N-hexane

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1971

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study is classified as reliable with restrictions because there was no GLP statement provided, and limited data on methods were reported, but the study seemed to be well-conducted.

Data source

Reference

Reference Type:

publication

Title:

Acute toxicity and limits of solvent residue for sixteen organic solvents

Author:

Kimura, E., Donn, M., Patrick, W.

Year:

1971

Bibliographic source:

Toxicology and Applied Pharmacology 19, 699-704

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

multiple ages tested

Principles of method if other than guideline:

Groups of 6 -12 rats were given doses of the test substance by oral gavage. Rats of 4 different ages were tested, newborns, 14 -days old, young adult, and older adults.

GLP compliance:

no

Test type:

acute toxic class method

Test material

Test material information

Constituent 1

Reference substance name:

N-hexane

EC Number:

203-777-6

EC Name:

N-hexane

Cas Number:

110-54-3

Molecular formula:

C6H14

IUPAC Name:

hexane

Details on test material:

- Name of test material (as cited in study report): hexane
- Analytical purity: analytical grade

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: rats of 4 different ages were studied - 24-48 hrs old, 14 days old, young adult rats, and older adult rats
- Weight at study initiation: newborn 5-8 g, immature 16-50 g, young adult 80-160 g, older adult 300-470 g

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

None

Doses:

1, 24, 49 ml/kg

No. of animals per sex per dose:

6 male rats were used in the young adult and older adult studies, and groups of 6-12 rats of both sexes were used in the newborn and immature rat studies.

Statistics:

Litchfield, J.T. and Wilcoxen, F. (1949). A simplified method of evaluating dose-effect experiments. J. Pharmacol. Exp. Ther. 96, 99-101.
probit analysis, and parallel probit analysis

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

24 mL/kg bw

95% CL:

22.5 - 25.8

Remarks on result:

other: ~16 g/kg; 14-day old rats

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

49 mL/kg bw

95% CL:

35.5 - 68

Remarks on result:

other: ~32 g/kg; young adult rats

Effect levels 3

Sex:

male

Dose descriptor:

LD50

Effect level:

43.5 mL/kg bw

95% CL:

31.4 - 58.8

Remarks on result:

other: ~30 g/kg; older adult rats

Mortality:

The test substance was significantly more toxic in 14-day old rats than in adult rats.

Applicant's summary and conclusion

Interpretation of results:

other: not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The LD50 for 14-day old rats was 24 ml/kg. The LD50 for young adult rats was 49 ml/kg. The LD50 for older adult rats was 43.5 ml/kg. The test substance is not classified under EU guidelines.

Executive summary:

This study determined the oral toxicity of hexane in rats of various ages. Groups of 6 -12 rats were given doses of the test substance by oral gavage. Rats of 4 different ages were tested, newborns, 14 -days old, young adult, and older adults.

Due to difficulty in administering small doses, the LD50 for newborn rats could not be determined, but was assumed to be <1.0 ml/kg. The LD50 for 14 -day old rats was 24 ml/kg, which was significantly lower than the LD50 for young adults rats, 49 ml/kg, and older adult rats, 43.5 ml/kg. Since the LD50s for rats older than newborns were 24 ml/kg (~16 g/kg) or above, the test substance would not be classified as toxic under OECD GHS guidelines.