Registration Dossier

Administrative data

Description of key information

Acute toxicity:
Oral LD50 612 mg/kg- bw in female rats (OECD TG 401)
Dermal LD50 251 mg/kg-bw in male and female rats (OECD TG 402)
Inhalation LC50 157 ppm in female rats (OECD TG 403)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
Value:
612 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion
Dose descriptor:
LC50
Value:
1 190 mg/m³

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
LD50
Value:
251 mg/kg bw

Additional information

The acute oral toxicity of the test material was evaluated in male and female Crl:CD BR rats by gavage. Since there was a statistically significant sex-related difference in mortality observed, the LD50 was calculated separately for males and females. The acute oral LD50 in male rats was 1177 mg/kg with 95% confidence limits of 974 and 1422 mg/kg. The acute oral LD50 in female rats was 612 mg/kg with 95% confidence limits of 442 and 848 mg/kg. The acute dermal toxicity of teh test material was evaluated in male and female Crl:CDBR rats. Since no statistically significant sex-related difference in mortality was observed, the LD50 was calculated from the combined mortality incidence data. The acute dermal LD50 in male and female rats (combined) was 251 mg/kg with 95% confidence limits of 190 and 322 mg/kg. Rats appear to be more sensitive than rabbits to acute dermal dosing of the test material.

The acute inhalation toxicity of the test material was assessed in Crl: CD Rats. The LC50 value was calculated from the female mortality incidence data. The acute inhalation LC50 for the test material in female rats was 157 ppm (1.19 mg/L) with 95% limits of 90 to 249 ppm. The acute inhalation LC50 for the test material in male rats was greater than 231 ppm (1.75 mg/L). 

The irritating effects of tissue contact with the test material were evident in studies by all exposure routes. Clinical signs indicative of acute neurotoxicity (e.g., abnormal gait, hyperactivity, tremors, convulsions, salivation, and ataxia) were observed in studies by all routes of exposure.

Justification for classification or non-classification

The acute oral toxicity classification is harmful based on an LD50 of 612 mg/kg in rats. The classification is toxic by the inhalation and dermal routes based on an acute dermal LD50 of 251 mg/kg and an acute inhalation LC50 of 1.19 mg/L under the EU criteria.

In consideration of an H335 classification of the test material, the acute rat inhalation study demonstrated that the toxicity was concentration dependant and elicited at the point of contact.  No further classification is needed based on the corrosive nature of the material.