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Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information

ORAL

The NOAEL for fertility in rats was determined to be 15 000 ppm in the diet, equating to about 1561 mg/kg bw/day for males and 2432 mg/kg bw/day for females, OECD 416 (and aspects of OECD 415 and OECD 407), Eiben (2003a)

Link to relevant study records
Reference
Endpoint:
one-generation reproductive toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
according to guideline
Guideline:
OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Principles of method if other than guideline:
One-generation study following OECD TG 416 (2001) without treatment of F1 weanlings after developmental milestones had occurred (balano-preputial separation or vaginal opening at an age of about 8 weeks). The conduct of this study includes also recommendations of OECD TG 415 (adopted 1983) and 407 (only open field observations and Functional Observation Battery)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
-number of animals F0: 25/sex/group
- number of viable pups F1: 196-244/group
- Age: about 6 w
- Weight at study initiation: males: 111-151 g; females: 96-132 g
Route of administration:
oral: feed
Details on exposure:
oral feeding in a diet containing 1 % peanut oil
diets were prepared twice weekly
Details on mating procedure:
- M/F ratio per cage: 1/1
- Length of cohabitation: up to 21 days
- Proof of pregnancy: sperm in vaginal smear
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The determination of diphenyl carbonate in the feed samples was done after extraction by gas chromatography. Content, homogeneity and stability of diphenyl carbonate in food was confirmed under GLP.
Duration of treatment / exposure:
Exposure period: about 18 weeks (see test conditions)
Premating exposure period (males): 11 weeks
Premating exposure period (females): 11 weeks
Frequency of treatment:
continuous
Details on study schedule:
Animals were exposed during the premating  period of about 11 weeks, and during the mating period of up to 3 weeks.  Males were sacrificed after the mating period. Females were further  exposed during pregnancy and lactation, and were sacrificed when F1  offspring was weaned (after 4 weeks). At the same time most F1 animals  were sacrificed, except of one F1 male and one F1 female per litter,  which were sacrificed after a further treatment period of about 4 weeks,  when developmental milestones had occurred (balano-preputial separation  or vaginal opening).
Dose / conc.:
1 500 ppm
Remarks:
(nominal in diet)
Dose / conc.:
5 000 ppm
Remarks:
(nominal in diet)
Dose / conc.:
15 000 ppm
Remarks:
(nominal in diet)
No. of animals per sex per dose:
25
Control animals:
yes, concurrent no treatment
Details on study design:
Rationale for dose selection:
based on a subchronic feeding pilot study (Eiben, 2002. Diphenylcarbonate (DPC) Subchronic study in Wistar rats (Pilot study for a one-generation study with administration in the diet). Report No. AT00045. Oct 22, 2002) See also chapter 7.5.1 (repeated dose toxicity: oral).

ACTUAL DOSE (mean) RECEIVED BY DOSE LEVEL BY SEX:
- low dose: 132 (m) or 219 (f) mg/kg bw/day
- mid dose: 427 (m) or 710 (f)  mg/kg bw/day
- high dose: 1561 (m) or 2432 (f) mg/kg bw/day 
Positive control:
none
Parental animals: Observations and examinations:
CLINICAL OBSERVATIONS AND FREQUENCY: 
- Clinical signs: at least weekly
- Mortality: twice daily
- Body weight: weekly
- Food consumption: weekly
- Water consumption: no data
- Ophthalmoscopic examination: no data
- Haematology: no data
- Biochemistry: no data
- Urinalysis: no data
- functional observation battery : yes
Oestrous cyclicity (parental animals):
yes
Sperm parameters (parental animals):
 yes (control and 15000 ppm group) spermatozoa motility  and viability, spermatozoa morphology, quantitative determination of  spermatozoa in epididymis, quantitative determination of homogenization  resistant spermatid heads in the testis
Litter observations:
- determination of offspring toxicity according to OECD TG 416
Postmortem examinations (parental animals):
- gross pathology F0: organs as given in OECD TG 416
- organ weights F0: as given in OECD TG 416
- Histopathology F0 (control and 15000 ppm group): adrenals, liver,  kidney spleen, pituitary, vagina, uterus/cervix, ovaries, oviducts,  seminal vesicles with coagulation glands, prostate, brain, mammary glands  with skin, testes, epididymides, thyroids/parathyroids
Postmortem examinations (offspring):
- gross pathology F1: organs as given in OECD TG 416
- organ weights F1: brain, spleen, thymus, testes, epididymides, uterus  were determined for the first male and female living F1 weanling of each  litter 
- Histopathology F1 weanlings: ovaries
Statistics:
Dunnet-Test with variance analysis for body and organ weights;  Kruskal-Wallis-Test with a Steel-Test for food consumption data
Reproductive indices:
- Reproduction parameters: estrus cycle staging, insemination rate,  duration of pregnancy, data on pups
Offspring viability indices:
- determination of offspring toxicity according to OECD TG 416
- developmental milestones and investigations in post weaned F1 rats: age  and body weight at which balano-preputial separation and vaginal opening  occurred
- Functional Observation Battery: yes
Clinical signs:
no effects observed
Description (incidence and severity):
No treatment-related effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Slightly reduced  mean body weights (up to 8%)  became obvious in high dosed animals
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No treatment-related effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
no indication of neurotoxic potential
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
no indication of neurotoxic potential
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
OVARIES: Number of corpora lutea slightly elevated in all dose groups;  large corpora lutea exhibited an infiltration of predominantly  mononuclear cells and contained granulated luteal cells. Number of  hypertrophic ovarian interstitial cells increased with severity score  increasing in a dose dependent manner.
LIVER: Hepatocellular hypertrophy was found in low frequency and severity  score predominantly in males. ADRENAL GLANDS: In mid and high dosed males the frequency of mixed-size  vacuolation of Zona fasciculata and partly also glomerulosa cells was  slightly and the severity moderately increased. In females microvesicular  vacuolation and hypertrophy of Zona fasciculata cells were found in high  incidences in all dose groups. The severity score increased  dose-dependently.
Histopathological findings: neoplastic:
no effects observed
Reproductive function: oestrous cycle:
no effects observed
Description (incidence and severity):
No treatment-related effects
Reproductive function: sperm measures:
no effects observed
Description (incidence and severity):
No significant findings were noted
Reproductive performance:
no effects observed
Description (incidence and severity):
No treatment-related effects
PARAMETERS OF REPRODUCTION IN F0: 
- fertility index (91.7%, 100%, 91.7%, 100%)
- gestation index (95.5%, 100%, 100%, 100%)
- duration of gestation (21.9, 22.29, 22.70, 22.33 days)
Dose descriptor:
NOAEL
Remarks:
parental toxicity
Effect level:
1 500 ppm
Sex:
male
Basis for effect level:
other: about 132 mg/kg bw/day
Dose descriptor:
LOAEL
Remarks:
parental toxicity
Effect level:
1 500 ppm
Sex:
female
Basis for effect level:
other: about 219 mg/kg bw/day based on  increased relative and absolute adrenal weights with histopathological changes in the zona fasciculata, and morphological changes in the ovaries
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
15 000 ppm
Sex:
male
Basis for effect level:
other: about 1561 mg/kg bw/day
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
15 000 ppm
Sex:
female
Basis for effect level:
other: about 2432 mg/kg bw/day
Critical effects observed:
not specified
Clinical signs:
no effects observed
Description (incidence and severity):
No treatment-related effects
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
body weights at weaning: in 15000 ppm pups reduced by 11-12% (this is  most likely directly induced by compound consumption rather than a  reprotoxic effect)
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
organ weights at weaning: at 15000 ppm reduced absolute spleen weights  in both sexes (ca. -20%; relative weights not affected) and reduced  absolute (-29%) and relative (-16%) thymus weights in females
Gross pathological findings:
no effects observed
Description (incidence and severity):
No treatment related effects
Histopathological findings:
effects observed, treatment-related
Description (incidence and severity):
histopathology F1 at weaning: at 1500 ppm and above in ovaries large  corpora lutea exhibited an infiltration of predominantly mononuclear  cells (1/5/9/11); many of corpora lutea contained granulated luteal cells  (0/2/7/8); hypertrophy of ovarian interstitial cells (0/4/10/23) with  severity score increasing in a dose dependent manner
Description (incidence and severity):
OFFSPRING TOXICITY F1: 
- total number of pups (228, 249, 204, 220) 
- mean litter size (10.71, 9.72, 8.73, 9.91) 
- sex ratio (% males: 49.31, 53.41, 45.66, 52.67)
- live birth index (98.74%, 97.47%, 93.12%, 99.04%)
- mean pup weight in g (m: 5.71, 5.97, 5.94, 5.79; f: 5.48, 5.57, 5.65,  5.39)
- viability index day 4 (98.68%, 86.67%, 85.51%, 94.17%)
- malformations: none
- developmental milestones in F1 weanlings:  no treatment effect on sexual maturation
Dose descriptor:
NOAEL
Remarks:
toxicity
Generation:
F1
Effect level:
5 000 ppm
Sex:
male
Basis for effect level:
histopathology: non-neoplastic
Dose descriptor:
LOAEL
Remarks:
toxicity
Generation:
F1
Effect level:
1 500 ppm
Sex:
female
Basis for effect level:
histopathology: non-neoplastic
Critical effects observed:
not specified
Reproductive effects observed:
no
Conclusions:
Reproduction parameters and fertility were not affected up to the highest administered dose. The NOAEL for fertility can therefore be considered as 15000 ppm or 1551 mg/kg bw for males and 2432 mg/kg bw for females.
Executive summary:

The reproductive toxicity of diphenyl carbonate was investigated in a one-generation study in rats, following the two-generation study protocol of OECD 416 (2001) without treatment of F1 weanlings after developmental milestones (balano-preputial separation or vaginal opening at an age of about 8 weeks) had occurred. The conduct of this study included also recommendations of OECD 415 (adopted 1983) and OECD 407 (open field observations and Functional Observation Battery).

Durng the study diphenyl carbonate was administered via the diet to 25 male and 25 female Wistar rats per group in doses of 1500, 5000, or 15 000 ppm. The rationale for dose selection was based on a sub chronic feeding pilot study. The calculated actual doses for parental animals were 132, 427, and 1561 mg/kg bw/day for males and 219, 710, and 2432 mg/kg bw/day for females.

The animals were dosed for a period of 11 weeks prior to mating, then for a period of up to three weeks during mating. Males were sacrificed after the mating period, females were further treated during pregnancy and weaning and were sacrificed together with F1 animals when 28 day-old F1 offspring was weaned.

One F1 male and one F1 female per litter were necropsied after a further treatment period of about 4 weeks, when sexual maturity was reached.

Mortality and clinical appearance of F0 and F1 animals were unchanged throughout all dose groups. Slightly reduced mean body weights (up to 8 %) became obvious in the high dose parental animals. F1 animals of the high dose group gained less body weight. This effect became significant at weaning when pups increasingly ingested diphenyl carbonate via their own food and can therefore be regarded as a primary effect.

Organ weight determination and histopathology revealed diphenyl carbonate dependent changes in the liver, adrenals and ovaries of F0 animals. Changes in ovarian morphology was also observed in treated F1 females in a dose dependent manner throughout all doses, showing a similar appearance to that observed in F0 females. Observations on spermatology parameters, performed on control and high dose males with regard to spermatozoa motility, viability and morphology, quantitative determination of spermatozoa in epididymis, and quantitative determination of homogenisation resistant spermatid heads in the testis, were not adversely affected by treatment.

Reproduction parameters such as insemination index, mating performance, fertility index, gestation index, duration of pregnancy, live birth index, birth weights, prenatal loss and percentages of pups born, litter size, viability and lactation index were not affected by diphenyl carbonate. Iin post weaned F1 animals (1 male and 1 female per litter; sacrificed at an age of 8 weeks) sexual maturation was not affected. The histopathological changes observed in F0 and F1 ovaries and F0 adrenals therefore did not influence reproductive performance.

The NOAEL for fertility in rats was determined to be 15 000 ppm diphenyl carbonate in the diet, equating to about 1561 mg/kg bw/day for males and 2432 mg/kg bw/day for females. For F1 males the NOAEL for general toxicity was 5000 ppm, with a LOAEL at 15 000 ppm based on reduced body weight gain. A NOAEL for F1 females could not be determined as changes in the ovaries were seen down to the lowest tested dose (1500 ppm). The NOAEL for general toxicity in parental males was 1500 ppm (about 132 mg/kg bw/day), with the LOAEL at 5000 ppm (about 427 mg/kg bw/day) based on increased relative liver weights with hepatocellular hypertrophy, and histopathological changes in adrenals. For parental females a NOAEL for general toxicity could not be determined in this study because of histopathological changes in adrenals and ovaries in all dose groups.

Effect on fertility: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 561 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
The study was performed under GLP conditions and in accordance with a standardised guideline. The quality of the database is therefore considered to be good.
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available
Additional information

Oral

The key study (Eiben, 2003a) was conducted under GLP conditions and in accordance with standardised guidelines. The study has therefore awarded a reliability score of 1 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997).

The reproductive toxicity of diphenyl carbonate was investigated in a one-generation study in rats, following the two-generation study protocol of OECD 416 (2001) without treatment of F1 weanlings after developmental milestones (balano-preputial separation or vaginal opening at an age of about 8 weeks) had occurred. The conduct of this study included also recommendations of OECD 415 (adopted 1983) and OECD 407 (open field observations and Functional Observation Battery).

Diphenyl carbonate was administered via the diet to 25 male and 25 female Wistar rats per group in doses of 1500, 5000, or 15 000 ppm. The rationale for dose selection was based on a sub chronic feeding pilot study. The calculated actual doses for parental animals were 132, 427, and 1561 mg/kg bw/day for males and 219, 710, and 2432 mg/kg bw/day for females.

The animals were dosed for a period of 11 weeks prior to mating, then for a period of up to three weeks during mating. Males were sacrificed after the mating period, females were further treated during pregnancy and weaning and were sacrificed together with F1 animals when 28 day-old F1 offspring was weaned.

One F1 male and one F1 female per litter were necropsied after a further treatment period of about 4 weeks, when sexual maturity was reached.

Mortality and clinical appearance of F0 and F1 animals were unchanged throughout all dose groups. Slightly reduced mean body weights (up to 8 %) became obvious in the high dose parental animals. F1 animals of the high dose group gained less body weight. This effect became significant at weaning when pups increasingly ingested diphenyl carbonate via their own food and can therefore be regarded as a primary effect.

Organ weight determination and histopathology revealed diphenyl carbonate dependent changes in the liver, adrenals and ovaries of F0 animals. Changes in ovarian morphology was also observed in treated F1 females in a dose dependent manner throughout all doses, showing a similar appearance to that observed in F0 females. Observations on spermatology parameters, performed on control and high dose males with regard to spermatozoa motility, viability and morphology, quantitative determination of spermatozoa in epididymis, and quantitative determination of homogenisation resistant spermatid heads in the testis, were not adversely affected by treatment.

Reproduction parameters such as insemination index, mating performance, fertility index, gestation index, duration of pregnancy, live birth index, birth weights, prenatal loss and percentages of pups born, litter size, viability and lactation index were not affected by diphenyl carbonate. Iin post weaned F1 animals (1 male and 1 female per litter; sacrificed at an age of 8 weeks) sexual maturation was not affected. The histopathological changes observed in F0 and F1 ovaries and F0 adrenals therefore did not influence reproductive performance.

The NOAEL for fertility in rats was determined to be 15 000 ppm diphenyl carbonate in the diet, equating to about 1561 mg/kg bw/day for males and 2432 mg/kg bw/day for females. For F1 males the NOAEL for general toxicity was 5000 ppm, with a LOAEL at 15 000 ppm based on reduced body weight gain. A NOAEL for F1 females could not be determined as changes in the ovaries were seen down to the lowest tested dose (1500 ppm). The NOAEL for general toxicity in parental males was 1500 ppm (about 132 mg/kg bw/day), with the LOAEL at 5000 ppm (about 427 mg/kg bw/day) based on increased relative liver weights with hepatocellular hypertrophy, and histopathological changes in adrenals. For parental females a NOAEL for general toxicity could not be determined in this study because of histopathological changes in adrenals and ovaries in all dose groups.

EOGRTS

In accordance with section 1 of REACH Annex XI, it is considered justified to omit the Extended One Generation Reproductive Toxicity Study (EOGRTS) required in section 8.7.3 of Annexes IX and X on the grounds that testing is not scientifically necessary. The data provided to address the repeat dose and reproductive toxicity endpoints do not suggest any adverse effects that would indicate this study to be necessary. The one-generation study provided was conducted with additional parameters and it is considered that the study is broadly equivalent to the EOGRTS and therefore the existing data are adequate to address this endpoint.

The one-generation study for diphenyl carbonate was performed in accordance with the standardised guideline OECD 416 of 2001 (without treatment of F1 weanlings), which covers several additional parameters when compared to the classical one-generation study (OECD 415). These include oestrous cycle staging and sperm parameter analysis in parental animals, but also determination of developmental milestones in F1 weanlings, measured as effects on vaginal opening and balano-preputial separation. Additionally, organ weights and gross pathology findings were recorded for F1 animals and the ovaries of F1 females were histopathologically investigated. Due to the fact that treatment with diphenyl carbonate had no influence on reproductive performance in this study and a NOAEL of greater than 1500 mg/kg bw/day could be established for fertility, it is considered that further invertebrate testing to investigate reproductive effects would not be a responsible use of animals.

Effects on developmental toxicity

Description of key information

ORAL

The NOAEL for maternal toxicity and developmental toxicity in rats was 50 mg/kg bw/day, OECD 414, Klaus (2002)

Link to relevant study records
Reference
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Details on test animals or test system and environmental conditions:
according to Guideline
body weight on day 0 p.c.: 207 to 249 g
age of females on day 0 p.c.: 12-16 weeks
Route of administration:
oral: gavage
Vehicle:
CMC (carboxymethyl cellulose)
Details on exposure:
vehicle: carboxymethylcellulose 0.5 % in deionized water
administration volume: 10 ml/kg bw
The dose levels used were selected according to a preceding dose-range  finding study (Study No. T0062796) in rats with dose levels of 0, 20,  125, and 750 mg/kg bw/d.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Investigations on stability and homogeneity of the test compound in samples of 1 mg/ml and 100 mg/ml were performed. Stability and homogeneity were confirmed.
Details on mating procedure:
1 male/2 females per cage; if sperm was detected in the vaginal smear  this day was day 0 of gestation
Duration of treatment / exposure:
days 6 - 19 of gestation
Frequency of treatment:
once daily
Duration of test:
cesarian section and sacrifice at day 20 of gestation
Dose / conc.:
50 mg/kg bw/day (actual dose received)
Dose / conc.:
200 mg/kg bw/day (actual dose received)
Dose / conc.:
750 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
No. of females/dose: 25 (50 mg/kg and 750 mg/kg group: 28) inseminated females
Control animals:
yes, concurrent vehicle
Details on study design:
Sex: female
Duration of test: sacrifice on day 20 of gestation
Maternal examinations:
Body weight gain: on day 0 p.c. and daily from day 6-20
Food consumption: yes
Water consumption: yes (by visual estimation)
Clinical observations: appearance, behaviour, excretory products and  mortality, from day 0 -20 twice daily
Gross pathological examination: at time of cesarian section on day 20  p.c. or after death/premature sacrifice
Ovaries and uterine content:
gravid uterine weight, no. of corpora  lutea, no. of implantations, no. of resorptions, placenta weight
Fetal examinations:
Examination of fetuses: number, weight and sex of live fetuses, external,  visceral and skeletal malformations
Total numer of live fetuses examined: 275/249/269/253
Statistics:
Kruskal-Wallis test, analysis of variance, Dunnett's test, Chi² test were  used
Historical control data:
yes
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
only in 750 mg/kg group: signs of severe toxicity after  administration (convulsions and ventral posture), which disappeared  within 4 hours; in surviving females such clinical signs became less  severe or were not longer evident with increasing duration of treatment;  piloerection;
Mortality:
mortality observed, treatment-related
Description (incidence):
In 750 mg/kg group 5 females died (4 after 1st dose, 1 after 7th dose) 
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Body weight development: stat. sign. reduced at 750 mg/kg throughout the  entire study (mean body weight gain day 0-20 reduced by 24%); in the 200  mg/kg bw/day group stat. sign. reduced only on day 6-7 p.c. and remained  marginally reduced up to sacrifice
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
distinctly reduced in 750 (up to 36%) and slightly reduced  in 200 mg/kg group (up to 12% on days 6-12)
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
effects observed, treatment-related
Description (incidence and severity):
water consumption increased only in high dosed females
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
Placenta weight: unaffected
Description (incidence and severity):
In 750 mg/kg group some females showed empty of  gas filled stomach, related to morbidity/mortility and regarded as unspecific finding.
Placenta appearance: at 750 mg/kg engorged placentae/ necrotic placental  borders
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Description (incidence and severity):
Total number of females with implantations (vehicle control, 50, 200, 750  mg/kg bw/d): 23/22/25/21
No. of resorptions: 0/0/1/0
Total number of females with viable fetuses: 23/22/24/21
No. of corpora lutea/female: 14.3/14.3/14.9/14.7
Postimplantation loss/female: no meaningful effects (0.7/0.8/1.1/1.2)  since no. of viable fetuses per litter not affected and inbetween historical control range
Dose descriptor:
NOAEL
Effect level:
>= 50 mg/kg bw/day
Basis for effect level:
other: maternal toxicity
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects: yes

Details on embryotoxic / teratogenic effects:
see Remarks on results
For selected fetuses a peer review of fetal visceral findings was  performed by Tesh Consultants International, UK.
Dose descriptor:
NOAEL
Effect level:
>= 50 mg/kg bw/day
Basis for effect level:
other: teratogenicity
Abnormalities:
not specified
Developmental effects observed:
not specified

No. of viable fetuses: 275/249/269/253

No. of dead fetuses: 0/0/2/1 (deaths did not affect the mean number of viable fetuses per litter and was comparable to the incidences in historical control, so that toxicological relevance was not assumed)

Sex ratio (% males): not affected (48.4/50.1/50.5/48.6)

Fetal weight (mean in g): 3.77/3.74/3.64/3.40 (high dose group p<0.01)

Fetal malformations: at 750 mg/kg bw (severe maternally toxic dose) incidence of common malformations increased on a fetal and litter basis as

- dysplastic forelimb bones: fetal incidence 5.5%, litter incidence 33.3% compared to 0% in control (in historical control groups indicences of up to 4.3/20% were seen)

- 2 cases of multiple malformations

- 3 cases of atrial septal defect of the heart within 3 litters

- 2 cases of flat and stretched kidneys

- 1 case of situs inversus

- 1 case of shortened tail with missing sacral and caudal vertebrae

Fetal external and visceral deviations: no TS-related effects

Fetal skeletal deviations including cartilaginous deviations: slightly retarded ossification in comparison to control could not be completely excluded in the 200 mg/kg group (retarded ossification of distal phalanges of toes, cervical vertebral bodies, sacral vertebral arches and wavy ribs: only stat. sign. when calculated on a fetal basis) and was evident to a more pronounced degree in the 750 mg/kg group.

Fetal cartilage was not affected. The overall number and type of malformations were not increased at a dose level up to and including 200 mg/kg bw/day.

Conclusions:
Under the conditions of this study, the NOAEL for maternal toxicity and developmental toxicity in rats was 50 mg/kg bw/day. At 200 mg/kg bw/day slight maternal toxicity occurred and a retarding effect on foetal skeletal ossification of toes and cervical vertebral bodies could not be completely excluded.
Executive summary:

The developmental toxicity of the substance was investigated in a study which was conducted in accordance with the standardised guideline OECD 414 under GLP conditions.

During the study test material was administered to rats once daily via oral gavage at dose levels of 50, 200 and 750 mg/kg bw to 25 females per dose. The vehicle was 0.5 % carboxymethylcellulose in deionised water and the dose volume was 10 mL/kg bw. Maternal animals were dosed on days 6 - 19 of gestation and underwent caesarean section and sacrifice on day 20 of gestation.

Administration of 750 mg/kg bw/day led to severe maternal toxicity (mortality, convulsions, piloerection, body weight loss). Foetuses of this dose group showed reduced body weights and increased incidences of unspecific malformations (mainly dysplastic forelimb bones).

No effects were observed on the number of females with implantations, number of resorptions, total number of females with viable foetuses, the number of corpora lutea per female, post implantation loss or placenta weight. At 750 mg/kg bw/day, placentae appeared to be engorged with necrotic placental borders.

The number of dead foetuses did not affect the mean number of viable foetuses per litter and was comparable to the incidences in historical control, so that toxicological relevance was not assumed.

The sex ratio of offspring was not affected by treatment. The foetal weight in the high dose group was statistically significantly reduced.

Foetal malformations were observed at 750 mg/kg bw (severe maternally toxic dose); the incidence of common malformations increased on a foetal and litter basis: dysplastic forelimb bones (foetal incidence 5.5 %, litter incidence 33.3 % compared to 0 % in control, though in historical control groups incidences of up to 4.3/20 % were seen); 2 cases of multiple malformations; 3 cases of atrial septal defect of the heart within 3 litters; 2 cases of flat and stretched kidneys; 1 case of situs inversus; and 1 case of shortened tail with missing sacral and caudal vertebrae.

There were no test material-related effects on foetal external and visceral deviations. The following foetal skeletal deviations (including cartilaginous deviations) were seen: slightly retarded ossification in comparison to control could not be completely excluded in the 200 mg/kg group (retarded ossification of distal phalanges of toes, cervical vertebral bodies, sacral vertebral arches and wavy ribs; this was only statistically significant when calculated on a foetal basis) and was evident to a more pronounced degree in the 750 mg/kg group. Foetal cartilage was not affected. The overall number and type of malformations were not increased at a dose level up to and including 200 mg/kg bw/day.

Under the conditions of this study, the NOAEL for maternal toxicity and developmental toxicity in rats was 50 mg/kg bw/day. At 200 mg/kg bw/day slight maternal toxicity occurred and a retarding effect on foetal skeletal ossification of toes and cervical vertebral bodies could not be completely excluded.

Effect on developmental toxicity: via oral route
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
50 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
The key study was conducted in accordance with a standardised guideline under GLP conditions. It was awarded a reliability score of 1 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997). Therefore, the quality of this database is considered to be high.
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available
Additional information

The key study (Klaus, 2002) was conducted in accordance with the standardised guideline OECD 414 under GLP conditions. It was awarded a reliability score of 1 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997).

In a developmental toxicity study in Wistar rats, the test material was administered once daily via oral gavage at dose levels of 50, 200 and 750 mg/kg bw to 25 females per dose. The vehicle was 0.5 % carboxymethylcellulose in deionised water and the dose volume was 10 mL/kg bw. Maternal animals were dosed on days 6 - 19 of gestation and underwent caesarean section and sacrifice on day 20 of gestation.

Administration of 750 mg/kg bw/day led to severe maternal toxicity (mortality, convulsions, piloerection, body weight loss). Foetuses of this dose group showed reduced body weights and increased incidences of unspecific malformations (mainly dysplastic forelimb bones).

No effects were observed on the number of females with implantations, number of resorptions, total number of females with viable foetuses, the number of corpora lutea per female, post implantation loss or placenta weight. At 750 mg/kg bw/day, placentae appeared to be engorged with necrotic placental borders.

The number of dead foetuses did not affect the mean number of viable foetuses per litter and was comparable to the incidences in historical control, so that toxicological relevance was not assumed.

The sex ratio of offspring was not affected by treatment. The foetal weight in the high dose group was statistically significantly reduced.

Foetal malformations were observed at 750 mg/kg bw (severe maternally toxic dose); the incidence of common malformations increased on a foetal and litter basis: dysplastic forelimb bones (foetal incidence 5.5 %, litter incidence 33.3 % compared to 0 % in control, though in historical control groups incidences of up to 4.3/20 % were seen); 2 cases of multiple malformations; 3 cases of atrial septal defect of the heart within 3 litters; 2 cases of flat and stretched kidneys; 1 case of situs inversus; and 1 case of shortened tail with missing sacral and caudal vertebrae.

There were no test material-related effects on foetal external and visceral deviations. The following foetal skeletal deviations (including cartilaginous deviations) were seen: slightly retarded ossification in comparison to control could not be completely excluded in the 200 mg/kg group (retarded ossification of distal phalanges of toes, cervical vertebral bodies, sacral vertebral arches and wavy ribs; this was only statistically significant when calculated on a foetal basis) and was evident to a more pronounced degree in the 750 mg/kg group. Foetal cartilage was not affected. The overall number and type of malformations were not increased at a dose level up to and including 200 mg/kg bw/day.

Under the conditions of this study, the NOAEL for maternal toxicity and developmental toxicity in rats was 50 mg/kg bw/day. At 200 mg/kg bw/day slight maternal toxicity occurred and a retarding effect on foetal skeletal ossification of toes and cervical vertebral bodies could not be completely excluded.

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Annex I, Regulation (EC) No 1272/2008, the substance does not require classification with respect to toxicity to reproduction and developmental toxicity.

Additional information