Investigation on the Use of Flame Retarded Foam Plastic Insulation Materials in Building Construction

摘要

The state of California enacted CA AB 127, which mandates the California State Fire Marshal to review the California flammability standards for building insulation materials so as to develop new standards (i.e. test methods) that do not require the use of added flame retardants but ensure that overall building safety is maintained. The State Fire Marshal convened a Working Group to make recommendations on the issue. The Working Group was composed of (a) parties interested in ensuring improved fire safety for California buildings based on time-tested consensus-based codes and flammability standards and (b) parties who want to eliminate the use of flame retardants in building insulation. This paper represents the opinions of Working Group members interested in ensuring improved fire safety. Many types of insulation are used in California residential buildings but the Working Group focused exclusively on the more common commercial foam plastic insulation materials. Such materials are required by code to comply with a material fire test and, additionally, are severely restricted in their permitted uses by further code requirements, such as the use of barriers and/or composite fire testing. Commercial grades of common foam plastic insulation materials contain added flame retardants to meet the material fire test, but no codes or standards require the use of flame retardants. In the US, federal (CPSC) fire safety regulations require that some other insulation materials, especially cellulosic insulation, meet some criteria that also require the use of flame retardants. However, these other types of insulation were not addressed by the report of the Working Group. The US code fire safety requirements for foam plastic insulation, in effect since the 1976 Uniform Building Code, came about as a result of tragic fire losses in the 1960s and an FTC consent decree demanding that the plastics industry produce insulation that is used in a safe way in case of fire. The FTC consent decree also required the plastics industry to educate customers, perform research and undertake other activities to minimize the potential impact of insulation in case of fire. Compliance with the FTC requirements has ensured an excellent fire safety record for these materials in the US (based on fire loss statistics) and that fire losses associated with code-compliant use of foam plastic insulation in the US are minimal. The Working Group spent much time discussing concerns regarding: (a) the health effects of the decomposition and/or combustion products of flame retardants especially on firefighters and (b) the effectiveness of the fire testing requirements in place today, primarily because of the use of ASTM E84 as the material fire test. This report demonstrates, via a series of 30 questions and answers, that both concerns are unfounded. Firefighters are exposed to more serious health effects from fires than the general population. However, abundant scientific data demonstrate that the added effect of flame retardants to this health hazard is virtually negligible and there is no evidence that the trace levels of flame retardants found (possibly due to improved measurement techniques) have an actual measurable effect on firefighter health. Foam plastic insulation materials must comply not only with requirements based on ASTM E84 but with added composite fire testing and severe limitations on their use (especially in terms of the habitable environment, as opposed to compartments, such as crawl spaces, which are not suitable to be occupied). The barrier and composite testing limitations are insufficient, on their own, to ensure the proper building fire safety, particularly in view of the fact that modern fires are hotter than those when thermal barrier tests were developed and because the thermal barriers used were always assessed with flame retarded foams. ASTM E84 is a fire test used for many building applications, since the 1950s. It has been shown that materials that exhibit poor flame spread index results in the ASTM E84 will inevitably have poor fire performance in real fires. The improvement in fire performance provided by flame retardants to foam plastic insulation materials has been demonstrated by multiple other fire tests as well, including critically heat release tests (heat release being the most important property in a fire). Thus, eliminating the added protection offered by using those foam plastic insulation materials which meet improved fire safety requirements would most likely lead to a severe decrease in fire safety.