Registration Dossier

Administrative data

Description of key information

Repeat dose toxicity via the oral route (OECD 422): Based on the results of the study, a NOAEL for general toxicity in males and females was considered to be 1000 mg/kg/day, the highest dose level tested.

Repeat dose toxicity via the oral route (comparable to OECD 408): The NOEL was found to be 1250 ppm, which is equivalent to an intake of approximately 120- 150 mg/kg/day.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: oral
Remarks:
combined repeated dose and reproduction / developmental screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 May 2012 to 15 Feb 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study.
Reason / purpose for cross-reference:
reference to same study
Qualifier:
according to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
GLP compliance:
yes (incl. QA statement)
Limit test:
no
Species:
rat
Strain:
other: RCCHan™:WIST(SPF)
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories, B.V., Kreuzelweg 53, 5961 NM Horst, Netherlands
- Age at study initiation: 10 weeks
- Weight at study initiation: males: 293 to 342 g, females: 204- 227 g
- Housing: Individually in Markrolon type-3 cages with wire mesh tops and sterilised standard softwood bedding with paper enrichment. During the pre-pairing period, cages with males were interspersed amongst those holding females to promote the development of regular estrus cycles.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3. Values outside of this range occasionally occured, usually following room cleaning, which was considered not to have any influence on the study.
- Humidity (%): 30-70. Values outside of this range occasionally occured, usually following room cleaning, which was considered not to have any influence on the study.
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 07 June 2012 To: 20 July 2012
Route of administration:
oral: gavage
Vehicle:
polyethylene glycol
Remarks:
PEG300
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: The dose formulations were prepared weekly. The test item was weighed into a glass beaker on a tared Mettler balance and the vehicle was added (w/v). The mixtures were stirred using a magnetic stirrer and stored at room temperature (15- 25 °C). Homogeneity of the test item in the vehicle was maintained during the daily administration period using a magnetic stirrer.

VEHICLE
- Concentration in vehicle: 0, 20, 60 and 200 mg/mL/day. Dose volume: 5mL/kg bodyweight.
- Lot/batch no. (if required): BCBF5743V
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The dose formulations were analysed using a GC-FID method.
Duration of treatment / exposure:
Males: up to 41 d
Females: up to 53 d
Frequency of treatment:
Once daily
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Remarks:
Group 1(Control group)
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Remarks:
Group 2
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Remarks:
Group 3
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
Remarks:
Group 4
No. of animals per sex per dose:
11/ sex/ dose
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: the dose levels were selected based on a previous non-GLP dose range-finsing study in Wistar rats
Observations and examinations performed and frequency:
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily cage-side clinical observations (once daily, during acclimatisation and up to day of necropsy). Additionally females were observed for signs of difficult or prolonged parturition, and behavioural abnormalities in nesting and nursing.

Once prior to the first administration of the test item and weekly thereafter, detailed clinical observations were performed outside the home cage. In females, it was performed on days 0, 6, 13 and 20 of the gestation period. Animals were observed for the following: changes in skin, fur, eyes, mucous membranes, occurrence of secretions and excretions, and autonomic activity (e.g. lacrimation, piloerection, pupil size and unusual respiratory pattern). Changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypies or bizarre behaviour were also reported.

BODY WEIGHT: Yes
- Time schedule for examinations: recorded daily from treatment start to day of necropsy.

FOOD CONSUMPTION: Yes. No food consumption was recorded during the pairing period.
-Males: weekly during pre-pairing and after pairing periods
- Females: pre-pairing period days 1-8 and 8-14; gestation days 0-7, 7-14 and 14-21 post coitum, and days 1-4 post partum.

HAEMATOLOGY: Yes
Blood samples were obtained at the end of the pre-pairing period from 5 males and 5 females from each group. Blood samples were drawn retro-orbitally from all animals under light isoflurane anesthesia. The animals were fasted for approximately 18 h before blood sampling but allowed access to water ad libitum. The samples were collected early in the working day to reduce biological variation caused by circadian rhythms.

The following haematology parameters were determined:

Complete blood cell count
Erythrocyte count, haemoglobin, haematocrit, mean corpuscular haemoglobin concentration, haemoglobin concentration distribution width, leukocyte count (total), mean corpuscular volume, red cell volume distribution width, mean corpouscular haemoglobin, differential leukocyte count, platelet count.

Coagulation
Prothrombin time (= Thromboplastin time), activated partial Thromboplastin time

Clinical biochemistry
The following clinical biochemistry parameters were determined:
Glucose, urea, creatinine, bilirubin (total), cholesterol (total), triglycerides, aspartate aminotransferase, alanine aminotransferase, alkaline phosphate, gamma-glutamyl-transferase, bile acids, sodium, potassium, chloride, calcium, phosphorous, protein (total), albumin, globulin, albumin/ globulin ratio

OTHER:
PUP DATA
The liiters were examined for litter size, live births, still births and any gross anomalies. The sex ratio of the pups was recorded. Pups were weighed individually on days 0 (if possible), 1 and 4 post partum.

FUNCTIONAL OBSERVATION BATTERY (FOB)
At one time during the study (males shortly before the scheduled sacrifice and females on day 3 or 4 post partum), relevant parameters from modified Irwin screen test was performed with 5 P generation males and 5 P generation females from each group in place of the usual weekly behavioural observation. This FOB assessment was conducted following the daily dose administration.
Additionally, locomotor activity was measured quantitatively for the same animals. Activity was measured with an Activity Monitor AMS-0151. Activity of the animals (based on beam count) was recorded for 10 minute intervals over a period of 60 min. These data and the total activity over 60 min were reported.
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Males were sacrificed after treatment of at least 28 d, when no longer needed for the assessment of reproductive effects. Dams and pups were sacrificed on day 4 post partum. If birth did not occur on the expected date (day 21 post coitum), the dam was sacrificed on day 25 post coitum.

All animals sacrificed or found dead were weighted and subjected to a detailed macroscopic examination to establish, if possible, the cause of death. Specimens of abnormal tissue were fixed in neutral phosphate buffered 4 % formaldehyde solution. At the scheduled sacrifice, all animals were sacrificed by an injection of sodium pentobarbital. All P generation animals were exsanguinated. Dead pups, except those excessively cannibalised, were examined macroscopically.

All parent animals were examined macroscopically for any structural changes at the scheduled necropsy or during the study if death occurred. Also pups were examined macroscopically for any structural changes at the scheduled necropsy and if possible also if death occured.

For the parent animals, special attention was directed at the organs of the reproductive system.

The number of implantation sites and corpora lutea was recorded for all dams with litters. The uteri of non-pregnant females were placed in a solution of ammonium sulphide to visualise possible haemorrhagic areas of implantation sites.
Other examinations:
Organ weights
At the scheduled sacrifice, the testes and epididymides of all parental males were weighted separately.

In addition, from 5 males and 5 females of each group, sacrificed at the end of the study, the following organs were trimmed from any adherent tissue, as appropriate, and their wet weight taken: adrenal glands (weighed as pairs), brain, heart, kidneys (weighed as pairs), liver, thymus, spleen.
Statistics:
The following statistical methods were used to analyze food consumption, body weights and reproduction data:
1. Means and standard deviations of various data were calculated.
2. The Dunnett-test (many to one t-test) based on the pooled variance estimate was applied if the variables could be assumed to follow a normal distribution for the comparison of the treated groups and the control groups for each sex.
3. The Steel-test (many-one rank test) was applied instead of the Dunnett-test when the data could not be assumed to follow a normal distribution.
4. Fisher’s exact-test was applied if the variables could be dichotomised without loss of information.
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
Viability/ mortaility
One male treated with 1000 mg/kg/day was found dead spontaneously on day 12 of the pre-pairing period.

One female treated with 1000 mg/kg/day of the test item was found spontaneously dead on day 11 of the pre-pairing and another female of this group was found dead on day 22 of the gestation period. Two further females of this group were found dead on day 2 of their lactation period.

All these deaths deemed to be caused by aspiration during gavage procedures of massive amount test item and it could be considered as the cause of death, not related to systemic toxicity of the test item. All other animals of this group survived until the scheduled necropsy.

All animals treated with 100 mg/kg/day or 300 mg/kg/day of the test item survived until the scheduled necropsy.

Daily clinical signs or observations
A kinked tail apex with scabs was seen in 1 control male from the treatment day 6 onwards, this was black coloured, additionally, from day 9 onwards. During the pairing period moderate necrosis of this apex was seen additionally. One male treated with 100 mg/kg/day of the test item had slight hair loss on the right shoulder from day 8 and another male of this group had slight breathing noises on one day. One male treated with 1000 mg/kg/day had slight breathing noises on up to 9 days of the pre-pairing period and also on 3 days on the pairing period.

Slight breathing noises and slight hair loss on the head were noted in 1 female treated with 300 mg/kg/day of the test item on single days of the pre-pairing period. Slight breathing noises were noted also in a few females treated with 1000 mg/kg/day on some single days of the pre-pairing and pairing period and slight hair loss on the neck in 1 female of this group. Slightly to moderately ruffled fur was seen in a few females of this dose group on 3 days in the lactation period and 1 day during gestation. In females slgiht breathing noises were noted also during a few days of the gestation and lactation period. One female neglected its litter and no milk was found in the stomach of the pups during the first litter check. The reason for this is unclear and it was considered to be an incidental finding.

One female treated with 1000 mg/kg/day had a mass on the neck in the gestation period. The mass was still seen during the lactation period. This finding was considered to be incidental.

All these possible findings were considered to be incidental and the slight breathing noises could be possibly treatment-related but not test item-related.

Findings at detailed weekly clinical observations
No toxicological relevant test item-related clinical signs were noted during the weekly observations.

One female treated with 1000 mg/kg/day showed ruffled fur on day 13 and another female of this dose group had a mass on the neck on day 20 post coitum.

FOOD CONSUMPTION, BODY WEIGHT AND WEIGHT GAIN
PRE-PAIRING PERIOD
There were no differences of toxicological relevance between the mean food consumption of test item-related or control males. The mean relative food consumption of test item treated groups was similar to this of the controls.

PRE-PAIRING, GESTATION AND LACTATION PERIODS
Females treated with 1000 mg/kg/day showed a tendency of a slightly decreased mean absolute and relative food consumption. This slight decrease was considered to be not adverse because it is a slight effect without statistical significance and no dose response relationship could be observed.

PRE-PAIRING AND PAIRING PERIODS
There were no differences of toxicological relevance between the mean body weights of test item-treated or control males. The mean body weight gain of all groups compared favourably.

PRE-PAIRING, PAIRING, GESTATION AND LACTATION PERIODS
On some days of the gestation and in the lactation period, mean body weight was slightly decreased (p <0.05) in the 1000 mg/kg/day treatment group when compared to the control animals. This was considered to be not adverse because it was seen on some single days only. No test item-related effects on body weights and body weight gain of females were observed during the pre-pairing and pairing period.

No test item-related effect on body weights and body weight gain of females treated with 100 mg/kg/day or 300 mg/kg/day of the test item were observed during the study.

HAEMATOLOGY
MALES
The assessment of the haematology data did not reveal any test item-related effects.

The differences of haematological parameters of test item treated males compared with the control animals show no dose response relationship. Therefore these changes were considered to be not test item-related.

FEMALES
The assessment of the haematology data did not reveal any test item-related effects.

The slightly decreased (p< 0.05) mean corpuscular haemoglobin concentration in females treated with 300 mg/kg/day or 1000 mg/kg/day of the test item compared to controls are within the range of the historical reference data. The mean value of relative monocytes was slightly decreased (P< 0.05) only in females treated with 300 mg/kg/day when compared with controls. Therefore no dose response relationship could be observed. The differences of these both parameters were therefore considered to be not test item-related.

BIOCHEMISTRY
MALES
No test item-related differences of biochemistry were noted when compared with control animals at the end of the pre-pairing period.

The slight increase (P< 0.01) of the mean chloride content in males treated with 300 mg/kg/day or 1000 mg/kg/day of the test item was within the range of the historical reference data and therefore considered to be not test item-related.

FEMALES
No test item-related differences in parameters of biochemistry were noted when compared with control animals at the end of the pre-pairing period.

ORGAN WEIGHTS
No test –item-related changes in the mean organ weights, organ to body weight ratios and organ to brain weight ratios were noted in males and females when compared with the control animals.

GROSS PATHOLOGY
There were no gross lesions that could be attributed to treatment with the test item in sacrificed animals. Although the liver enlargement was recorded in a few males including control group animals, there was no histological correlate. All other gross lesions recorded were considered to be within the range of normal background alterations.

HISTOPATHOLOGY: NON-NEOPLASTIC
The respiratory disorder consisted of necrosis and inflammatory cell infiltration of the trachea, congestion, alveolar edema and alveolar macrophaes of the lung were recorded in dead animals. Major microscopic findings with macroscopic findings in each animal were described as follows:
FINDINGS IN DEAD ANIMALS
Animal No. 34
Trachea: moderate mucosal necrosis and slight inflammatory cell infiltration were recorded and acute reactive and inflammatory changes were considered.
Lung: reactive change consisting of slight congestion and slight alveolar macrophages was recorded. (Macroscopic findings: discolouration, dark red)
Thymus: multifocal slight haemorrhage as lesion during agonal period. (Macroscopic findings: focus/ foci, dark red)

Animal No. 83
Trachea: moderate mucosal necrosis and moderate inflammatory cell infiltration were recorded and acute reactive and inflammatory changes were considered.
Lung: reactive change consisting of moderate congestion, slight alveolar edema and slight alveolar macrophages was recorded. (Macroscopic findings: discolouration, dark red).

Animal No. 87
Trachea: ,oderate mucosal necrosis and moderate inflammatory cell infiltration were recorded and acute reactive and inflammatory changes were considered.
Lung: reactive change consisting of minimal congestion and slight alveolar macrophages was recorded. (Macroscopic findings: discolouration, dark red)
Thymus: multi focal slight haemorrhage as lesion during agonal period. (Macroscopic findings: gelatinous, focus/ foci, dark red)

Animal No.88
Trachea: moderate inflammatory cell infiltration was recorded and acute reactive and inflammatory changes were considered.
Lung: reactive change consisting of moderate congestion, slight alveolar edema and minimal alveolar macrophages was recorded. (Macroscopic findings: discolouration, dark red)

FINDINGS IN SACRIFIED ANIMALS
All findings recorded were within the range of normal background lesions which may be recorded in animals of this strain and age.

OTHER FINDINGS
FUNCTIONAL OBSERVATIONAL BATTERY
None of the parameters under investigation during the functional observational battery gave an indication of a test item-related effect. Mean values of grip strength (fore- and hind paws) of males and females gave no indication of test item-related effects. The mean body temperature of test item treated males and females were similar to this of control animals.

LOCOMOTOR ACTIVITY
The mean locomotor activity of females treated with 1000 mg/kg/day was slightly decreased (p< 0.05 at 20-30 min interval) when compared with controls during the lactation period. No test item-related effects on locomotor activity of males and females of the other dose groups were noted.
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No adverse effects at 1000 mg/kg bw/day in any of the parameters assessed
Critical effects observed:
no

Reproduction and Breeding Data

Summary of performance

P animals breeding for F1 Litters

Group

(mg/kg/day)

1

(0)

2

(100)

3

(300)

4

(1000)

Female numbers

45 - 55

56 - 66

67 – 77

78 – 88

Number of females paired (A)

11

11

11

10

Number of females mated

11

11

11

10

Number of females, which dies before the scheduled necropsy (B)

0

0

0

4

Number of females not pregnant (C)

0

1

0

0

Number of females which reared their pups until day 4 post partum

11

9

11

7

(A) Female no. 88 died spontaneously during preparing

(B) Females died spontaneously, no. 88 during pre-pairing, 86 during gestation, 83/87 during lactation

(C) Female no. 63 was not pregnant

Mating Performance and Fertility

Eleven, 10, 11 and 10 females in dose groups 0, 100, 300 and 1000 mg/kg/ day, respectively, were mated within the first or second pairing period.

The median and mean precoital times were unaffected by treatment with the test item. Mean precoital times were 3.9, 3.7, 2.4 and 3.2 days in dose groups 0, 100, 300 and 1000 mg/kg/ day, respectively. The median precoital time was 2, 3, 2 and 3 days in order of ascending dose level. For the 1 control female that mated during the second pairing period, precoital time was 1 day.

The fertility index was 100.0%, 90.9%, 100.0%, 100.0% and the conception rate showed exactly the same values in the groups treated with 0 mg/kg/day, 100 mg/kg/day, 300 mg/kg/day or 1000 mg/kg/day, respectively.

Corpora Lutea Count

Mean number of corpora lutea per dam (determined at necropsy) was similar in all groups (14.9, 13.4, 13.8 and 14.2 in order of ascending dose level) and gave no indication of a test item-related effect.

Duration of Gestation

The mean duration of gestation was unaffected by exposure to the test item. Mean duration of gestation was 21.4, 21.8, 21.5 and 21.6 days, in order of ascending dose level.

Implantation Rate and Post-implantation Loss

No test item-related effects were noted on implantation rate and implantation loss.

The total post-implantation loss was significantly decreased (p<0.05) in females treated with 1000 mg/kg/day of the test item when compared with the controls, which was considered to be incidental. The mean numbers of implantations per litter were 13.6, 11.4, 13.1 and 13.1 in order of ascending dose level. The mean incidence of post-implantation loss as a percentage of total implantations was 16.0, 17.5, 13.9 and 8.5%, in order of ascending dose level.

Litter Size at First Litter Check

No effects were noted on litter size at first litter check.

In dose groups 0, 100, 300 and 1000 mg/kg/ day the birth index was 84.0, 83.5, 86.1 and 91.5% and mean litter size at first litter check was 11.5, 9.6, 11.3 and 12.0, respectively.

Postnatal Loss Days 0 - 4 Post Partum

No effects on the postnatal loss between day 0 and 4 post partum were noted.

Mean postnatal loss was 1.6, 1.2, 1.6 and 9.6% in dose groups 0, 100, 300 and 1000 mg/kg/ day, respectively. Correspondingly, in dose group 1000 mg/kg/day, the viability index was statistically significantly decreased (90.4%). In does groups 0, 100 and 300 mg/kg/day, the viability index was 98.4, 98.8 and 98.4%.

The cause of the slightly higher postnatal loss in dose group 1000 mg/kg/day was the loss of 7 pups on day 2 and 3 post partum for dam no. 84. For this dam already 6 dead pups at first litter check were noted. This isolated occurrence was considered to be incidental.

Litter Data - F1 Pups

External Examination at First Litter Check and during Lactation

No abnormal findings were noted at first litter check or during the first 4 days post partum.

Sex Ratios

Sex ratios at first litter check and on day 4 post partum were unaffected by exposure to the test item.

Body Weights to Day 4 Post Partum

Mean pup weights on day 1 and day 4 post partum were unaffected by treatment of their dams with the test item.

The mean difference in pup weight in dose group 1000 mg/kg/day, was slightly decreased (p<0.05) when compared male and female pups of this group with the control group. Since the difference of the mean absolute body weights of pups on days 1 and 4 post partum was not statistically significant, it was considered to be not test item related.

Macroscopical Findings

No test item-related macroscopic findings were noted in pups at necropsy.

Conclusions:
The repeated dose toxicity via the oral route of the test item was assessed according to OECD Guideline 422 at dose levels of 100, 300 and 1000 mg/kg/day. Based on the results of the study, a NOAEL for general toxicity in males and females was considered to be 1000 mg/kg/day, the highest dose level tested.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
Two separate repeat dose toxicity studies via the oral route have been conducted on the test material, namely Harlan Laboratories Ltd (2012) and Gaunt et al (1969). The Harlan Laboratories Ltd (2012) study has been conducted to OECD guideline 422 and GLP and is well documented and has been assigned reliability 1. The Gaunt et al (1969) study is comparable to OECD guideline 408 and is adequately documented and has been assigned reliability 2.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Two repeat dose toxicity studies via the oral route have been conducted on the test material, as follows:

Repeat dose toxicity via the oral route (OECD 422): A 28 day repeat dose oral toxicity study combined with a reproductive/ developmental toxicity screening test was performed in the rat in accordance with GLP and OECD Guideline 422. The test item was administered by gavage to 3 groups, each of of 11 male and 11 female RCCHan™:WIST strain rats for up to 8 weeks (including a 2 week pre-pairing phase, pairing, gestation and early lactation for females), at dose levels of 100, 300 and 1000 mg/kg bw/day. There were no treatment related effects observed on mating, fertility or gestation length at any dose level. The offspring litter size, sex ratio, viability, growth and development were al comparable to controls and no adverse effects were noted. Since no treatment-related effects were observed for reproduction, a NOAEL was considered to be 1000 mg/kg bw/day. Furthermore, the study showed that the administration of the test item over a period of 28 days did not results in any toxicologically significant effects and hence the NOAEL for systemic toxicity was considered to be 1000 mg/kg bw/day.

Repeat dose toxicity via the oral route (comparable to OECD 408): A 98 day repeat dose oral toxicity study was performed in the rat in accordance with a guideline that is equivalent or similar to OECD Guideline 408. The test item was administered by drinking water to 3 groups, each of 15 male and 15 female SPF-derived CFE strain rats for up to 98 days, at dose levels of 310, 1250 and 5000 ppm. No toxicologically significant effects were noted at dose levels 310 and 1250 ppm and hence the NOEL was considered to be 1250 ppm which is equivalent to 120-150 mg/kg bw/day.

At the highlest level of treatment (5000 ppm) there was a transitory anaemia in females, but the absence of this finding after more prolonged feeding or at any time in males shows it to be of little significance.

At the 5000 ppm level the relative kidney weight was increased in males but thrre were no histological signs of renal damage and no indications of abnormal kidney function. The urine produced by these animals after a standard water load was slightly more concentrated than that of the controls. Similarily there was no indication of nephrotoxic action at lower dosage levels in males nor at any level in females.

Justification for classification or non-classification

Two separate repeat dose toxicity studies via the oral route have been conducted on the test material, namely Harlan Laboratories Ltd (2012) and Gaunt et al (1969). The studies have been assigned a reliability 1 and 2, respectively, and are considered as acceptable for classification. Both studies show that the test item is not toxic following repeated exposure via the oral route. As such, the test item can be considered to be non-classified.

Based on the CLP guidance values for STOT-RE Category 2 classification is applicable when significant toxic effects observed in experimental animals are seen to occur within the following guidance range values:

90-day study: 10 - 100 mg/kg bw/day

28-day study: 30 - 300 mg/kg bw/day

In the 98 -day study (Gaunt et al (1969)) no significant toxic effects were observed between 10 - 100 mg/kg bw/day.

In the OECD 422 study (Harlan Laboratories Ltd (2012)) no significant toxic effects were observed between 30 -300 mg/kg bw/day. Therefore a STOT-RE 2 classification is not applicable.