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Merck

Exposure of hairdressers to ortho- and meta-toluidine in hair dyes.

Occupational and environmental medicine (2014-06-11)
Gabriella M Johansson, Bo A G Jönsson, Anna Axmon, Christian H Lindh, Marie-Louise Lind, Mats Gustavsson, Karin Broberg, Anders Boman, Birgitta Meding, Carola Lidén, Maria Albin
ABSTRACT

Carcinogenic aromatic amines derived from hair dyes have recently received new attention. One of these is ortho (o)-toluidine, which is classified as carcinogenic to humans. To clarify exposure of hairdressers to potentially carcinogenic aromatic amines, including o-toluidine. We measured eight potentially carcinogenic aromatic amines in the blood of 295 hairdressers, 32 users of hair dyes and 60 controls. The study was restricted to female non-smokers. Lifestyle data were collected for all participants using self-administered questionnaires. Blood samples were taken for analysis of ortho-, meta (m)- and para (p)-toluidine; 2-, 3- and 4-ethylaniline, 2,3- and 3,4-dimethylaniline as haemoglobin adducts. The samples were analysed with gas chromatography-tandem mass spectrometry. Generally, adduct concentrations were in the range of 0-200 pg/g haemoglobin. A comparison of the adduct concentrations found in hairdressers, consumers and controls showed no statistically significant differences. However, for hairdressers, o- and m-toluidine concentrations increased significantly with the weekly number of hair waving (p=0.020) and permanent hair dyeing treatments (p=0.026), respectively. o-Toluidine and m-Toluidine concentrations also tended (p=0.076 and 0.080, respectively) to increase with the frequency of light-colour permanent hair dye treatments. Hairdressers who use light-colour permanent hair dyes, other permanent hair dyes and hair waving treatments seem to be exposed to o- and m-toluidine as indicated by associations with the number of treatments performed. Analyses of hair waving and hair dye products should be performed to identify the possible sources of exposure to o- and m-toluidine.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
m-Toluidine, 99%
Sigma-Aldrich
4-Ethylaniline, 98%
Sigma-Aldrich
o-Toluidine, purum p.a., ≥99.5% (GC)
Sigma-Aldrich
p-Toluidine hydrochloride, purum, ≥99.0% (AT)
Supelco
p-Toluidine, for spectrophotometric det. of Au, Tl(III), W, ≥99.0%
Sigma-Aldrich
o-Toluidine, 98%
Sigma-Aldrich
o-Toluidine, ≥99%
Sigma-Aldrich
o-Toluidine solution, 0.6 M in glacial acetic acid, contains thiourea as stabilizer
Sigma-Aldrich
3,4-Dimethylaniline, 98%
Sigma-Aldrich
p-Toluidine, 99%
Sigma-Aldrich
p-Toluidine, 99.6%
USP
Prilocaine Related Compound A, United States Pharmacopeia (USP) Reference Standard