ROCKFORD, Ill. (WTVO) — If your smoke detector has turned yellow or a yellowish brown, it’s not dirty – that’s by design and means it’s time to replace it.

The Federal Emergency Management Agency (FEMA) recommends replacing smoke detectors every ten years.

Smoke detector manufacturers inject a fire retardant, bromine, into the plastic, which discolors over time from oxidation.

According to Illinois law, home smoke alarms must be equipped with 10-year sealed batteries. That law went into effect in 2023.

According to Public Act 100-0200, which was passed in 2017, smoke alarms that were installed in homes prior to January 1st can remain in place until they are 10 years old.

Homes built after 1988 that already have hardwired alarms or wireless integrated alarms are exempt from the new law.

Working smoke detectors are required in almost all 50 states, and it is illegal not to have at least one.