Alcohol consumption can be detected in an individual’s system through various types of tests, each with its own window of detection. Here’s a general overview:

1. Breath Tests: These measure the current level of alcohol in the breath, which correlates with blood alcohol concentration (BAC). Breathalyzers can detect alcohol for up to 24 hours after consumption, depending on the amount of alcohol consumed and individual metabolism.
2. Blood Tests: Alcohol can be detected in the blood for up to 12 hours after consumption, though this window can vary based on several factors, including the amount of alcohol consumed.
3. Urine Tests: Traditional urine tests can detect alcohol from 12 to 48 hours after drinking. There are also more sensitive urine tests, such as ethyl glucuronide (EtG) tests, that can detect alcohol metabolites for up to 3-5 days after alcohol consumption.
4. Saliva Tests: These can detect alcohol for approximately 24 to 48 hours after the last drink.
5. Hair Tests: Alcohol can be detected in hair through markers like ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs). Hair tests can provide a history of alcohol consumption for up to 90 days, as hair grows about 0.5 inches per month, and the standard length tested is 1.5 inches from the scalp.

The detection period for alcohol varies significantly based on the type of test used, the amount of alcohol consumed, the rate of metabolism, and other individual factors such as age, health, and liver function.