Kaolin, calcined

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Additional information

There are no data available for Kaolin, calcined. However, some data are available for structurally related compounds. Sodium silicoaluminate and Syloid 244 were examined for embryotoxic and developmental effects during the gestation phase in various animals species (rat, mouse, rabbit and hamster) at an oral dose of 1600 mg/kg bw/day (Syloid 244: up to 1340 mg/kg bw/day in rats and mice, respectively).

There were no significant signs of maternal or embryotoxic/developmental effects. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the frequencies occuring spontaneously in the control animals (Food and Drug Research Laboratories, 1973).

Short description of key information:
No data available.

Effects on developmental toxicity

Description of key information

Oral:
RA from Synthetic silica sodium silicoaluminate:
NOAEL (maternal toxicity): 1600 mg/kg bw/day (for rat, mouse, rabbit and hamster) 
NOAEL (teratogenicity): 1600 mg/kg bw/day (for rat, mouse, rabbit and hamster) 
RA from Syloid 244 (Silica aerogel):
NOAEL (maternal toxicity): 1340 mg/kg bw/day (for rat and mouse) 
NOAEL (teratogenicity): 1340 mg/kg bw/day (for rat and mouse) 
NOAEL (maternal toxicity): 1600 mg/kg bw/day (for rabbit and hamster) 
NOAEL (teratogenicity): 1600 mg/kg bw/day (for rabbit and hamster) 

Effect on developmental toxicity: via oral route

Dose descriptor:

NOAEL

1 600 mg/kg bw/day

Additional information

There are no data available for Kaolin, calcined regarding developmental toxicity/teratogenicity. However, there are data available for structural analogue substances.

Within the scope of a comprehensive and valid testing programme, sodium silicoaluminate was examined for embryotoxic and developmental effects during the gestation phase in various animals species (rat, mouse, rabbit and hamster) at an oral dose of 1600 mg/kg bw/day. There were no significant signs of maternal or embryotoxic/developmental effects. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the frequencies occuring spontaneously in the control animals (Food and Drug Research Laboratories, 1973).

The administration of up to 1340 mg Syloid 244/kg bw/day to pregnant mice and rats for 10 consecutive days had no clearly discernible effect on nidation or on maternal or fetal survival.

The results of Syloid 244 look similar to the results of silicoaluminate. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls. Syloid 244 was tested up to 1600 mg/kg bw/day in rabit and hamster. Under the experimental conditions Syloid 244 showed no significant effects on teratogenicity in (Food and Drug Research Laboratories, 1973).

An additional study determined the effects of kaolin (clay) ingestion on the maternal blood and embryonic development of the pregnant rat (Patterson and Staszak, 1977, RL2). Thirty-six Sprague-dawley female rats were divided into three groups: control diet, 20% kaolin diet, and iron-supplemented 20% kaolin diet. The diets were fed 37 to 68 days, 69 to 95 days, and 96 to 117 days prior to fertilization, and the same diets were fed for the duration of the gestation period. Results of analysis of variance indicates that the kaolin fed rats did produce pups weighing significantly less than pups born to the controls or the iron-supplemented kaolin fed group. The length of the pups was not significantly different among the three groups across time and no morphological abnormalities were observed in any of the pups.

In another study examining reproductive effects Sprague-Dawley rats were administered calcium montmorillonite orally on pregnancy days 1-15 (Wiles et al., 2004, RL2). No effects were examined on the maternal body weights, litter weights or embryonic resorptions. Detailed examination of fetuses for malformations was not performed; dams were killed to early (on gestational day 16).

Justification for classification or non-classification

Based on data for structurally related compounds it is not expected that Kaolin, calcined produces adverse effects on the reproductive performance or embryonic/foetal development. No classification is required according to DSD (67/548/EEC) or CLP (1272/2008/EC).