I should say at the outset of this article that I was Counsel instructed by Trimega Labs as intervenors in the recently reported decision of Moylan J LB Richmond v B  EWCA 2903 Fam - http://www.familylawweek.co.uk/site.aspx?i=ed71271 . This is one reason why I have become interested in the science behind the testing and the place of the test results in the family court process.
The need for testing of drinking levels may seem obvious to family lawyers; where residence and contact issues are concerned it is estimated that there are about 1 million children in the UK with at least one parent drinking more than the hair test cut-off level of 7.5 units a day. Last year Childline reported 5,700 calls from children concerned about their parents’ abuse of drugs or alcohol. Recent research suggests that 1 in 4 drinkers exceed safe limits. About 350,000 cases of domestic violence are alcohol related.
The World Health Organisation considers that we should be concerned about drinking more than 60g of alcohol per day - roughly 7.5 units a day (less than a bottle of wine a day or 2.5 – 3 pints) Drinking this amount is most likely to lead to difficulties in social functioning and parenting.
Traditional alcohol tests use blood and urine but with drawbacks. Urine can only cover the past 36 hours maximum and blood about 4-6 weeks. Blood tests show liver damage which is not necessarily specific to alcohol and may not be present even in heavy drinkers.
Hair tests for alcohol are relatively new – but they have a 10 year history and are based on extensive research. Much of this research has been pioneered by Professor Pragst, an advisor to Trimega Labs and renowned international expert.
There is no imposed regulation on test providers (although there are a number of international standards & accreditation requirements imposed on laboratories). The industry has a self-regulatory body – the Society of Hair Testing - http://www.soht.org/ and Professor Pragst is a board member as is Hans Sachs (a founder member of SOHT) who is a member of Trimega’s newly appointed Advisory Board. The Society has a wide international membership and meets regularly to discuss aspects of hair testing for drugs and alcohol and in July 2009 agreed guidelines- http://www.soht.org/pdf/Consensus_EtG_2009.pdf - in relation to testing for alcohol markers, specifically the cut off levels which should be used, above which one can safely conclude that someone is drinking to excess.
There are two main tests available to test hair for alcohol. Each test identifies chemicals in the body which are only found in hair when ethanol has been present in the body – generally this will only happen when alcohol itself has been ingested. I say generally because it is important to note that in rare circumstances it may be that ethanol by-products will be found in hair samples provided by teetotallers, perhaps because of the production of alcohol in the body as a result of eating certain products or because of environmental contamination. In general terms, the presence of the markers in the hair of teetotallers is rare and usually only detected at low levels. The significance of this in a legal context is that it is not currently and never likely to be possible to use the hair test to prove abstinence although there will be results that can be said to be consistent with abstinence and it may be possible in future to conclude from them that abstinence can be ruled out on a balance of probabilities.
The two markers which can be tested for are Ethyl Glucoronide (EtG) and Fatty Acid Ethyl Esters (FAEEs). A number of labs in the UK test for EtG – only Trimega Labs currently have accreditation to test for FAEEs.
EtG is a water soluble, incorporated into the hair through sweat. Over time it may be washed out of hair so it has a relatively limited shelf life. FAEEs are fat-loving and are much less sensitive to hair treatments and washing.
In order to provide the court with the best information the ideal is to commission tests for both EtG and FAEEs and this practice was specifically approved by Moylan J. By doing this you ensure the greatest possible degree of accuracy because the relative strengths of each test compensate for the possible shortcomings of the other. The use of the two tests together should ensure that the maximum number of accurate results are given, particularly in any case with readings close to the cut-off level.
The SOHT recommends that hair samples of 3 cm are taken and that in respect of EtG cut-off levels of 30 picograms per milligram (pg/mg) are applied. In respect of FAEEs the cut-off recommended for a 3cm sample is 0.5 milligrams per nanogram (mg/ng). It is right to say that there is perfectly credible scientific justification for using a slightly lower level of cut-off for EtG but SOHT has concluded that a higher level is used to have the greatest confidence that positive results are not false. Readings above the cut-off levels therefore mean that a family court can confidently conclude that a subject has been drinking more than 60gm of alcohol a day on average (6-7 bottles of wine, 20 pints).
What the test results cannot do is to discriminate between those who distribute their drinking during the week and those who drink in binges, particularly at weekends or – for the moment at least - to discriminate reliably ie to a good enough standard for court purposes between those who are abstinent and those who are social drinkers. However, the test results can also be described as consistent with abstinence or perhaps more properly put as not evidence of drinking. Below the cut-off for excessive drinking it is not possible to say that a reading of say 15pg/ng equates to drinking 30 grams of alcohol – the correlation is not linear either for EtG or FAEE. EtG tends to be more concentrated in the section of hair closest to the scalp whereas FAEE tends to pool at the end of the hair. In other words, neither substance is evenly distributed.
In the particular case in which all this was considered by Moylan J, a situation arose which may be all to familiar to family lawyers. The mother had a long-standing alcohol dependency. She claimed to have given up drink altogether. Hair tests were regularly commissioned and one particular test, said to relate to one particular month, came back from Trichotech which was reported to indicate that she had been drinking in that month. Trichotech had adopted a practice - commonly used in relation to drug testing - of using one centimetre segments of hair to represent one month in time and dividing the cut-off by 3. They interpreted the result which was above 10pg/ng as indicative of alcohol use. This has the all-too predictable effect of causing the local authority to lose confidence in the mother’s veracity and reliability and as a result they would not agree that she could care for her children. Had the tests been reported by Trichotech in accordance with SOHT guidelines they would have had to say that the results did not provide evidence of drinking.
The Judge was understandably critical of some of the literature produced by both laboratories which had not helped the lawyers to understand and interpret the test results. What became clear from the case is that we lawyers have tended to interpret the tests in a very black and white way and to assume that the tests can reliably tell us exactly how much someone is drinking rather than that someone is drinking excessively. He emphasised the need to instruct test providers in the same way as any other expert ie by following the Practice Direction. He accepts that in many cases chemical test results are treated as factual assertions and not opinions but there will be situations in which interpretation is required particularly where the results are at the margins. I do not take him to mean that every request for a hair test needs a complicated letter of instruction that if assistance with interpreting the results is needed, the Practice Direction should be observed. An alternative, of course, is to instruct an expert who is entirely independent of the test providers themselves.
The Judge’s other conclusions were in summary:-
(a) Hair tests should be seen as one part of the overall evidential picture;
(b) Where hair tests are undertaken, tests for both FAEE & EtG should be done;
(c) The tests can only support findings that the results are consistent with / indicative of excessive drinking – below cut-off they can be said to be consistent with either abstinence or social drinking and they cannot show how much someone may have been drinking;
(d) Tests involving 1cm samples should not be used as they cannot be said to produce reliable evidence of excessive drinking.
It may be tempting to think that there may be an advantage to the client to maximise the likelihood of a false negative by requesting an EtG test alone. This has clearly been disapproved by Moylan J but in any event it was the EtG test result which caused the problem in this case, being interpreted as positive for drinking some alcohol. The FAEE results provided by Trimega were negative for excess drinking, consistent with abstinence although not wholly probative of it.
It is difficult to gauge how many cases may have been effected by the incorrect interpretation of hair tests but family lawyers should review any case in which segmenting has been used or unlikely results are received and consider whether to ask for re-testing and / or FAEE testing, particularly where the test results seem to be out of synch with the overall evidential picture and the client is insistent that no alcohol has been drunk. An incidental practice point is that it is important to fill in the form which accompanies the sample accurately so that the lab has full information about any hair products used, medication taken or extreme weight loss which may affect the results.
Jacqui is a family law barrister with over 18 years’ experience practising from 4 Brick Court in Temple, London. Called to the Bar in 1992, Jacqui’s practice areas are children, community care, domestic, violence, and public law. Jacqui regularly accepts instructions in all children cases (public and private) including child abduction & international relocation, divorce & nullity and domestic violence. Jacqui is the General Editor of the Family Law Week Blog & has her own Bloody Relations blog.
If you believe a loved one is showing signs of alcohol dependency, do convince that person to undergo alcohol testing so you can act on it accordingly should the results return positive.