As an employee, you may have problems if you do not want to take the test, says Petra Herzfeld Olsson, professor of labour law at Stockholm University.

"There may be labour law consequences if the employer has the right to require you to undergo a drug test. For example, you can be laid off," she says.

Action plan and procedures

Magnus Nyqvist from the occupational health company Feelgood, which sells drug tests to various companies, sees the tests as an important part of working to prevent addiction.

"It's not just to introduce it, but you also have to work with other parts. You have to work with policy, action plan and routines linked to it," he says.

Can employers always force employees to agree to random drug tests? Professor Petra Herzfeld Olsson tells us more in the video above.