An Air Canada flight crew did nothing to stop a man "vaping" an electronic cigarette during a flight from Calgary to Toronto two weeks ago, says a passenger.

On March 28, Calgary businesswoman Elizabeth Cole arrived at Calgary International Airport for a flight to Toronto. While waiting to board the plane, she says she noticed a man using the e-cigarette in line and figured the flight crew would make him stop once he was on the plane — but they did not.

"I was very surprised that it was allowed to happen," Cole said. "I don't understand how flight attendants did not see him. He wasn't hiding it."

Electronic cigarettes work by vapourizing a liquid which usually — but not always — contains nicotine. The vapour, which is sometimes flavoured to taste like mint or candy, is then inhaled, or "vaped."

Cole says she stood behind the man during boarding and watched him vape while getting on the plane.

She then moved to her seat behind the man and saw him continue to puff out vapour during the flight.

She says none of the flight crew told the man to stop, despite Air Canada policy stating passengers are forbidden to vape on their flights.

"Air Canada's policy, which crews are aware of and uphold, is that e-cigarettes are not permitted to be used on board Air Canada flights," said Angela Mah, a spokeswoman for the airline, in an email to CBC News.

"Had the crew been aware of or been alerted during the flight about the purported use of an e-cigarette on board, they would have addressed the matter immediately."

Flight crew lack of reaction confusing

Many e-cigarette makers advertise that their products will not set off airplane smoke alarms like traditional ignited cigarettes do, and spokespeople from both WestJet and Porter have admitted to CBC News they are not aware whether smoke detectors can detect the vapour.

Health Canada has not approved e-cigarettes that contain nicotine for sale in Canada, but has not banned them. Many just buy the product online.

Transport Canada also has not implemented specific rules banning the use of e-cigarettes on airplanes but rather has left the decision up to individual airlines.

However, the U.S. Department of Transportation officially banned the use of the devices in 2011, citing the unknown safety implications of e-cigarettes as a concern.

Both Air Canada and WestJet do ban the use of e-cigarettes on aircraft, but Cole says she had no idea about Air Canada's policy and would have spoken up had she known vaping was banned.

She says the flight crew's lack of reaction made her doubt whether the vaping passenger was doing anything wrong.

"It's kind of awkward to tell a flight attendant when the flight attendants are allowing it to happen," Cole said. "We don't know if it's a rule or not. If you complain about the individual sitting right next to you or right in front of you, what's going to happen if it's actually OK? Then you look like the person who just tattle-taled."

Announce ban during flight, Cole urges

Cole says she did confront the pilot and flight crew while getting off the plane — that's when she saw the passenger sitting beside the vaping man complain to the crew.

"They didn't apologize," she said. "They just said, 'Well, you should have told us.' Well, you should be looking out for puffs of [vapour] on your plane."

Along with several other people, Cole again complained to crew at the desk while waiting to pick up luggage at the baggage carousel.

They told her to send an email complaint to the airline, which she did. Two weeks later the airline replied, saying Cole should have told flight crew while it was happening.

Cole says the entire experience has been disappointing and she would like to see Air Canada act to make sure people know vaping is forbidden.

"I think they need to treat it like smoking a cigarette and announce it at the beginning of the flight," she said. "This is not OK and it's not allowed."