Drugs testing is a very complex science. This web page just gives a fairly simplified 'broad brush' outline of this.

Drugs testing is becoming increasingly common. Sport is perhaps where we hear most about it. However, some employers use drugs tests on their actual or potential employees and some schools, particularly public schools, have begun drugs testing their students. There are even tests that parents can buy to test their children!

There are different types of tests. The most commonly used method is a urine test. Other methods are saliva, blood or hair testing. Saliva or blood tests detect drugs that have been taken over the last 24 hours. Saliva tests would also be used, along with urine testing, to see if someone is 'under the influence'.

Urine Testing

As already said, urine testing is by far the most commonly used method of testing. If done correctly it is a very accurate scientific procedure.

It is very difficult to tell how long a substance will be detectable in the urine. The amount of time since the drug was taken, the frequency of use, and the weight, age, health and body chemistry of any particular individual all affect this. However, the following table gives a rough ESTIMATE of some of the more commonly used drugs:

The results of tests are not always accurate. There can be false positives (a positive result where there is no drug use) and false negatives (a negative result where there has been drug use). Some medicines, if taken, may give a positive result, for example

Hair Testing

Hair testing can be as much as 5-10 times more effective in detecting drugs than urine testing but is very much more expensive. It also needs to be done in a competent laboratory or can be less reliable. A standard test provides up to a three month history of drug use. This type of testing would be used by employers, for example, who want evidence of drug use or abstinence, or in the treatment of addictions.

Drugs can be detected in the hair approximately 5-7 days from the time of drug use to the time of the test, as it takes this long for the affected hair to grow above the scalp. Drugs have to be ingested over a period of time and taken at least three or four times for use to register. Second hand or atmospheric smoke do not alter the results.

Hair tests can be run on people with little or no hair, as hair can be collected from several locations on the head and combined to obtain the required amount of hair. Body hair can be used as an alternative to head hair.

The drugs covered by the standard test are: cocaine/crack; cannabis; opiates (including heroin); amphetamines (including ecstasy); and phencyclidine (PCP).

Testing the Drugs

Drugs can be tested to check purity or contamination. Testing kits are available that show what a drug contains. These kits are useful for indicating if a drug contains dangerous chemicals or unwanted drugs. However, most tests do not indicate how strong the drug is, or whether there are more than one type of drug found in the specimen.

Some pressure groups in the UK have set up drug testing stalls at parties and clubs so that people have a better idea of what they are taking. This has legal implications as handing the drug over for testing and giving it back can be regarded as supplying the drug. Also, most tests do not indicate how strong the drug is, or whether there are more than one type of drug found in the specimen.

Testing for Spiked Drinks

Date rape is a crime that has increased in the last few years. Drugs like GHB and Rohypnol can be used to spike drinks. Now you can buy products to discreetly test your drink whilst on a night out. They come either in the form of test strips or beer mats. They can also detect the drug in urine and can be used as a morning after test.