Carpets for US Transportation Markets: Flammability Testing Requirements

R. Carroll Turner
Technical Services Manager
The Carpet and Rug Institute
Dalton, Georgia

Carroll Turner has been with The Carpet and Rug Institute, the national trade association for carpet manufacturers, since 1989. He serves as staff and committee support in several areas including the CRI Indoor Air Quality Testing and Labeling programs, installation specifications, product safety, product stewardship, and environmental regulatory issues. He is past chairman of the American Association of Textile Chemists and Colorists (AATCC) committee RA 57 for textile floor coverings. He currently serves as secretary of American Society of Testing and Materials (ASTM) subcommittee D 13.21 on textile floor coverings. Prior to joining CRI, Mr. Turner was with Synthetic Industries and BASF Corporation (Fibers Division) in various technical and market development positions involving textile yarn and fiber processing in woven, knitted and tufted end-use areas. Mr. Turner is a graduate of North Carolina State University (B.S. Textile Technology) and received an MBA degree from Western Carolina University.

In the United States, carpets are subject to specific flammability standards including small scale ignition tests for carpet used in residences and in commercial buildings. The latter applications may also be subject to additional requirements of regulatory code to assure safety in high occupancy, commercial or institutional areas. Commonly, the flooring radiant panel test is referenced in code requirements for these specific regulated areas.

Carpets are used also in many transportation applications including automobiles, busses, rapid transit vehicles, aircraft and marine vessels. In these applications, carpet is not subject to the traditional carpet test methods, but subject to the rules and requirements of the U.S. Department of Transportation or other agencies, such as the U. S. Coast Guard.

Automobile, Truck and Bus Requirements

Standard No. 302, Flammability of Interior Materials, describes a small scale burn resistance test for materials used in the compartments of motor vehicles. This standard, published by the Office of Vehicle Safety Compliance of the National Highway Traffic Safety Administration, applies to floor coverings as well as other interior materials.

For this test, a specimen is mounted in a face-down horizontal position in a draft-free chamber and an open flame ignition source from a Bunsen burner applied to the open end of the mounted specimen for 15 seconds. The igniting flame is removed, the burn time and distance are measured, and a rate of burn calculated. The material must not burn nor transmit a flame front across its surface of more than 102 mm per minute.

Aircraft Interior Requirements

The flammability regulations for carpets in passenger aircraft and onboard ships are probably the most stringent for any interior textile application. The overall demands for these uses dictate the carpet should resist ignition, produce little smoke, and low concentrations of toxic gases. These are highly specialized markets: therefore a limited number of manufacturers participate.

The Federal Aviation Regulation (FAR) 14CFR25 (Airworthiness Standards: Transport Category Airplanes) describes a vertical flame test whereby a carpet sample is suspended vertically in a chamber. An open flame is applied to the lower edge of the specimen for 12 seconds. After removal of the flame, the after-flame time, burn length, and any flaming drippings are measured and recorded. The minimum requirements under FAR 25.853(b) for crew or passenger compartments are that the average flaming and glowing time not exceed 15 seconds, the average burn length not exceed 200mm, and that average flaming time of any droppings not exceed 5 seconds. It should be understood that to demonstrate compliance, the tests should be witnessed by the FAA or their representatives.

Wool and nylon face carpets dominate the market in the U.S.; however, on a world basis woven wool carpets dominate.

U.S. Marine Vessels

The U. S. Coast Guard enforces rules and regulations for approval of materials used onboard U.S. flag commercial vessels including many cruise ships and casinos. Ships going on international voyages must comply with the provisions of the Safety of Life at Sea (SOLAS) Treaty. The SOLAS treaty makes reference to the fire test methods of the International Maritime Organization (IMO). The IMO Fire Test Procedures (FTP) includes tests for flammability (vertical test), smoke density and fire gas toxicity. For domestic passenger ships not traveling into international waters, the Coast Guard allows compliance for “fire resistant” carpets with the IMO FTP requirements, or Title 46 of the Code of Federal Regulations. This latter rule, 46CFR72.05-55, requires compliance by meeting specific flammability (Flooring Radiant Panel) and smoke density criteria. An exception is made for 100% wool carpet whereby there is no fire test requirement.

Rapid Rail Transit

Requirements are usually based on specific project or application and may involve combustion toxicity test requirements in addition to flammability and smoke density criteria.

Carpet and Rug Institute

The Carpet and Rug Institute (CRI) is the national trade association representing the carpet and rug industry. Headquartered in Dalton, Georgia, the Institute's membership consists of manufacturers representing 94% of all carpet produced in the United States, and suppliers of raw materials and services to the industry. There is continued coordination with other segments of the industry, including manufacturers, distributors, retailers, and installers. Additional information about the industry as well as technical resources can be found in Technical Bulletins