Isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol

Endpoint summary

Additional information

Acute Oral Toxicity

The acute oral toxicity of Texanol Ester-Alcohol is well understood. Six acute oral toxicity studies, 4 in rats and 2 in mice, were available for review. In a pre-guideline published study by Carpenter et al. (1974) in which groups of five male rats were administered single doses of undiluted test material by oral gavage and observed for two weeks, the LD50 was reported as 6.86 (4.64-10.1) mL/kg bw, equivalent to approximately 6500 mg/kg bw. In an acute oral toxicity study conducted by an internal Eastman Kodak Company protocol similar to OECD Guideline 401 but with limited study details, Texanol Ester-Alcohol had an acute oral LD50 value of >3200 mg/kg bw in male and female rats. Clinical signs of toxicity were limited to slight transient weakness between one and four hours after dose administration. Two lesser non-guideline studies in rats and two in mice support the oral LD50 value. In these studies when the animals were administered undiluted test material, no deaths were observed in rats or mice receiving 3200 mg/kg bw while both animals of each species died when administered doses of 6400 mg/kg bw. When rats and mice were administered the test material as a 10% suspension in corn oil, the oral LD50 was reported to be between 1600 and 3200 mg/kg bw. While CNS effects were reported in the older non-guideline Kodak studies, no clinical signs were observed in the more recent Kodak rat study when Texanol Ester-Alcohol was tested by a method similar to OECD Guideline 401. 

Acute Dermal Toxicity

The acute dermal toxicity of Texanol Ester-Alcohol is well understood. Three non-guideline studies were available for review. In a pre-guideline published study by Carpenter et al. (1974) in which groups of four male rabbits were administered single doses of undiluted test material to the clipped abdomen under occluded contact for 24 hours and observed for two weeks, the single dose dermal LD50 was reported as > 16 mL/kg bw, equivalent to > 15200 mg/kg bw. In an acute dermal toxicity study conducted according to an internal Eastman Kodak Company method, up to 20 mL/kg bw of undiluted Texanol Ester-Alcohol was applied to the depilated abdomens of 1-3 guinea pigs under occlusive wrap for 24 hours. No deaths or clinical signs were observed and the dermal LD50 was considered to be > 20.0 mL/kg bw (equivalent to > 19000 mg/kg bw). In an earlier non-guideline study conducted by the same laboratory, three guinea pigs were exposed to 5, 10 or 20 mL/kg bw of the undiluted test material on shaved intact skin under occlusive wrap for 24 hours. No animals died. No clinical signs indicating systemic toxicity were reported and all animals gained weight over the 14-day observation period. 

Acute Inhalation Toxicity

The acute inhalation toxicity of Texanol Ester-Alcohol is well understood. Although a study conducted according to OECD Guideline 403 is not available, three non-guideline studies conducted in rats were available for review. No deaths, significant clinical signs, or adverse effects on body weight gain were observed in groups of three rats exposed (whole body) to 2.73 mg/L or 3.55 mg/L of the test substance for 6 hours followed by a 2-week observation period. The latter exposure level could only be generated by heating the test material to 100 °C in a gas washing bottle before it was passed into the chamber containing the rats. These two studies are supported by the work of Carpenter et al. (1974) which found no mortality in groups of six male or female rats exposed to concentrated vapors of Texanol Ester-Alcohol in air for up to eight hours. Texanol Ester-Alcohol is a liquid at room temperature, has a boiling point of 254-260.5°C, and has a low vapor pressure (0.013 mbar) at 20°C. Based on the physical properties of Texanol Ester-Alcohol, the potential for significant inhalation exposure is limited. 

Justification for classification or non-classification

Based on a weight-of-the-evidence assessment, isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3 -diol is not classified for lethality by the oral, dermal, or inhalation routes according to GHS. Based on a weight-of-the-evidence assessment, isobutyric acid, monoester with 2,2,4 -trimethylpentane-1,3 -diol is also not classified for “Specific Target Organ Effects – Single Exposure” according to GHS. No significant clinical signs, body weight changes or gross pathological observations to indicate systemic toxicity were observed by any route of exposure.