Hair alcohol testing

As the hair grows, it absorbs special markers called fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) into its structure, which remain in the hair indefinitely. These markers are only produced when there is alcohol in the bloodstream, such that the more markers there are, the more alcohol you have consumed.

Tests detecting both FAEE and EtG levels have been used by UK courts.

Trimega Laboratories were the first company to commercialise FAEE testing in UK courts.^{[citation needed]} Tricho-Tech were the first company to commercialise EtG testing in UK courts.^{[citation needed]}

Analysis of hair samples has many advantages as a preliminary screening method for the presence of toxic substances deleterious to health after exposures in air, dust, sediment, soil and water, food and toxics in the environment. The advantages of hair analysis include the non-invasiveness, low cost and the ability to measure a large number of, potentially interacting, toxic and biologically essential elements. Hence, head hair analysis is now increasingly being used as a preliminary test to see whether individuals have absorbed poisons linked to behavioral health problems.[2]

The use of hair alcohol analysis to establish and verify persistent alcohol abusers within the United Kingdom has steadily increased in recent years.

In contrast to other drugs consumed, alcohol is not deposited directly in the hair. For this reason the investigation procedure looks for direct products of ethanol metabolism. The main part of alcohol is oxidized in the human body. This means it is released as water and carbon dioxide. One part of the alcohol reacts with fatty acids to produce esters. The sum of the concentrations of four of these fatty acid ethyl esters (FAEEs: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) are used as indicators of the alcohol consumption. The amounts found in hair are measured in nanograms (one nanogram equals only one billionth of a gram), however with the benefit of modern technology, it is possible to detect such small amounts.

However there is one major difference between most drugs and alcohol metabolites (FAEE) in the way in which they enter into the hair: on the one hand like other drugs FAEEs enter into the hair via the keratinocytes, the cells responsible for hair growth. These cells form the hair in the root and then grow through the skin surface taking any substances with them. On the other hand the sebaceous glands produce FAEEs in the scalp and these migrate together with the sebum along the hair shaft (Auwärter et al., 2001, Pragst et al., 2004). So these glands lubricate not only the part of the hair that is just growing at 0.3 millimeters per day on the skin surface, but also the more mature hair growth, providing it with a protective layer of fat.

FAEEs (nanogram = one billionth of a gram) appear in hair in almost one order of magnitude higher than (the relevant order of magnitude of) Etg (picogram = one trillionth of a gram). It has been technically possible to measure FAEEs since 1993, whereas the technique for measuring (the relevant range of) Etg is still in its infancy.

In practice, most hair which is sent for analysis has been cosmetically treated in some way (bleached, permed etc.). It has been proven that FAEEs are (surprisingly) not significantly affected by such treatments (Hartwig et al., 2003a). So far no systematic investigations in this regard have been carried out for Etg

FAEE concentrations in hair from other body sites can be interpretated in a similar fashion as scalp hair (Hartwig et al., 2003b). Etg: no information available.

Extensive studies involving over 1000 donors have been carried out since 2000. These have enabled us to establish reliable reference ranges for FAEEs with respect to drinking habits of the various groups: non-drinkers <> 1ng/mg

There are no reliable reference ranges for Etg from comprehensive studies. Further investigations are in progress to examine the applicability of the method in practice of the detection of alcohol abuse.

Literature Pragst F., Balikova M.A.: State of the art in hair analysis for detection of drugs and alcohol abuse; Clinica Chimic Acta 370 2006 17-49.

Auwärter V.: Fettsäureethylester als Marker exzessiven Alkoholkonsums – Analytische Bestimmung im Haar und in Hautoberflächenlipiden mittels Headspace-Festphasenmikroextraktion und Gaschromatographie-Massenspektrometrie. Dissertation Humboldt-Universität Berlin 2006.

Pragst F., Auwärter V., Kiessling B., Dyes C.: Wipe-test and patch-test ror alcohol misuse based on the concentration ratio of fatty acid ethyl esters and squalen CFAEE/CSQ in skin surface lipids. Forensic Sci Int 2004; 143:77-86.

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