Understanding Alcohol Testing: Beyond the Breathalyser

Digging Deeper Into Measuring Alcohol Consumption for Legal Purposes

When most people think of alcohol testing, the first thing that comes to mind is usually roadside tests, such as breathalysers, like those used at AttoSure. These tests measure blood alcohol concentration (BAC) at a specific moment, often used by police to assess intoxication levels on the spot.

At AttoLife, our focus is on something different—long-term alcohol consumption. We dive deeper by testing various alcohol biomarkers to provide a more comprehensive picture of an individual’s drinking habits over time. This is especially useful in the family law space, where a parent might need to prove a change in drinking behaviour or abstinence.

Exploring Alcohol Biomarkers

Alcohol biomarkers are indicators in the body that can reveal the presence and patterns of alcohol consumption. Some common biomarkers we look at include EtG (Ethyl Glucuronide, measured in hair and nails) and EtPa (Ethyl Palmitate, measured in hair only). When it comes to blood, PEth (Phosphatidylethanol) and CDT (Carbohydrate-Deficient Transferrin) can be used. Alcohol biomarkers in blood give a window of detection of approximately two to four weeks. These blood biomarkers can be divided into two main categories: direct and indirect.

Direct vs. Indirect Alcohol Biomarkers

PEth is a prime example of a direct alcohol biomarker. It’s considered 'direct' because it is only formed when ethanol (the type of alcohol found in alcoholic drinks) is consumed and, therefore, is present in the bloodstream. This makes PEth a highly specific and sensitive biomarker that directly correlates with alcohol intake, which can differentiate between various drinking behaviours, such as teetotalers, social drinkers, and individuals with excessive drinking patterns.

On the other hand, CDT (Carbohydrate-Deficient Transferrin) is known as an indirect alcohol biomarker. Unlike PEth, CDT is produced in the liver due to prolonged alcohol consumption rather than directly from alcohol in the bloodstream. This makes it a useful tool for understanding the long-term effects of drinking on the body, particularly in cases of chronic alcohol use. However, a limitation of CDT is that it can be elevated due to factors such as hormonal changes, diseases, and nutritional deficiencies, which must be considered on a case-by-case basis, especially in legal contexts.

Why PEth Testing Is Useful in the Legal Space

At AttoLife, we highly recommend the use of PEth as a powerful biomarker for investigating alcohol consumption. Courts often favour PEth tests because they offer a broader view of an individual’s alcohol consumption history. For example, if someone has a history of heavy drinking, monthly PEth testing can track their progress, showing a gradual decrease in alcohol consumption leading to eventual abstinence. This capability makes PEth an essential tool in monitoring recovery or compliance with court-ordered sobriety.

The Simplicity of PEth Testing

One of the advantages of PEth testing is its simplicity. Rather than the invasive method of withdrawing blood using a needle, a PEth test only needs a small amount of blood—just a drop of blood obtained through a simple finger prick. This small sample is stable enough to be safely sent through the mail, making the process convenient and non-invasive for the individual.

Blood Testing Vs. Hair Strand Testing and Nail Testing

When it comes to even longer detection periods of alcohol, a Hair Strand Test (HST) can examine up to 6 months of alcohol use. (If head hair is unavailable, body hair can be used with the same accuracy, but less specific timeframe.)

In a similar way to hair, fingernails are composed of the same protein called keratin, just like hair. Testing nails is straightforward, carries fewer cosmetic concerns than hair testing, but cannot offer month-by-month analysis like hair strand tests. Nail tests can show up to a 12 month history of alcohol use. 

In hair and nail testing, two indicators of alcohol are typically used: EtG (Ethyl Glucuronide) and EtPa (Ethyl Palmitate, also known as Fatty Acid Ethyl Ester or FAEE). The amount of these indicators in the hair will depend on the amount of alcohol consumed. Both kinds of markers are absorbed in distinct ways, and measuring their levels can help determine whether or not a person uses alcohol chronically and excessively.

Testing for PEth in blood serves a different purpose compared to hair or nail testing, as it provides a snapshot of alcohol consumption over the past month and is less influenced by long-term drinking patterns, unlike CDT. If you are looking to show a quick trend in someone's drinking behaviour, PEth testing is ideal.

Check out Our Webinar

We have a webinar dedicated to “Understanding Alcohol Testing in Care Proceedings.” For a complete deep dive, sign up before September 24th 2024, or watch on demand afterwards. AttoLife remains committed to supporting legal professionals with accurate, reliable, and court-admissible testing services, ensuring that every case is as robust and well-informed as possible. Please get in touch with our team for any inquiries about, hair strand drug testing, nail drug testing or blood drug testing.