Dear Mr. Cole:
This responds to your letter asking about the test procedures of Federal Motor Vehicle Safety Standard No. 302, Flammability of Interior Materials. I regret the delay in responding.
In your letter, you explained that the National Van Conversion Association (NVCA) gathers samples of materials used for vehicle floor coverings, seat covers, etc., in van conversions to determine the compliance of the material with Standard No. 302. In your test program, you have found that many samples do not appear to comply. You said that a closer look at the conditions under which these samples were tested revealed that use of support wires affected whether many materials passed or failed the standard's test. You ask for clarification as to when support wires are used in Standard No. 302 testing.
The conditions and procedures under which Standard No. 302 compliance testing is conducted using support wires are stated in paragraphs S5.1.3 and S5.3(a) of the standard. Basically, these two paragraphs specify, respectively, that support wires are used: (1) when testing a specimen "that softens and bends at the flaming end so as to cause erratic burning," to keep the specimen horizontal; and (2) when testing a specimen that has an available width of not more than 2 inches, to position and mount the specimen on the U-shaped frames used in the test. Standard No. 302 makes no provision for using the wires other than in these two situations.
The agency follows the test procedure specified in Standard No. 302 when testing vehicles for compliance with the requirements of the standard. The agency uses heat-resistant wires as specified in S5.1.3 when there is a reasonable expectation that a test specimen will bend or curl while burning. NHTSA bases its determination about the likelihood of bending or curling on observations made in previously-conducted compliance tests of the specimen, or on the agency's knowledge of or testing experience with materials similar to a test specimen. I would like to point out that manufacturers are not required by Standard No. 302 to test the flammability of their vehicles in only the manner specified in the standard. The standard only sets the procedure that the agency will use in its compliance testing. Thus, a manufacturer is not required to use wires only with specimens that are anticipated to bend or curl, or that are too small to fit in the test frame without wires. However, manufacturers must exercise due care in making their certification of compliance that their product will meet the standard's requirements when tested by the agency according to the specified procedures of the standard. Whether a manufacturer meets that due care standard when using heat-resistant wires in situations other than those described in Standard No. 302 is a matter that can be determined only in the context of an enforcement proceeding.
Please contact us if you have any further questions.
Erika Z. Jones Chief Counsel