News Analysis

Do Flame Retardants Work? Putting Foam Insulation to the Test

A deeper look at California’s decision to allow flame-retardant-free foam under concrete slabs

April 2, 2019

It will be a great day for health advocates, who’ve been fighting for years to eliminate toxic flame retardants from insulation: on January 1, 2020, California will begin allowing flame-retardant-free foam insulation below grade. And the recommendations that were ultimately accepted by the California Building Standards Commission came from an unlikely place: the fire marshal.

Yet the report that the fire marshal’s office commissioned and reviewed in order to make its recommendation was not necessarily clear cut. In fact, it showed that flame retardants do make a difference in how quickly fires start and spread, and it pointed out problems with allowing foam without flame retardants into the marketplace.