A Halifax man had a job offer rescinded from the local water treatment plant because he tested positive for cannabis use in a pre-employment drug test 鈥 even though the substance is legal in Canada.

鈥淚 don鈥檛 do any illicit drugs, I鈥檓 a hard worker,鈥 Patrick Whalen told CTV Atlantic. 鈥淚 thought 鈥極K, I鈥檓 not a frequent user, I use it once in a while.鈥欌

Whelan had applied for the job in April, had an interview early May and was offered the job the same day. It was then he was told he would have to undergo a drug test as a condition of his employment.

After waiting five days, Whalen submitted his urine. The results came back positive for cannabis and Halifax Water withdrew their job offer.

鈥淚 got penalized,鈥 Whalen said. 鈥淸I] did not receive the position because I smoke legal cannabis.鈥

A spokesperson for the water treatment company said that the drug screening is 鈥渁 matter of safety.鈥

鈥淲e鈥檙e around heavy moving equipment,鈥 said James Campbell, a spokesperson for Halifax Water. 鈥淭hat鈥檚 really dangerous and we want to make sure that the folks working here are in their best possible position.鈥 

Employment attorney Jill Houlihan told CTV Atlantic that 鈥渋t鈥檚 generally not prohibited for an employer to conduct drugs testing鈥 before someone becomes an employee.

鈥淭he reality is, if you are in the job market鈥ou would be well advised to abstain from cannabis,鈥 Houlihan said.

Cannabis stays in the body longer than alcohol, meaning that prospective employees may still fail drug tests several days after using the substance.

Whalen has found other work, but is warning Canadians that their use of a legal substance may affect their job prospects.