Parents driving their kids to Canada Day events on Tuesday will have to make sure they are properly secured in the car under a new law that requires children up to the age of nine to use a booster seat.

And if parents don't follow the new rules, they'll face a $109 fine.

"It's fabulous if it helps save lives and helps prevent injuries," said Mariane Salvail, whose five-year-old son Sam will sit in a booster seat on Tuesday.

Previously, children in B.C. could outgrow infant car seats at 40 pounds and move to regular seat belts.

But now, those children must sit in a booster seat until they are either nine years old or four feet, nine inches tall, no matter how much they might weigh.

Infants must be rear-facing until at least 12 months old, and a weight of 20 pounds.

After that, a child seat must be used until the child weighs 40 pounds.

Ultimately the driver is responsible, whether or not they are related to the child.

One of the new rules is that an exemption for rental cars has been removed.

CTV News tested several rental cars from a variety of rental car companies to see if they were ready for the change -- or if the rental seats you were renting could expose you to the fine.

It turned out that all were technically safe to use, whether or not you might want to.

We found one booster seat whose plastic edge had been mangled, and it was missing a shoulder adjustment strap.

"If this was a garage sale I probably wouldn't buy it," said Marg Diebert of the BCAA Traffic Safety Foundation as she inspected the seats.

It wasn't clear where many of the seats had been, she said, and one seat had nearly reached its ten-year expiry date on the back.

It's hard to tell if the seats have been in an accident, she said.

"If you don't know what the history of the seat is, don't buy it, don't use it," said the BCAA's David Dunne.

With a report from CTV British Columbia's Sarah Galashan

Tomorrow, we compare the new seat laws to those across the country.