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Fire Performance

Polyiso Maintains its High Level of Inherent Fire Resistance 

All construction materials, including foam plastics materials such as polyiso insulation, must provide a suitable margin of fire safety. Polyiso possesses a high level of inherent fire resistance when compared to other foam plastic insulations due to its unique structure of strong isocyanurate chemical bonds. These bonds result in improved high temperature resistance (up to 390oF, more than twice the temperature resistance of other building insulation foams) which in turn leads to enhanced fire resistance. In addition, because polyiso does not melt or drip when exposed to flame but rather forms a protective surface char, its fire resistance is further enhanced, especially in terms of flame spread and flashover potential.

Polyiso passes both the ANSI UL 1256 and FM 4450 fire tests without a thermal barrier. Polyiso, a thermoset material, stays intact during fire exposure in the ASTM E84 or "Tunnel Test.” It forms a protective char layer and remains in place during the test, thereby meeting all building code requirements and contributing to a fire-safe building. For more information on Polyiso’s performance in fire tests, consult the Technical Bulletins and Products Stewardship sections where you can find the following papers:

Technical Bulletin 103:"Fire Performance in Walls and Ceilings"
Technical bulletin 103 discusses polyiso insulation as it relates to building codes in construction and fire tests in walls and ceilings including ASTM E84 and ASTM E119. 

Technical Bulletin 104:"Fire Performance in Roof Systems"

Technical bulletin 104 provides an overview of polyiso insulation requirements for roof systems and key issues in fire performance, including the importance of the FM 4450 Calorimeter Tests and the UL 1256 resistance to interior spread of flame test. 

Technical Bulletin 105: "Fire Test Definitions"
Technical bulletin 105 provides an in-depth look at fire test procedures to building applications. Specifically, the bulletin reviews the following tests:

  • ASTM E84 Standard Test Method for Surface Burning Characteristics of Building Materials

  • ASTM E119 Standard Test Method for Fire Tests of Building Construction and Materials

  • Factory Mutual Roof Tests · Underwriters Laboratories, Inc.

  • Roof Tests FM Calorimeter Test

  • ANSI/UL 1256/Resistance to Interior Fire Spread Test

  • The White House Test FM 4880 25" High Full Scale Corner Test

Technical Bulletin 111: "Class A and Class 1 Roof Assemblies Are Not the Same"
Technical bulletin 111 explains why Class 1 and Class A are not the same. B&W version. 

Technical Bulletin 111C: "Roofing Regulations in Canada: Class A and Class 1 Roof Assemblies Are Not the Same"
Explains why Class 1 and Class A are not the same. B&W version.  

Technical Bulletin 405: Fire Resistance Properties of Polyiso Foam Plastic Insulation Used in Wall Assemblies - Facts and Comparisons"
Technical Bulletin 405 looks at the minimum fire resistance properties required for foam plastic insulation and compares data on polyiso with other recognized combustible materials.

Product Stewardship Paper 100: "Polyiso Insulation and Flame Retardants"
New Product Stewardship report on polyiso and flame retardants.


Flame Retardants - TCPP:

Because of the high level of fire resistance inherent in its isocyanurate structure, polyiso offers flexibility in the selection and amount of additional fire retardants needed to meet the demands of modern fire codes. As a result, the polyiso industry was able to evaluate a variety of suitable plastic flame retardants and choose a product that optimizes both fire and non-fire aspects of product performance.

After a thorough review of authoritative global research covering fire safety, health and environmental effects, TCPP was selected by the polyiso industry to provide the additional level of fire resistance required by building codes.

Not a Chemical of Concern.
TCPP, or Tris (2-chloro-1-methlyethyl) phosphate, is unique among commonly available foam plastic flame retardants1 in that it is not classified as a chemical of concern by any authoritative global, national or state authority, including the European Chemicals Agency (ECHA), the U.S. Environmental Protection Agency (EPA), and prominent state authorities such as the California Office of Health Hazard Assessment (OEHHA) and the Massachusetts Toxics Use Reduction Administrative Council (TURA). Based on the best available scientific studies, including a comprehensive risk assessment completed by ECHA in 2008, TCCP is not considered to be toxic or bioaccumulative, and its environmental persistence is lower than other common foam plastic flame retardants.

No Environmental Risks.
The 2008 ECHA risk assessment2, conducted as part of the world-leading REACH program for the registration, evaluation, authorization and restriction of chemical substances, provides exhaustive documentation regarding the environmental performance of TCPP. In regard to environmental risks associated with TCPP, the study found:

· "No identified risks to the freshwater aquatic and sediment compartments or sewage micro-organisms from local sources associated with any life cycle stage;

· No identified risks to the soil compartment from local sources associated with any life cycle stage;

· No identified risks of biotic or abiotic effects on the atmosphere;

· No identified risks of secondary poisoning of predators (including marine predators) from local sources associated with ant life cycle stage;

· No identified risks to the marine aquatic and sediment compartments from local sources associated with any life cycle stage.” (ECHA 2008 Summary Risk Assessment, page 7.)

No Consumer Health Risks.
In addition to an environmental assessment for TCPP, the ECHA risk assessment also addressed human health risks for TCPP used in a variety of foam plastic consumer applications. In all cases, the ECHA study concluded that there was "no concern” in regard to consumer health risks, based on measured margins of safety (MOS) ranging from a low of 667 to a high of 395,000 times anticipated exposure levels. In the case of foam plastic used in building insulations, the ECHA study concluded that indoor insulation risks were assumed to be so negligible that they were not included in the final risk characterization phase of the study.

Beyond the 2008 ECHA risk assessment, we believe a recent meta-study conducted by Battelle Memorial Institute3 provides additional support to the inherent safety of TCPP. After reviewing thirty of the most relevant laboratory and field studies involving TCPP gathered by Battelle, we arrived at conclusions similar to the ECHA risk assessment. In regard to exposure levels and margins of safety, Battelle stated in general, "estimated indoor exposures to TCPP … are lower than applicable reference doses (RfDs), threshold daily intake (TDI), or to other applicable health-risk based values.” And in regard to the potential for latent TCPP or other flame retardants within buildings, the documents that were part of the review revealed that any indoor concentration of TCPP or any other organo-phosphate flame retardant is "not present as a result of building material emissions (e.g., wall insulation) but rather due to releases from furnishings and consumer products.”

No Need for Further Testing / Risk Reduction at Present.
Based on these detailed findings, the overall conclusion of the 2008 ECHA risk assessment stated:
"There is at present no need for further information and/or testing (for TCPP) and no need for risk reduction measures beyond those which are being applied already.”

1.   Including HBCD, TCEP and TDCPP which are currently used as flame retardants in a variety of foam plastic applications.

2.   Tris (2-Chloro-1-Methlyethyl) Phosphate (TCPP) Full and Summary Risk Assessment Reports. European Chemicals Agency (ECHA), 2008.

3.   Potential Exposure to Flame Retardants such as TCPP Emitted from Polyurethane and Polyisocyanurate Foam Insulation: Literature Evaluation Results. Battelle Memorial Institute, 2013.

Battelle Memorial Institute (Battelle) does not endorse or recommend particular companies, products, services, technologies, nor does it endorse or recommend financial investments and/or the purchase or sale of securities.



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