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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route
Dose descriptor:
500 mg/kg bw/day
Additional information

Specific investigations on fertility to current standards are not available for hydrophilic SAS and synthetic amorphous silicates. The one-generation study conducted with a hydrophilic SAS type is not adequate to contribute reliable information for biostatistical reasons.

However, given the inherent physico-chemical properties and ubiquitous nature of this class of compounds, there is no structural alert to indicate a potential for reproductive and developmental toxicity. Therefore, based on the weight of evidence, prolonged exposure to synthetic amorphous silica or silicates, applied before and during pregnancy at high doses, is not expected to produce harmful effects on the reproductive performance or embryonic/foetal development in experimental animals (see OECD SIDS Initial Assessment Report for SIAM 19, 2004. The data summarised are for synthetic amorphous silica; synthetic amorphous silicate species; sodium aluminium silicate and calcium silicate). Hence, further testing is not justified. Waiving of this toxicological endpoint is in line with REACH Regulation 1907/2009. Annex VIII, 8.7.1, Annexes IX, X, 8.7.

Summary of the result of the reproduction study:

A one-generation study on Wistar rats gave no evidence of any adverse effects arising from long-term feeding of Aerosil [500 mg/kg bw/d] to both genders for a premating period of 4.5 months and continued up to 6 months [Leuschner 1963]. Five pregnant test females and four pregnant untreated control females delivering 45 and 37 pups, respectively, were included in this test.

The study had shortcomings with respect to the low number of pregnant animals used and the mating ratio of 1(m):5(f) which was too low according to current standards.

Short description of key information:

No adverse effects on fertility and development from administration of 500 mg/kg bw/d in rats in a limited one-generation study (see discussion).

Effects on developmental toxicity

Description of key information

No adverse maternal and embryo-/foetotoxic effects in four species (mouse, rat, rabbit and hamster) following doses of up to 1600 mg/kg bw/d during gestation. The lowest NOAEL was 1340 mg/k bw/d in mice. The NOAEL in rats was similar - 1380 mg/kg bw/day.

Effect on developmental toxicity: via oral route
Dose descriptor:
1 340 mg/kg bw/day
Additional information

The experimental data on intra-uterine development produced in four animal species by a synthetic amorphous silica suggest that there is no potential for adverse effects on embryonal/foetal development arising from exposure to these silica-based substances.

Summary of test results

Within the scope of a comprehensive and valid testing programme, SAS (and also silicates) were examined for embryotoxic and developmental effects during the gestation phase in various animals species, rat, mouse, rabbit and hamster, at oral doses up to 1600 mg/kg bw/d. There were no significant signs of maternal or embryotoxic/developmental toxic effects in any species tested. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the untreated control groups.The lowest of the top doses tested were 1340 and 1380 mg/kg bw/d in mice and rats respectively, which therefore are considered as relevant NOAEL values.

Justification for classification or non-classification

Read-across based on the fact that synthetic magnesium silicate and silicon dioxide have similar basic physicochemical properties and are highly stable, inert substances can justify the use of silicon dioxide data in this endpoint.  In addition, it will eliminate the need for further vertebrate studies that are unwarranted on ethical and animal welfare grounds.

Magnesium silicate was not classified as it did not fulfil the criteria detailed in Regulation EC No. 1272/2008 or Directive 67/548/EEC.

Additional information