Changes to federal laws governing recreational cannabis use this summer has employers seeking to clear the haze on some burning questions when it comes to worker safety and company liability at the job site.

Questions of note include: As with alcohol consumption, can the same workplace restrictions apply to cannabis use? And how do employers handle workers who are heavy users of cannabis and may have a residual level of Tetrahydrocannabinol (THC), the principal psychoactive ingredient of cannabis, in their bloodstream for days or a week after smoking a joint?

“A lot of people are very nervous about cannabis and rightfully so because there’s not much written information out there,” said Nadine Wentzell, a Halifax-based consultant who has spent the past 25 years building industry-specific workplace alcohol and drug policies and programs.

She said just because it will become a legal drug doesn’t mean a user can light up when he or she feels like it.

“Whether it’s recreational cannabis or medical cannabis, your body doesn’t care. It still has the same impairing effects on you,” Wentzell said.

“We don’t get rid of cannabis like we do alcohol. We store it in our fat cells and it sticks around for up to 14 days even after one joint.

“A recreational user may use it once and have the acute high, that’s obviously a concern, but equally if not more of a concern are chronic users who have a baseline level that makes them unsafe to work.”

A lack of a standard threshold to determine how much pot is too much isn’t available to employers.

Each company is left to determine how to quantify when an employee is considered stoned, and many organizations – both large and small – have inadequate policies to address the complex issue, Wentzell said.

And it’s not as simple as an employer randomly testing employees for drug use in occupations where safety is always in the foremost of managers’ minds.

National rules for random drug and alcohol testing were established following a 2013 decision by the Supreme Court of Canada. Employers must be able to prove there’s pervasive abuse of a substance in order to legally enforce a drug testing program.

A survey released in January by the Human Resources Professionals Association indicated 71 per cent of employers were still not prepared for the legalization of cannabis.

Best practices in the workplace was cited as a major concern among employers who are seeking guidance, guidelines and sample policies to prepare for legalization, according to the report.

A workshop will be hosted by the Construction Association of Nova Scotia in Sydney on Tuesday where Wentzell will present ways for managers and human resource professionals to form policy on cannabis use.

It is the third workshop the construction association has held recently, said its president Duncan Williams.

Among the 780 members in the Construction Association of Nova Scotia, he said there is a “significant concern” on how to handle employees who may show up on the construction site or at the warehouse unable to perform delicate tasks with heavy equipment.

“With alcohol, there are pretty clear symptoms where you can tell if somebody is intoxicated, then address the issue and send someone home if that’s the case,” he said.

“With marijuana, it could be very different. Can (a manager) who smells marijuana off somebody’s jacket but it was from Saturday night when (the worker) was at home,” and still send the employee home?

It’s likely many companies will turn to designing their own “fitness to work” policies, said Williams, but that it’ll be largely a judgment call a manager will still be left to make.

It could lead to legal challenges from employees forced off a worksite without due process or sufficient evidence to prove intoxication, he said.

“In some cases, the judgment may be wrong but hopefully wrong for the right reasons and somebody doesn’t get injured.”