Talc (Mg3H2(SiO3)4)

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

review article or handbook

Title:

Unnamed

Year:

1973

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Groups of 20-22 gravid albino CD-1 mice and groups of 20-24 gravid Wistar rats were dosed by gavage with 0, 16, 74, 350, or 1600 mg/kg bw talc as an anhydrous corn oil suspension on days 6-15 of gestation. Aspirin was used as a positive con-trol in both species.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Talc (Mg3H2(SiO3)4)

EC Number:

238-877-9

EC Name:

Talc (Mg3H2(SiO3)4)

Cas Number:

14807-96-6

Molecular formula:

H2Mg3O12Si4

IUPAC Name:

Talc (Mg3H2(SiO3)4)

Test material form:

solid

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

[TEST ANIMALS]
- Groups of 20-24 gravid Wistar rats
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: approximately 7 days
[ENVIRONMENTAL CONDITIONS]
- Temperature (°C): 20.8–23.1 °C
- Humidity (%): 38.4–77.8 %
- Air changes (per hr): 10–15 clean, fresh, filtered air changes per hr
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

Groups of 20-24 gravid Wistar rats were dosed by gavage with 0, 16, 74, 350, or 1600 mg/kg bw talc as an anhydrous corn oil suspension on days 6-15 of gestation. Aspirin was used as a positive control.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

not specified

Duration of treatment / exposure:

on days 6-15 of gestation.

Frequency of treatment:

Once a day

Duration of test:

on day 20 of gestation

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

16 mg/kg bw/day

Doses / concentrations 3

Dose / conc.:

74 mg/kg bw/day

Doses / concentrations 4

Dose / conc.:

350 mg/kg bw/day

Doses / concentrations 5

Dose / conc.:

1 600 mg/kg bw/day

No. of animals per sex per dose:

groups of 20-24 gravid Wistar rats
Aspirin was used as a positive control

Control animals:

yes, concurrent vehicle

Details on study design:

Groups of 20-22 gravid albino CD-1 mice and groups of 20-24 gravid Wistar rats were dosed by gavage with 0, 16, 74, 350, or 1600 mg/kg bw talc as an anhydrous corn oil suspension on days 6-15 of gestation. Aspirin was used as a positive con-trol in both species. The mice were killed on day 17 and the rats on day 20 of gestation and the number of implantation sites, resorptions sites, and live and dead fetuses, and the live pup body weights were recorded.

Examinations

Maternal examinations:

CLINICAL OBSERVATIONS:
- All animals were observed once a day throughout the study on mortality, general condition and gross evidence of clinical signs and symptoms
Detailed physical examinations :
- All animals were once in pretest period, once a week throughout the dosing and recovery periods on central and autonomic nervous system effects, motor activity, and behaviour.

Ovaries and uterine content:

Examinations included:
- Number of corpora lutea: Yes
- Number of implantations: Yes

Fetal examinations:

- External examinations: Yes

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Maternal developmental toxicity

Number of abortions:

not examined

Details on maternal toxic effects:

the administration of up to 1600 mg/kg bw talc in corn oil had no effect on reproductive or developmental parameters and had no effect on maternal or fetal survival.

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

>= 1 600 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

maternal abnormalities

mortality

other: developmental toxicity

Remarks on result:

other:

Remarks:

the administration of up to 1600 mg/kg bw talc in corn oil had no effect on reproductive or developmental parameters and had no effect on maternal or fetal survival.

Maternal abnormalities

Abnormalities:

not specified

Results (fetuses)

Fetal body weight changes:

no effects observed

Details on embryotoxic / teratogenic effects:

the administration of up to 1600 mg/kg bw talc in corn oil had no effect on reproductive or developmental parameters and had no effect on maternal or fetal survival.

Effect levels (fetuses)

Dose descriptor:

NOAEL

Effect level:

1 600 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

fetal/pup body weight changes

changes in litter size and weights

Remarks on result:

other:

Remarks:

the administration of up to 1600 mg/kg bw talc in corn oil had no effect on reproductive or developmental parameters and had no effect on maternal or fetal survival.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The NOAEL was considered to be 1600 mg/kg bw/day for developmental toxicity study.
The administration of up to 1600 mg/kg bw talc in corn oil had no effect on reproductive or developmental parameters and had no effect on maternal or fetal survival.

Executive summary:

Groups of 20-22 gravid albino CD-1 mice and groups of 20-24 gravid Wistar rats were dosed by gavage with 0, 16, 74, 350, or 1600 mg/kg bw talc as an anhydrous corn oil suspension on days 6-15 of gestation. Aspirin was used as a positive control in both species. The mice were killed on day 17 and the rats on day 20 of gestation and the number of implantation sites, resorptions sites, and live and dead fetuses, and the live pup body weights were recorded. In both mice and rats, the admini-stration of up to 1600 mg/kg bw talc in corn oil had no effect on reproductive or developmental parameters and had no effect on maternal or fetal survival.