Reason Foam Fails #1: Dangerous Toxic Ingredients

Reason Foam Fails #1: Dangerous Toxic Ingredients

Dangerous Toxic Ingredients

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The chemical companies selling polyurethane foam as green and sustainable, demonstrate chutzpah second only to that of the tobacco and coal industries. Admittedly, if you believe in “clean coal”, foam might be what you’re looking for. But if you didn’t believe the tobacco scientists and executives when they said that cigarettes weren’t addictive, and you think the proposition of clean coal is a sick joke, then maybe it is time to take a closer look at foam.

Like cigarettes, foam fails at the most basic level of sustainability: its ingredients. And as with coal, the effect of its processing and use is significant and detrimental to our environmental well being. The EPA, CDC and other government agencies are taking action to study foam building insulation products, their ingredients and their effects on workers, building occupants and the environment generally. There are innumerable variations between polyurethane (PUR) open cell, closed cell, expanded polystyrene (EPS), extruded polystyrene (XPS) and spray polyurethane foam (SPF), as well as polyisocyanurate (Polyiso/PIR), ingredients and processes – yet there are some general commonalities, and the news is not good. Typically the ingredients include isocynate and polyol, with a dash of blowing agent and additives. The polyol which combines with the isocynate to form polyurethane, is generally a relatively benign alcohol compound and is used primarily as greenwash PR as it can be made with soy and other natural materials. Unfortunately this bit of soy based green(wash) is obliterated in a toxic stew.

blog MDI

The isocyanate is typically formed from methylene diphenyl diisocyanate or MDI. The manufacture of MDI is always done in the factory and involves such ingredients as benzene, chlorine compounds, and formaldehyde which lead to emissions of dioxins and furans; bioaccumulative toxicants, carcinogens and endocrine disruptors. The resulting MDI may be handled on the jobsite in making SPF. (Polyiso has a much higher proportion of MDI to polyol than other polyurethane foams.) MDI is a known allergen and sensitizing toxicant. From the EPA:

Diisocyanates are well known dermal and inhalation sensitizers in the workplace and have been documented to cause asthma, lung damage, and in severe cases, fatal reactions."

Once you have been “sensitized” from exposure to MDI, even the tiniest subsequent exposure can have severe health effects.The catalyst for the reaction/curing is often an amine compound or lead naphthenate. Amine is derived from ammonia (and can produce the fishy off-gassing smell many encounter, for more on this see, Reasons Foam Fails #7 Unhealthy Off-Gassing & Dust.)

From the Alliance for the Polyurethanes Industry:

“Many amine-based compounds can induce histamine liberation, which, in turn, can trigger allergic and other physiological effects, including bronchoconstriction or bronchial asthma and rhinitis.

Systemic symptoms include headache, nausea, faintness, anxiety, a decrease in blood pressure, tachycardia (rapid heartbeat), itching, erythema (reddening of the skin), urticaria (hives), and facial edema (swelling). Systemic effects (those affecting the body) that are related to the pharmacological action of amines are usually transient. Typically, there are four routes of possible or potential exposure: inhalation, skin contact, eye contact, and ingestion.”

Lead naphthenate may have effects on the central nervous system and kidneys and it is advised that avoid exposure to pregnant women. The National Institute for Occupational Safety and Health (NIOSH), a division of the CDC, states: “It is strongly advised that this substance does not enter the environment." The hydrocarbon blowing agent HFC-245fa is now commonly used and is a potent greenhouse gas (more on this in post #11, Irredeemable global warming potential). EPS foam boards use pentane as a blowing agent. Pentane doesn’t have high global warming potential but is a relatively poor blowing agent due to relatively high boiling point.

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Primary flame retardants include HBCD and TCPP: Hexabromocyclododecane (HBCD), made of halogenated organic compounds with chlorine or bromine bonded to carbon, and Tris(1-chloro-2-propyl) phosphate (TCPP), are both persistent bioaccumulative toxins which can be found worldwide in humans, wildlife, and the environment. A recent scientific study notes:

“The chemicals are released during the product life cycle and move into the environment, humans and animals. Such halogenated flame retardants act by releasing active halogen atoms (called free radicals) which can quench the chemical reactions occurring in the flame. HBCD and TCPP are used additively, which means they are not chemically bonded to foam and have the potential to migrate out. They can enter the environment as releases during chemical and product manufacturing, as well as leaching from products during use and disposal.”

The same study comes to the astonishing conclusion that flame retardants, while poisoning our planet and our bodies, have been shown to be ineffective.

“Studies demonstrate that the Steiner Tunnel [ASTM E84] test does not give reliable fire safety results for foam plastic insulations. Foams that meet the Steiner Tunnel test still pose a fire hazard if used without a code-mandated thermal barrier. Insulations protected by a thermal barrier are fire safe and the use of flame retardants does not provide any additional benefit.”

So in this last case we’re effectively poisoning ourselves for the illusion of fire protection. It’s not like we don’t have a choice. We can do better than foam - much better. Kick the foam habit.


EPA Takes Action on Spray-Foam Health Risks, by Peter Yost, EBN, 2011 (

Health and Safety Produt Stewardship Workbook for High-Pressure Application of Spray Polyurethane Foam (SPF), American Chemistry Council, Center for the Polyurethanes Industry, 2010 (

Help Wanted: Spray Polyurethane Foam Insulation Research, by David A. Marlow, NOISH/CDC, 2012 (

Identification and Analysis of Product/Chemicals Exchange Information within thte Building Product Sector, by Catherine A. Wilt et al., The Center for Clean Products, 2011 (

Isocyanates, NOISH/CDC. (

Flame retardants in building insulation: a case for re-evaluating building codes, by Vytenis Babrauskas et al., Routledge, 2012 (

Letter to EPA from Mr. Miller and Mr. Bloom, by Bernard Bloom and Robert Miller, 2012 (

Polyisocyanurate, Widipedia (

Polyurethane Amine Catalysts: Guidelines for Safe Handling and Disposal, Alliance for the Polyurethanes Industry, 2000 (

Sprayed Polyurethane Foams: An Explosive Issue, by Jim Vallette, Pharos, 2010 (

The Flame Retardant Dilemma: Should Green Buildings Contain Halogenated Flame Retardants?, Green Science Policy Institute, 2010 (

Ten Reasons “Clean Coal Is Offensive, by Kevin Grandia, Climate Progress, 2012 (

Tobacco Chiefs Say Cigarettes Aren’t Addictive, by Philip J. Hilts, The New York Times, 1994 (

Understanding Spray Foam – Spray Foam Problems, Law Offices of Wolf & Pravato (

Urethane Foams Move From HCFCS To “Cleaner” Blowing Agents, Plastics Technology, 2003 (