Interpretation ID: nht93-4.29

DATE: June 9, 1993

FROM: William D. McIntosh -- Quality Assurance Manager, Perstorp Components

TO: Chief Council, NHTSA (via John Messera)

TITLE: None

ATTACHMT: Attached to letter dated 4/1/94 from John Womack to William D. McIntosh (42; STD. 302)

TEXT:

This letter is a request for a clarification on FMVSS 302 on an acoustical application in motor vehicles. Reference to the following typical diagram will be made throughout the text.

GRAPHICS OMITTED - SEE ORIGINAL

The composite assembly is an acoustical abatement product that is installed with layer C against vehicle sheet metal inside passenger vehicles. Layer B is always covering and adhering to layer C. The material is not visible to the occupants of the vehicle. It could be covered with carpet, trim, instrument panel etc. It resembles the B and C layers diagrammed in FMVSS 302.

Typical Flammability Results

Layer B SE Full Composite SE to B50 C Sliced at 1/2" SE/NBR to B200 - very dependant on cut quality.

- burning is restricted to C.

We recognize that FMVSS 302 says that test samples are to be cut to 1/2" thickness in preparation to perform the test. The standard goes on to say that the requirement concerning the transmission of a flame front shall not apply to a surface created by the cutting of a test specimen for the purposes of testing. Throughout the development of this product we have worked closely with our automotive customers to ensure that the installed product meets the 101 mm/min propagation criteria of the standard.

I have had discussions with two independent testing labs as well as Mr. John Messera of NHTSA. They agree that we appear to be meeting the spirit of the standard but we received varying comments on how to certify our material to the standard.

Mr. John Messera suggested that we put this question to the NHTSA legal department in the form of a request for a ruling. This letter is a request for such a ruling.

In subsequent conversation with John Messera, he indicated that our product was not listed in S4.1 of FMVSS 302 and as such was not covered by the standard.

If a previous ruling has been made to that effect I would like a copy of that as well.