Igniting the Debate on Flame Retardants

Bill Walsh:
How did you get started working on flame retardants?

Arlene Blum:
Thirty years ago, as a researcher at the University of California, Berkeley, I published a paper in Science magazine showing that “Tris” flame retardants in children’s sleepwear caused mutations, were possible cancer hazards, and migrated from pajamas into children. The flame retardants were removed from children’s sleepwear in 1977, but chlorinated tris is now back in use in foam in furniture and other products.

BW:
Why are you so concerned about flame retardants in building materials?

AB:
If a building contains halogenated flame retardants in the insulation, they can filter into the building throughout its life and also form toxic dioxins if the building burns.

I know it’s a real dilemma for people when they learn that plastic insulation materials, such as polystyrene, polyisocyanurate, and polyurethane, that can help reduce climate change, often contain flame retardants which can cause serious health and environmental harm. But the good news is that this is a problem that can be solved.

Once green building professionals understand the issue, they can move to safer substitutes and strategies that don’t have potential adverse health impacts. In fact of the various groups with which I’ve worked on reducing toxics in products, the green building community has been the most responsive. So I am very happy to have the opportunity to share the message about moving away from the use of halogenated flame retardants at Greenbuild.

The new LEED Pilot Credit on Chemical Avoidance for not using phthalates and halogenated flame retardants inside buildings should accelerate our progress towards healthier buildings.

BW:
You mentioned that this is also a chemical contamination problem that could have negative impacts on our health and well-being at a global level? How?

AB:
Many halogenated flame retardant chemicals are persistent and bioaccumulate especially in humans and animals high on the food chain. It is almost impossible to clean them up once they are out in the world. For example, PCBs, chlorinated chemicals that were also used as flame retardants, were banned in 1977, but very high concentrations can still be found in wildlife and some human populations today. Studies show that human breast milk contains flame retardants, and toddlers have three to four times higher body levels than their mothers.

When tested in animals, many halogenated flame retardants have been found to cause health problems like cancer, reduced fertility and IQ, thyroid disorders, and developmental impairment. Many halogenated flame retardants are also endocrine disrupting chemicals that can harm us at very low concentrations.

BW:
How do you weigh the known benefits today against long term unproven risks?

AB:
In furniture there is no proven benefit. It makes more sense to reduce the sources of ignition with fire-safe cigarettes and candles than to put potentially toxic chemicals in all the possibly flammable materials in our homes. Today the risk of home fires is diminishing due to a 50% decrease in cigarette consumption since 1980, enforcement of improved building, fire, and electrical codes, increased use of sprinklers and smoke detectors. These strategies provide measurable improvements in fire safety without toxicity.

Smoke and toxic gases kill people in fires, more than flames. Research on furniture fires show that while halogenated flame retardants can reduce the time for ignition by seconds, they greatly increase the carbon monoxide, smoke, and soot. The chemicals also release dioxin and related compounds when burned at relatively low temperatures. So the benefits of retarding the fire with toxic chemicals is greatly reduced by the increased fire toxicity and dioxins at the fire scene.

Given the lack of proven benefit in some cases, the risk-benefit calculation on chemical flame retardants can be tenuous even before you start to consider the widespread exposure to these chemicals on a daily basis.

Better methods of reducing fire risks include careful material selection and alternative fire suppression strategies that can be designed into products and buildings.

BW:
How can people take this knowledge and translate it into action?

AB:
When people know about the hazards of the flame retardants that are commonly used in many plastic foam insulations, furnishings and other building materials, they can choose alternative products or push for less toxic flame retardants. When green building professionals make these choices, this will increase the availability and decrease the cost of the alternatives.