Polyurethane foam (PU foam) is a polymer used widely in modern homes for cushioning in furniture, mattresses, and carpet padding. Its durability, light weight, and low production cost have made it the standard material for comfort products. Consumers are concerned about whether the chemicals within PU foam pose a health risk. The answer depends on two factors: the temporary release of unreacted manufacturing chemicals and the long-term presence of chemical additives. This article examines the foam’s composition, volatile emissions, and persistent concerns regarding fire retardants.
Understanding Polyurethane Foam Composition
Polyurethane foam is a synthetic polymer created by reacting two primary liquid components: polyols and diisocyanates. Common diisocyanates used in flexible foam include Toluene Diisocyanate (TDI) and Methylene Diphenyl Diisocyanate (MDI). Mixing these components with water and other agents causes a foaming reaction, resulting in the solidified, cellular structure of the finished foam.
The manufacturing goal is a complete reaction, yielding a stable and chemically inert polymer. Once the foam is fully “cured” (typically 24 to 72 hours), the core material is stable. Toxicity concerns arise not from the finished polymer, but from trace amounts of unreacted starting materials and chemical additives.
Short-Term Exposure Risks: Volatile Organic Compound Off-Gassing
The most immediate health concern from new polyurethane foam is the temporary release of volatile organic compounds (VOCs). Off-gassing occurs when residual, unreacted manufacturing chemicals evaporate into the air, causing the distinct “new furniture” smell. These VOCs may include trace amounts of unreacted isocyanates, which are respiratory irritants.
Short-term exposure can cause acute symptoms such as eye and throat irritation, headaches, or dizziness. The health risk from these chemicals is generally low, and VOC concentrations decrease rapidly over the first few days or weeks. Proper ventilation of a new item, such as airing out a new mattress, is sufficient to mitigate this initial short-term exposure.
Long-Term Health Concerns: Persistent Fire Retardants
A more substantial, long-term health concern involves persistent fire retardants added to the foam. For decades, these chemicals were mixed directly into polyurethane foam to meet flammability standards, such as older versions of California Technical Bulletin 117. Since these retardants are additives and not chemically bound to the foam structure, they slowly leach out over the product’s lifespan.
The most notorious additives are organohalogen flame retardants, particularly Polybrominated Diphenyl Ethers (PBDEs). Although PBDEs are largely phased out, furniture made before the mid-2000s may still contain them. As older foam ages and degrades, these substances release into the indoor environment and accumulate in household dust. Exposure occurs primarily through inhaling or ingesting this contaminated dust, especially for children.
These persistent chemicals do not easily break down and have been linked to endocrine disruption and potential developmental toxicity. Newer replacement flame retardants, such as chlorinated Tris (TDCIPP) and organophosphate flame retardants (OPFRs), have replaced PBDEs. However, some substitutes also show evidence of adverse effects, including reproductive and developmental issues. This chronic exposure from dust shedding poses a greater long-term risk than transient VOC off-gassing.
Navigating Safety Standards and Safer Alternatives
Consumer safety standards have changed significantly to address the risks posed by persistent fire retardants. The revised California Technical Bulletin 117-2013 standard is now the de facto national standard. It focuses on the smolder resistance of the cover fabric and barrier materials, rather than the foam itself. This shift allows manufacturers to meet flammability requirements without adding chemical flame retardants directly into the foam.
This regulatory change has decreased the use of concerning flame retardants in new furniture, though they are not explicitly prohibited. Consumers should look for products labeled as meeting the TB 117-2013 standard, indicating compliance with modern smolder-resistance requirements. Safer alternatives to polyurethane foam are available for furniture and bedding. These options include natural latex foam, derived from rubber trees, and natural materials like wool, cotton batting, and coconut coir.