Health Canada is warning parents about the dangers of button batteries and what could happen to children if the small, coin-shaped objects are swallowed.

Shelley Curlew, a compliance and enforcement specialist with the consumer product safety division of Health Canada, said it doesn't take long for a child to suffer the consequences of swallowing a button battery.

"In as few as a couple of hours, button batteries can cause serious internal burns and potential poisonings," she said.

"Because they are so attractive to children — they're shiny, they're small — children under the age of five are prone to put shiny things in their mouth."

Health Canada said every year, about 65 children are rushed to hospital after swallowing a button battery.

Button battery acid burn simulation

Health Canada simulated these burn injuries to show what could happen to a child's body about three hours after a button battery is swallowed. (Health Canada)

The batteries are found in toys, but that's not the main concern. Curlew said batteries in toys tend to be well secured, with many needing a screwdriver to access them. She said the bigger danger is in products such as musical greeting cards, flashing jewelry or remote controls where kids can easily get at the batteries inside.

"Parents need to be aware that button batteries are found in novelty items and things that wouldn't necessarily come to mind as a potential hazard to children," she said.

Once it's swallowed, Curlew warns the acid in the battery can burn through the stomach or the esophagus. If the button gets stuck in the body it could lead to serious injuries, she said.