Commentary on current changes of the SoHT 2016 consensus on alcohol markers in hair and further background information

- The SoHT consensus on alcohol markers in hair was revised by an expert group.
- The EtG cut-offs 7 pg/mg (abstinence) and 30 pg/mg (alcohol abuse) remained unchanged.
- Instead of the sum of four fatty acid ethyl esters only ethyl palmitate is applied.
- Cut-offs for abstinence and alcohol abuse were derived from data of 7 laboratories.
- These are 0.12 (0.15) ng/mg and 0.35 (0.45) ng/mg for 0-3 (0-6) cm hair segment.

The consensus on alcohol markers in hair was revised for the fourth time by an expert group of the Society of Hair Testing based on current state of research. This revision was adopted by the members of the Society during the business meeting in Brisbane on August 29th 2016. For both markers, ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs), two cut-off values for discrimination between teetotalers or occasional low amount consumption and moderate alcohol drinking (low cut-off), and between non-excessive (abstinence up to moderate alcohol intake) and chronic excessive drinking (high cut-off value) were critically examined. For the current revision, the cut-off values for EtG (7 pg/mg and 30 pg/mg, respectively) remained unchanged despite different findings or discussions published in the meantime. This was mainly due to the lack of broader data collections from new studies with great numbers of volunteers following thorough study concepts. In contrast, an essential change of the consensus was accepted for the FAEEs, where the concentration of ethyl palmitate (E16:0) can be used autonomously for interpretation instead of the concentration sum (ΣFAEE) of the four esters ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate, as previously applied. After evaluation of the data from seven laboratories, the E16:0 cut-off for abstinence assessment was defined at 0.12 ng/mg for the 0-3 cm segment and at 0.15 ng/mg for the 0-6 cm segment. The cut-off for chronic excessive drinking was fixed at 0.35 ng/mg for the 0-3 cm segment and at 0.45 ng/mg for the 0-6 cm segment. The use of E16:0 with these cut-offs in place of ΣFAEE for alcohol intake assessment produces only a minor loss in discrimination power, leads to no essential difference in the interpretation concerning chronic excessive alcohol consumption and is suitable to confirm EtG results in abstinence assessment if ethanol containing hair sprays or lotions are excluded.