A pub owner in B.C.'s Interior is utilizing a police tool commonly used to test driver impairment to help ease his customer's fears about drinking and driving.

Dennis Graham, owner of the Pheasant & Quail Pub in Kelowna, has purchased two $200 breathalyzer machines so his patrons can test their blood alcohol level before they leave to make sure they're within legal limits to get back on the road after having a drink with dinner.

Graham said he has a dwindling number of patrons because of the introduction of Canada's toughest drinking and driving laws and B.C. He says many people are unsure about how much they can safely drink to remain under the .05 limit.

"[It's probably the biggest impact in the last 50 years that I've been in this business," he said.

Spy vs. Spy, a Kelowna security store, said the demand for personal breathalyzers has spiked in recent months. Frank Caron said his first six were sold out within a day, and another dozen were gone in just a few more.

"Now I've got 24 on back order," he said.

But the real issue for bars thinking of using the devices is how much the results can be trusted.

There's almost no way to guarantee the level of accuracy of the police-operated instruments, something Graham tells his bar patrons.

"If some of the customers want to try it out, fine. But there's no guarantee that it's calibrated like the RCMP or the police's machines are," he said.

B.C.'s solicitor general has stopped short of endorsing the use of these devices for bars and pubs.

"I haven't come across a device that anybody's recommended that we would approve just to have in operation in bar somewhere because then somebody's taking liability to say it's actually accurate," Rich Coleman said.

Still, bar patrons who spoke with CTV said they would like the opportunity to use one in the pub rather than on the roadside with the police.

And some people are taking matters into their own hands with an even less reliable but much cheaper alternative. Consumers can purchase a $20 version of a breathalyzer at 7-11. The product carries a warning on the label – saying it's a novelty item only.

With a report from CTV British Columbia's Kent Molgat