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Interpretation ID: 2621y


Mr. Ed McCarron Western Star Trucks Inc. 2076 Enterprise Way Kelowna, British Columbia, Canada V1Y 6H8

Dear Mr. McCarron:

This responds to your letter asking about the application of Safety Standard No. 302, Flammability of Interior Materials, to a particular mattress design, and how the mattress would be tested under the standard. I regret the delay in responding.

Paragraph S4.1 of Standard 302 sets forth a listing of the vehicle occupant compartment components that must be certified as complying with the flammability resistance requirements of paragraph S4.3. Paragraph S4.1 includes a reference to "mattress covers." You ask whether NHTSA would consider six components of your mattress design to be included in the term "mattress cover" and thus subject to Standard 302. (The first five components you ask about, and a portion of the sixth, satisfy the criterion in S4.2 of being within 1/2 inch of the occupant compartment air space.)

As we understand your sketch, the first three components (which you called the "cover," "foam" and "foam backing") encase the mattress core, or filling. As such, if our understanding is correct, these three constitute the mattress ticking, which we consider as the fabric case permanently enclosing the filling of a mattress. NHTSA has said in past interpretations of Standard 302 that the term "mattress cover" includes both a removable covering put over a finished mattress and the mattress ticking. Thus, the first three components would be subject to the standard.

These three components, which you said in a telephone conversation are quilted together, would be tested separately under S4.2.1 of the standard if they do not adhere to other materials at every point of contact. (The fact that these three are quilted, or stitched, indicates to us that they do not so adhere.) If any of these components adhere to other material at every point of contact, then it would be tested as a composite with the other material.

The fourth component in your sketch is the mattress "fill." Paragraph S4.1 of the standard lists mattress covers only. NHTSA has consistently interpreted S4.1 as not including the mattress filling.

The fifth component is a fabric "corner reinforcement" that appears to be approximately two inches in length and stitched on the outside of the mattress cover. NHTSA indicated in interpretative letters of Standard 302 dated December 15, 1972 and May 1, 1972 that a component that is "incorporated into" a component that is listed in S4.1 is subject to the standard. (The agency said in the December 1972 letter that "mattress cover" includes tufting, since tufting is incorporated into mattress covers.) Since the fifth component is sewn to the corner of the mattress and appears to be made part of the mattress cover, we believe that the corner reinforcement is incorporated into the mattress cover. Thus, the fifth component would be subject to the standard. If it does not adhere to another material at every point of contact, it is tested separately under S4.2.1.

The sixth component is the "fill backing" which appears to be an internal divider between the mattress fill and the springs. It appears from your sketch that the fill backing is not part of the mattress ticking, because the backing is inside the mattress and is separate from the mattress ticking. Thus, we conclude the sixth component is excluded from the standard.

I hope this information is helpful.


Paul Jackson Rice Chief Counsel

/ref:302 d:7/ll/90