Drug testing is commonly used by employers, courts, schools, and other organizations to determine if someone has recently used illegal drugs or misused prescription medications. However, most standard drug tests do not screen for alcohol use. Alcohol behaves differently than other drugs in the body, so it requires specialized testing methods.
What do typical drug tests screen for?
Standard drug tests, also known as panel tests or urine drug screens, look for evidence of recent use of several illegal drugs and commonly abused prescription medications. The Substance Abuse and Mental Health Services Administration (SAMHSA) has established guidelines for the federally mandated, 5-panel drug test that is widely used for employment and court-ordered screening. This test looks for:
- Marijuana (THC)
- Cocaine
- Amphetamines, including methamphetamine
- Opiates, including heroin and prescription painkillers
- Phencyclidine (PCP)
Some drug tests include an expanded opiates panel that can detect the presence of synthetic opioids like fentanyl. There are also 10-panel and 12-panel tests that screen for additional substances like barbiturates, benzodiazepines, and methaqualone.
Why don’t standard drug tests detect alcohol?
Ethanol, the type of alcohol found in alcoholic beverages, is metabolized and cleared from the body relatively quickly. Alcohol byproducts called metabolites can be detected in urine for only a short time after someone has been drinking.
Most standard workplace drug tests use a urine sample collected at a testing facility. Because alcohol metabolites clear quickly, using a urine sample would only detect very recent alcohol use from the past few hours. It would not reveal longer-term patterns of excessive drinking.
What types of tests can detect alcohol use?
While regular urine drug screens don’t pick up alcohol use, there are specialized laboratory-based tests that can identify longer-term alcohol use:
Ethyl glucuronide (EtG) urine tests
EtG urine tests detect ethyl glucuronide, a metabolite that forms when the body breaks down alcohol. EtG can be found in urine for up to 3-4 days after alcohol use and is considered a reliable indicator of recent drinking.
Ethyl sulfate (EtS) urine tests
Like EtG, ethyl sulfate is an alcohol metabolite that can be detected for 1-2 days after drinking. EtS urine tests are less common than EtG but can help confirm recent alcohol consumption.
Phosphatidylethanol (PEth) blood tests
PEth blood tests look for phospholipids that form only in the presence of ethanol alcohol. Unlike urine tests, PEth can detect moderate to heavy drinking patterns over a longer 2-4 week period.
Carbohydrate-deficient transferrin (CDT) blood tests
CDT is a biomarker found in the blood when alcohol is consumed heavily over a sustained period of at least 2-3 weeks. CDT has a high accuracy for identifying chronic heavy drinkers.
Hair alcohol tests
Alcohol metabolites become trapped within hair as it grows. Analyzing a small hair sample can detect regular alcohol use over a timeframe of months. Hair testing is not widely available and results may be affected by hair treatments and cosmetics.
Breath alcohol tests
Breathalyzers and other breath alcohol testing devices are able to detect very recent alcohol use from the past few hours. However, they cannot identify longer-term drinking habits.
When are alcohol tests used?
Here are some situations when testing specifically for alcohol may occur:
- Court-ordered testing programs: People convicted of alcohol-related offenses like DUIs may be court ordered to undergo regular drug and alcohol screening that includes EtG urine testing or other methods.
- Treatment programs: Addiction treatment facilities often test patients for a wide range of substances including alcohol to support recovery.
- Workplace safety: Alcohol testing helps identify employees in safety-sensitive jobs who may be unfit for duty due to recent drinking. Urine, breathalyzers, and saliva swabs can be used.
- Pre-employment screening: Some employers require drug and alcohol testing for job applicants or as a condition of employment.
- Child custody: Courts may mandate alcohol testing of parents in custody disputes where alcohol abuse is a concern.
- Medical screening: Doctors can test for alcohol use in patients with potential liver problems or when evaluating suspected substance abuse issues.
Key factors about alcohol testing
There are some important things to understand about alcohol screening:
- Alcohol tests detect alcohol use only, not impairment. Blood alcohol concentration (BAC) is needed to gauge impairment.
- Over-the-counter mouthwash and hand sanitizers also contain alcohol that could lead to positive test results for recent use.
- A positive alcohol test does not necessarily indicate alcoholism or an alcohol use disorder.
- Alcohol testing methods, limits, and use for employment purposes are regulated differently in some states.
- Prescription medications, foods, and flavorings made with alcohol can sometimes affect test results.
Summary
In summary:
- Standard workplace drug tests do not detect alcohol use.
- Special tests like EtG, PEth, and CDT can identify alcohol use from the past few days up to several weeks.
- Hair testing can detect longer-term alcohol use over months.
- Breathalyzers measure very recent alcohol consumption from the past few hours.
- Alcohol testing has applications in law enforcement, employment, medicine, and addiction treatment.
- Alcohol tests do not indicate impairment or necessarily signify alcoholism.
While alcohol causes serious safety and health consequences, alcohol testing remains complex due to social attitudes, testing limitations, and regulation of its use by employers and legal systems. Organizations must weigh both ethical and efficacy considerations when determining the appropriate role of alcohol testing.