Air passengers travelling to the United States got some good news on Wednesday.

"So you know you're allowed to take carry-ons now? Just one per guest and as long as it's your computer -- no liquids or gels over 100 millilitres," a WestJet employee told travellers at Pearson International Airport.

This thrilled Jackie Morra, en route to Disney World in Florida with her young son.

"Oh, it's amazing, especially with the little guy," she said. "We need a ton of stuff for him, like his diaper bag, my purse. We need the phone, we need the cameras -- we need everything."

Other travellers wish they'd heard the news before they reached the airport.

The news was released Tuesday evening. Transport Minister John Baird said the new rules would take place on Wednesday.

The carry-on bag must not exceed a size of 23 cm x 40 cm x 55 cm (9 in x 16 in x 22 in), or about the size of a small gym bag.

Here are the medical exemptions:

  • a cane, walker, crutches or other life-sustaining items may be carried in addition to the carry-on bag
  • medical equipment (oxygen tank, doctor's bag) may be carried in addition to the carry-on bag
  • diaper bags and other essential items for those carrying infants may be carried in addition to the carry-on bag

Travellers are also allowed the following in addition to the carry-on bag:

  • a purse or laptop or briefcase or camera bag
  • a musical instrument
  • pets
  • all duty free items purchased after the security check

These rules do not apply to travellers flying within Canada or to international destinations.

The tightened restrictions followed a botched attempted by a suspected extremist to blow up a flight travelling from Amsterdam to Detroit.

The federal government has said it will be introducing new security measures, including an investment in full-body scanners and a screening method known as behaviour pattern recognition.

Israel, which is considered to have the world's best airline security, uses behaviour pattern recognition. It consists of questioning people who show suspicious behaviour.

Full-body scanners allow security to conduct the electronic equivalent of a strip search. There will be some measures to protect peoples' privacy, and travellers can also opt for a full-body pat-down.

A Canadian Press-Harris Decima poll found that about 80 per cent of respondents surveyed about two weeks ago thought use of the scanners was reasonable.

With a report from CTV Toronto's Andria Case and files from The Canadian Press