Posted by Heidi Schwartz
Researchers in the United States are calling for a change to the U.S. building codes, following a study showing that the mandatory flame retardants routinely added to foam insulation* are not only harmful to human health and the environment, but also make no difference to the prevention of fire in buildings where a fire-safe thermal barrier already exists. Such a change would bring the codes in line with regulations in Sweden and Norway.
The research team, which is drawn from the University of California and Lawrence Berkeley National Laboratory, conducted a thorough review of fire safety literature since the mid-1970s and concluded that the addition of halogenated organic compounds to plastic insulation materials such as polystyrene, polyisocyanurate and polyurethane is costly, ineffective, and environmentally damaging. Their conclusions were published in late 2012 in the the journal, Building Research and Information, an international peer-reviewed journal.
Led by internationally renowned fire expert Dr Vytenis Babrauskas of Fire Science & Technology Inc., the research team investigated the impact of the “Steiner Tunnel test,” which is used to test the propagation of fire over the surface of all sorts of building materials in the early stages of fire (before flashover point is reached). Their paper suggested that changing building codes to exempt foam plastic insulation materials from the test would avoid the use of thousands of tons of flame retardants that are known or suspected to be persistent organic pollutants. They concluded:
“Such a change would…decrease the cost of foam plastic insulation and encourage the use of insulation materials for increasing building energy efficiency and mitigating climate change. The potential for health and ecological harm from the use of flame retardant chemicals would be reduced and the fire safety of buildings would be maintained.”
The research acknowledges that foam plastics used for insulation have required a thermal barrier (usually 12.7 mm (1/2 inch) thick gypsum wallboard) since 1976. In addition, chemicals such as hexabromocyclododecane (HBCD) and Tris (1-chloro-2-propyl) phosphate (TCPP) are routinely added in order to meet the requirements of the Steiner Tunnel test.
The building codes have never stipulated that chemicals be added to foam plastic insulation, however doing so is the most common way to meet the Steiner test. These additives are semi-volatile organic compounds (SVOCs) which do not bind to the insulation material and are known to be released into the environment throughout the life cycle of insulation. The chemicals can persist and accumulate and have been implicated in thyroid hormone disruption and nervous system development problems and are potentially carcinogenic. The experts suggest that exempting foam plastic insulation materials from the Steiner Tunnel test would mean there was no longer a need to add these flame retardants.
Research in the article illustrates that such an action would not be without precedent. Flame retardants were once routinely added to children’s pajamas, but their use was discontinued after a range of adverse environmental and health impacts were identified. Dr Babrauskas and his team concluded that, in the light of their evidence, an equivalent volte-face should be implemented in building codes as soon as possible. They also recommend a root and branch review of the process of designing fire standards and building codes, in particular to ensure that fire scientists, building code officials, and other regulators consider the efficacy, life cycle, health, and ecological impacts of building materials.
*Not all insulation used in buildings is foam insulation. The study only focuses on foam insulation and not other types.