Registration Dossier

Administrative data

Description of key information

One key study (Hine et al., 1970; Klimisch score=2) was identified to support each acute toxicity endpoint (oral, dermal, and inhalation).
Acute Toxicity-Oral LD50>16750 mg/kg in rats (OECD TG 401)
Acute Toxicity-Dermal LD50>3350 mg/kg in rabbits (OECD TG 402)
Acute Toxicity-Inhalation LC50>259354 mg/m3 in rats (OECD TG 403)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
Value:
16 750 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion
Dose descriptor:
LC50
Value:
259 354 mg/m³

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
LD50
Value:
3 350 mg/kg bw

Additional information

The acute toxicity of hexane solvent containing between 5 and 80% n-hexane has been fully evaluated.  All of the animal studies were performed in a manner similar or equivalent to currently established OECD guidelines.  Based on data for commercial hexane, this substance has a low order of acute toxicity by the oral, dermal, and inhalation routes of exposure.

In a key acute oral toxicity study (Hine et al., 1970; Klimisch score=2), 6 male rats were administered doses up to 25 ml/kg of commercial hexane by oral gavage, and observed for 14 days post-dosing. No mortality was observed at any of the doses. The oral LD50 is therefore > 25 ml/kg (16750 mg/kg; density of 0.67) which makes this substance not classified under EU criteria.

In a key acute dermal toxicity study (Hine et al., 1970; Klimisch score=2), 5.0 ml/kg of test substance was placed on the shaved skin of 3 male rabbits. The test area was then covered with a saran wrap sleeve for 4 hrs. After the exposure period, the test substance washed off, and the animals observed for toxicity and mortality over the next 14 days. No animals died; however, they did show signs of discomfort and uncoordination after the exposure. The LD50 for dermal exposure is > 5.0 ml/kg (3350 mg/kg). Therefore, this substance is not classified under EU criteria.

In a key acute inhalation toxicity study (Hine et al., 1970; Klimisch score=2), groups of 10 male rats were exposed to concentrations of commercial hexane vapor for 4 hours. Animals were then observed for clinical signs and mortality for at least 6 days post-exposure. Several animals died during the exposure period. Surviving animals experienced severe toxicological effects during the exposure. One animal experienced convulsions during and after exposure and died on day 6 post-exposure. The LC50 was determined to be 73,680 ppm (259354 mg/m3), and this substance is therefore not classified under EU criteria.

Justification for classification or non-classification

The test substance, C6 aliphatics, 5-80% n-hexane, is classified as a Category 1 aspiration hazard.