By What is a PEth Test?
PEth stands for phosphatidylethanol, a type of biomarker only produced in the presence of alcohol. The test involves taking a small blood sample and can detect alcohol use over the previous 2 to 4 weeks. Unlike urine or breath tests, it’s extremely difficult to cheat and is considered highly accurate.
When Does the DVLA Use the PEth Test?
The DVLA may require a PEth test in the following situations:
- When a high-risk offender applies to reinstate their driving licence after a disqualification.
- During medical reviews related to alcohol misuse or dependence.
- For drivers applying for or renewing Group 2 licences (e.g. HGV or bus drivers).
PEth Test Detection Period
PEth can identify moderate to heavy drinking within the last few weeks. Light or occasional drinking may not always be detected, but high levels of alcohol consumption will raise a red flag.
Can You Pass a PEth Test?
To pass a PEth test, you’ll generally need to show that you’ve been completely abstinent from alcohol for at least 3–4 weeks. If you’re preparing for one, here are some tips:
- Avoid alcohol entirely for at least a month before the test.
- Be cautious with foods and medications that may contain ethanol (like mouthwash or some cold remedies).
- Document any treatment or rehabilitation programme you’ve followed.
Consequences of Failing a PEth Test
Failing the PEth test could mean:
- Licence reinstatement refusal
- Being classed as medically unfit to drive
- Loss of employment for professional drivers (taxi, HGV, etc.)
PEth Test vs. Other Alcohol Biomarkers
The DVLA may also require other alcohol tests alongside PEth, including:
- CDT (Carbohydrate-Deficient Transferrin) – indicates sustained drinking over weeks
- Liver Function Tests (LFTs)
- MCV (Mean Corpuscular Volume)
Frequently Asked Questions
Can I drink a little and still pass?
Even small amounts can be detected. Total abstinence is the safest route.
Is the PEth test used for first-time offenders?
Typically not, unless there is a medical review involved or signs of persistent misuse.
How much does a PEth test cost?
Private testing costs around £100–£150 depending on the provider.
Final Thoughts
The PEth test plays an increasingly important role in UK driving licence reinstatement, especially for those with a history of alcohol misuse. It’s accurate, reliable, and gives authorities confidence in a driver’s sobriety. If you’re preparing for a DVLA review, be sure to plan ahead and abstain completely to give yourself the best chance of success.
Need help? Consult a legal or medical professional who specialises in DVLA medical fitness cases.