Butyryl chloride

Endpoint summary

Description of key information

In rats the oral LD50 was 1000-1470 mg/kg bw; in rabbits the dermal LD50 was >2000 mg/kg bw.

Based on the results of an inhalation-risk test an LC50 between 3.6 - 5.6 mg/L was calculated using Haber's rule.

Additional information

Oral toxicity

In an acute oral toxicity study comparable to OECD guideline 401 (BASF AG, 1979), Sprague Dawley rats (5/sex/dose) were exposed to 316-4640 mg/kg bw butyryl chloride in olive oil by gavage and observed for 14 days. Clinical findings included dyspnea, apathy, uncoordinated movement, atonia, tremor, tonic convulsion, clonic cramp, cyanosis, dehydration and salivation. No mortality was observed at 316 mg/kg bw and 464 mg/kg bw. At 681 mg/kg bw, 1/10 animals died, 0/10 animals died at 1000 mg/kg bw and 10/10 animals died at 1470, 2150, 3160 and 4640 mg/kg bw. At pathology, the following was observed: hart: dilatation both sides, local acute hyperaemia; thorax: slight hydrothorax; lungs: emphysema; stomach: astringent surface, diffuse dark-redness, deep heomorrhagic ulcerations; bowles: astringent serosa, diffuse redness. The organs of the surviving animals were without findings. The LD50 was 1000-1470 mg/kg bw for both sexes.

 

Dermal toxicity

In an acute dermal toxicity test, comparable to OECD guideline 402, Sprague Dawley rats were treated with 1000 (n=3/sex) and 2000 (n=6/sex) mg/kg bw butyryl chloride at 42 cm2 of skin for 24 hours and subsequently observed for a 14-day period (BASF AG, 1979). Clinical signs consisted of dyspnea (at the start of the test), apathy, aggression, uncoordinated movement, spastic gait, anaemic appearance, poor general condition, and local skin irritation converting to necrosis. One animal dosed at 2000 mg/kg bw died during the test. Pathological investigation of this animal revealed the following: hart: acute atrial dilatation, local acute hyperaemia; liver: anaemia. No pathological abnormalities were observed in animals sacrificed after the observation period. The LD50 was determined to be >2000 mg/kg bw.

 

Inhalation toxicity

In a study on inhalation toxicity comparable to OECD guideline 403, groups of rats (3-6/sex/concentration) were exposed to butyryl chloride concentrations of 14.0-14.4 mg/L for 3, 10 or 30 minutes (BASF AG, 1979). Animals were observed up to 14 days after exposure after which they were sacrificed for pathological examination. During exposure animals showed strong attempts to escape, salivation, lacrimation, nasal discharge, dyspnea, cyanosis, and cloudy cornea. In the 3-minutes exposure group 3 of 12 animals died, in each of the 10-minute and 30-minute exposure groups 5 of 6 animals died. Pathological examination of animals dying during the test showed the following: hart: acute dilatation, local acute hyperaemia; lungs: emphysema (mid-section), abundant foamy fluid in trachea and bronchi, spotted bleedings in both lobes. Animals sacrificed 14 days after exposure were without findings. Using a graphical probability analysis, an LT50 value of 5 - 8 min can be estimated. The theoretical vapour saturation concentration in the chamber can be calculated to be ca. 171 mg/L (MW 106.6 and a vapour pressure at 20°C of 39 mbar). Using Haber's rule an LC50 between 3.6 - 5.7 mg/L can be calculated.

Justification for classification or non-classification

Based on the available data, butyryl chloride has to be classified for acute oral and inhalation toxicity. According to to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008, the classification is acute oral Cat. 4 (H302) and acut inhalation Cat. 3 (H331).