The duration for which alcohol stays in the body coupled with the effects experienced by the individual is highly reliant on an individual’s demographics. These generally are appurtenant with age, gender, amount of time elapsed since the consumption of the last meal, any underlying pathology and consequent medication intake. Likewise, the time up to which alcohol is detectable is contingent on a number of factors mainly comprising the test being taken. When measuring alcohol in the bloodstream, it is usually referred to as Blood Alcohol Concentration (BAC). BAC is usually represented as a percentage of ethanol per volume of blood.
BAC tests are usually done through blood, hair and urine. Alcohol can be detected through a blood test for up to 11-12 hours as it gets eliminated from the blood at the rate of 0.015/hour. In a urine test, it can be detected for up to 3-5 days using the ethyl glucuronide (EtG) test or 10-12 hours via the traditional method. It can also be done with hair through a hair follicle test. Alcohol can be detected for up to 90 days through a hair follicle test while when tested through breath or saliva alcohol can be detected up to 12-24 hours.
Driving under influence referred to as DUI is one of the main contributing factors to road accidents. Alcohol tests are dominant at traffic stops. The way in which this is done differs based on the country. For instance in the USA, if a police officer finds someone driving erratically, the person might be stopped for a standard field sobriety test (SFST). The officer may point a flashlight or pen at the driver and ask
them to follow the moving object. This typically includes the horizontal gaze nystagmus test. Some officers may also make the individual do a walk-and-run test in a straight line or stand on one foot and count backwards from 1,001. The following 30 seconds is the time the officers use to determine whether the person needs a breathalyser test.
In India, breathalyser tests are more commonly used to measure BAC at a traffic stop. Post the consumption of alcohol, during respiration, some amount of alcohol keeps getting vaporised thus gaining entry into the lungs. This vaporised alcohol that exits through the mouth and nose is what the breathalyser measures and converts into an indicative BAC. The precision is heightened when it is a lung breath for three seconds. That said, in comparison to the other tests, the accuracy of a breathalyser is a lot lesser which is mainly due to the improper calibration of the device. As per section 185 of the Motor Vehicle Act 1988, a permissible limit of BAC is 30mg of alcohol per 100 ml of blood in a test by a breathalyser. When stopped by a traffic officer, an individual has the right to refuse to take the breathalyser test. However, the officer may then want the individual to take a blood test instead. Post consumption, alcohol does not get digested immediately and chemically remains unchanged. It is imperative to be honest with the officers without levity. If the officers find out the reason for refusal is to veneer, they can arrest the individual without a warrant to be taken to the nearest police station or hospital.
BAC within 30-60 mg per 100 ml of blood shall amount to imprisonment up to 6 months or a fine of Rs 2,000, 60 mg-150 mg can be imprisonment of 1 year and or fine of Rs 4,000 and the repetition of offence within a span of three years can be punishable with an imprisonment of three years and or fine of Rs 8,000. If the BAC is above 150 mg per 100 ml of blood, then it attracts two years of imprisonment and or a fine of Rs 5,000. Repetition portends cancellation of driving license, jail term and a possible penalty of Rs 10,000. If someone is intoxicated, it can often be difficult to stop them from driving. Approach them in a non-confrontational way to explain the ruinous consequences of the same. Offer to call a cab or ask them to
stay over. Even if there is the risk of their car being towed, the price paid for that shall still be lesser than a legal penalty or a jail term.
(The author is a multidisciplinary professional who works in the UK.)