2014 consensus for the use of alcohol markers in hair for assessment of both abstinence and chronic excessive alcohol consumption.

1.1 The direct determination of ethanol itself in hair is not possible due to its volatility and its potential absorption from external sources. Instead, the minor ethanol metabolites ethyl glucuronide (EtG) and/or fatty acid ethyl esters (FAEEs) can be measured in hair as direct markers of alcohol consumption. 1.2 In this consensus FAEEs are defined as: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate. For interpretation, the sum of the concentrations of these four esters should be used. 1.3 It is not advisable to use the results of hair testing for alcohol markers in isolation; all relevant factors surrounding a case 2.6 Cosmetic treatments 2.6.1 The concentration of EtG and FAEEs in hair can be influenced by cosmetic treatments and thermal hair straightening tools. 2.6.2 The type of cosmetic hair treatment should be documented during sampling and considered during interpretation. 2.6.3 Bleaching, perming and dying of hair may lead to lower concentrations of EtG or false-negative results; and may also influence concentrations of FAEEs. 2.6.4 EtG appears not to be influenced by hairspray, gel, wax, oil, grease or ethanol-containing hair care products. 2.6.5 Use of ethanol-containing hair care products (e.g. hair