Newer FM200 (HCL227) products that have largely replaced Halon in computer room systems I’ve seen are probably safer, but have side effects like carbon monoxide, so you still want to skedaddle when the fire bell goes off.

Dry chem you mostly vacuum up the excess (though it makes a mess on the hot parts. Heck, you should see what foam does.) Water wrecks stuff.

That said, I recall an IBM type telling me once he’d rather pay to repair a computer room’s machines after a fire dowsed with water (power off) than with even Halon. Lack of residue.

We used to get the same thing with car engine fires – you’d blast CO2 through the radiator grille and kill the flames, walk away, and then hear a “woomp” as the hot engine reignited! In the end, we took the example of the USAF, and used CO2 to knock down, backing it up with a foam unit to cool the surroundings and emulsify the oil.

Obviously in a household location, where bulk solids, electricals and minor liquid hazards are likely to be the main fire load, CO2′ s less that ideal; hence you (and me) choosing dry chem as a good multipurpose household extinguisher. It’s a really interesting advert though, and a window in to the beginnings of the modern home safety/security market.

That said, I have 2 x 3lb dry chem units in and near my kitchen/bbq.

Top marks for the advertiser though: “The new wonder-extinguisher: how ofter have you sat there with your shoes alight and thought “oh heck, I’ll ruin the carpet if I put myself out”? Well fear no more, anxious householder – the latest in shoe safety gear is here…..”

CO2 extinguishers are good on Class B fires (flammable and combustible liquids, plastics and other hydrocarbon based materials) but are most often used on Class C fires – fires in energized electrical equipment.

While we’re on the subject … is your smoke alarm working? Save a life, maybe your own and test yours today!