Drug testing policy issues highlighted in recent decision

Last year, New Zealanders voted on whether or not we should legalise the recreational use of cannabis.

A number of employers were concerned that if cannabis were legalised for recreational used, they might no longer be able to test their workers for this.

It is worth remembering, however, that testing for alcohol in the workplace is a well-accepted practice.

As it turns out, the concerns didn’t eventuate as the majority voted against legalisation.

Whether or not cannabis is eventually legalised, there may still be legitimate workplace safety concerns which warrant testing. One problem with testing for cannabis is that the test results cannot indicate impairment levels.

Urine testing is the most common method of drug testing in New Zealand workplaces, but it is somewhat problematic in that THC can remain in urine for lengthy periods.

This can mean a positive result several days after a person has smoked cannabis may amount to a breach of a drug policy, even though the drug use was in their own time and did not affect their capacity to do their job safely.

Australian Courts have held that saliva testing should be used instead of urine testing. The Employment Court in New Zealand, in referring to the Australian decisions, ruled that urine testing had not yet been held to be unjust or unreasonable.

A recent decision from the Employment Relations Authority traversed some of these issues. The decision in Vulcan Steel Ltd v Manufacturing and Construction Workers’ Union resolved whether the collective agreement entitled an employee required to undergo a drug test to choose an oral test as opposed to a urine test.

This was ultimately decided on the specific wording of the collective agreement in question.

However, the decision covers a number of other interesting issues. Vulcan Steel Ltd and the Manufacturing and Construction Workers’ Union were parties to a collective agreement.

Attached to the collective agreement is the drug and alcohol substance policy. This includes a further document entitled "The Drug, Alcohol and Substance Procedure".

The policy is committed to ensuring employees can perform their duties in a safe, productive and healthy manner.

Vulcan Steel has a policy of zero tolerance to illegal drugs and alcohol in the workplace. Employees who believe they have a problem with drugs or alcohol are encouraged to confidentially advise their manager and arrangements for leave and counselling/rehabilitation will be made.

Employees undertaking rehabilitation will be tested before returning to work and will not be disciplined because of admitting a problem.

The policy strictly prohibits possession, consumption, sale or transfer of drugs or alcohol on Vulcan Steel property.

The policy also strictly prohibits reporting to work under the influence of drugs, alcohol or prescription medication that impacts performance, judgement or behaviour.

The policy subjects potential employees to testing. Random, reasonable cause, post-incident and return to work testing are also conducted.

It indicates that drug testing will utilise hair follicle and/or urine and/or saliva test techniques. The authority decided that the wording of the collective allowed the employee to choose their preferred testing technique.

The testing is conducted in a confidential and private manner, and meets current Australian standards.

The employee is required to sign a consent form and a chain of custody statement certifying that the specimen is theirs and has not been charged or altered at the time of collection.

The procedure also references confidentiality and the Privacy Act. All information gathered as a result of testing is expressly collected for the purpose of implementing the drug and alcohol policy and, except as required by law, no testing information can be disclosed to an external party without the employee’s consent.

At the Employment Relations Authority hearing, both Vulcan Steel and the union called expert evidence about drug testing methods and the joint Australian/New Zealand standard-setting procedures for specimen collection, and the detection and quantification of drugs.

The experts for Vulcan Steel supported the efficacy of urine drug testing over oral swab testing to meet the aims of the policy.

In summary, urine testing detects a wider range of drugs, across a longer window of time since drug use, with fewer false-negatives.

The on-site urine testing is conducted to minimise intrusion into the donor’s privacy while ensuring the integrity of the specimen collection.

A difficulty with confirmation testing of non-negative oral swab specimens is that samples have to be sent to Australian laboratories as no New Zealand laboratories provide this service.

The union’s expert was of the opinion that urine testing and oral fluid testing each have acknowledged and well-understood strengths and weaknesses. Where knowledge of "recent use" is more important than knowledge of "any use", oral fluid testing is more useful.

An employee who never uses illegal drugs will not be at risk of being under the influence of drugs in the workplace apart from prescribed medications.

However, an employee who uses illegal drugs away
from work poses a risk of being under the influence of drugs in the workplace, especially if "hangover impairment", "chronic impairment" and "being under the influence" are taken into account.

Urine testing gives a longer window to an employer and therefore a greater chance of identifying use of illegal drugs away from work.

The authority found that there is a New Zealand standard covering oral swab testing procedures, and oral swab testing devices are available and used by drug detecting agencies, despite limitations compared with urine testing. The authority concluded that ultimately both methods were capable of achieving the purposes of the policy and compliance with the Health and Safety at Work Act 2015, specifically whether an employee was using drugs in the workplace or reporting to work under the influence of drugs.

This case highlights the need for a comprehensive policy that addresses consent and privacy issues, and testing methodology.

It also highlights the need to specify who will determine the preferred testing method.

■ The opinions in this article are those of the writer and do not purport to be specific legal or professional advice. John Farrow is a litigation partner with Dunedin law firm Anderson Lloyd.