Case for Oral Fluid Testing
How can workplaces manage risk due to substance use?
In spite of rigid urine and hair testing regimes, drug use in NZ has not decreased, rather they have opened pathways for ventures that provide powdered/synthetic urine. Drug Screening has mainly become a tick exercise and we have lost the intent of why we are screening. It can be made simpler…
The Case for Oral Fluid Testing in Workplaces
Healthy and safe workplaces start with identifying and understanding what your work-related health and safety risks are. It then involves doing what is reasonable and practicable to eliminate those risks. Where the risk cannot be eliminated, it must be minimised so far as is reasonably practicable.
NZ Road Safety Initiatives
In 2019, 103 people were killed in crashes where a driver was found to have drugs other than alcohol in their system. This represented 30% of all road deaths. Enhancing drug driving testing is one of 15 actions proposed as part of the initial action plan under the new Road to Zero strategy.
In July 2020, the Government introduced legislation that would introduce a compulsory random roadside drug testing scheme in New Zealand. Under the proposed drug driving regime, oral fluid (OF) tests will detect the most prevalent impairing (illicit and prescription) drugs at the roadside. The proposed change will allow police to test drivers for the presence of drugs anywhere, anytime, just as they can for alcohol.
Even with road-side saliva testing happening in other countries like Australia, Belgium, France, UK and Germany there seems to be a hesitation in NZ workplaces to adopt this methodology.
Accuracy of the Devices
In 2006 when AS4760 -Oral Fluid Drug Testing Standard was established, science was not as strong to develop oral fluid devices, therefore only target values were provided for the detection of drugs. In March 2019 AS/NZS 4760:2019 was published that overcame weaknesses of the previous standard. There are now devices that have been verified against Appendix A of the standard, with some devices performing better than the cut off required by the standard.
Since February 2021, there is an IANZ accredited lab in New Zealand to provide confirmation on the screening sample and this has enabled workplaces to manage oral fluid drug screening completely. Initially, some workplaces had an oral fluid screening regime but conducted urine confirmatory. This was not an ideal way as oral fluid detects the parent compounds that cause that psychoactive behaviour and urine detects the non-psychoactive metabolites taken at some stage.
Fair Works Commission – 2015 CFMEU v Port Kembla Coal Terminal
In the 2015 appeal made by the Construction, Forestry, Mining and Energy Union (CFMEU) against Port Kembla Coal Terminal Ltd (PKCT) in Australia, it was clear from all the evidence presented during the hearings that neither oral fluid nor urine testing devices were perfect. Seen from one perspective, urine testing can be seen as more ‘accurate’ in that it is more likely to pick up whether an employee has at some stage taken certain substances. However, that is not necessarily the goal of a workplace drug testing regime. This was even pointed to in Hayllar v The Goodtime Food Company [2012] NZEmpC and for the first time the value of oral fluid testing was recognised in New Zealand.
In the PKCT case neither party disputed that random testing for drugs (or alcohol) was unjust or unreasonable. Further, both parties also recognise that random testing is an intrusion on the privacy of the individual which can only be justified on health and safety grounds. The employer has a legitimate right (and indeed obligation) to try and eliminate the risk that employees might come to work impaired by drugs or alcohol such that they could pose a risk to health or safety. Beyond that the employer has no right to dictate what drugs or alcohol its employees take in their own time. Indeed, it would be unjust and unreasonable to do so.
The case concluded that both methods were susceptible to cheating. Urine can also be adulterated. There is some evidence that oral fluid screening is less susceptible to specimen adulteration or substitution compared to urinalysis. In practice, however, the likelihood of someone being in a position to cheat effectively when an OF test is conducted at random and with no prior warning was relatively low according to the commissioner.
Furthermore, the case pointed out that not only is urine testing potentially less capable of identifying someone who is under the influence of cannabis, but it also has the disadvantage that it may show a positive result even though it is several days since the person has smoked the substance. This means that a person may be found to have breached the policy even though their actions taken in their own time in no way affected their capacity to do their job safely.
Given the aim of random drug testing policies is to identify persons who may be impaired, in circumstances where both urine and oral fluid methods have problems in relation to identifying a person as possibly impaired, it is a question of weighing various factors in reaching a conclusion. These include: the potential for urine testing to fail to identify a person as potentially impaired at the time of greatest impairment; the failure of oral fluid testing to identify a person who may still have some residual impairment; the incorrect identification of a person as potentially impaired by reason of a urine test which might be conducted days after the person consumed cannabis; the availability of effective on-site oral fluid testing devices which provide a quick, less offensive, effective and reasonably reliable means of determining whether an employee has used a drug recently and who may therefore not be fit for work.
Impairment is a risk at workplaces, which can be attributed to substance use or fatigue. Providing a practicable solution of testing through OF that is reasonable, non-invasive and detects fitness for work, helps create deterrents to drug use at work in forestry, mining and other safety sensitive industries.
According to Dr. Alain Verstraete, former President of The International Association of Forensic Toxicologists, “Oral fluid will probably become the most prevalent matrix. The main advantages are ease of collection and a generally shorter window of drug detection than urine, hence a better correlation with duration of impairment.”
These same principles can be hugely applicable to our workplaces to create a healthier and safer New Zealand.
Written by: CK Rahi:
Operations Director – Advance Diagnostics NZ Ltd
Member of the Joint Standards Committee for review of AS 4760 & AS/NZ4308
Date: 30.04.2021