Interpretation ID: nht89-2.53

TYPE: INTERPRETATION-NHTSA

DATE: 08/02/89

FROM: STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL

TO: FRANK MILLER -- GERRY BABY PRODUCTS

TITLE: NONE

ATTACHMT: LETTER DATED 02/12/88 FROM FRANK H. MILLER -- GARRY BABY PRODUCTS TO ERIKA Z. JONES -- NHTSA

TEXT: Dear Mr. Miller:

This responds to your letter to me asking whether the "binding" you use of the edges of a seat cushion should be tested under Standard No. 302, Flammability of Interior Materials, separately from the cushion assembly or as a composite with the other mate rials. I regret the delay in responding. You said that you currently test the binding separately, but would find it easier to test the binding "as a portion of a cushion assembly."

Paragraph S4.2.1 of Standard No. 302 provides that "any material that does not adhere to other material(s) at every point of contact" must meet the standard's flammability resistance requirements when tested separately. Thus, if the binding is joined to the cushion assembly so that it does not adhere to the cushion at every point of contact, the agency would test it separately. If, on the other hand, the binding adheres to the cushion at every point of contact, paragraph S4.2.2 requires it to meet the performance requirements of the standard when tested as a composite with the other materials.

In your letter, you did not directly state whether the binding adheres to the cushion at every point of contact. However, we presume that you currently think it does not, since you said you test the binding separately from the cushion. I am enclosing c opies of two previous interpretations of Standard No. 302 that might be helpful in determining whether there is the requisite adherence. In a March 10, 1978 letter to Mr. Edmund Burnett, the agency discussed the application of S4.2.1 to a seat cushion c onsisting of vinyl stitched at varying internals to padding. In that letter, the agency stated that the vinyl, which did not adhere to the material at every point of contact, must be tested separately. On the other hand, a July 17, 1972 letter to Mr. S atoshi Nishibori concerned materials glued together, which NHTSA said would be tested by us as a composite.

Your inquiry follows our December 3, 1987 letter to you in which we said that thread that is used in the manufacture of a seat cushion may be tested as part of the component. We explained in our letter that although the agency recognizes that stitching that does not adhere at every point of contact should be tested separately under S4.2.1 of Standard No. 302, NHTSA has determiend that it is more practical to test stitching as part of the material since the test apparatus cannot readily accommodate stit ching alone. I note that the issue you now appear to raise is whether your binding, which presumably does not adhere at every point of contact, may be tested as part of the cushion material (i.e., as a composite) in the same manner thread is tested. Th e answer to this question is that the agency would probably separately test such binding under S4.2.1.

We have no reason to believe that it is not practicable to separately test binding that does not adhere at every point of contact, as specified in Standard No. 302. In fact, your present procedure which tests binding separately indicates that S4.2.1 is practicable. Since the practicability problems arising when separately testing thread are not encountered when the binding is tested, the agency will test binding that does not adhere at every point of contact in the manner specified in Standard No. 302 .

This does not mean to say, however, that you are prohibited from testing the binding as a composite. Standard No. 302 does not require you to test your products using the test procedure set forth in the standard. The standard only specifies how the age ncy will conduct its compliance test for the flammability resistance requirements of Standard No. 302. A manufacturer may choose any means of evaluating its products to determine whether the vehicle or item of equipment complies with the requirements of Standard No. 302, provided, however, that the manufacturer exercises due care in ensuring that its products will comply with the standard when tested by the agency according to the procedures specified therein.

I hope this information is helpful.

Sincerely,

ENCLOSURES