Modern materials make fires more lethal

Materials used in modern housing, such as plastics and foams, have cut the time it takes for a home blaze to become deadly, the fire service says.

The average time between the start of a fire and when it becomes unsurvivable is now three to five minutes, compared with 12 minutes in the mid-1950s, the service said in its annual statement of intent, released yesterday.

At the same time, the temperature of house fires had increased.

It stressed there should now be more emphasis on fire prevention, as "response is no longer as effective in reducing the consequences of fire for people and, to a lesser extent, property".

The use of highly flammable products and materials inside homes have contributed to the problem, principal adviser for fire risk management Alan Merry said.

"The main difference is all the construction materials, plastics, polystyrene foams and materials that give off toxic fumes in the home - there is more of that now, than the 1950s, say. So fires now are growing more rapidly and quickly - less time for us to get in."

Temperatures recorded at ceiling level had increased from 750C in the mid-1950s to up to 1100C in the mid-1990s. The report also showed that home insulation - which had increased over the years - was a key factor in the rapid growth of a fire, as the insulation would act as an oven, keeping the heat sealed in.

But the problem was more to do with the way the insulation was installed, not the material itself, Pink Batts general manager Tony Te Au said.

"There have been some cases in Australia where fires have started because the insulation has been installed over down lights - flushed into the ceiling - whereas it should've been cut around the lights to prevent that from happening."

Mr Te Au said about 150mm of the insulation had to be cut around the downlight, for it to be safe.

He said Pink Batts were made out of recycled spun glass - rather than highly flammable polyester - meaning the timber of a house would most likely burn before the insulation would.

"I don't know how high the heat would get, but it would have to be really high, for the glass melting."

Mr Te Au said other factors and items in a house - including frayed wiring, flammable sprays, polystyrene and even the design of a house - were also things to consider.

Mr Merry said because fires were becoming more deadly, more educational programmes at schools and within the community had been set up by the fire service.

- NZPA