Oral Fluid Drug Testing Methods

Rail Industry

In response to proposals some few years ago for the use of mouth swabs to collect oral fluid for drug screening purposes, the RMT called upon the rail industry to commission independent research to evaluate the various drug testing methods.

HSR/1/1
17 May 2005
Circular No. NP/207/05
ALL BRANCHES AND REGIONAL COUNCILS

Dear Colleague,

DRUG TESTING METHODS

In response to proposals some few years ago for the use of mouth swabs to collect oral fluid for drug screening purposes, the RMT called upon the rail industry to commission independent research to evaluate the various drug testing methods. Our aim was to ensure that whatever method of screening was used, it must provide an accurate result so as to avoid any member being falsely accused and possibly losing their jobs. A research project was eventually agreed and a contract awarded to the Health & Safety Laboratory to carry out a study of the various methods of drug testing, and in particular the efficacy of oral fluid/saliva testing.

Accuracy of oral fluid drug tests

‘The outcome of that study was considered by the General Grades Committee. They noted that the accuracy of oral fluid drug testing was largely equivalent to that achieved through urine testing, but as the introduction of oral fluid testing could raise other concerns, it was felt that Branches should be sent a summary of the study findings and their views sought on the matter.

A copy of that summary and any views should be submitted before the end of July. After that the matter will again be considered by the GGC. However, in the meantime, local or company level representatives should not engage in any discussions with management on the possible introduction of oral fluid testing. Any such proposal by any individual company should be reported to this Office immediately.’

Yours sincerely,

B. CROW
General Secretary

REVIEW OF DRUG TESTING METHODS: RESEARCH FINDINGS

* Current workplace drug testing is predominantly performed using urine samples. It is the de facto method within most industries, but it is by no means the only effective method for testing. Urine and oral fluid drug tests reflect recent exposure, whereas hair testing is about past drug misuse over periods of time from weeks to many months.

Oral fluid drug tests v urine drug tests

* The scientific evidence from large-scale workplace studies suggests that laboratory analysis of urine or oral fluid and urine are largely equivalent in terms of their accuracy in detecting recent drug use. However, as the following chart shows, the time window for the detection of most drugs in oral fluid is shorter than that for urine and may, therefore, indicate a closer relationship with actual impairment at the time of testing.

Drug Detection Times

Drug Group—————-Urine—————Oral Fluid

Cocaine………………………1 ? 5 days………….    Up to 24 hours
Cannabinoids……………….Hours/Days/weeks.    Up to 12 hours
Opiates……………………….Hours/Days……….. .  Up to 24 hours
Amphetimines………………Days………………….  Up to 48 hours
Benzodiazepines…………..Days………………….   Up to 24 hours
Barbituates…………………. Days…………………. Up to 48 hours
Methadone…………………..Days………………….  Over 24 hours

* The shorter window of detection for oral fluid measurements implies that the period of pre-announcement that an individual receives prior to testing should be as short as possible. The shorter timeframe could also mean that a different result might be obtained from the same worker using a different testing method.

* This has obvious implications where workers from different companies may work alongside each other, and each of their companies have different methods of testing. In such a situation it is possible that workers having ingested the same amount of drug/medication at the same time could obtain different results. One testing positive and the other negative.

* Because oral fluid testing is more likely to detect only recent drug use, it may be more compatible with the guidance issued by the Information Commissioner in regard to the gathering of personal information covered by the Data Protection Act. This suggests that testing should be largely designed to ensure safety at work rather than to reveal the use of drugs taken in a workers private life.

* Oral fluid testing is in practice much easier to carry out than urine testing and is more difficult to fool. It also reduces the indignity that some workers feel during supervised urine collections. Equally it has practical advantages for unannounced random testing and post incident testing as it does not require special toilet facilities, samples are also far quicker to obtain and thus it may not need staff rosters to be altered.

* Any collection device used for oral fluid testing must be appropriately validated for all drugs of interest. Similarly, any laboratory undertaking oral fluid testing must have accreditation and quality assurance schemes at least equal to those doing urine drug testing.

Orascan is considered one of the most sensitive and easy-to-use oral fluid tests currently available.