As with any detector they are suited to particular risks. One thing to be aware of is that these detectors operate at 40-60ppm and only if it is smouldering combustion. instances have been recorded where only these detectors have been used, and there has been a chip pan fire and they have not gone off (for obvious reasons), installed selectivey and carefully they are ideal for sleeping accomodation and can provide a very fast response to a smouldering fire (e.g smoker falls asleep in bed) compared to a standard optical. They also benefit from being immune to steam, dust and cooking fumes, golden rule is not to put all your eggs in one basket and opt for a fire engineered approach. Careful and selective design of these detectors is required for optium performance.
Regards
Gary.