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

Dermal absorption

Administrative data

Endpoint:

dermal absorption in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 11, 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well conducted study.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: 40 CFR 795.226

Principles of method if other than guideline:

HEADME
Dermal absorption

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Radiolabelling:

yes

Remarks:

(14C)Cyclohexane

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Duration of exposure:

dermal, 6 hrs

Doses:

1 and 100 mg/cm2

No. of animals per group:

4/sex

Control animals:

no

Applicant's summary and conclusion

Executive summary:

Cyclohexane was rapidly excreted after dermal administration. Expired breath was the major route of excretion of radiolabels accounting for ca. 78% of the excreted radiolabel at 1 mg/cm2 and ca 57% of the excreted radiolabel at 100 mg/cm2. Urine was a lesser route of excretion of radiolabel, accounting for ca. 20% at 1 mg/cm2 and ca. 40% at 100 mg/cm2. Essentially no radiolabel was excreted in the feces following dermal administration. The areas under concentration of total radiolabel in blood vs. time curves were ca. 3 times greater at 1 mg/cm2 and ca. 2 times greater at 100 mg/cm2 for females than males. Less than 0.1% and less than 0.4% of the dose of cyclohexane at 100 and 1 mg/cm2, respectively, remained in the carcass 72 hours after dermal exposure. Thus, neither cyclohexane nor its metabolites would be expected to accumulate after repeated exposure to cyclohexane.