SCRAM Testing vs. Hair Testing

Up till now, hair strand testing has been considered the gold standard in toxicological analyses. This long-established method can provide a history of drug and alcohol abuse and is routinely used in the forensic and family law fields. However, a novel detection technique that provides a means of continuous alcohol monitoring is gaining popularity and is increasingly being selected by the legal profession. Both detection methods assess alcohol consumption but work in very different ways.

Hair testing works by looking at two markers of alcohol: ethyl glucuronide (EtG) and ethyl palmitate (EtPa), a fatty acid ethyl ester (FAEE). The level of alcohol consumed will determine the level of these markers in the hair. Both types of markers are absorbed via different routes and their levels can assist in assessing excessive alcohol use by an individual.

The reasons that both EtG and EtPa markers are analysed is because they are affected by external factors in different ways. EtG is produced by the liver and incorporated into the hair, mainly through sweat, and is measured in pg/mg (trillionth of a gram per mg of hair). It is hydrophilic, meaning that it is water soluble. As such, some EtG may be lost through the use of hair dye and excessive hair washing. EtPa is produced in the blood and incorporated into hair via sebum (an oily substance secreted by glands in the skin). Their levels are measured in ng/mg (billionth of a gram per mg of hair). EtPa is lipophilic and therefore not water soluble, so although not affected by hair washing, the amount detected could be affected by use of hairsprays, gels and wax.

Head hair is preferred over body hair for alcohol testing. It is possible to perform both EtG and EtPa analyses on hair samples collected from locations other than the scalp, such as pubic, underarm, chest, arm, leg, abdomen and beard. However, these tests have limitations. Pubic hair can be contaminated with EtG from urine. Underarm and chest hair samples can give false positive EtPa findings following the use of alcohol-containing products such as deodorant and perfume or aftershave. We therefore only test body hair for the EtG marker.

Real-time results

An accurate way of pinpointing exactly how much alcohol has been ingested and when is now possible with SCRAM Continuous Alcohol Monitoring® (SCRAM CAM®). 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 base station could be located in the individual’s home, a solicitor’s office or anywhere convenient. The base station is wireless and therefore a telephone line or internet connection is not essential to enable regular analysis and reporting. Incidents of drinking and tampering are recorded and made known weekly, monthly or at the end of the testing programme.

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.

The SCRAM CAM® bracelet needs to be fitted to the ankle by a trained person to ensure that it is fitted correctly. The ankle bracelet is water resistant, but shouldn’t be submerged so showers are preferred to baths or swimming. Ideally the bracelet should be worn for 30 days or more as that gives a good overview of the wearer’s drinking behaviour.

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. It is also known as an alcohol tag, sobriety tag and alcohol bracelet.