Flame Retardants in Insulation
What problematic flame retardants are used?
See the table below to learn more about the most common three flame retardants used in foam plastic building insulation.
| Flame Retardant Name and CAS # | HBCDD Hexabromo-cyclododecane CAS RN: 25637-99-4 |
TCPP Tris (1-chloro-2-propyl) phosphate CAS RN: 13674-84-5 |
Poly FR Brominated styrene butadiene copolymer Also known as BLUEEDGE, Emerald Innovation 3000, GreenCrest, and FR-122P |
| Use in Insulation | Older expanded and extruded (EPS and XPS) foam board insulation | Polyurethane and polyisocyanurate insulation (foam spray and boards) | Expanded and extruded (EPS and XPS) foam board insulation |
| Chemical Class | Brominated flame retardant | Chlorinated organophosphate flame retardant | Brominated flame retardant |
| Health & Environmental Concerns | Persistence and long-range transport Bioaccumulation Neurodevelopmental toxicity Aquatic toxicity |
Persistence Accumulation in liver and kidneys Potential carcinogen, endocrine disruptor, reproductive toxin, and neurotoxin |
Persistence Degrades into smaller, likely toxic compounds Poorly studied |
| Legal Restrictions | Banned or phased out in Japan, the European Union, and Canada Recommended for global elimination by the Stockholm Convention |
European Union: Regulated under Toy Safety Directive Under study at U.S. Environmental Protection Agency and National Toxicology Program Listed on the California Safer Consumer Products Candidate List |
None |
Do they provide a fire safety benefit?
Our peer-reviewed paper, Flame retardants in building insulation: a case for re-evaluating building codes, concluded that flame retardants in building insulation do not provide a fire safety benefit for many applications.
What We Found
- Since 1961, building codes have required foam plastic insulation materials to meet flame spread requirements as measured by the Steiner Tunnel test.
- The Steiner Tunnel test does not accurately measure the flame spread of foam plastics.
- Flame retardants are added to foam plastic materials to pass the Steiner Tunnel test, but they do not provide fire safety benefits in many building applications.
- Fire safety for foam plastics is provided instead by code provisions requiring firestopping and thermal barriers.