Minor metabolites of alcohol can be measured in hair. Their presence can be used as an indicator of excessive alcohol consumption.
Ethyl glucuronide (EtG) is the primary target metabolite and its presence in a hair sample above an internationally agreed concentration can be used as evidence of excessive alcohol consumption.
Fatty acid ethyl esters (FAEE’s) can also be used for this purpose and their presence above the recommended cutoff concentration can be used to provide additional evidence.
A useful strategy is to collect 2 hair samples, but to initially analyse only one of these for EtG. The reserved second sample can be subsequently analysed if the EtG concentration has been shown to lie above the cutoff value.
This strategy is both cost effective and significantly strengthens evidential value if the levels detected are above cutoff.
Although EtG/FAEE analysis in hair is a useful tool, the analytical findings should not be taken in isolation, and other factors surrounding the case should be taken into consideration. The analysis of a blood sample for liver function can also be a useful complementary test.
A sample of hair (roughly the width of a thin pencil) is taken from the back of the crown of the head. For the evidential value of EtG/FAEE analysis to be maximised, a 3 cm (proximal) sample of scalp hair should be analysed.
Body hair, although not ideal, can also be used (underarm or chest). Pubic hair is not suitable.
Drug analysis can be combined with EtG analysis.
NIVHA provides a complete service: from sample collection, laboratory analysis and expert interpretative report for court purposes.
All analytical work is accredited to UKAS 17025 standard.
Hair collection and analysis for alcohol follows international guidelines established by the Society for Hair Testing (www.SOHT.org)