Smoke and carbon monoxide (CO) detectors save lives from domestic fires and CO poisoning. They are crucial appliances in millions of houses and palladium plays a key role in each.

In CO detectors, a mixture including palladium isotopes is reduced to palladium metal by the presence of CO and changes colour, warning of the poisonous gas's presence.

As a smoke detector may be used after long periods of inaction, its components must be durable and reliable which is why palladium - with its corrosion resistance, durability and conductivity - is used.