Isoheptane

Endpoint summary

Description of key information

Oral LD50 (rat) > 5000 mg/kg bw
Dermal LD 50 (rabbit) > 2000 mg/kg bw
Inhalative LD50 (rat) > 29300 mg/m³

Additional information

Oral

 

There are no data available on the acute oral toxicity of isoheptane. However, there are reliable data available for another category member. Thus, read-across was conducted based on a category-approach.

The acute oral LD₅₀value in rats was greater than 5000 mg/kg for iso-octane (CAS No. 540-84-1). Clinical observations noted one-hour post exposure in 8 of 10 animals included depression, salivation, wheezing, rough coat, and soft faeces. Two female rats appeared normal throughout the study. All animals appeared normal from day 2 through termination of the study. (Chevron Phillips, 1982).

 

Inhalation

 

There are no data available on the acute toxicity of isoheptane upon inhalative exposure. However, there are reliable data available for another category member. Thus, read-across was conducted based on a category-approach.

Ten male and female Sprague-Dawley rats were exposed to n-heptane (CAS No. 142-82-5) via whole body inhalation at nominal concentration of 29290 mg/m³ for 4 hours (similar to OECD 403). The analytical concentration was determined to be ca. 73500 mg/m³. There was no mortality during the course of the study. A slight reduction of mean male body weights was noted on day 2 post-exposure but males recovered by day 4. All animals appeared normal throughout the study and at terminal necropsy with the exception of one female observed with enlarged mandibular lymph nodes on the right side. The LC₅₀was greater than the nominal concentration of 29300 mg/m³ (Chevron Phillips, 1982).

 

Dermal

 

There are no data available on the acute dermal toxicity of isoheptane. However, there are reliable data available for another category member. Thus, read-across was conducted based on a category-approach.

The dermal LD₅₀value of iso-octane (CAS No. 540-84-1), as determined in rabbits, was greater than the limit dose of 2000 mg/kg. All rabbits appeared normal throughout the study. Very slight dermal erythema was noted in all animals on day 1 after dosing, which persisted in one male and one female on day 3. All erythema had cleared by day 7. Very slight oedema was noted in two males and one female on day 1 and cleared by day 3. Epidermal scaling was noted in one female on day 10 (Chevron Phillips, 1982).

Justification for classification or non-classification

Based on read-across within a category approach, the available data on the acute toxicity of isoheptane are conclusive but not sufficient for classification. However, acute inhalative exposure may result in non-lethal narcotic effects and, as a hydrocarbon, it poses aspiration hazard.

 

DSD: R65-67

 

CLP: Aspiration Toxicity Category 1, STOT Single Exposure Category 3 (narcosis)