Dive Brief:

• Maine's state fire marshal worries, he says, because newer, lighter building materials have changed the dynamics for firefighters arriving at a fire.
• Joseph Thomas says that firefighters used to be able to follow a "20-minute rule" that said they had about that much time after arriving at a blaze to see white smoke replacing black smoke, meaning the fire was coming under control, or they were ordered out of the building for their safety.
• Now, Thomas said, engineered lumber and other materials provide strength with less bulk, but they also burn faster. Firefighters may now be facing very dangerous conditions as soon as they arrive, giving them no time to attack the fire inside a structure.

Dive Insight:

The fire marshal said National Institute of Standards and Technology tests found some lightweight construction materials "failed completely in eight minutes" in a fire. Firefighters may enter a building and suddenly find themselves in the basement, he said in an address to firefighters in Houlton, Maine.