SCRAM vs. hair alcohol testing

In terms of pricing, hair strand testing and SCRAM Continuous Alcohol Monitoring® (SCRAM CAM®) are comparable. Legal Aid Agency funding is also available for both. So which method of alcohol detection is superior? Both have their pros and cons. To determine the best method for your case, the main question to ask is what period of detection do you wish to cover?

Hair alcohol testing

Biomarker testing in head hair can establish a person’s history of alcohol consumption for up to 6 months. The recommended minimum length of hair is a 3 cm section taken from nearest the scalp which covers a 3-month time period. This is consistent with the consensus on hair alcohol testing for chronic excessive alcohol consumption published by the Society of Hair Testing (SoHT) in June 2009 [1].

AlphaBiolabs determines alcohol abuse in head hair by detecting two metabolites of alcohol: ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs). These markers of alcohol intake are incorporated into the hair via different routes: EtG via sweat and FAEEs via sebum (an oily substance secreted by glands in the scalp). The reasons that both EtG and FAEE markers are analysed is because they are affected by external factors in different ways. Therefore, performing these two different types of hair analyses can assist in building evidence to support the diagnosis of chronic excessive alcohol consumption with a greater degree of certainty.

Head hair is preferred over body hair for alcohol testing. However, body hair can be useful to measure EtG if head hair is not available. The time period would also be more approximate due to the nature of body hair growth. Chest, arm, leg and beard hair can be analysed to provide up to a 12-month overview. In all cases, we would also recommend a blood test to detect alcohol biomarkers, in conjunction with clinical assessment, to gain a greater insight into an individual’s alcohol use.

SCRAM Continuous Alcohol Monitoring®

SCRAM Continuous Alcohol Monitoring® (SCRAM CAM®) provides an accurate way of pinpointing exactly how much alcohol has been ingested and when. This device is a bracelet that is worn on the ankle and tests for the presence of alcohol in perspiration. It is the first device of its kind to detect the drinking of alcohol in real-time and the results are automatically gathered and uploaded to a base station. The wireless base station could be located in the individual’s home, a solicitor’s office or anywhere convenient. Incidents of drinking and tampering are recorded and made known weekly, monthly or at the end of the testing programme. The bracelet can be worn for 1 day up to as many months as needed.

The principle behind this transdermal form of testing is based on how the human body metabolises alcohol. Once alcohol is absorbed and distributed through the bloodstream, it is eliminated in various forms. About 1–2% of the alcohol that is consumed is eliminated through the skin in the form of perspiration. These transdermal emissions are sampled every 30 minutes. As such, the frequency and pattern of alcohol consumption can be easily shown.

This method of testing for alcohol makes it easier to adhere to low or no-alcohol schemes as samples are taken on a continuous basis, every half-an-hour, 24 hours a day, 7 days a week. The technology is so advanced it can even differentiate between very low alcohol consumption (such as 1–2 units) and environmental alcohol sources. This helps enforce participant sobriety, compliance and accountability. This form of continuous monitoring (also called sobriety tagging) can provide local authorities, courts and child-protection agencies with the tools to change behaviours in vulnerable and higher-risk alcohol-dependent clients.

In summary

Hair strand testing is valuable to form part of an evidential picture when the aim of the testing is to determine whether a person has been overconsuming alcohol, on average, over the testing period. However, the results should ideally be used in conjunction with other forms of testing and other forensic evidence.

Transdermal testing is not suitable to gain evidence of past misuse of alcohol; for example, to check if an individual has been truthful about their alcohol intake. So, hair strand testing is the most appropriate method as it can go back for up to 6 months with 6 cm of hair. However, if the court wishes to monitor current and future alcohol intake, SCRAM CAM® is the best option as it tests for alcohol every 30 minutes over specified time periods and provides information on precise drinking events.

As such, both testing methods have their uses and both will continue to be heavily relied upon when a definitive decision is needed in cases involving alcohol abuse.



Head Hair alcohol testing




What does the test measure? Fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) alcohol markers Ethanol in perspiration
Period of detection 3 or 6-month overview 1 day up to as many months as needed
Method of detection Liquid chromatography tandem mass spectrometry (LC/MS/MS) Fuel cell technology
Can the test measure the amount of alcohol consumed? No. It is not possible to determine alcohol dose. The result provided will give an average over the length of time tested – which is determined by the length of the sample (3 or 6 months) Yes. The device can measure mg alcohol per 100 ml blood. The report also describes these values as equivalent units of alcohol
Can the test identify the frequency that alcohol is/was consumed? No. It is not possible to determine frequency of alcohol use. Only an average can be measured over a 3 or 6-month time period

Yes. The device can pinpoint alcohol use at the exact time of day, which day and which day of the week


Can environmental exposure cause any problems? Yes, excessive use of cosmetic treatments on hair could affect results. Based on guidance from the SoHT it is advised that both EtG and FAEE are analysed together to provide mutual confirmation of the result Although the ankle bracelet is waterproof and tamper-resistant, it can pick up readings from hygiene products containing alcohol. Such products should not be applied to the ankle
Can the test prove abstinence? No. Abstinence cannot be established. Research has shown that even individuals who have not consumed alcohol can test positive for both EtG and FAEEs. This can be explained because everyday foods can contain alcohol and endogenous alcohol can be produced via normal human metabolism. Yes. SCRAM CAM® has been proven to enforce participant sobriety.
Sample collection requirements At least 3 cm length of hair and around 200 individual strands are needed (about the width of a pencil), cut as close to the scalp as possible The bracelet needs to be fitted to the ankle by a trained person
Is the Chain of Custody procedure legally defensible in court? Yes. Proof of ID, donor’s and collector’s signature, and a photograph of sample donor is collected by the sample collector Yes. ID can be checked and a photograph taken at the time the SCRAM CAM® device is fitted

For expert advice on alcohol testing solutions, please call our Customer Services team on 0333 600 1300 or email us at

[1] Consensus of the Society of Hair Testing on hair testing for chronic excessive alcohol consumption 2011.