measured for all the females during the intervals GD 1-7, 7

- 14, 14 – 17 and 17 - 21. At scheduled sacrifice, on GD 21, a macroscopic examination of the visceral

organs was performed, the gravid uterine weight was recorded and the dams were evaluated for

number of corpora lutea, number and status of implantations (resorptions, dead and live fetuses). In

addition, heart, liver, kidneys, spleen and adrenals were weighed. Live foetuses were removed from the uteri, counted, weighed, sexed and examined externally. Their bodyweights were recorded and the

crown-rump lengths were measured. About half the foetuses from each litter and all foetuses found dead in the uterus (skeletal foetuses) were fixed in alcohol, dissected under a magnifying-glass where possible, eviscerated and bleached in aqueous potassium hydroxide. The skeletons were stained with Alizarin Red S and examined for development and anomalies.

The remaining foetuses (cross-section foetuses) were fixed in Bouin's fluid and examined in body

cross-sections under a stereomicroscope for organ anomalies. One dam died at 250 mg/kg/day and 4/20 females at 50 mg/kg/day and 8/20 females at 250 mg/kg/day were sacrificed following vaginal haemorrhages. Vaginal haemorrhages were observed in connection with intra-uterine deaths. One female at 250 mg/kg/day delivered only dead fetuses. All these females presented neurological signs, food intake restriction and body weight loss. Neurological signs were observed from 50 mg/kg/day and food consumption was slightly decreased from GD7 to 17 at 250 mg/kg/day. The number of corpora lutea and the number of implantations in all treatment group animals were comparable with those of the control dams. The litters of the dams that carried live foetuses to full term without signs of maternal toxicity were of the same sizes as those in the control group. The NOAEL for maternal toxicity was 10 mg/kg bw/day based on clinical signs of intolerance at 10 mg/kg bw/day. The NOAEL for developmental toxicity was 10 mg/kg bw/day based slight anomalies (pelvic and uretal dilatations) at 10 mg/kg bw/day. However, both these findings could not be observed at the same concentration in a follow-up study (supplementary study in the IUCLID dossier).

 

In a supplementary developmental toxicity study, glufosinate ammonium was administered daily by gavage from gestation day (GD) 7 to 16 to groups of 20 pregnant Wistar rats per dose-group. The doses given were 0, 0.50, 2.24 and 10 mg/kg/day dissolved in water to better assess the NOEL for maternal and embryonic toxicity. Clinical observations were recorded daily and body weights were recorded for all females on GD 0, 7, 14, 17 and 21. Food consumption was also measured for all the females during the intervals GD 1-7, 7 - 14, 14 – 17 and 17 - 21. On GD 21 the dams were killed and delivered by caesarean section. At scheduled sacrifice, a macroscopic examination of the visceral organs was performed, the gravid uterine weight was recorded and the dams were evaluated for number of corpora lutea, number and status of implantations (resorptions, dead and live fetuses). In addition, heart, liver, kidneys, spleen and adrenals were weighed. Live foetuses were removed from the uteri, counted, weighed, sexed and examined externally. Their bodyweights were recorded and the crown-rump lengths were measured. About half the foetuses from each litter and all foetuses found dead in the uterus (skeletal foetuses) were fixed in alcohol, dissected under a magnifying-glass where possible, eviscerated and bleached in aqueous potassium hydroxide. The skeletons were stained with Alizarin Red S and examined for development and anomalies. The remaining foetuses (cross-section foetuses) were fixed in Bouin's fluid and examined in body cross-sections under a stereomicroscope for organ anomalies. Glufosinate ammonium administered to pregnant Wistar rats up to 10 mg/kg/day from GD 7 to 16 did not impair the general health condition of the dams or the intra-uterine foetal development. There were no treatment-related changes in foetuses. In conclusion, the NOEL for maternal and development toxicity in this study was 10 mg/kg/ bw/day. Based on the results of both the key study and the supporting study, it can be concluded that a dose of 10 mg/kg bw/d of Glufosinate ammonium is near the tolerance level for Wistar rats.

 

In a third rat developmental toxicity study(RSS not included in the IUCLID dossier), glufosinate ammonium was administered daily by gavage from gestation day (GD) 7 to 16 to groups of 20 pregnant Wistar female rats per dose-group. The doses given were 0, 0.50, 2.24 and 10 mg/kg/day dissolved in water. The dams delivered their litter normally and reared their offspring for 21 days. During the rearing period, the physical development and survival rate of the offspring were examined. The study was terminated by autopsy of dams and offspring. Special attention was paid at the autopsy of the offspring to distensions of renal pelvis and ureter. Glufosinate ammonium administered to pregnant Wistar rats up to 10 mg/kg bw/day from GD 7 to 16 did not impair the general health condition of the dams, the intra-uterine or post-natal development of the offspring. In conclusion, the NOEL for maternal and development toxicity was at least 10 mg/kg bw/day.

 

In the rabbit developmental toxicity study, maternal toxicity was indicated by neurological signs in one female (with extensive spasms and high-legged position on day 16 followed by drowsiness on day 17) and by a reduction in food consumption and body weight gains and increased kidney weights observed at 20 mg/kg/day. An increased number of abortions were also noted at the same dose. Reduced food consumption and body weight loss were also observed in these females. However, the foetuses delivered in all treated groups were normally developed and showed no increase in malformations, anomalies or variations. Therefore, the NOAEL was set at 6.3 mg/kg body weight for maternal toxicity. The NOAEL for development toxicity was 6.3 mg/kg/day based on resorptions and abortions in three dams at 20 mg/kg/day.

 

In a developmental neurotoxicity study (see IUCLID chapter 7.8.2), female rats were administered glufosinate ammonium via the diet from 200 ppm up to 4500 ppm (equivalent to 14 up to 292 mg/kg/day). Palatability issues were observed in all treated groups on GD6 to 7 with a 33% decrease in food consumption compared to controls at 4500 ppm and a slight body weight loss on GD7 in all treated groups. However, the impact on overall mean body weight at 4500 ppm was only slight with an 8.3% decrease compared to control mean on GD20. No effect on pregnancy rate or embryotoxicity was observed.

Link to relevant study records

Referenceopen allclose all

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Sep - Nov 1983
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:
yes
Limit test:
no
Species:
rabbit
Strain:
Himalayan
Remarks:
Hoe:HIMK(SPFWiga)
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Hoechst AG
- Age at study initiation: 6-7 months
- Weight at study initiation: 2547 +/- 203 g
- Fasting period before study:
- Housing: individually
- Diet: ad libitum plus 40-50 g autoclaved hay
- Water: ad libitum
- Acclimation period: not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 47-65
- Air changes (per hr): 16-20
- Photoperiod (hrs dark / hrs light): 10/14, illumination from 6 am to 8 pm

IN-LIFE DATES: From: To:
Route of administration:
oral: gavage
Vehicle:
water
Remarks:
distilled water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: daily
- an equal liquid volume of 5 ml/kg bodyweight was administered to each animal between 8 and 11 a.m.
Analytical verification of doses or concentrations:
no
Details on mating procedure:
- Impregnation procedure: [artificial insemination / purchased timed pregnant / cohoused]
- If cohoused: yes
- M/F ratio per cage: not specified
- Length of cohabitation: In the morning hours during estrous
- When sperm was detected, animals were paired again 6 h later
- Determination of GD: Day of pairing was counted as day 0 of gravidity
- Proof of pregnancy: presense of implantation sites in the uterus
Duration of treatment / exposure:
GD 7-19
Frequency of treatment:
once daily
Duration of test:
On GD 29, the dams were killed and delivered.
Dose / conc.:
2 mg/kg bw/day
Dose / conc.:
6.3 mg/kg bw/day
Dose / conc.:
20 mg/kg bw/day
No. of animals per sex per dose:
15
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Before the start of the study, the test substance was administered in a range-finding test at the dose levels 10.0, 22.4 and 50.0 mg/kg bodyweight, in each case to 2 gravid Himalayan rabbits. In this test, 10.0 mg/kg was tolerated without complications by dams and foetuses alike. At 22.4 mg/kg bodyweight, both dams showed reduced body weights and one showed, in addition to six normally developed live foetuses, three dead foetuses and a conceptus under resorption in the uterus. At 50.0 mg/kg, a decrease in body weight, food consumption, and marked clinical signs of intolerance were observed. One of the animals was therefore killed on the following day (day 14 of gravidity), and the other died in the night from days 15 to 16 of gravidity. Based on these results, the following dose levels were established for the main study:
2.0 mg/kg as the dose likely to be tolerated by both dams and foetuses;
6.3 mg/kg as the geometrical mean between the selected low and high doses;
20.0 mg/kg as the dose likely to produce signs of intolerance.

- Rationale for animal assignment (if not random): random, scheme No. 364/83
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly in the first three weeks and then once again after a further 9 days.

FOOD CONSUMPTION: Yes
- Time schedule: continuous

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 29
- Organs examined: uterus, heart, liver, kidneys, spleen
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of resorptions: Yes
- Other: conceptuses, placentae, placental weights
Fetal examinations:
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No
Statistics:
Dunnett, Nemenzi/Dunnett, Goodman, Wilcoxon (pairwise)
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
A decrease in water consumption and/or quantity of faeces was observed between GD13 and 25 in 4 dams of the 2.0 mg/kg group, 2 dams of the 6.3 mg/kg group, 7 dams of the 20.0 mg/kg group and one control dam. The same findings were observed in the dams which did not survive until the end of the study.
Dermal irritation (if dermal study):
no effects observed
Mortality:
mortality observed, treatment-related
Description (incidence):
One dam from the 6.3 mg/kg/day treated group died on GD29 while giving premature birth. One dam from the 20 mg/kg/day treated group was sacrificed on GD17 after having shown extension spasms for 5 seconds immediately after administration on GD16 followed by high-legged position with the head stretched out and tilted for 10 minutes and then a phase of head tilting and drowsiness. On GD17 just before sacrifice the animal was lying on its stomach in a state of apathy. Another dam from this group aborted in the night from GD19 to 20 and a third one delivered prematurely in the night from GD24 to 25.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
- 20 mg/kg bw/day: decreased body weights during the first week of treatment and continued thereafter until GD 29
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
- 6.3 mg/kg bw/day: slight decrease in food consumption during the first week of treatment. However, this had no effect on body weight gains and was therefore regarded as a not particulary important finding.
- 20 mg/kg bw/day: marked decrease of food consumption in the first week of treatment and a moderate decrease in the second week.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
effects observed, treatment-related
Description (incidence and severity):
- 2.0 mg/kg bw/day: decrease in water consumption in four dams
- 6.3 mg/kg bw/day: decrease in water consumption in 2 dams
- 20 mg/kg bw/day: decrease in water consumption in 7 dams
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
effects observed, treatment-related
Description (incidence and severity):
- 20 mg/kg bw/day: one dam showed extension spasms (ca. 5 sec) immediately after the 10th application on GD 16; the animal subsequently remained for about 10 minutes in high-legged position, with the head stretched out and tilted, followed by a phase of head tilting and drowsiness; on the next morning the dam was lying on its stomach in a state of apathy
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
- 20 mg/kg bw/day: Kidney weights were slightly higher. All dams showed relatively high liver weights (not statistically significant and within the range of historical controls).
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
- 6.3 mg/kg bw/day: dark brown areas from 0.3 to 0.5 mm in diameter on the surface of both kidneys in one dam.
- 20 mg/kg bw/day: a cyst approximately 3 mm in size with greenish brown liquid contents was found on the surface of the lobus dexter accessorius of the liver in one dam, and also on the surface of the lobus caudatus of the liver in another dam. One dam showed recesses of different sizes on the surface of both kidneys.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Number of abortions:
effects observed, treatment-related
Description (incidence and severity):
-20 mg/kg bw/day: increase in the number of abortions
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
effects observed, non-treatment-related
Description (incidence and severity):
The total number of resorptions in the treatment groups was in the same range as that in the control group.
Dead fetuses:
effects observed, non-treatment-related
Description (incidence and severity):
- 2.0 mg/kg bw/day: all 15 dams bore live fetuses. Three dams bore one dead fetus each.
- 6.3 mg/kg bw/day: 14 dams bore live fetuses. One dam presented 5 plancentae and 5 living and 3 dead fetuses, another 8 living and one dead fetus
- 20 mg/kg bw/day: 11 dams bore live fetuses. One had seven implantation sites and two conseptuses under resorption in the uterus, but no living fetuses. One dam presented 6 dead fetuses, another revealed 7 conceptuses and a resorption site, and the dam that aborted bore 6 live fetuses and one dead fetus. From the dams that bore live fetuses, four bore one dead fetus and one bore two dead fetuses.

The total number of dead foetuses and resorptions in the treatment groups was in the same range as that in the control group.
Changes in pregnancy duration:
effects observed, treatment-related
Description (incidence and severity):
- 20 mg/kg bw/day: increase in premature births
Changes in number of pregnant:
no effects observed
Other effects:
no effects observed
Description (incidence and severity):
The number of corpora lutea, as an indication of the number of ovulations which had occurred, and the number of implantations were within the same range for the treated dams as for the controls.
Dose descriptor:
NOAEL
Effect level:
6.3 mg/kg bw/day
Based on:
act. ingr.
Basis for effect level:
body weight and weight gain
clinical signs
food consumption and compound intake
number of abortions
organ weights and organ / body weight ratios
water consumption and compound intake
other: increase in premature births
Abnormalities:
effects observed, treatment-related
Localisation:
uterus
Description (incidence and severity):
An increase in the number of premature births and abortions was observed at 20 mg/kg bw/day.
Fetal body weight changes:
no effects observed
Reduction in number of live offspring:
effects observed, non-treatment-related
Description (incidence and severity):
The live foetuses delivered in all three treatment groups were normally developed. The total number of dead foetuses in the treatment groups was in the same range as that in the control group.
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
no effects observed
Description (incidence and severity):
No disturbance of the viability of the foetuses during the first 24 hours after delivery.
External malformations:
effects observed, non-treatment-related
Description (incidence and severity):
- 2 mg/kg bw/day: One fetus showed an encephalocele which was due to a marked fissuration in the region of the os frontale and os parietale. This foetus died after one hour in the incubator.
Skeletal malformations:
effects observed, non-treatment-related
Description (incidence and severity):
The skeletons of the live foetuses in the treatment groups were at the same stage of development as the control foetuses. Skeletons of the foetuses found dead in the uterus were more weakly ossified.
- 2 mg/kg bw/day: calvarial fissuration in one fetus. One fetus showed fragmentation of the right dorsal vertebral arch on the 2nd vertebra.
- 6.3 mg/kg bw/day: slight splintering on the os parietale in one fetus. One or more fetuses showed a rib primordium on the 7th cervical vertebra
- 20 mg/kg bw/day: slight splintering on the os parietale in one fetus and another showed fused caudal vertebrae.

Other foetuses in all groups a primordium of a 13th rib or fused, dysplastic and dislocated sternebrae.
Visceral malformations:
effects observed, non-treatment-related
Description (incidence and severity):
Fetuses in all groups revealed aplasia of the lobus inferior medialis of the lung and/or adhesion of pulmonary lobes. One or more foetuses in all
groups also showed the stomach in transverse position, or taut with fluid and/or enlarged. Caudad displacement and/or transverse position of the left kidney was also encountered in a number of foetuses. Blood was found in the pericardium in one foetus of the 2.0 mg/kg group, and in the abdomen in one foetus of the 6.3 mg/kg group. In one foetus of the 20.0 mg/kg group both renal pelves were dilated.
Other effects:
no effects observed
Description (incidence and severity):
The placentae of the live foetuses in all groups were normal in weight and showed no macroscopic abnormalities. The placentae of the dead foetuses were in most cases smaller than those of the live foetuses, and were also anaemic.
Details on embryotoxic / teratogenic effects:
Morphological examination of the offspring in all three treatment groups revealed no abnormal findings, apart from an encephalocele in one foetus of the 2.0 mg/kg group. This was certainly of spontaneous origin, since it was an isolated instance, and did not occur in the foetuses of the medium and high dose groups (6.3 and 20.0 mg/kg). All other morphological findings in both dams and foetuses were within the limits of the spontaneous rate. Only a few animals were affected, and they were distributed at random over the various groups.
Dose descriptor:
NOAEL
Effect level:
6.3 mg/kg bw/day
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: dead fetuses, resorption and abortion at 20 mg/kg bw/d
Remarks on result:
other: developmental toxicity
Abnormalities:
no effects observed
Developmental effects observed:
yes
Lowest effective dose / conc.:
20 mg/kg bw/day
Treatment related:
yes
Relation to maternal toxicity:
developmental effects occurring together with maternal toxicity effects, but not as a secondary non-specific consequence of maternal toxicity effects
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Mar - Jun 1980
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Hoechst
- Age at study initiation: about 70 days
- Weight at study initiation: 193 +/- 12 g
- Housing: single
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-23
- Humidity (%): 55-65
- Air changes (per hr): 16-20
- Photoperiod (hrs dark / hrs light): 12/12 (illumination 6 am to 6 pm)

IN-LIFE DATES: From: To:
Route of administration:
oral: gavage
Vehicle:
water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: an equal liquid volume of 5 ml/kg bodyweight was
administered between 8 and 11 a.m. to each animal. Whenever the animals were weighed, the subsequent doses were adjusted accordingly.
Analytical verification of doses or concentrations:
no
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: not specified
- Length of cohabitation: overnight (between 3.30 pm and 7.30 am)
- Proof of pregnancy: sperm in vaginal smear referred to as day 1 of pregnancy
Duration of treatment / exposure:
GD 7-16
Frequency of treatment:
once daily
Duration of test:
GD 21
Dose / conc.:
10 mg/kg bw/day
Dose / conc.:
50 mg/kg bw/day
Dose / conc.:
250 mg/kg bw/day
No. of animals per sex per dose:
20
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Before the start of the study, an oral range-finding test had been performed in groups of two or three gravid Wistar rats in doses of 32, 63, 125 or 250 mg/kg bodyweight. Treatment took place from days 7 to 1 6 post copulationem. This study showed that doses up to and including 125 mg/kg bodyweight had no discernible effect on gravidity or foetuses. Hence the following dose levels were established for the main study:
10 mg/kg as the dose likely to be tolerated by both dams and foetuses
50 mg/kg as the geometrical mean between the selected low and high doses
250 mg/kg as the dose likely to produce slight signs of intolerance
- Rationale for animal assignment (if not random): random
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION: Yes
- Time schedule: continuous

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: uterus, heart, liver, kidneys, spleen, adrenals
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Resorption sites: Yes
- Live and dead fetuses: Yes
- Placenta: Yes
Fetal examinations:
- External examinations: Yes, about 50%
- Soft tissue examinations: Yes, about 50%
- Skeletal examinations: Yes, about 50%
- Head examinations: No
Statistics:
Fisher's Exact test: findings in the foetuses at autopsy and at the examination of body cross-sections and skeletons were evaluated for foetuses and litters separately,
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
- 10 mg/kg bw/day: motorial unrest in two females
- 50 mg/kg bw/day: motorial unrest in seven females, hyperactivity, pilo-erection in three females, flabbiness in two dams, arching of the spine in one dam, squatting in two dams, vaginal hemorrhages in four dams
- 250 mg/kg bw/day: motorial unrest in five females, hyperactivity, pilo-erection in nine females, flabbiness in seven dams, arching of the spine in five dams, squatting in one dam, vaginal hemorrhages in eight dams, blood around the mouth in three dams, purulent lacrimation in one dam
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, treatment-related
Description (incidence):
- 250 mg/kg bw/day: One female died
Females with vaginal hemorrhages observed at 50 (4/20) and 250 mg/kg bw/day (8/20) were sacrificed.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
- 50 mg/kg bw/day: In the dams with vaginal hemorrhages, bodyweights decreased
- 250 mg/kg bw/day: In the dams with vaginal hemorrhages, bodyweights decreased.
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
- 250 mg/kg bw/day: food consumption was slightly lower from GD 7 to 17 but was within the range of previous control values
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
effects observed, treatment-related
Description (incidence and severity):
- 10 mg/kg bw/day: motorial unrest
- 50 mg/kg bw/day: motorial unrest, hyperactivity, aggressiveness
- 250 mg/kg bw/day: motorial unrest, hyperactivity
Immunological findings:
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
- 50 mg/kg bw/day: one dam had large adrenals and small spleen
- 250 mg/kg bw/day: five dams had large adrenals and small spleen in two females; in one dam, the liver also showed accentuated lobular markings which was regarded as spontaneous finding

A number of dams in all groups exhibited varying degrees of distension of one or both renal pelves, which in some instances were filled with fluid and nephrolithic gravel. This finding was considered spontaneous and not treatment-related.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Number of abortions:
effects observed, treatment-related
Description (incidence and severity):
The vaginal haemorrhages are in all probability to be seen in connection with abortions. That abortions occurred is suggested by the vacant implantation sites in the uterus of one dam of the 50 mg/kg group and three dams of the 250 mg/kg group. An abortion was already in progress in one dam each from the 50 and 250 mg/kg groups, where one or several conceptuses were present in the birth canal. In one dam of the 50 mg/kg group and four dams of the 250 mg/kg group, which had only early implants or stunted foetuses, both live and dead, in the uterus, abortions were probably at the incipient stage.
Early or late resorptions:
effects observed, treatment-related
Description (incidence and severity):
- 50 mg/kg bw/day: In one dam, only embryonic resorptions were found
- 250 mg/kg bw/day: In three dams, only embryonic resorptions were found
Dead fetuses:
effects observed, treatment-related
Description (incidence and severity):
In the dams of the 50 mg/kg group with vaginal haemorrhages and in the dams of the 250 mg/kg group, dead foetuses were found more frequently in the uterus. Dead foetuses alone were found in only one dam, which had been treated with 250 mg/kg.
Changes in pregnancy duration:
not examined
Changes in number of pregnant:
no effects observed
Other effects:
effects observed, treatment-related
Description (incidence and severity):
- 50 mg/kg bw/day: One dam had only stunted, live fetuses with weights up to 1.15 g (premature delivery) and a supernumerary implantation site without embryonic tissue
- 250 mg/kg bw/day: One dam showed stunted foetuses, both live and dead, with weights up to 0.62 g. No remnants of aborted foetuses from any of the dams with vaginal haemorrhages were found in the cage-litter. One dam without vaginal haemorrhages delivered only stunted, dead foetuses and a supernumerary implantation site without foetal tissue on day 21 of gravidity. The dam in the 250 mg/kg group which died in the night from days 16 to 17 of gravidity had 13 normally developed conceptuses.
- no effects on number of corpora lutea
- no effects on number of implantations
Details on maternal toxic effects:
In the 4 dams of the 50 mg/kg group and the 8 dams of the 250 mg/kg group which were killed intercurrently due to vaginal haemorrhages, the following uterine findings were recorded: three early implants in the birth canal were found in one animal of the 50 mg/kg group and one in an animal of the 250 mg/kg group. There were nine other normally developed early implants in the uterus of each of these animals.
One animal in the 50 mg/kg group and three in the 250 mg/kg group had only implantation sites without embryonic tissue.
Dose descriptor:
NOAEL
Effect level:
10 mg/kg bw/day
Based on:
act. ingr.
Basis for effect level:
clinical signs
Abnormalities:
not specified
Fetal body weight changes:
no effects observed
Reduction in number of live offspring:
no effects observed
Description (incidence and severity):
The live foetuses delivered on day 21 of gravidity in the treated groups were normally developed.
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
not examined
External malformations:
no effects observed
Skeletal malformations:
effects observed, treatment-related
Description (incidence and severity):
- 250 mg/kg bw/day: skeleton was rather more weakly ossified, which manifested itself among other things in non-ossification of the os metacarpale 5 which was the only indicator of retarded ossification among the parts of the skeleton
Visceral malformations:
effects observed, treatment-related
Description (incidence and severity):
The frequency of pelvic and ureteral distension in the foetuses of the three treated groups (10 mg/kg group: 18.4 %, 50 mg/kg group: 25.2 %, 250 mg/kg group: 31.4 %) showed dose related increases as compared with the control foetuses (10 %) and the previous control values.

- control: One fetus showed distension of one renal pelvis and a hematoma on the right hind-limb; one fetus had hematoma on the back of the head; one fetus showed a hematoma on the left fore-limb; another fetus exhibited slight ectopia of lungs and heart
- 10 mg/kg bw/day: One fetus showed distension of one renal pelvis and a hematoma on hind-limb; In one fetus, a hematoma in the lobus sinister of the liver was observed
- 50 mg/kg bw/day: One fetus showed distension of one renal pelvis and a hematoma on hind-limb; One fetus had blood in the abdominal cavity

The haematomas, the blood in the abdominal cavity and the scapular findings occurred only sporadically in the various groups and are therefore isolated findings within the spontaneous rate, particularly since they occurred only in the 10 and 50 mg/kg groups.
Other effects:
effects observed, treatment-related
Description (incidence and severity):
- Placentae of live fetuses showed no abnormalities. Placentae of dead fetuses from dams treated with 250 mg/kg bw/day were smaller than those of the live fetuses in the other litters.
Dose descriptor:
NOAEL
Effect level:
10 mg/kg bw/day
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: slight anomalies (pelvic and ureteral distentions)
Abnormalities:
effects observed, treatment-related
Localisation:
visceral/soft tissue: urinary
other: skeletal ossification
Developmental effects observed:
yes
Lowest effective dose / conc.:
10 mg/kg bw/day
Treatment related:
yes
Relation to maternal toxicity:
developmental effects occurring together with maternal toxicity effects, but not as a secondary non-specific consequence of maternal toxicity effects

Because the frequency of the effects observed (pelvic distentions) exceeded slightly those of historical control data, they have been investigated in an additional study (supplementary study).

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
Jun - Sep 1981
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Qualifier:
no guideline followed
Principles of method if other than guideline:
The aim of the present study in the rat was to determine whether the pure herbicidal active test substance impaired the general health condition of the dams and the intra-uterine development of embryos if administered during gravidity.
The test animals were sexually mature virgin Wistar rats. Groups of 21 - 24 female animals were treated orally by gavage once daily from days 7 to 16 post copulationem.
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Hoechst breeding colony
- Age at study initiation: about 70 days
- Weight at study initiation: 186 +/- 11 g
- Housing: individually in plastic cages on wood-shavings
- Diet (e.g. ad libitum): Altromin 1314 in the form of pellets 10 mm in diameter, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 24 °C
- Humidity (%): 51 - 81 %
- Air changes (per hr): 16 - 20
- Photoperiod (hrs dark / hrs light): 12 h / 12 h
Route of administration:
oral: gavage
Vehicle:
water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: The test substance was freshly dissolved every day shortly before treatment in distilled water at concentrations of 0.100, 0.448 or 2.000 g/L, and an equal liquid volume of 5 mL/kg body weight was administered between 8 and 11 a.m. to each animal. Whenever the animals were weighed, the subsequent doses were adjusted accordingly.

VEHICLE
- Concentration in vehicle: 0.100, 0.448 or 2.000 g/L
- Amount of vehicle (if gavage): 5 mL/kg body weight
Analytical verification of doses or concentrations:
not specified
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused: overnight
- M/F ratio per cage: 1/1
- Length of cohabitation: overnight, between 3.30 p.m. and 7.30 p.m.
- Proof of pregnancy: sperm in vaginal smear referred to as day 1 of pregnancy
Duration of treatment / exposure:
days 7 - 16 of gravidity
Frequency of treatment:
once daily
Duration of test:
10 days
Dose / conc.:
0 mg/kg bw/day
Dose / conc.:
0.5 mg/kg bw/day
Dose / conc.:
2.24 mg/kg bw/day
Dose / conc.:
10 mg/kg bw/day
No. of animals per sex per dose:
20 gravid females
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: In tests carried out prior to the present study it had been established that repeated oral administration of the active ingredient of the test substance to gravid Wistar rats in doses of 10, 50 or 250 mg/kg body weight caused disturbances in general health conditions. The clinical signs and the number of animals affected showed a dose-relationship. The disturbances consisted in particular of motorial unrest, which was accompanied at 50 and 250 mg/kg bw by hyperactivity, piloerection, flabbiness, arching of the spine, squatting, vaginal haemorrhages, weight reduction, relatively large adrenals and small spleen, and at 250 mg/kg bw also by blood aroung the mouth, purulent lacrimation, intra-uterine deaths and the death of one dam. Morphological examination of the foetuses in all three dose groups revealed frequent distension of the renal pelvis and ureter. In the foetuses of the 250 mg/kg bw group the skeletons were also more weakly ossified. In order to determine the "no effect level" for maternal and embryonic toxicity, it was therefore necessary to conduct further tests with low doses.
10 mg/kg/day corresponded to the dose at which the first signs occurred during the previous developmental toxicity study; 0.50 mg/kg/day as no effect level and 2.24 was the geometric mean between the selected low and high doses.
Maternal examinations:
CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly and also one day after the final treatment

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Time schedule: continuously

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: placentae,, corpora lutea on the ovaries, uterus, heart, liver, kidneys, spleen and adrenals
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No data
Statistics:
Statistical evaluation of the test data was performed for each parameter with reference to an examination of basic data. The standard evaluation comprises simultaneous comparisons of the dose groups with the control group and comparison of all groups with normal ranges. The findings in the foetuses at autopsy and at the examination of body cross-sections and skeletons were evaluated for foetuses and litters separately, using the exact Fisher test or the simultaneous comparison with the control in a contingency table.
Clinical signs:
no effects observed
Description (incidence and severity):
No disturbance of behaviour or general health conditions were observed.
In one dam each of the 2.24 and 10.00 mg/kg groups and the control group, and in three dams of the 0.50 mg/kg group, hairloss occurred on nape, abdomen, flanks or fore-limbs. In four of these animals, the hairloss began before the start of treatment, in one animal during the treatment period, and in one dam only after the termination of treatment on day 21 of gravidity. A circumscribed area of scab formation was observed on the neck of the dam from the 2.24 mg/kg group and on the head of the control group dam.
Mortality:
no mortality observed
Description (incidence):
All of the animals survived until the termination of the study.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
The body weight gains of the dams in all groups remained unaffected by treatment.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
The food consumption of the dams in all groups remained unaffected by treatment.
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
The weights of heart, liver, kidney, spleen and adrenals in the dams treated with the test substance did not differ from the values of the control animals.
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
Slight to severe distension of one or both renal pelves was observed in several dams from all groups. There were no other discernible changes in the other organs.
Number of abortions:
no effects observed
Description (incidence and severity):
All of the dams carried live foetuses to full term.
Pre- and post-implantation loss:
no effects observed
Description (incidence and severity):
The number of implantations and live foetuses per dam were comparable with those in the control dams.
Early or late resorptions:
no effects observed
Description (incidence and severity):
All dams in all groups carried live foetuses to full term. The number of corpora lutea, as an indication of the number of ovulations which had occurred after mating, and the number of implantations and live foetuses per dam were comparable with those in the control dams.
Dead fetuses:
effects observed, non-treatment-related
Description (incidence and severity):
Dead fetuses were found in all groups, and were almost invariably conceptuses under resorption. The placentae of the live foetuses showed no macroscopic abnormalities, and their weights were within the range of previous control values.
Other effects:
no effects observed
Dose descriptor:
NOEL
Effect level:
10 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: absence of effects
Abnormalities:
no effects observed
Fetal body weight changes:
no effects observed
Description (incidence and severity):
The body weights and body lengths were comparable with those of the control foetuses.
Changes in sex ratio:
no effects observed
Description (incidence and severity):
The ratio of males and females was relatively balanced.
External malformations:
effects observed, non-treatment-related
Description (incidence and severity):
At autopsy no treatment-related findings were recorded. A few malformations were observed in most groups including controls. A foetus at 2.24 mg/kg/day exhibited a gastroschisis, a diaphragmatic hernia was seen in one foetus of the control group and at 10 mg/kg/day, one foetus showed a cleft palate and two fetuses from a single litter haematocysts at the top of both hind-paws, accompanied by aplasia of the corresponding toes.
Skeletal malformations:
effects observed, non-treatment-related
Description (incidence and severity):
A few observations were noted at skeletal examinations but without any dose relationship. The skeletons of the live foetuses were at the same stage of development as those of the control foetuses, corresponding to day 21 of gravidity. The skeleton of the stunted foetus in the 0.50 mg/kg group were only weakly ossified. In addition to these anomalies, a short rib at the 7th cervical vertebra was found in one foetus of the 10.00 mg/kg group and a 14th thoracic vertebra with ribs attached in another foetus of the same group; several foetuses from the 2.24 and 10.00 mg/kg groups revealed a fragmented thoracic vertebral centrum or fragmented, dislocated, dysplastic and longitudinally displaced sternebrae. Also, several foetuses in all groups exhibited thickened, undulated or bent ribs, and numerous foetuses had a 14th rib anlage on the 1st lumbar vertebra.
Visceral malformations:
effects observed, non-treatment-related
Description (incidence and severity):
Blood in the abdominal cavity was observed in several foetuses in all groups, distension of the renal pelvis was observed in a few fetuses of the control, 0.50 and 2.24 mg/kg/day groups but with no dose – relationship.
Other effects:
effects observed, treatment-related
Description (incidence and severity):
Autopsy and examination of the body cross-sections revealed several foetuses in all groups with blood in the abdominal cavity. Also, several foetuses of the 0.50 and 2.24 mg/kg groups and the control group revealed distension of the renal pelvis. Finally, haematomas were found in three foetuses of the 2.24 g/kg group, on the head, the head and neck, and the tail respectively.
Dose descriptor:
NOEL
Effect level:
10 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: absence of adverse effects
Abnormalities:
no effects observed
Developmental effects observed:
no

Table 1: Daily food consumption g/100 g body weight

Dose

[mg/kg]

Day of pregnancy

1 – 7

7 – 14

14 – 17

17 – 21

N

Mean

SD

 

N

Mean

SD

N

Mean

SD

 

N

Mean

SD

 

Control

20

9.36

0.57

N

20

8.61

0.52

20

8.09

0.61

N

20

8.01

0.58

N

0.50

20

9.76

0.61

- N

20

8.92

0.49

20

8.47

0.69

- N

20

8.16

0.76

- N

2.24

20

9.53

0.75

- N

20

8.44

0.62

20

8.40

0.56

- N

20

8.03

0.78

- N

10.00

20

9.51

1.21

- N

20

8.41

0.71

20

8.07

0.90

- N

20

8.22

0.48

- N

- = No difference from control

N = within the normal range

Table 2: Body weight in gram

Dose

[mg/kg]

Day of pregnancy

0

7

14

17

21

N

Mean

SD

 

N

Mean

SD

N

Mean

SD

N

Mean

SD

 

N

Mean

SD

 

Control

20

187

7

N

20

217

10

20

246

15

20

264

18

N

20

311

24

N

0.50

20

181

11

- N

20

216

10

20

249

13

20

270

15

- N

20

317

17

- N

2.24

20

187

9

- N

20

220

10

20

250

11

20

270

12

- N

20

317

14

- N

10.00

20

190

13

- N

20

223

12

20

253

12

20

270

12

- N

20

315

14

- N

- = No difference from control

N = within the normal range

Effect on developmental toxicity: via oral route
Endpoint conclusion:
adverse effect observed
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the effects observed (pre- and post-implantation losses), glufosinate ammonium is classified according to EC/1272/2008 Annex VI for reproductive toxicity with Cat. 1B (H360Fd - May damage fertility. Suspected of damaging the unborn child).

Additional information