Drug Test Information

Random drug tests in the workplace are becoming more common, and are mandatory in many industries where safety rather than productivity is of concern. Many employers in non 'safety-critical' industries are also choosing to conduct pre-employment and sometimes random screening. Drug tests are also commonly requested by social services or the courts in family and criminal law cases. This page helps provide general information to those facing a situation where drug testing may occur.

Drug Test Topic 1

Methods of Conducting a Drug Test

Saliva Drug Test

Saliva drug tests have one of the shortest detection windows for drug use and therefore are most effective when used to confirm very recent drug usage, typically within the previous 4 to 24 hours. Saliva drug tests are a useful tool for employers who wish to conduct pre-employment, random, or return-to-duty testing, and can also be used in situations where a urine drug test is impractical.

Saliva drug tests will detect drug usage almost immediately for:

• Cannabis - an hour after ingestion up to 24 hours
• Cocaine - from time of ingestion up to 2 to 3 days
• Opiates - from time of ingestion up to 2 to 3 days
• Methamphetamine and ecstasy - from time of ingestion up to 2 to 4 days
• Benzodiazepines - from time of ingestion up to 2 to 3 days

Urine Drug Test

Urine drug testing, or urinalysis is the most common type of drug test, although it is not the most accurate. The accuracy of results is called into question both by the risk of false positives and the widespread use of 'detox' products by those hoping to cheat the test.

Urine drug tests can confirm recent drug usage within the previous 1 and up to 8 days, depending on the drug used. However, many drugs, such as cocaine, methamphetamine, opiates and PCP are rapidly metabolised by the body and are undetectable in urine after as little as 72 hours.

Urine drug testing is considered an invasive test; and one of the major disadvantages to this type of test is that samples can easily be tampered with in order to cheat the test. To prevent this, samples must be taken under observation to ensure that it is obtained directly from the donor and has not been adulterated or switched. Not only does this add an embarrassment factor, but there are obvious implications for employers to provide both toilet facilities and the manpower to accomplish this.

Many laboratories will perform adulteration testing, which attempts to identify any sample that has been tampered with. For example, checking the pH balance of the sample will identify the presence of many adulterants and cross-checking the temperature of the sample with the time that it was taken can identify a sample that has been diluted. However, the prevalence of sample tampering with urine drug testing remains a major drawback to establishing accurate, un-contestable results.

Urine drug testing can also only confirm recent drug use. In order to establish a pattern of drug use over time, repeated testing (along with repeated expense) is necessary.

Blood Drug Test

Blood drug tests have advantages over urine drug tests in that the sample can only be taken directly from the donor, and using this type of drug test therefore removes the possibility of sample tampering. However, the need to have the test administered by medically qualified personnel means that tests can take longer to arrange and tend to be more expensive.

The detection windows for drugs found in the bloodstream are similar to saliva drug tests and will typically confirm drug usage within 1-7 days, depending on the drug used:

• Cannabis - 24 hours
• Cocaine - 2-5 days
• Amphetamines - 12 hours
• Methamphetamine - 1-3 days
• Ecstasy - 24 hours
• Benzodiazepines - 1-2 days
• Barbiturates - 1-2 days

The level of drug found in the bloodstream does correlate to the level of usage; so high levels on the test results will indicate a heavy or habitual user within the timeframe of the test, and low levels indicate sporadic or social use. One of the drawbacks to blood testing is that again, it can only confirm recent drug usage and does not establish a pattern of drug abuse over time.

Hair Drug Test: Hair drug testing has several advantages over the other types of drug tests, and is considered to be the 'gold standard' of drug testing by the courts. Firstly, and most importantly, traces of any drugs taken or their metabolites remain present in hair indefinitely, meaning that hair drug testing can establish a pattern of drug use over time. Hair drug testing is therefore able to differentiate between a one-off user and a habitual abuser with a single test, and negates the need for repeated screenings. In addition, there are no known ways to cheat a hair drug test. The combination of a longer detection window, non-invasive collection of samples, lack of false positives, and impossibility of cheating the test makes hair drug testing far more reliable than other methods in correctly identifying drug abusers.

When a drug enters the bloodstream, it is broken down by the body into a specific metabolite. As hair growth is fed by the bloodstream, these metabolites (as well as minute traces of the drug itself) are deposited directly into the shaft of the hair and remain there indefinitely. The detection window for either the parent drug or its metabolite is therefore limited only by the length of hair sample available.

Hair grows at a rate of approximately 0.5 inches per month, and the industry standard in hair drug testing is to use a 1.5 inch sample of hair, which provides a record of drug misuse in the donor for the previous 90 days.

Hair drug testing is most effective in tracking patterns of drug use over time. For example, if a donor denies current drug use but admits to having used drugs two months ago, the hair sample can be cut into sections and analysis of the appropriate section of hair will verify the donor's self-reported history.

In the past, some concerns have been raised over a possible racial bias in hair drug testing. It has been shown that some drugs tend to bind themselves to melanin, the primary determinant in skin and hair colour. The theory is that the more melanin there is in the hair the more drug binding occurs. In practical terms, this would mean that darker-haired, black, Caribbean or Asian populations would absorb or retain more drug in their hair than lighter skinned people. However, recent scientific studies have shown that neither hair colour or race is a significant factor in hair analysis, and in the US, case law has established that there is no scientific basis for racial bias in hair. There has not yet been any significant challenge to the results of hair drug testing in the UK courts.

Hair growth begins slightly below the scalp, and because of this, the sample cannot confirm any drug use within 4-7 days prior to the sample being taken. The window of detection for all drugs covered by this test therefore begins at 7 to 14 days. Hair drug tests are typically used to check for:

• Cocaine
• Amphetamine and Methamphetamines
• Opiates (Morphine, Heroin)
• PCP
• Cannabis (tests for the metabolite, THC);

but can also be used to screen for other drugs, including:

• Barbiturates
• Benzodiazepines
• Codeine
• Hydrocodone (Vicodin, Lorcet, Lortab)
• Hydromorphone (Dilaudid)
• Methadone
• Oxycodone (Percocet)

The results of hair drug tests are measured in picograms (trillionths of a gram) per milligram of hair. Most if not all drug testing companies use the cut-off levels established by the Substance Abuse and Mental Health Services Administration (SAMHSA), a branch of the US federal government. In the UK, the Parliamentary Office of Science and Technology recommends following the SAMHSA thresholds, which are as follows:

• Cocaine - 500 picograms per milligram of hair
• Methamphetamine, Amphetamines & Ecstasy - 500 picograms per milligram of hair
• Opiates - 300 picograms per milligram of hair
• PCP - 300 picograms per milligram of hair
• Cannabis (tests for the metabolite, THC) - 1 picogram per milligram of hair

Drug Test Topic 2

Drug Test Myths: A quick trawl on the internet will find hundreds of products and tips designed to help people 'beat' a drug test. The vast majority of these products apply to the most common combination, a urine drug test screening for cannabis use. Urine drug tests can sometimes generate a false positive result. However, it is a myth that you can claim that your positive result for marijuana can be explained away by passive smoking, or that your positive result for opiates can be explained away by eating food containing poppy seeds.

The cut off levels have been set where they are because they confirm a relatively sustained level of use, certainly more than that generated by passive smoking or accidental ingestion. The commonest myth out there is that you can beat the test by 'flushing' your system; i.e., drinking lots of water to dilute the drug concentrations in your urine. However, doing this will also lower the specific gravity and creatinine levels of the sample (creatinine is a metabolic byproduct produced by the muscles), and all laboratories routinely use these markers to test for dilution. There is little or no evidence to suggest that 'detox' products actually work, even on urine tests, and there are no proven ways for beating a hair drug test. The only foolproof way of passing a drug test is to be clean when you take the test!

Drug Test Topic 3

What to do if you have a drug problem

If you are concerned about either your own or someone else's drug use, a good place to start is either your GP or an independent confidential 24-hour helpline. Both can put you in touch with further help and support services.

Talk to Frank: This organisation is run by the National Drugs Helpline offering free and confidential advice, information and support to anyone concerned about drugs and substance misuse, 24 hours a day.

Helpfinder is Drugscope's database of drug treatment services in England, Wales and Scotland, searchable by treatment available and region.

Cannabis Help: This site has been created to help people who want to cut down or stop using cannabis. It includes information about the effects, risks, and the legal status of cannabis in the UK.

Cocaine Help: This site, with online discussion forums, aims to help people addicted to cocaine or crack find help and support among others.