Health Canada is recalling a series of heat-activated fire alarms over concerns the fuse can degrade over time and fail to signal a fire.

The affected alarms were made by Sure Signal Products, Inc. and include:

- Masterguard QR50
- ThermaLINK QR50
- DeTech FST2004H

The alarms have a round fuse in the middle.

They were manufactured between January 2004 and last June.

Health Canada says approximately 4,500 units were sold in Canada, and approximately 375,000 were sold in America.

For more information on the recall visit Health Canada’s website.