PYDT Saliva Drug Testing FAQ

Saliva blood tests operate by checking for tiny residual amounts of drugs within the saliva. The person being tested wets the test strip with their saliva, and the test shows results using colored bands. Saliva tests check for the presence of opiates, marijuana, cocaine, methamphetamine, and phencyclidine drugs. Any trace of one of these drugs will cause the band corresponding to that drug to change color. A drug-free result would show no color at all.

Important Saliva Drug Test Facts

Saliva is a refined version of plasma, that has the capability to contain trace amounts of drugs and their ensuing metabolites for a period of 24-36 hours. This forms the basis of saliva drug test. It is also known as oral fluid drug test.

The saliva drug test kits comes in many forms and shapes. The general way of using such a kit is to place it in the mouth of the individual being tested. The kit draws the saliva through a membrane. The membrane allows saliva to wet the strips containing media of antigen dyes. The antigen dyes act as an indicator. Formation of color on the strip suggests a positive result. There is a particular color for each drug in question.

Saliva drug test can detect the following drugs. The detection time for each drug is given against them:

Alcohol - from time of intake to 12 hours.
PCP - from a few minutes after ingestion to the next three days.
Methamphetamine and ecstasy - half an hour from ingestion up to 3 days.
Amphetamines - a few minutes to 3 days of consumption.
Barbiturates - less than an hour after ingestion up to 3 days.
Opiates - from an hour after intake to 3 days.
Cocaine - a few minutes after ingestion up to one day.
Benzodiazepines - not yet known
Cannabis - a few minutes after ingestion up to one day.

Saliva tests are used primarily for employment drug screenings. Federal mandates require screening for each of the drugs detected by the saliva testing prior to employment. The convenience and quick results make saliva testing an attractive choice for employers.

Saliva tests can be performed in any location and do not require a professional nurse or lab technician to conduct the test or read the results. In addition, the results appear very quickly and can be read within five minutes. They are a low-cost, and non-invasive alternative to sending potential employees to a lab for drug testing and also are virtually impossible to trick.

Traces of the drugs will only show in the saliva for 10 to 24 hrs after use. For this reason, a long-term drug user who stays clean for a few days before testing will appear to be completely drug free. In addition, while it is very difficult to trick a saliva test, it is possible to mask the traces of drugs by smoking cigarettes or eating certain foods.

Hair follicle testing shows the history of a person's drug use, but the testing is not virtually instantaneous as with the saliva testing. Urine testing is more easily faked than a saliva test, but traces of drugs show in a urine test for a longer period of time than in a saliva test. Blood tests are extremely accurate and extremely difficult to fake, but are invasive and test results are slow.


Saliva Drug Test Chart


Target Drug


Nanograms (ng) per milliliter (ml)

Marijuana (THC)

11-nor-∆-THC--9 COOH

12 ng/ml

Cocaine (COC)


20 ng/ml

Opiates (OPI)


40 ng/ml

Methamphetamine (M-AMP)


50 ng/ml

Amphetamine (AMP)


50 ng/ml

Phencyclidine (PCP)


10 ng/ml

Benzodiazepines (BZO)


50 ng/ml

Barbiturates (BAR)


300 ng/ml

Methadone (MTD)


75 ng/ml

Buprenorphine (BUP)


10 ng/ml

Alcohol (ACL)


> 0.02 BAC


Explanations of Blood, Hair and Saliva Drug Tests

Blood tests are a better detector of recent use, since they measure the actual presence of THC in the system. Because they are invasive and difficult to administer, blood tests are used less frequently. They are typically used in investigations of accidents, injuries and DUIs, where they can give a useful indication of whether the subject was actually under the influence.

Urine Test to perform a drug test on someone's urine, a sample has to be collected in an examination cup, (often in a controlled environment). For immediate results, the test is performed with a test card. If the test calls for most sophisticated results, the urine is sent out to a testing facility and the results are given after a week or two.

The urine test is very reliable and is performed at most federally mandated facilities that require drug testing.

Hair tests are the most objectionable form of drug testing, since they do not measure current use, but rather non-psychoactive residues that remain in the hair for months afterwards. These residues are absorbed internally and do not appear in the hair until 7-10 days after first use. Afterwards, they cannot be washed out by shampoos (though shampoos may help remove external smoke particles that get stuck in the hair). Hair tests are more likely to detect regular than occasional marijuana use. One study found that 85% of daily users tested positive for marijuana, versus 52% of occasional smokers (1-5 times per week). Ingested cannabis was less likely to be detected than smoked marijuana. It is doubtful whether hair tests are sensitive to one-time use of marijuana.

Saliva testing is a newer, less proven technology. The sensitivity of saliva tests is not well established in the case of marijuana. In theory, they are supposed to detect recent use, but this may range from several hours to over a day. They are supposed to detect secretions from inside the oral tissues that cannot be washed out with mouthwash. Because they are less intrusive than blood or urine tests, the industry has been eager to develop saliva tests. Due to reliability problems, they have yet to gain acceptance in the U.S., but they have come into use in some other countries, such as Australia.