Hydrocarbons, C6-C7, isoalkanes, cyclics, <5% n-hexane

Endpoint summary

Description of key information

Key read across studies of C-6 normal and iso paraffins (hexanes) and naphthenes (methyl-cyclohexane, dimethylcyclohexane), 25-35% n-hexane (Hine et al., 1970; Klimisch score=2) were identified to support each acute toxicity endpoint (oral, dermal, and inhalation) for this substance.
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 air

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

3 350 mg/kg bw

Additional information

In a key read-across acute oral toxicity study of C-6 normal and iso paraffins (hexanes) and naphthenes (methyl-cyclohexane, dimethylcyclohexane), 25-35% n-hexane (Hine et al., 1970; Klimisch score=2), 6 male rats were administered doses up to 25 ml/kg of commercial n-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 the test substance not classified under EU criteria.

In a key read-across acute inhalation toxicity study (Hine et al., 1970; Klimisch score=2), groups of 10 male rats were exposed to concentrations of

C-6 normal and iso paraffins (hexanes) and naphthenes (methyl-cyclohexane, dimethylcyclohexane), 25-35% n-hexane

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 the test substance is therefore not classified under EU criteria.

In a key read-across acute dermal toxicity study of C-6 normal and iso paraffins (hexanes) and naphthenes (methyl-cyclohexane, dimethylcyclohexane), 25-35% n-hexa

ne (Hine et al., 1970; Klimisch score=2), 5.0 ml/kg 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, the test substance is not classified under EU criteria.

Justification for classification or non-classification

The substance is not classified as acutely toxic under EU criteria. It is classified as a Category 1 aspiration hazard.