Alarm bells ring over old smoke detectors

OLDER types of household fire alarms are taking twice as long to go off than newer models, a study has found.

Tests done by Which?, the consumer watchdog, have revealed that older-style “ionisation” fire alarms can take nearly 10 minutes to sound after a fire starts. This is about four minutes longer than newer “optical” alarms, which take just over five minutes to go off.

Despite slow reaction times and, in one case, failure to go off at all, every alarm tested had received British Standards Institution approval, although it does not set a maximum acceptable time for alarm reactions.

Neil Wallington, a former chief fire officer for Devon, said: “A delay of nearly 10 minutes is completely unacceptable”, and described it as “potentially the difference between life and death”.

He added: “Fire is very unforgiving and smoke is the real killer. When escaping a burning building, minutes are absolutely critical.”

Which? has called for a new, tougher standard that only rewards models that sound more quickly. The BSI is said to be shortly due to review its standards.

“People will be surprised to see such a big variation in response times from alarms currently classed as being safe,” said a Which? spokesman. “We want to see stricter testing criteria because every minute counts in a fire.”

The research comes as the contractor responsible for fire alarms at Grenfell Tower is being probed after claims it installed ineffective safety equipment in hundreds of London properties.