kresoxim-methyl (ISO);methyl (E)-2-methoxyimino-[2-(o-tolyloxymethyl)phenyl]acetate

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPP 83-4 (Reproduction and Fertility Effects)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Japan/MAFF: Testing Guidelines for Toxicology Studies: Reproduction Study, pp. 44 - 48 (1985)

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

methyl (2E)-2-methoxyimino-2-[2-[(2-methylphenoxy)methyl]phenyl]acetate

EC Number:

604-351-6

Cas Number:

143390-89-0

Molecular formula:

C18 H19 N O4

IUPAC Name:

methyl (2E)-2-methoxyimino-2-[2-[(2-methylphenoxy)methyl]phenyl]acetate

Details on test material:

- Name of test material (as cited in study report): Reg. No. 242 009 (test substance number: 91/180-2)
- Lot/batch No.: N 36 (III C1); date of manufaturing: 1991-10-23
- Storage condition of test material: room temperature; in darkness
- Physical state: solid (powder) / light brown
- Analytical purity: ≥93.7% (Reversed-Phase - HPLC with UV-Detection)
- Stability under test conditions: the storage stability was guaranteed over the study period
- Other: the homogeneity of the test substance was confirmed by analysis (Reversed-Phase - HPLC with UV-Detection)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Wistar rats (Chbb:THOM (SPF)) supplied by Dr. Karl THOMAE, Biberach an der Riss, FRG, which were free from any clinical signs of disease, were used for the investigations. The females were nulliparous and non-pregnant at the beginning of the study. According to verbal information from the breeder, male and female animals were derived from different litters. This was necessary to rule out the possibility of sibling mating.
- Age at study initiation: (P) 28±1 days when arrived, 35±1 days at the beginning of the treatment; (F1) before weaning
- Weight at study initiation: (P) Males: 142.9 (127 - 158) g; Females: 125.4 (112 - 140) g
- Fasting period before study: 16 hours
- Housing: during the study period, the rats were housed individually in type DK III stainless steel wire mesh cages supplied by BECKER & CO., Castrop-Rauxel, FRG (floor area of about 800 cm2), with the following exceptions: during mating periods, the males designated for mating were kept individually in Makrolon cages, type M III (floor area of about 800 cm2).
- Diet (e.g. ad libitum): ground Kliba maintenance diet rat/mouse/hamster GLP 343 meal (supplied by KLINGENTALMUEHLE AG, Kaiseraugst, Switzerland) available throughout the study (from the day of supply to the day of or the day before necropsy).
- Water (e.g. ad libitum): drinking water of tap water quality was supplied from water bottles
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
The animals were accommodated in fully air-conditioned rooms (floor area about 18 or 22 m2) in which central air conditioning (ranges of temperature and relative humidity were guaranteed).
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): the test substance preparations were prepared at intervals of not more than 32 days (the period for which stability was proven).
- Mixing appropriate amounts with (Type of food): the test substance preparations were prepared by weighing in the test substance and mixing this thoroughly with a small amount of the food. This mixture was then mixed in a BOSCH household mixer. An appropriate amount of food was then added to obtain the desired concentration and mixing was carried out for about 10 minutes in a GEBR. LODIGE laboratory mixer.
- Storage temperature of food: 32 days at room temperature

Details on mating procedure:

- M/F ratio per cage: 1 : 1 (generally male No. 1 with female No. 201, male No. 2 with female No. 202 etc.) for parental animals;
- Length of cohabitation: overnight
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 and the following day day 1 post coitum (p.c.)
- Each of the male and female animals was mated for a maximum of 3 weeks. Generally, throughout the mating period, each male animal was mated with a predetermined female animal from the same dose group. Matings occurred by placing the female in the cage of a male from 16:00 hours until 7:00 – 9:00 hours the following morning.
- After successful mating each pregnant female was caged (how): For the overnight mating the females were put into the cages of the males. From day 18 of pregnancy until day 14 after birth, the pregnant animals and their litters were housed in Makrolon type M III cages. The M III cages were also supplied by BECKER & CO. Pregnant females were provided with nesting material (cellulose wadding) toward the end of pregnancy.
- Further matings after two unsuccessful attempts: yes; if an F0 generation parental animal (after both mating intervals) or an Fl generation parental animal had not produced any offspring, it was again mated for not more than 3 weeks with one fertile male or female animal of the control group. After re-mating male animals were sacrificed together with the majority of the other animals as scheduled. Females were sacrificed before littering (if an animal after these matings had proved to be fertile) or about 10 days after the last mating (if an animal after these matings likewise had proved to be infertile).
Those parental animals from test groups 01, 02, 03 and 04 (F0 generation parental animals) and 11, 12, 13 and 14 (F1 generation parental animals) whose fertility had to be reevaluated, were offered substance-free diet only during the specific nightly matings (when they were kept together with fertile animals of the control group). In the remaining times (i.e., the period between the individual matings as well as after the last mating until sacrifice), these animals were offered food with the test substance specified for the group to which they belonged.
- Any other deviations from standard protocol: Deviations from the specified times were possible on weekends and public holidays and were reported.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses of the stability of test substance in the diet up to 32 days at room temperature were carried out before the start of the study in another rat feeding study for a similar batch. The homogeneity of the test substance in the maintenance diet was analytically investigated before the start of the study for a similar batch in two previous rodent studies. In order to check the correctness of the concentration, samples of each one of the doses were sent for analysis to the analytical laboratory at the beginning of the study and thereafter at intervals of 3 months.

Duration of treatment / exposure:

continuously in diet starting from 70 days before exposure for the F0 parental animals

Frequency of treatment:

continuously in diet

Details on study schedule:

- F1 parental animals not mated until 98 days after selected from the F1 litters.
- Selection of parents from F1 generation when pups were 4 days of age.
- Age at mating of the mated animals in the study: at adult age

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
50, 1000, 4000 and 16000 ppm
Basis:
nominal in diet

Doses / concentrations 2

Remarks:

Doses / Concentrations:
5, 100, 407 and 1625 mg/kg bw
Basis:
analytical conc.
Based on diet consumption; the content of test substance in the test substance/food mixes was determined by HPLC with UV detection.

No. of animals per sex per dose:

25

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: The doses were chosen on the basis of results from various previous studies (la, lb, le, Id).

FIRST PREVIOUS STUDY (1a)
In a 4-week feeding study the test substance was administered to 5 male and 5 female Wistar rats/group in doses of 0, 1000, 4000 and 16000 ppm. At 16000 ppm (approx. 1455 mg/kg body weight) increases in y-glutamyltransferase and in albumin of the males were the only effects which were considered to be substance-related. No substance-induced effects were seen at 1000 or 4000 ppm (approx. 93 or 370 mg/kg body weight/day).

SECOND PREVIOUS STUDY (1b)
The test substance was administered to each 10 male and 10 female Wistar rats per sex and group in doses of 0, 500, 2000, 8000 and 16000 ppm in the diet over a period of 3 months.
Food consumption and body weight were determined each week. The animals state of health was checked each day. When the animals were weighed they were subjected to an additional comprehensive clinical examination. One day prior to the start of the administration period and 86 days thereafter ophthalmological examinations were carried out in the animals of the control and highest dose group. Two urinalyses and two clinicochemical and hematological examinations were carried out. At the end of the study all animals were subjected to gross-pathological assessment and histopathological examination. Following substance-related adverse effects were obtained:

(1)16000 ppm (about 1272 mg/kg body weight): (a) slightly reduced body weights in males, resulting in reduced values of about 6% at the end of the study; (b) reduced body weight change in males, resulting in reduced values of about 9% at the end of the study; (c) decrease in aspartate aminotransferase in the males; (d) increase in y-glutamyltransferase in the serum of the males; (e) statistically significant increase of the relative liver weight in both sexes distinct change of the distribution and the amount, concerning the fatty infiltration in the liver of both sexes.
(2) 8000 ppm (about 625 mg/kg body weight): (a) slightly reduced body weights in the males, resulting in reduced body weights of about 9% at the end of the study; (b) reduced body weight change in males, resulting in reduced values of about 14% at the end of the study; (c) decrease in aspartate aminotransferase in the males; (d) increase in y-glutamyltransferase in the serum of the males; (e) statistically significant increase of the relative liver weight in the females; (f) distinct decrease of the amount and a change of the distribution pattern of the fat in the liver of the females.
(3) 2000 ppm (about 159 mg/kg body weight): statistically significant increase of the relative liver weight in the female animals, without a morphological correlate.
(4) 500 ppm (about 40 mg/kg body weight): no substance-related adverse effects.

THIRD PREVIOUS STUDY (1c)
The test substance was tested for its prenatal toxicity in pregnant Wistar rats at doses of 400; 800 and 1200 mg/kg body weight/day on day 6 through day 15 post coitum (p.c.). A standard dose volume of 10 ml/kg body weight was used. One control group, which was treated with the vehicle only (0.5% aqueous carboxymethyl cellulose solution was used in addition. On day 16 p.c., all females were sacrificed and assessed by gross pathology. Due to this study design, only a rough and very limited external examination of the fetuses was possible at necropsy. The following, possibly substance-induced effects were recorded:

(1) 1200 mg/kg body weight/day: (a) reduced food consumption between days 6 and 8 p.c.; (b) reduced body weight change between days 6 and 8 p.c.; (c) increased postimplantation loss in comparison to the concurrent control group, but not in comparison to the historical control data.
(2) 800 and 400 mq/kg body weight/day: no substance-induced effects in dams, gestational parameters and fetuses

FOURTH PREVIOUS STUDY (1d)
In a reproduction toxicity range-finding study 10 male and 10 female Wistar rats in each group received the test substance via the diet at doses of 4000; 8000 and 16000 ppm. After an about 6-week premating period the animals (= F0 generation parental animals) were mated. The F1 generation pups derived from this mating were reared until day 4 p.p. (standardization of litters) or about day 21 p.p. and then sacrificed. Food and drinking water consumption, body weights, clinical signs and symptoms were recorded regularly for the parental animals. As soon as possible after birth the status of the pups and their sex was determined. Furthermore, the pups were weighed regularly and examined for clinical findings. Towards the end of the study hematological and clinicochemical examinations as well as organ weight determinations were carried out for the F0 parental animals. The following adverse, possibly substance-induced changes were obtained during examinations of clinics, clinical chemistry and hematology as well as pathology (macroscopy and organ weights):

(1) 16000 ppm (approx. 1,800 mg/kg body weight): (a) marginal reduction in food consumption in the female rats during premating; (b) compared to the control group slightly reduced body weights (by about 5% in the male rats (at the end of the study period) and by about 4% (premating) and 5% (gestation) in the females); (c) body weight gain also marginally reduced: (i) in the males by a total of about 7% in comparison to the control, (ii) in the females by about 9% (premating) and 5% (gestation), but not during the lactation period; (d) decreased aspartate aminotransferase values in the male parental animals only; (e) slightly increased relative liver weights in the F0 parental females; (f) up to 11% lower pup weights compared to the control (on day 21 p.p.) and statistically significantly retarded growth of pups
(2) 8000 ppm (approx. 900 mg/kg body weight): (a) decreased aspartate aminotransferase values in the male parental animals; (b) only statistically significantly retarded growth of pups between days 4 - 21 and 14 - 21 p.p.
(3) 4000 ppm (approx. 460 mg/kg body weight): no substance-related adverse effects on the parental animals or pups

CONCLUSION
Due to the above investigations (la, 1b, le, Id), the following concentrations were chosen for the twogeneration reproduction toxicity study with the test substance: (a) 50 ppm as an expected "no observed adverse effect level"; (b) 1000 and 4000 ppm as intermediate concentrations; (c) 16000 ppm: as a concentration at which clear toxic effects were expected (e.g. body weight gains), but which should not induce mortality in the parental animals.


- OTHER:
1) F0 generation parental animals and their progeny
After the acclimatization period, the F0 generation parental animals continuously received the test substance at the appropriate concentrations via the diet until or up to about 16 hours before they were sacrificed (with the exception of the female animals, which were taken for the reevaluation of fertility). At least 70 days after the beginning of treatment, males and females from the same dose group were mated.
The parental F0 females were allowed to litter and rear their pups (Fla generation pups) until day 4 or 21 after parturition. At least 10 days after the last weaning of the F1a generation pups, the F0 generation parental animals were mated again. The partners were assigned randomly to one another; matings of the same partners which produced the F1a litters were, however, avoided. The females were allowed to litter and rear their pups (Flb generation pups) until day 4 or 21 after parturition. After the F1b generation pups were weaned, the F0 generation parental animals were sacrificed.

2) F1 generation parental animals and their progeny
Before weaning, 25 males and 25 females (each litter was taken into account) of the F1a pups were chosen per group (randomly) as the basis of the F1 generation parental animals. If fewer than 25 litters in these groups were available for selection or if one sex was missing in a litter, more animals were taken from different litters from the relevant test group to give the full number.
All selected animals were exposed continuously to the test substance at the same dose level as their parents from their growth into adulthood until or up to about 16 hours before they were sacrificed (with the exception of the female animals, which were taken for the reevaluation of fertility). At least 98 days after assignment of the F1 generation parental animals, the males and females were mated. The partners were randomly assigned to one another, matings between siblings were, however, avoided.
The females were allowed to litter and rear their pups (F2 generation pups) until day 4 or 21 after parturition. Some weeks after the F2 generation pups had been weaned, the fasted (about 16 hours) F1 generation parental animals were sacrificed (with the exception of the female animals, which were taken for the reevaluation of fertility).

3) Standardization of litters (F1a, F1b and F2 generation pups)
On day 4 p.p., the individual litters were in general standardized in such a way that, where possible, each litter contained 4 male and 4 female pups (always the first 4 pups/sex and litter were taken for further rearing). If it was not possible in single litters to have 4 pups/sex, it was proceeded in such a way that 8 pups per litter were present for further rearing (e.g., 5 male and 3 female pups). Standardization of litters was not performed in litters with ≤8 pups.

Positive control:

None; however, fertility studies are regulary conducted in the testing laboratory

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: see clinical observations; Animals in a moribund state were sacrificed and examined in the laboratory of pathology. At least once daily a check was made for dead or moribund animals. If animals were in a moribund state, they were sacrificed and necropsied.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: all parental animals were checked daily for clinically evident signs of toxicity. The nesting, littering, and lactation behavior of the dams was generally evaluated in the mornings in connection with the daily clinical inspection of the dams. Only special findings (e.g., animal could not litter, umbilical cord not cut), were documented on an individual dam basis.
The littering behavior of the dams was also inspected on weekdays (except holidays) in the afternoons in addition to the evaluations in the mornings. The day of littering was considered the 24 hour period from about 15:00 hours of one day until about 15:00 hours of the following day. Deviations from this procedure were possible on Saturdays, Sundays and on public holidays. Animals in a moribund state were sacrificed and examined in the laboratory of pathology.

BODY WEIGHT: Yes
- Time schedule for examinations: in general, the body weight of the male and female parental animals was determined once a week at the same time of the day (in the morning); if possible, the weightings were carried out until the end of the study. The body weight change of the animals was calculated from these results.

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: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OTHER: Clinical examinations (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum-y-glutamyltransferase) carried out in the first 12 surviving animals per test group and sex of the F0 and F1 parental generations.

Oestrous cyclicity (parental animals):

the number of mating days until vaginal sperm could be detected, and pregnancy status were recorded for F0 and F1 females. For the females, mating, fertility and gestation indices were calculated for F1a, F1b and F2 litters.

Sperm parameters (parental animals):

Parameters examined in all P/F1/F2 males: testis weight, epididymis weight

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter.

PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring: clinical observation (each day), number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain (days 1, 4, 7, 14 and 21), development stages (pinna unfolding on day 4 after birth before standardization, opening of the auditory canal on day 13 after birth and opening of the eyes on day 15 after birth), physical or behavioural abnormalities (gripping reflex, hearing [acoustic startle] and pupillary reflex [pupil constriction]).

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities

Postmortem examinations (parental animals):

SACRIFICE
- Male and maternal animals: after the F1b generation pups were weaned, the F0 generation parental animals were sacrificed. Some weeks after the F2 generation pups had been weaned, the fasted (about 16 hours) F1 generation parental animals were sacrificed (with the exception of the female animals, which were taken for the reevaluation of fertility)

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera

HISTOPATHOLOGY / ORGAN WEIGHTS
Following tissues (vagina, cervix, uterus, ovaries, oviducts, pituitary gland, testes, epididymides, prostate, seminal vesicle, coagulation gland, liver, kidneys, all gross lesions) were prepared for microscopic examination and weighed, respectively.

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed after standardisation or weaning.
- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows:

GROSS NECROPSY
- Gross necropsy consisted of external and visceral examinations

HISTOPATHOLOGY / ORGAN WEIGTHS
The tissues (vagina, cervix, uterus, ovaries, oviducts, testes, epididymides, seminal vesicle, coagulation, gland, prostate, pituitary gland, liver, kidneys and all gross lesions) were prepared for microscopic examination and weighed, respectively.

Statistics:

- Clinical examinations: DUNNETT-Test for a simultaneous comparison of several dose groups with the control (hypothesis of equal means tested; test was performed two-sided) used for the statistical evaluation of food consumption (parental animals), body weights and body weight change (parental animals and pups), number of mating days, duration of gestation, and number of pups delivered per litter. FISHER's Exact Test used for a pairwise comparison of each dose group with the control for the hypothesis of equal proportions. This test was
performed one-sided for statistical evaluation male and female mating index, male and female fertility index, gestation index, females with liveborn, stillborn and with all stillborn pups, live birth index, pups stillborn, pups died, pups cannibalized, pups sacrificed moribund, viability index, lactation index, number of litters with affected pups at necropsy. WILCOXON-Test used for a comparison of each dose group with the control for the hypothesis of equal medians. This test was performed one-sided and was used for the proportion of affected pups per litter with necropsy observations and concerning physical development and reflex data for the proportion of pups reaching special criteria in each litter (statistical unit = litter).
- Clinical chemistry: parametric one-way analysis of variance done via the F-test (ANOVA) followed by DUNNETT's test (both performed two-sided) for the hypothesis of equal means if the resulting p-value equal or less than 0.05.
- Pathology: Mean and standard deviation calculated for the statistical evaluation of the study for the variables of terminal body weight and of absolute and relative organ weights (related to terminal body weight) of the animals in each test group and tabulated together with the individual values (absolute and relative organ weights). DUNNETT test used for a simultaneous comparison of several dose groups with a control group.

Reproductive indices:

Male mating and fertility indexes; female mating, fertility and gestation index

Offspring viability indices:

live birth index, viability index, lactation index

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Details on results (P0)

Only test substance-dependant findings

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
One F0 50 ppm female had to be sacrificed in a moribund condition due to a vaginal prolapse during the reevaluation of fertility after day 4 of mating.
1) F0 PARENTAL ANIMALS
a) 16000 ppm groups (approx. 1625 mg/kg body weight/day)
- marginally, but statistically significantly reduced food consumption in the males and females during the premating period and in the dams during the gestation and lactation periods of F1a pups

2) F1 PARENTAL ANIMALS
a) 16000 ppm groups (approx. 1625 mg/kg body weight/day)
- statistically significantly reduced food consumption in males and females during several weeks of the premating period and in the FI dams during gestation of the F2 litter.

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
1) F0 PARENTAL ANIMALS
a) 16000 ppm groups (approx. 1625 mg/kg body weight/day)
- distinctly lower body weights in comparison to the controls and clear impairments of the body weight gains in males throughout the whole study period and in females during premating, gestation and lactation (F1a and F1b).
b) 4000 ppm groups (approx. 407 mg/mg body weight/day)
- statistically significantly decreased body weights and/or body weight gains in the males during several weeks of the study period and in the females during premating, gestation and lactation (F1a and F1b).

2) F1 PARENTAL ANIMALS
a) 16000 ppm groups (approx. 1625 mg/kg body weight/day)
- distinctly lower body weights (compared to controls) and/or clear impairments in body weight gains in the males (during the whole study phase) and in the females during premating, gestation and lactation.
b) 4000 ppm groups (approx. 407 mg/mg body weight/day)
- statistically significant impairments concerning body weights and/or body weight changes in males (during several weeks of the study period) and in females during the premating period and during the gestation and/or lactation period of F2 litters.

ORGAN WEIGHTS (PARENTAL ANIMALS)
1) F1 PARENTAL ANIMALS
a) 4000 and 16000 ppm groups (approx. 1625 mg/kg body weight/day)
- statistically significantly decreased absolute kidney weights in female rats

GROSS PATHOLOGY AND HISTOPATHOLOGY (PARENTAL ANIMALS)
1) F1 PARENTAL ANIMALS
a) 4000 and 16000 ppm groups (approx. 1625 mg/kg body weight/day)
- decreased number of fat storing cells in the liver in male rats

OTHER FINDINGS (PARENTAL ANIMALS)
- CLINICAL CHEMISTRY
- statistically significant increase in serum y-glutamyltransferase in the males (in the 16000 ppm groups for F0 and F1 parental animals and in the 16000 ppm group for F0 parental animals)

Effect levels (P0)

1

Dose descriptor:

NOAEL

Remarks:

reproductive function (fertility)

Effect level:

> 16 000 other: ppm (nominal in diet) corresponding to approx. 1625 mg/kg bw per day

Sex:

male/female

Basis for effect level:

other: No indications for a substance-induced impairment of the reproductive function of the parental animals of both F0 and F1 generations were observed up to this highest dose level

Remarks on result:

other: Generation: F0 and F1 (migrated information)

2

Dose descriptor:

NOAEL

Remarks:

systemic toxicity

Effect level:

1 000 other: ppm (nominal in diet) corresponding to approx. 100 mg/kg bw per day

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Remarks on result:

other: Generation: F0 and F1 (migrated information)

3

Dose descriptor:

NOAEL

Remarks:

developmental toxicity

Effect level:

ca. 1 000 other: ppm (nominal in diet) corresponding to approx. 100 mg/kg bw per day

Sex:

male/female

Basis for effect level:

other: retarded growth and some delays in physical development were exhibited by the F1a, F1b and/or F2 pups at 16000 ppm and - much less pronounced - at 4000 ppm

Remarks on result:

other: Generation: F0, F1 and F2 (migrated information)

Results: F1 generation

General toxicity (F1)

Clinical signs:

effects observed, treatment-related

Mortality / viability:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Sexual maturation:

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings:

effects observed, treatment-related

Details on results (F1)

Only test substance - related findings

BODY WEIGHT (OFFSPRING)
1) 16000 ppm groups (approx. 1625 mg/kg body weight/day)
a) F1a and F1b pups: statistically significantly lower mean pup body weights than the controls and clear impairments of pup body weight gains of the male and female F1a and F1b pups.
b) F2 pups: statistically significantly lower mean pup body weights compared to controls and marked reduction of pup body weight gains (both sexes).

2) 4000 ppm groups (approx. 407 mg/mg body weight/day)
a) F1a and F1b pups: statistically significantly lower mean pup body weights and impairments in pup body weight gains in the F1a and F1b pups.
b) F2 pups: slightly lower mean pup body weights compared to controls and impaired pup body weight gains.

GROSS PATHOLOGY AND HISTOPATHOLOGY (OFFSPRING)
1) 16000 ppm groups (approx. 1625 mg/kg body weight/day)
a) F1a and F1b pups: retarded morphological development (delays in pinna unfolding) in the F1b pups.

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

The dietary administration of the test substance to Wistar rats over two generations resulted in clear signs of systemic toxicity in the parental animals of both generations at 16000 ppm and, generally less pronounced, also at 4000 ppm.

 

The systemic toxicity observed at these concentrations (4000 or 16000 ppm) was substantiated by distinct reductions in body weight in comparison to the concurrent controls, impairments in body weight gain (at the end of the premating periods 7 - 13% less weight gain than the controls), an increase in serum y-glutamyltransferase, decreased number of fat storing cells in the liver and reduced absolute kidney weights. These adverse findings are causally related to the test substance administration.

 

There were no signs of substance-induced systemic adverse effects in the F0 or Fl parental animals at 1000 or 50 ppm.

 

No indications for a substance-induced impairment of the reproductive function (Table 1) of the parental animals of both generations were present up to and including the highest dose level.

Table 1: Fertility indices for F0 and F1 generations (in %) concerning the indicated litters

 

Evaluated concentration		0 ppm		50 ppm		1000 ppm		4000 ppm		16000 ppm
Parental generation		F0	F1	F0	F1	F0	F1	F0	F1	F0	F1
Fertility indices concerning	F1a litters	100	-	92	-	100	-	88	-	96	-
	F1a litters	100	-	96	-	100	-	92	-	96	-
	F1a litters	-	96	-	88	-	96	-	100	-	92

 

Signs of developmental toxicity in the form of retarded growth and some delays in physical development were exhibited by the F1a, F1b and/or F2 pups at 16000 ppm and - much less pronounced - at 4000 ppm, whereas 50 and 1000 ppm test substance levels were tolerated by all three pup generations (F1a, F1b, F2) without any indications for substance-induced adverse effects.