Registration Dossier

Administrative data

Endpoint:
dermal absorption
Type of information:
experimental study
Adequacy of study:
supporting study

Data source

Reference
Reference Type:
publication
Title:
A preliminary study of the dermal absorption of aluminum from antiperspirants using aluminum-26
Author:
Flarend, R. et al.
Year:
2001
Bibliographic source:
Food and Chemical Toxicology 39 (2001) 163-168

Materials and methods

Principles of method if other than guideline:
Aluminium chlorohydrate (ACH), the active ingredient in many antiperspirants, was labeled with the radioisotope 26Al. 84 mg of the labeled ACH was then applied to a single underarm of two adult subjects with blood and urine samples being collected over 7 weeks. Tape-stripping and mild washings of the skin were also collected for the first 6 days.

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Percutaneous absorption
Parameter:
percentage
Absorption:
0.012 %
Remarks on result:
other: Results indicate that only 0.012% of the applied aluminium was absorbed through the skin. At this rate, about 4 microg of aluminium is absorbed from a single use of ACH on both underarms.

Applicant's summary and conclusion

Executive summary:

Abstract:

Aluminium chlorohydrate (ACH), the active ingredient in many antiperspirants, was labeled with the radioisotope 26Al. The labeled ACH was then fractionated into about 100 samples using gel filtration chromatography. Each fraction was analyzed for 26Al and total aluminium content. Aluminium-26 was only detected in the fractions that also contained aluminium, which verified that the ACH was uniformly labeled. 84 mg of the labeled ACH was then applied to a single underarm of two adult subjects with blood and urine samples being collected over 7 weeks. Tape-stripping and mild washings of the skin were also collected for the first 6 days. Results indicate that only 0.012% of the applied aluminium was absorbed through the skin. At this rate, about 4 microg of aluminium is absorbed from a single use of ACH on both underarms. This is about 2.5% of the aluminium typically absorbed by the gut from food over the same time period. Therefore, a one-time use of ACH applied to the skin is not a significant contribution to the body burden of aluminium.