2-methyldecan-1-al

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 September - 30 November 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted in accordance with international guidelines and in accordance with GLP. All relevant validity criteria were met.

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS 870.3650, Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test, July 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Undecanal

EC Number:

203-972-6

EC Name:

Undecanal

Cas Number:

112-44-7

Molecular formula:

C11H22O

IUPAC Name:

Undecanal

Test material form:

liquid

Specific details on test material used for the study:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
n/a
- Specific activity:
n/a
- Locations of the label:
n/a
- Expiration date of radiochemical substance:
n/a

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
Dark, under nitrogen
- Stability under test conditions:
Stable
- Solubility and stability of the test substance in the solvent/vehicle:
Test item formulated in propylene glycol. Analysis conducted to confirm stability.
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:
n/a

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
Test item formulated in propylene glycol.
- Preliminary purification step (if any):
n/a
- Final dilution of a dissolved solid, stock liquid or gel:
n/a
- Final preparation of a solid:
n/a

FORM AS APPLIED IN THE TEST (if different from that of starting material)
n/a

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)
n/a

OTHER SPECIFICS: n/a

Test animals

Species:

rat

Strain:

other: Crl:WI(Han)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:
Charles River Deutschland, Sulzfeld, Germany
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation:
ca. 12 weeks
- Weight at study initiation:
all an im als within ± 20% of the sex mean.
- Fasting period before study:
no
- Housing:
Pre-mating: Animals were housed in groups of 5 animals/sexlcage in Macrolon cages (MIV type, height 18 cm). Mating: Females were caged together with males on a one-to-one-basis in Macrolon cages (MIII type, height 18 cm). Post-mating: Males were housed in their home cage (Macrolon cages, MIV type, height 18 cm) with a maximum of 5 animals/cage. Females were individually housed in Macrolon cages (MIII type, height 18 cm). Lactation: Pups were kept with the dam until termination in Macrolon cages (MIII type, height 18 cm). General: Sterilised sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ud), Surrey, United Kingdom) were supplied. Certificates of analysis were examined and then retained in the NOTOX archives. During activity monitoring, animals were housed individually in Macrolon cages (MIII type; height 15 cm) with sterilised sawdust as bedding material. No cage-enrichment was provided during activity monitoring.
- Diet (e.g. ad libitum):
Free access to pelleted rode nt diet (SM R1M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany). Results of analyses for nutrients and contaminants were examined and archived. A sampie (approximately 500 grams) of each batch was retained at room temperature until finalization of the study report.
- Water (e.g. ad libitum):
Free access to tap-water. Certificates of analysis (performed quarterly) were examined and archived.
- Acclimation period:
≥ 5 days

DETAILS OF FOOD AND WATER QUALITY:
Not reported

ENVIRONMENTAL CONDITIONS
- Temperature (°C):
21 ± 3 ºC
- Humidity (%):
40-70 %
- Air changes (per hr):
ca. 15
- Photoperiod (hrs dark / hrs light):
12:12 light:dark

IN-LIFE DATES: From: 14 September 2009 To: 30 November 2009

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on exposure:

- PREPARATION OF DOSING SOLUTIONS:
Not reported

- DIET PREPARATION
- Rate of preparation of diet (frequency):
n/a
- Mixing appropriate amounts with (Type of food):
n/a
- Storage temperature of food:
n/a

- VEHICLE
- Justification for use and choice of vehicle (if other than water):
Based on trial formulations performed at NOTOX.
- Concentration in vehicle:
Not reported
- Amount of vehicle (if gavage):
Dose volume was 5 mL/kg bw
- Lot/batch no. (if required):
Not reported
- Purity: Not reported

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses were conducted on a single occasion during the treatment phase, according to a validated method (NOTOX project 492005). Sampies of formulations were analyzed for homogeneity (highest and lowest concentration) and accuracy of preparation (all concentrations). Stability in vehicle over 6 hours at room temperature was also determined (highest and lowest concentration).

The accuracy of preparation was considered acceptable if the mean measured concentrations were 90-110% of the target concentration. Homogeneity was demonstrated if the coefficient of variation was ≤ 10%. Formulations were considered stable if the relative difference before and after storage was maximally 10%.

Details on mating procedure:

- M/F ratio per cage: Females were caged together with males on a one-to-one-basis.
- Length of cohabitation: A maximum of 13 days was allowed for mating.
- Proof of pregnancy: Detection of mating was confirmed by evidence of sperm in the vaginal lavage, by staging of the oestrus cycle and/or or by the appearance of an intravaginal copulatory plug. This day was designated Day 0 post-coitum.
- After successful mating each pregnant female was caged (how): Females were individually housed in Macrolon cages (MIII type, height 18 cm). Pups were kept with the dam until termination.
- Any other deviations from standard protocol: No

Duration of treatment / exposure:

Males were exposed for 28 days, Ie. 2 weeks prior to mating, during mating, and up to termination. Females were exposed for at 42-48 days, Ie. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation. Female nos. 69 and 70 (Group 3) were not dosed during littering.

Frequency of treatment:

Once daily for 7 days per week, approximately the same time each day with a maximum of 6 hours difference between the earliest and latest dose. Animals were dosed up to the day prior to scheduled necropsy.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

100 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

300 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Details on study design:

40 males and 40 females

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily

BODY WEIGHT: Yes
- Time schedule for examinations: Males and females were weighed on the first day of exposure and weekly thereafter. Mated females were weighed on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum and during lactation on Days 1 and 4.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: Subjective appraisal

OTHER: haematology (F0) / clinical chemistry (F0) / gross pathology (F0) / nerurobehavioural examination (F0)

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 early resorptions: No
- Number of late resorptions: No
- Other:

Fetal examinations:

- External examinations: Yes: all litter
- Soft tissue examinations: Yes: all litter
- Skeletal examinations: No
- Head examinations: No

Statistics:

The following statistical methods were used to analyse the data:
- If the variables could be assumed to follow a normal distribution, the Dunnett-test (Dunnett, 1955) (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (Miller, 1981) (many-to-one rank test) was applied if the data could not be assumed to follow a normal distribution.
- The Fisher Exact-test (Fisher, 1950) was applied to frequency data.

All tests were two-sided and in all casesp < 0.05 was accepted as the lowest level of significance.

Group means were calculated for continuous data and medians were calculated for discrete data (scores) in the summary tables. Test statistics were calculated on the basis of exact values for means and pooled variances. Individual values, means and standard deviations may have been rounded off before printing. Therefore, two groups may display the same printed means for a given parameter, yet display different test statistics values.

No statistical analysis was performed on histopathology findings.

The number of implantation sites was subjected to the Kruskal-Wallis nonparametrie ANOVA test (Kruskal, 1952) to determine intergroup difference. If the results of the ANOVA were significant (p<0.05), the Wilcoxon test (Wilcoxon, 1945) was applied to the data to compare the treated groups to the control group.

Indices:

For each group the following calculations were performed;
% mating females
Fertility index females
Conception rate
Gestation index
Duration of gestation
% live males
% live females
% post-natal loss (Day 0-4)
Viability index

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

No clinical signs of toxicity were noted during the observation period.

Salivation seen during/after dosing among all animals of the 300 and 1000 mg/kg dose group during most of the treatment period was considered to be a physiological response rather than a sign of systemic toxicity considering the nature and minor severity of the effect and its time of occurrence (Le. after dosing). This sign may be related to irritancy/taste of the test substance. Rales, scabs and alopecia occurred within the range of background findings to be expected for rats of this age and strain which are housed and treated under the conditions in this study. At the incidence observed, these were considered signs of no toxicological significance.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Body weights and body weight gain of treated animals remained in the same range as controls over the treatment period.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

No toxicologically significant changes in food consumption before or after allowance for body weight were noted.

The statistically significant lower food consumption of females at 1000 mg/kg between Days 0-4 of the post-coitum phase was of a temporary and slight nature, and therefore considered to be of no toxicological relevance.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Description (incidence and severity):

Haematological parameters of treated rats were considered not to have been affected by treatment.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

A statistically significant higher potassium value was measured for males at 1000 mg/kg/day, but the mean remained within the range considered normal for rats of this age and strain. In females at 1000 mg/kg/day, a higher mean cholesterollevel was recorded (being slightly outside the range considered normal for rats of this age and strain) along with notably higher bile acid levels in some females (means not statistically significant). Given that these changes were generally slight in nature, were not present as a group response (bile acids) and occurred in the absence of supportive morphological changes, these were considered to be of no toxicological relevance.

Other statistically significant variations in clinical biochemistry parameters were considered to be of no toxicological relevance as these occurred in the absence of a treatment-related distribution and/or remained within the range considered normal for rats of this age and strain. These variations consisted of higher or lower alkaline phosphatase activity (ALP) in males and females at 300 mg/kg/day, lower total bilirubin level in males at 300 mg/kg/day, higher urea level in males at 300 mg/kg/day, higher cholesterollevel in males at 300 and 1000 mg/kg/day, and lower urea level in females at 1000 mg/kg/day.

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

Hearing ability, pupillary reflex, static righting reflex and grip strength were normal in all animals.

The variation in motor activity did not indicate a relation with treatment.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

A higher Iiver weight and liver to body weight ratio, and lower prostate and prostate to body weight ratio was noted for males at 1000 mg/kg/day (statistically significant for liver to body weight ratio only). These changes were only slightly outside the normal range for rats of this age and strain.

The higher prostate to body weight ratio of males at 100 mg/kg/day occurred in the absence of a dose-related trend, and the mean remained within the range considered normal for rats of this age and strain. No toxicological relevance was ascribed to this change. Other organ weights and organ to body weight ratios among the dose groups were similar to control levels.

The higher liver weight and Iiver to body weight ratio, and lower prostate and prostate to body weight ratio for males at 1000 mg/kg/day was not supported by any histopathological changes. Moreover, since these changes were slight in nature (only slightly outside the normal range), these were considered to be of no toxicological relevance.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

The following necropsy findings were considered to be related to treatment with the test substance:
- An irregular surface of the forestomach in all males at 300 and 1000 mg/kg/day, and in 6 females at 300 mg/kg/day and ni ne females at 1000 mg/kg/day.
- Foci (black or red) in the forestomach in two males at 300 mg/kg/day.
- Yellowish discolouration of the forestomach in one male at 300 mg/kg/day and one female at 1000 mg/kg/day.
- Reddish discolourationlreddish foci in the glandular mucosa in two males at 1000mg/kg/day.
- Thickened glandular mucosa in three females at 1000 mg/kg/day.

Incidental findings among control and treated animals included reddish foci on the lungs, a nodule on the liver, epididymides or clitoral glands, agenesis of the testes and epididymides, reduced size of the seminal vesicles or preputial glands, tan foci on the preputial glands, a greenish/red-brown foci on the clitoral glands, a yellowish nodule on the uterine adipose tissue, scab formation on the skin, alopecia and exophthalmus. The incidence of these findings was within the background range of findings that are encountered among rats of this age and strain, and the incidence did not show a dose-related trend. These necropsy findings were therefore considered to be of no toxicological significance.

Neuropathological findings:

no effects observed

Description (incidence and severity):

Hearing ability, pupillary reflex, static righting reflex and grip strength were normal in all animals.

The variation in motor activity did not indicate a relation with treatment.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Histopathological changes were confined to the stomach, and consisted of Iymphogranulocytic inflammation and hyperplasia of the squamous epithelium of the forestomach in both sexes at 100, 300 and 1000 mg/kg/day, and ulcer formation in the forestomach in three males at 300 mg/kg/day (correlating to red/black foci in the forestomach of two males) and in one male at 1000 mg/kg/day. Hyperplasia ofthe squamous epithelium was the microscopic correlate to the irregular surface and yellowish discolouration of the forestomach recorded at necropsy at 300 and 1000 mg/kg/day. Congestion of the glandular stomach (correlating to red discolouration of of the glandular mucosa) was observed in two males at 1000 mg/kg/day. There was no microscopic correlate to thickening of the glandular mucosa recorded in three females at 1000 mg/kg/day.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Maternal developmental toxicity

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

no effects observed

Changes in number of pregnant:

no effects observed

Other effects:

not examined

Description (incidence and severity):

No toxicologically significant effects on developmental parameters were observed.

Gestation index, duration of gestation, number of dead and Iiving pups at first Iitter check, sex ratio, post-natal loss, viability index, and early post-natal pup development (mortality, clinical signs, body weight and extern al macroscopy) were unaffected by treatment.

Details on maternal toxic effects:

No deficiencies in maternal care were observed. Examination of cage debris of pregnant females revealed no signs of abortion or premature birth. No signs of difficult or prolonged parturition were noted among the pregnant females.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Maternal abnormalities

Key result

Abnormalities:

no effects observed

Results (fetuses)

Fetal body weight changes:

no effects observed

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

no effects observed

External malformations:

no effects observed

Skeletal malformations:

not examined

Visceral malformations:

not examined

Other effects:

not examined

Details on embryotoxic / teratogenic effects:

Incidental macroscopic findings among pups found dead included autolysis, cannibalism and absence of milk in the stomaeh. Some surviving pups were small in size. The nature and incidence of these findings remained within the range considered normal for pups of this age, and were therefore considered to be unrelated to treatment.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Any other information on results incl. tables

Table 3      Mean body weights and body weight gains/ losses (F0)

 

Sex / Day	Bodyweight (g)
	Control	100 ppm	300 ppm	1000 ppm
MALES (TOXICITY TEST GROUP)
Pre-mating
Day 1 (total body weight gain)	321 -	318 -	316 -	319 -
Day 8 (total % body weight gain)	344 (7)	340 (7)	338 (7)	338 (7)
Mating
Day 1 (total % body weight gain)	367 (14)	360 (13)	360 (14)	359 (13)
Day 8 (total % body weight gain)	378 (18)	373 (17)	370 (17)	374 (17)
Day 14 (total % body weight gain)	391 (22)	386 (21)	386 (22)	388 (22)
Day 15 (total % body weight gain)	-	-	-	-
FEMALES (TOXICITY TEST GROUP)
Pre-mating
Day 1 (total % body weight gain)	213 -	213 -	214 -	212 -
Day 8 (total % body weight gain)	221 (4)	219 (3)	221 (4)	216 (2)
Mating
Day 1 (total % body weight gain)	225 (6)	225 (6)	227 (6)	222 (5)
Day 8 (total % body weight gain)	237 (13)	-	-	225 (10)
Day 15 (total % body weight gain)	253 (20)	-	-	-
Day 22 (total % body weight gain)	311 (48)	-	-	-
Post coitum
Day 0 (total % body weight gain)	232 -	230 -	231 -	225 -
Day 4 (total % body weight gain)	245 (6)	244 (6)	247 (7)	238 (6)
Day 7 (total % body weight gain)	251 (8)	251 (9)	253 (9)	244 (8)
Day 11 (total % body weight gain)	264 (14)	264 (15)	268 (16)	259 (15)
Day 14 (total % body weight gain)	276 (19)	277 (21)	278 (20)	268 (19)
Day 17 (total % body weight gain)	296 (28)	299 (30)	299 (30)	292 (29)
Day 20 (total % body weight gain)	331 (43)	335 (46)	339 (47)	327 (45)
Lactation
Day 1 (total % body weight gain)	256 -	258 -	256 -	252 -
Day 4 (total % body weight gain)	268 (5)	272 (6)	271 (6)	263 (5)

* statistically significantly different from control values p < 0.05

** statistically significantly different from control values p < 0.01

 

Table 4      Haematology, clinical chemistry, urinalysis and pathology findings (F0)

 

Doses (ppm)	Control	100	300	1000	Control	100	300	1000
	male (toxicity group)				female (toxicity group)
Haematology
- Hb (mmol/L)	9.2	9.3	9.0	9.6	8.6	8.7	8.4	8.5
- RBC (10^12/L)	8.06	8.23	8.07	8.33	7.27	7.46	7.33	7.29
- Hct (%)	0.412	0.420	0.405	0.426	0.378	0.388	0.376	0.379
- Retic (% RBC)	3.2	2.8	2.5	2.8	4.7	5.7	6.5	5.7
- MCH (fmol)	1.14	1.13	1.12	1.16	1.19	1.16	1.15	1.16
- MCV (fl)	51.2	51.1	50.3	51.1	52.0	52.1	51.3	52.0
- MCHC (mmol/L)	22.26	22.16	22.32	22.59	22.95	22.34	22.31	22.40
- RDW (%)	13.9	16.4	15.1	13.2	15.7	15.6	15.4	14.6
- WBC (10^9/L)	7.4	6.2	6.8	8.0	5.4	5.5	4.2	4.6
- Neut (% WBC)	15.4	14.9	11.2	12.7	23.5	27.5	27.5	27.3
- Lymph (% WBC)	82.3	82.2	86.5	84.7	73.5	69.6	69.5	70.1
- Mono (% WBC)	1.5	1.7	1.4	1.5	1.9	2.1	1.9	1.7
- Eos (% WBC)	0.6	0.9	0.7	0.9	1.0	0.8	0.9	0.7
- Bas (% WBC)	0.2	0.2	0.2	0.2	0.1	0.1	0.1	0.2
- PT (secs)	18.3	18.3	18.5	17.8	18.7	18.6	17.9	17.4
- PLT (10^9/L)	841	765	829	932	1072	1230	1228	1194
- APTT (secs)	15.5	15.1	17.6	15.0	17.3	17.5	19.2	16.0
Blood chemistry
- Glucose (µmol/L)	9.94	10.88	11.66	11.32
- Tot. Prot. (g/L)	64.9	65.2	64.5	65.9
- Albumin (g/L)	33.9	33.7	32.7	33.7
- A/G ratio
- Na+ (mmol/L)	142.6	141.6	141.6	141.7
- K+ (mmol/L)	4.02	4.13	4.26	4.34*
- Cl- (mmol/L)	103	103	104	103
- Ca++ (mmol/L)	2.73	2.70	2.73	2.82
- P (mmol/L)	1.89	1.76	1.64	1.75
- ASAT (U/L)	72.1	73.6	63.9	71.5
- ALAT (U/L)	38.1	42.4	51.8	49.7	53.6	56.5	53.3
- ALP (U/L)	145	180	231*	214
- Creat (µmol/L)	43.2	43.7	43.2	43.7
- Chol (µmol/L)	1.28	1.52	1.79*	1.79*
- Bili (µmol/L)	2.4	2.1	2.0*	9.1
- Bile ac. (µmol/L)	43.2	37.5	25.8	41.0
- Urea (mmol/L)	7.5	9.1	9.5*	9.1
Clinical Signs (% of individuals affected throughout treatment period, n=10)
- Skin (scabs)	5-10	0	0	0	0	0	0	0
- Breathing (rales)	0	5-10	0	0	0	0	5-10	0
- Secretion / excretion (salivation)	0	0	100	100	0	0	100	100
- Skin (alopecia)	0	0	0	0	0	0	0	5-10
Pathology(No. of individuals affected throughout treatment period, n=10)
No findings	7	9	0	0	8	9	3	1
Lungs (foci)	0	0	1	0	0	0	0	0
Stomach (foci)	0	0	2	1	0	0	0	0
Stomach (irregular surface)	0	0	10**	10**	0	0	6*	9**
Stomach (discoloration)	0	0	1	1	0	0	0	1
Stomach (thickened)	0	0	0	0	0	0	0	3
Liver (nodules)	0	0	0	1	0	0	0	0
Testes (agenesis)	0	0	1	0	-	-	-	-
Epididymides (nodules)	2	0	0	0	-	-	-	-
Epididymides (agenesis)	0	0	1	0	-	-	-	-
Seminal vesicles (size reduced)	0	1	0	0	-	-	-	-
Preputial glands (foci)	0	0	1	0	-	-	-	-
Preputial glands (size reduced)	0	0	0	1	-	-	-	-
Skin (scab formation)	1	0	0	0	0	0	0	0
Skin (alopecia)	0	0	0	0	1	0	0	1
Eyes (right side exophthalmos)	0	0	0	1	0	0	0	0
clitoral gland (nodules)	-	-	-	-	0	0	1	0
Clitoral gland (foci)	-	-	-	-	1	0	1	0
Body cavities (nodules)	0	0	0	0	0	1	0	0

* P<0.05, ** P<0.01

 

Table 5      Absolute and adjusted organ weights (F0)

 

Doses (ppm)	Control	100	300	1000	Control	100	300	1000
	male (toxicity group)				female (toxicity group)
BODY WEIGHT (n=10)
Weight (g)	370	363	367	370	235	244	233	229
ADRENALS (n=5)
Weight (g)	0.065	0.064	0.067	0.070	0.079	0.073	0.082	0.075
Organ/Body Weight Ratio (%)	0.018	0.018	0.018	0.019	0.034	0.030	0.035	0.033
BRAIN (n=5)
Weight (g)	2.05	2.03	2.05	2.05	1.86	1.93	1.86	1.86
Organ/Body Weight Ratio (%)	0.56	0.57	0.55	0.55	0.79	0.79	0.80	0.81
EPIDIDYMIDES (n=10)
Weight (g)	1.153	1.155	1.169	1.146	-	-	-	-
Organ/Body Weight Ratio (%)	0.312	0.318	0.320	0.311	-	-	-	-
HEART (n=5)
Weight (g)	1.081	1.009	1.062	1.043	0.780	0.823	0.760	0.750
Organ/Body Weight Ratio (%)	0.293	0.281	0.284	0.280	0.332	0.338	0.326	0.327
KIDNEYS (n=5)
Weight (g)	2.57	2.45	2.57	2.50	1.66	1.74	1.67	1.52
Organ/Body Weight Ratio (%)	0.70	0.68	0.69	0.67	0.70	0.71	0.72	0.66
LIVER (n=5)
Weight (g)	9.79	9.31	10.43	10.75	7.47	7.86	7.59	7.73
Organ/Body Weight Ratio (%)	2.65	2.59	2.79	2.87*	3.18	3.22	3.26	3.37
OVARIES
Weight (g)	-	-	-	-	0.119	0.131	0.121	0.128
Organ/Body Weight Ratio (%)	-	-	-	-	0.051	0.054	0.052	0.056
PROSTATE (n=5)
Weight (g)	0.556	0.693	0.576	0.498	-	-	-	-
Organ/Body Weight Ratio (%)	0.150	0.193*	0.154	0.133	-	-	-	-
SEMINAL VESICLES (n=5)
Weight (g)	1.742	1.685	1.538	1.628	-	-	-	-
Organ/Body Weight Ratio (%)	0.470	0.471	0.411	0.436	-	-	-	-
SPLEEN (n=5)
Weight (g)	0.675	0.674	0.704	0.588	0.490	0.542	0.535	0.547
Organ/Body Weight Ratio (%)	0.182	0.187	0.188	0.157	0.208	0.223	0.230	0.239
TESTES (n=10)
Weight (g)	3.44	3.56	3.57	3.57	-	-	-	-
Organ/Body Weight Ratio (%)	0.93	0.98	0.98	0.97	-	-	-	-
THYMUS (n=5)
Weight (g)	0.396	0.348	0.373	0.413	0.187	0.163	0.158	0.148
Organ/Body Weight Ratio (%)	0.107	0.097	0.100	0.111	0.079	0.067	0.068	0.065
THYROID (n=5)
Weight (g)	0.029	0.030	0.029	0.030	0.026	0.021	0.027	0.020
Organ/Body Weight Ratio (%)	0.008	0.008	0.008	0.008	0.011	0.009	0.012	0.009
UTERUS
Weight (g)	-	-	-	-	0.697	0.758	0.706	0.708
Organ/Body Weight Ratio (%)	-	-	-	-	0.297	0.311	0.304	0.308

* P<0.05, ** P<0.01

  

Table 6      Summary of incidence of mating performance, fertility and gestation lengths

Group (ppm)	# of paired males	# of females			Pre-coital interval (days)				Mating index (%)	Pregnancy index (%)	Gestation length (days)			Females with live offspring	Gestation index (%)
		Paired	Mated	Pregnant	1-4	5-8	9-12	13-14			21	22	23
Control	10	10	10	10	10	0	0	0	100	100	10	0	0	10	100
100	10	10	10	10	10	0	0	0	100	100	10	0	0	10	100
300	10	10	10	10	10	0	0	0	100	100	10	0	0	10	100
1000	10	10	10	10	10	0	0	0	100	100	10	0	0	10	100

 

Table 7      Offspring Survival Indices

 

Group (ppm)	Mean # of corpora lutea	Mean # of implantation sites	Mean total litter size	Number of live offspring		Viability index (%)	Male : Female ratio
				Day 1	Day 4
Control	14.2	12.9	12.3	123	121	98.4	52 : 48
100	14.2	12.6	12.1	121	121	100	48 : 52
300	15.9	13.8	13.2	132	132	100	55 : 45
1000	15.4	12.2	11.4	114	114	100	48 :52

Table 8      Pup weights

 

Group (ppm)	Mean Weight Day 1 (g)	Mean Weight Day 4 (g)
Control	5.7	8.3
100	5.8	8.6
300	5.9	8.5
1000	6.0	8.9

Applicant's summary and conclusion

Conclusions:

No toxicologically significant effects on reproductive parameters were noted.

Mating, fertility and conception indices, precoital time, and number of corpora lutea and implantation sites were unaffected by treatment.

No toxicologically significant effects on developmental parameters were observed. Gestation index, duration of gestation, number of dead and Iiving pups at first Iitter check, sex ratio, postnatalloss, viability index, and early postnatal pup development (mortality, clinical signs, body weight and extern al macroscopy) were unaffected by treatment. No deficiencies in maternal care were observed. Examination of cage debris of pregnant females revealed no signs of abortion or premature birth. No signs of difficult or prolonged parturition were noted among the pregnant females.

Executive summary:

OECD 422 (2010) - In a combined repeat dose toxicity study with reproductive toxicity screening (OECD 422), n-Undecanal was administered to 30 male and 30 female Crl:WI(Han) strain rats by oral gavage at dose levels of 100, 300 and 1000 ppm for up to 7 weeks. In addition, 10 male and 20 female control rats were treated with the formulation vehicle, without test item.

A summary of adult responses to the test item are described below;

Mortality- No mortality was observed during the test.

Clinical signs- No clinical signs or dose observations related to treatment were observed during the test.

Behavioural, functional and sensory assessments- Individuals were unaffected by the treatment.

Bodyweight- Body weights and body weight gain of treated animals remained in the same range as controls over the treatment period.

Food consumption and efficiency- No toxicologically significant changes in food consumption before or after allowance for body weight were noted.

Haematology- Haematological parameters of treated rats were considered not to have been affected by treatment.

Blood chemistry- A statistically significant higher potassium value was measured for males at 1000 mg/kg/day, but the mean remained within the range considered normal for rats of this age and strain. In females at 1000 mg/kg/day, a higher mean cholesterol level was recorded (being slightly outside the range considered normal for rats of this age and strain) along with notably higher bile acid levels in some females (means not statistically significant). Given that these changes were generally slight in nature, were not present as a group response (bile acids) and occurred in the absence of supportive morphological changes, these were considered to be of no toxicological relevance.

Other statistically significant variations in clinical biochemistry parameters were considered to be of no toxicological relevance as these occurred in the absence of a treatment-related distribution and/or remained within the range considered normal for rats of this age and strain. These variations consisted of higher or lower alkaline phosphatase activity (ALP) in males and females at 300 mg/kg/day, lower total bilirubin level in males at 300 mg/kg/day, higher urea level in males at 300 mg/kg/day, higher cholesterol level in males at 300 and 1000 mg/kg/day, and lower urea level in females at 1000 mg/kg/day.

Necropsy- The following necropsy findings were considered to be related to treatment with the test substance:

- An irregular surface of the forestomach in all males at 300 and 1000 mg/kg/day, and in 6 females at 300 mg/kg/day and nine females at 1000 mg/kg/day.

- Foci (black or red) in the forestomach in two males at 300 mg/kg/day.

- Yellowish discolouration of the forestomach in one male at 300 mg/kg/day and one female at 1000 mg/kg/day.

- Reddish discolouration reddish foci in the glandular mucosa in two males at 1000mg/kg/day.

- Thickened glandular mucosa in three females at 1000 mg/kg/day.

Incidental findings among control and treated animals included reddish foci on the lungs, a nodule on the liver, epididymides or clitoral glands, agenesis of the testes and epididymides, reduced size of the seminal vesicles or preputial glands, tan foci on the preputial glands, a greenish/red-brown foci on the clitoral glands, a yellowish nodule on the uterine adipose tissue, scab formation on the skin, alopecia and exophthalmus. The incidence of these findings was within the background range of findings that are encountered among rats of this age and strain, and the incidence did not show a dose-related trend. These necropsy findings were therefore considered to be of no toxicological significance.

Organ weights- A higher liver weight and liver to body weight ratio, and lower prostate and prostate to body weight ratio was noted for males at 1000 mg/kg/day (statistically significant for liver to body weight ratio only). These changes were only slightly outside the normal range for rats of this age and strain.

The higher prostate to body weight ratio of males at 100 mg/kg/day occurred in the absence of a dose-related trend, and the mean remained within the range considered normal for rats of this age and strain. No toxicological relevance was ascribed to this change. Other organ weights and organ to body weight ratios among the dose groups were similar to control levels.

The higher liver weight and liver to body weight ratio, and lower prostate and prostate to body weight ratio for males at 1000 mg/kg/day was not supported by any histopathological changes. Moreover, since these changes were slight in nature (only slightly outside the normal range), these were considered to be of no toxicological relevance.

Histopathological changes-Histopathological changes were confined to the stomach, and consisted of Iymphogranulocytic inflammation and hyperplasia of the squamous epithelium of the forestomach in both sexes at 100, 300 and 1000 mg/kg/day, and ulcer formation in the forestomach in three males at 300 mg/kg/day (correlating to red/black foci in the forestomach of two males) and in one male at 1000 mg/kg/day. Hyperplasia ofthe squamous epithelium was the microscopic correlate to the irregular surface and yellowish discolouration of the forestomach recorded at necropsy at 300 and 1000 mg/kg/day. Congestion of the glandular stomach (correlating to red discolouration of of the glandular mucosa) was observed in two males at 1000 mg/kg/day. There was no microscopic correlate to thickening of the glandular mucosa recorded in three females at 1000 mg/kg/day.

A summary of reproductive and developmental findings is described below;

Reproduction data- No toxicologically significant effects on reproductive parameters were noted. Mating, fertility and conception indices, precoital time, and number of corpora lutea and implantation sites were unaffected by treatment.

Developmental data- No toxicologically significant effects on developmental parameters were observed. Gestation index, duration of gestation, number of dead and living pups at first litter check, sex ratio, postnatal loss, viability index, and early postnatal pup development (mortality, clinical signs, body weight and extern al macroscopy) were unaffected by treatment. No deficiencies in maternal care were observed. Examination of cage debris of pregnant females revealed no signs of abortion or premature birth. No signs of difficult or prolonged parturition were noted among the pregnant females.  Incidental clinical symptoms of pups consisted of small size, red spots on the head/nose and a pale appearance. No relationship with treatment was established for these observations and they were considered to be of no toxicological relevance. A total of three pups of the control group, and one pup each at 100, 300 and 1000 mg/kg/day were found dead or missing during lactation. No toxicological relevance was ascribed to these dead/missing pups since the mortality incidence did not show a dose-related trend and remained within the range considered normal for pups of this age. Incidental macroscopic findings among pups found dead included autolysis, cannibalism and absence of milk in the stomach. Some surviving pups were small in size. The nature and incidence of these findings remained within the range considered normal for pups of this age, and were therefore considered to be unrelated to treatment.

Based on these considerations, a No Observed Adverse Effect Level (NOAEL) for reproductive and developmental toxicity was therefore concluded to be 1000 mg/kg/day.

This combined toxicity study with reproduction screening in the rat is acceptable and satisfies the guideline requirements for an OECD 422 in the rat.