Registration Dossier

Administrative data

Description of key information

The key acute oral toxicity study (similar to the now deleted OECD 401; DCC, 1976), in which Wistar rats were given a single gavage dose of gamma-glycidyloxypropyltrimethoxysilane gave an LD50 of 8025 mg/kg bw (based on a density of 1.07g/cm3). Piloerection and lethargy within one hour of administration, followed by coma and death. All deaths occurred within 48 hours of administration. 
In the key acute dermal study (Mellon Institute, 1962), which was similar to OECD 402, male New Zealand white rabbits were exposed to the test substance under an occlusive dressing for 24 hours. The LD50 was 4250 mg/kg bw (based on a density of 1.07g/cm3). No clinical signs were observed, apart from skin irritation. Necropsy revealed congested lungs, mottled livers with prominent acini, and off-colour kidneys with internal congestion.
For the inhalation route the key study ( Allied Corporation, 1982) was conducted according to OECD 403. Fischer-344 rats were exposed to the aerosol, whole-body. The LC50 was >5300 mg/m3 (>5.3 mg/l). Clinical signs observed in the first week after exposure included excessive lacrimation, dry and moist rales, nasal discharge, and yellow staining in the anal-genital area. Discolored lungs and autolytic changes were seen in the three rats that died. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
8 025 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion
Dose descriptor:
LC50
5 300 mg/m³

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
LD50
4 250 mg/kg bw

Additional information

The most reliable study for each route was chosen as the key study.

Justification for classification or non-classification

There are no existing or proposed classifications for the acute toxicity of [3 -(2,3 -epoxypropoxy)propyl]trimethoxysilane.