4-tert-butylcyclohexyl chloroformate

Endpoint summary

Description of key information

Tert butylchloroformate is toxic via the inhalative route of exposure (R23;acute inhal. Cat 3). A LC50 value of >0.72 - < 0.88 mg/l/4h for tert-Butylcyclohexyl-chlorformate aerosol was determined. 4-tert.-butylcyclohexyl chlorformiate is practically non toxic via the oral and dermal rout of exposure as LD50 values ar >6700 mg/kg, >2000 mg/kg, respectively.

Additional information

Oral

In the first study groups of 10 rats per sex and dose were administered 200, 1600, 3600, 6400 ml/kg of4-tert.-butylcyclohexylchloroformate in olive oil. 3/20 animals died within two days after administration of 6400 ml/kg bw. No mortality was observed in the other dose groups. Hunched posture, irregular breathing and a poor general condition was observed on the first and the second day post application. There were no substance related symptoms observed from the following days on. No clinical symptoms have been reported for the 200 mk/kg dose group. There were no substance related findings in the sacrificed animals noted. Bloody smeared snouts, diarrhea in three cases and a atonic gastro-intestinal tract in one case was observed for the animals found dead after administration of the test substance.LD50 >6400 mg/kg

This result is confirmed by the second study. No mortality at 2000 mg/kg and 5000 mg/kg The test substance caused apathy, ataxia, dyspnoe, diarroe and a bad general condition. However, all animals recoverd within 3 days. No testsubstance related findings were observed at necropsy. 4-tert.-butylcyclohexylchloroformate is practically non-toxic after oral administration.

 

Inhalation

A study on acute inhalative toxicity of 4 tert butylchloroformate has ben conducted. The study is comparable to OECD 403 with acceptable restrictions mostly due to reduced documentation (e.g. only mean body weights are reported) and no GLP. Five Sprague-Dawley rats /sex and dose were exposed to 3.58; 1.18, 1.09; 0.88; 0.72 mg/l aerosol. Animals tried to escape from exposure. Salivation dyspnoea, anaemic pallor, apathy, red discharge from eyes and nose and alopecia were observed. Animals that died after exposure died with in the first 24 h and showed haemoragic and edematous lungs at necropsy. The animals recovered completely within 9 days. There was no finding at necropsy at the termination of the study. A LC50 value of >0.72 - < 0.88 mg/l/4h for tert-Butylcyclohexyl-chlorformate aerosol was determined in this study. The substance therefore is classified as toxic after inhalation.

Dermal

A dose of 400, 1000, 2000 mg/kg of the test substance (50 % in olive oil) was applied on the back of Sprague Dawley rats in a dermal acute toxicity study. 5 animals per sex were used in the 400 and 1000 mg/kg dose groups, but only 3 animals per sex were used in the 2000 mg/kg dose group (limit dose). No mortality nor any substance related clinical finding, besides a skin irritating/caustic effect was noted. LD50 >2000 mg/kg. 4-tert.-butylcyclohexyl chlorformiate is practically non toxic when in contact with skin.

Justification for classification or non-classification

Tert butylchloroformate is toxic via the inhalative route according to the classification criteria laid down in EU Regulation 67/548 (R23) and EU Regulation 1272/2008 (acute inhal. Cat 3).

No classification is warranted concerning the oral and dermal rout of exposure as classification criteria EU Regulation 67/548 (R23) and EU Regulation 1272/2008 are not met.