More and more we are seeing both in Canada & the US that drug tests are becoming mandatory for residents on welfare. Some governments are saying that if welfare applicants or recipients refuse to take the drug test, they will be denied welfare.
https://drugtestsinbulk.com/drug_and_alcohol_information.html

In the Province of Ontario, Canada, with over 460,000 people on welfare, the Progressive Conservative Ontario government wants to require people on welfare to take a drug test to see if they’re on the influence, something no other government in Canada does and refusal to do so would lead in immediate suspension of welfare. There has been much debate about this since the opposition challenging this idea says it violates basic human rights. The CBC reports that:

The Human Rights Commission sent a letter to the government last year warning that denying welfare benefits to drug addicts is illegal. Source

However, Minister John Baird indicated that the government’s plan is not meant to penalize people. To borrow his words:

“It’s tough to get a job and hold a job if you’re addicted to drugs. These people are in desperate need of help and if we can turn just one life around, we’ve met with success,”Source

In North Carolina, USA, one of 14 states including Alabama, Arkansas, Arizona, Florida, Georgia, Kansas, Michigan, Mississippi, Missouri, North Carolina, Oklahoma, Tennessee and Utah have strict laws concerning welfare recipients. They actually published welfare recipient’s drug test results online and found that Non-welfare recipients are twenty six times more likely to abuse illegal drugs than North Carolina’s welfare recipients, according to North Carolina’s findings. Source

Still, Social Welfare workers required recipients to share with them about their drug use. If there was any indication that the recipient used drugs, they were obligated to take a drug test. If in the past the recipient had a history involving drugs, the drug test would be mandatory.