Wellington, June 2 NZPA - Materials in modern homes mean house fires kill up to four times faster than in the 1950s, the Fire Service says.

Its yearly statement of intent shows that in the mid-1990s fires became unsurvivable generally at three minutes, compared to 12 minutes in the mid-1950s.

Temperatures recorded at ceiling level had increased from 750degC in the mid-50s to up to 1100degC in the mid-90s.

The changes were due to increased use of plastics and other polycarbonate materials in furniture and fittings, which produced high volumes of toxic gases such as hydrogen cyanide, hydrogen chloride and carbon monoxide.

Increased insulation also unintentionally contributed to the problem as it kept heat in, similar to an oven.

"Accordingly, response is no longer as effective in reducing the consequences of fire for people and, to a lesser extent, property," the statement said.

"The change in the speed of fire growth highlights the need for an increasing focus on fire safety education."

The Fire Service responded to 74,057 emergency call-outs during 2007/08, of which 25,008 were fires, 27,272 were false alarms and 21,777 were non-fire emergencies such as vehicle crashes and hazardous events.