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Toxicological information

Direct observations: clinical cases, poisoning incidents and other

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Administrative data

Endpoint:
direct observations: clinical cases, poisoning incidents and other
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non-guideline human experimental study, published in peer reviewed literature, limitations in design but otherwise adequate for assessment

Data source

Reference
Reference Type:
publication
Title:
In vivo percutaneous absorption of benzene in man: Forearm and palm
Author:
Modjtahedi, B.S. and Maibach, H.I.
Year:
2008
Bibliographic source:
Food Chem. Toxicol., 46, 1171-1174

Materials and methods

Study type:
study with volunteers
Endpoint addressed:
dermal absorption
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The percutaneous absorption of [14C]-benzene was determined by measuring excretion of radioactivity.

GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Radiolabelled - 14C
Benzene (purity, 100%) was supplied by ARC, St. Louis, Missouri.

Method

Type of population:
general
Subjects:
- Number of subjects exposed: 8 (4 per route)
- Sex: Male
- Age: Adult
Ethical approval:
confirmed, but no further information available
Route of exposure:
dermal
Details on exposure:
Adult male volunteers were exposed dermally, the dose was applied while the exposed limb was inside a fume hood with the partition down. Volunteers wore a respirator during application to the forearm and until the dose had evaporated, no respiratory protection was used during palmar exposure.
Examinations:
Palmar exposure: Pooled urine samples were collected at 4, 8, 12 and 24h and then daily up to 7 days after dosing.
Forearm exposure: Pooled urine samples were collected at 4, 8, 12 and 24h and then daily up to 7 days after dosing; Stool samples were also collected.
Samples were analysed for radioactivity, values were corrected for incomplete collection.

Results and discussion

Results of examinations:
Percutaneous absorption from a 100uL applied dose was approx. 0.1%

Any other information on results incl. tables

Total recovery

48 and 42% of the recovered radioactivity was excreted within 24h following palm and forearm exposure respectively. Radioactivity in stool samples was below the limit of detection.
0.13±0.04% of the palmar dose was absorbed, the corresponding value for forearm exposure was 0.07±0.04%; there was no statistically significant difference between the results for palm and forearm.

Applicant's summary and conclusion

Conclusions:
Percutaneous absorption of benzene through human fore-arm and palm skin is low. Total absorption was approximately 0.1 % (0.07% for forearm and 0.13% for palm).
Executive summary:

Absorption of benzene through human skin in vivo was investigated in 2 groups of 4 male volunteers following one topical application to the forearm or palm. A dose of 100uL of benzene/14C benzene was applied under controlled conditions. Urine and stool samples were collected for a total of 6 or 7 days and analysed for radioactivity. Absorption values were found to be nominal with forearm exposure showing an average total absorption of 0.07±0.04% and palmar exposure an average total absorption of 0.13±0.04% of the applied dose.