Registration Dossier

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:
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

Reference
Name:
Unnamed
Type:
Constituent
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 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 levelsopen allclose all
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
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
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:
not classified
Remarks:
Migrated information 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.