Interpretation ID: 24333
Mr. Wayne Millson
Collins & Aikman
500 Laird Road
Guelph, Ontario N1G 3X7
Canada
Dear Mr. Millson:
This responds to your e-mail of March 22, 2002, in which you ask several questions about Federal Motor Vehicle Safety Standard (FMVSS) No. 302, "Flammability of Interior Materials." Each of your questions is addressed below.
Frequency of Testing
First, you ask whether the National Traffic and Motor Vehicle Safety Act ("the Safety Act," Title 49, United States Code, Chapter 301), specifies how frequently an item of motor vehicle equipment must be tested for the purpose of compliance with the FMVSSs. Specifically, you ask: "If a part is tested once, is there any requirement to re-test the part at a model year change if there has been no change to the part itself?"
The answer is the Safety Act does not specify how frequently an item of motor vehicle equipment must be tested. However, the Safety Act does require that manufacturers exercise "reasonable care" to ensure that their products conform to each applicable standard (49 U.S.C. 30115(a)). A manufacturer must take whatever steps are necessary to ensure that each part covered by FMVSS No. 302, if tested according to the requirements of the standard, would meet those requirements.
Surrogate Testing Requirement
Second, you ask about a provision in S5.2.1 for surrogate testing. You ask: "The end of paragraph S5.2.1 refers to a surrogate testing requirement under S4.1.1. S4.1.1 only says [Reserved]. What does this mean? How do I find out when it is acceptable to use surrogate data?"
The answer is there is no surrogate testing provision in FMVSS No. 302. As explained below, the reference in S5.2.1 to surrogate testing is an obsolete provision from a 1975 rulemaking, and should be disregarded.
S5.2.1 contains specifications for the preparation of test specimens. The last sentence of S5.2.1 reads: "The maximum available length or width of a specimen is used where either dimension is less than 356 mm or 102 mm, respectively, unless surrogate testing is required under S4.1.1." As you note, S4.1.1 is reserved.
The National Highway Traffic Safety Administration had added the surrogate testing option in a March 31, 1975 final rule (40 FR 14318) in response to comments suggesting that small components be exempted from the testing requirements of FMVSS No. 302. The agency denied the request to exempt small components, but added S4.1.1 to the standard to provide for surrogate testing of small components, e.g., switches, knobs, gaskets, and grommets, because they were too small to be effectively tested under the procedures in place at the time.(1) In a September 16, 1975 final rule (40 FR 42746), NHTSA deleted S4.1.1 (and "reserved" the paragraph for codification purposes) because several vehicle manufacturers wanted an opportunity to comment on the surrogate testing provision. NHTSA reissued the provision in the form of a notice of proposed rulemaking that same day (40 FR 42756). However, the agency did not later adopt the surrogate testing proposal. NHTSA also did not remove S4.1.1 or the reference to it in S5.2.1. Thus, the reference to a surrogate testing requirement in S5.2.1 remained even though the surrogate testing requirement was deleted.
Surfaces Created By Cutting a Test Specimen
Finally, you ask about the meaning of the last sentence in S4.3(a) of FMVSS No. 302. S4.3(a) reads:
When tested in accordance with S5, material described in S4.1 and S4.2 shall not burn, nor transmit a flame front across its surface, at a rate of more than 4 inches per minute. The requirement concerning transmission of a flame front shall not apply to a surface created by cutting a test specimen for purposes of testing pursuant to S5.
You ask how the last sentence would apply to:
a sectioned instrument panel where the sample consists of an outer PVC skin that is the finished surface the vehicle occupant sees and is only a couple of millimeters thick fully adhered to a polyurethane foam which comprises the remainder and bulk of the one-half inch sample being tested. In this instance, the PVC skin does not burn, but the flame is transmitted across the foam portion of the composite.
Our answer is that any surface not created by the cutting of the test specimen is required to comply with the burn-rate limit of S4.3(a). However, surfaces created by the cutting of the test specimen are excluded from this requirement because cutting certain materials to the prescribed thickness produces a tufted surface upon which a flame front may be propagated at a faster rate than it would be upon the surface of the material before cutting, thereby creating an artificial test condition.
Based on the information in your e-mail, this exclusion would not apply to the polyurethane foam portion of your test sample because that surface was not created by cutting the material to be tested to the prescribed thickness. Rather, the foam portion and the PVC outer skin should be tested as a composite material, as required by S4.2 of FMVSS No. 302. (S4.2 requires any portion of a single or composite material that is within 13 mm of the occupant compartment air space to meet the burn-rate requirements of S4.3. S4.2.2 specifies that any material that adheres to other materials at every point of contact shall meet the requirements of S4.3 when tested as a composite with the other materials.)
I hope you find this information helpful. For your convenience, I have enclosed an information sheet that briefly describes NHTSA's requirements and that tells you how you can obtain copies of our regulations. If you have any further questions, please contact Dion Casey of my staff at (202) 366-2992.
Sincerely,
Jacqueline Glassman
Chief Counsel
Enclosure
ref:302
d.5/17/02
1. S4.1.1 had read: "If a test sample at least 6 inches long cannot be produced from a component because of its size, a test sample or samples with composition identical to that of the component material(s) shall be produced in the shape of a rectangle 4 inches wide, 14 inches long, and as thick as the component, up to inch, and shall be used for testing pursuant to S5."