How do floors containing vinyl behave in accidental fires? Are any potentially harmful gases released when floors containing vinyl burn?

Vinyl has excellent fire performance qualities. Vinyl building products are based on a naturally fire retardant polymer, and some flexible products like vinyl flooring and carpet backing contain non-combustible additives and fillers such as calcium carbonate that further improve the fire performance of the material.

Vinyl is one of the few materials meeting the stringent requirements of the National Electrical Code of the National Fire Protection Association for insulating electrical cords and wires and data transmission cables, even in
plenum applications. In addition, floors containing vinyl meet the requirements of relevant national building codes. Carpets are required to pass the Federal Flammability test DOC FF 1-70 which ensures they will not propagate the spread of flame in the early stages of a fire.

The vinyl industry and third-party organizations have conducted research on the combustion toxicity of vinyl products. The contribution of the combustion products from floors containing vinyl to the overall toxic threat of fires containing many types of combustibles is not significant. The Pittsburgh Protocol is a standard test method for evaluating the combustion toxicity of floorcovering products. In this test, vinyl-backed carpets are no more toxic when burning than red oak wood.9

Fire scientists recognize that the largest hazard in a fire is carbon monoxide (CO), an odorless asphyxiant gas produced in abundance by all organic materials, natural and synthetic.10 11 The mix of gases produced when vinyl products burn is very similar to those of other common materials, including wood and fabric.

Hydrogen chloride (HCl), an irritant gas having a pungent odor, is produced when vinyl burns and is detectable in very small quantities long before it reaches a dangerous concentration. An argument can be made that HCl can act as an early warning that there is a fire, and alert occupants to evacuate. HCl is unique in that its concentration in the air decreases rapidly when it reacts with humidity and most construction surfaces, like cement block, ceiling tile and gypsum board.12 13 14 15 16

The U.S. fire death rate is decreasing, dropping from a rate of 76 per million in the 1940s to 15 per million in the 1990s (by which time vinyl and other plastics had achieved significant market share in numerous applications). This downward trend can be attributed in large part to improved building codes, as well as the broader use of sprinkler systems and smoke detectors. However, the increased use of more fire-retardant materials – like vinyl – deserves part of the credit for this improvement.

9 Test for Combustion Product Toxicity, University of Pittsburgh Graduate School of Public Health, Oct. 30, 2002.

10 W.A. Burgess, R.D. Treitman and A. Gold, "Air Contaminants in Structural Firefighting," N.F.P.C.A. Project 7X008, Harvard School of Public Health, 1979.

11 A.F. Grand, H.L. Kaplan and G.H. Lee, "Investigation of Combustion Atmospheres in Real Fires," U.S.F.A. Project 80027, Southwest Research Institute, 1981.

12 J.J. Beitel, C.A. Bertelo, W.F. Carroll, R.A. Gardner, A.F. Grand, M.M. Hirschler and G.F. Smith, "Hydrogen chloride transport and decay in a large apparatus. I. Decomposition of poly(vinyl chloride) wire insulation in a plenum by current overload," J. Fire Sciences, 4, 1986.

13 C.A. Bertelo, W.F. Carroll, M.M. Hirschler and G.F. Smith, "Thermal decomposition of poly(vinyl chloride). Kinetics of generation and decay of hydrogen chloride in large and small systems and the effect of humidity," in "Fire Safety Science, Proceedings of the 1st International Symposium," C.E. Grant and P.J. Pagni, editors, Hemisphere, Washington, 1986.

14 J.J. Beitel, C.A. Bertelo, W.F. Carroll, R.A. Gardner, A.F. Grand, M.M. Hirschler and G.F. Smith, "Hydrogen chloride transport and decay in a large apparatus: II. Variables affecting hydrogen chloride decay," J. Fire Sciences, 5, 1987.

15 F.M. Galloway, M.M. Hirschler and G.F. Smith, "Model for the generation of hydrogen chloride from the combustion of poly(vinyl chloride) under conditions of forcefully minimized decay," Eur. Polymer J., 25, 1989.

16 F.M. Galloway, M.M. Hirschler and G.F. Smith, "Surface parameters from small scale experiments used for measuring HCl transport and decay in fire atmospheres," Fire and Materials, 15, 1992.