Pull ionisation smoke alarms off shelf, Consumer NZ says

Ionisation-type smoke alarms performed so "poorly" in tests watchdog Consumer NZ is calling for them to be pulled from shelves.

While all smoke alarms would respond to a fire eventually, the difference was in responding to visible smoke, Consumer NZ head of testing Dr Paul Smith said.

"A smouldering fire can fill a home with deadly smoke long before it bursts into flames."

Ionisation alarms gave much less warning of smouldering fires than photoelectric alarms, the consumer watchdog's tests found.

You can identify an ionisation-type smoke alarm because it will have a radioactive symbol somewhere on the alarm body – it may be underneath, so you might need to remove it to check, Consumer NZ says.

Smouldering flames include those caused by faulty electrical wiring, curtains draped over a heater, or a hot ember igniting upholstery foam, making it less likely for people to be able to get out of their homes safely.

The tests showed ionisation models were great at detecting flames, but not so good with visible smoke.

"The four ionisation alarms in our test were faster at detecting flaming fires (burning oil and wood) but much slower at detecting smoke from smouldering foam.”

Paul said people should purchase photoelectric alarms instead.

These were also recommended by the New Zealand Fire Service, and the Residential Tenancies Act required all new alarms landlords installed to be photoelectric with a long-life battery.

"We think ionisation alarms should not be sold and are working with retailers to remove them from their shelves,” Paul said.