Interpretation ID: nht71-1.45

DATE: 12/02/71

FROM: ROBERT L. CARTER -- NHTSA ACTING ASSOCIATE ADMINISTRATOR MOTOR VEHICLE PROGRAMS

TO: LOUIS C. LUNDSTROM DIRECTOR, AUTOMOTIVE SAFETY ENGINEERING GENERAL MOTORS TECHNICAL CENTER

TITLE: NONE

TEXT: Dear Mr. Lundstrom:

This is in reply to your petition of September 10, 1971, requesting that Motor Vehicle Safety Standard No. 302, "Flammability of Interior Materials," be amended by (1) substituting a 12-inch-per-minute burn rate for the 4-inch-per-minute burn rate presently specified in the standard and (2) making certain specified changes in the test cabinet and test procedure. For the reasons stated below, your request for a 12-inch-per-minute burn rate is hereby denied.

The arguments you offer as a basis for your petition are stated below, and are followed by our responses. Generally, your position is that while you admit that "the available data may provide justification for a standard on flammability," you claim there is no evidence in the docket that supports the basis for, or establishes any safety benefit of, a 4-inch-per-minute burn rate. You argue also that the number of non-fuel fires is too small to warrant a 4-inch-per-minute burn rate. Finally, you claim that using materials having a 4-inch-per-minute burn rate would add an average retail cost of $ 10 to vehicles you manufacture, which cannot be justified under your analysis of the safety need. You indicate, however, that your present materials will or can be made to meet a 12-inch-per-minute burn rate.

"The 4-inch-per-minute burn rate was incorporated into the standard as a result of the agency's determination that it provided a flammability rate sufficiently low to provide adequate escape time from a vehicle in the event fire should occur." At no point in your petition do you present any data that shows that the 4-inch-per-minute burn rate is unreasonable or excessive from a safety standpoint. Moreover, despite your statement to the contrary, the Administration believes there is sufficient data on the number and degree of non-fuel fires in motor vehicles to justify the 4-inch-per-minute rate.

Much of the argument in your petition concerns a variability in the burn rate of materials you have tested. You apparently maintain that the variability makes it difficult for a manufacturer to know whether or not the material he uses in fact complies with the standard. The Administration realizes that the burn rate of any particular material may vary. This fact will be taken into account, along with the frequency and extent of any test failures, in assessing whether a manufacturer has exercised due care. It would not be appropriate, however, to respond to the problem of variability by raising the overall burn rate requirement. Such an action would probably result simply in manufacturers choosing cheaper and less safe materials.

You also argue that, under the specified test procedure, there may also be variations in burn rate results caused by inconsistencies of interpretation.

You provide data showing that GM and its suppliers obtained different results using adjacent material on the same roll. We find this argument to be without merit. General Motors is completely free to specify to its suppliers the method which it considers satisfactory under the standard to measure burn rates, or to test the materials themselves. This is no less than NHTSA itself does when it monitors test laboratories that are contracted to perform compliance tests.

You also provide data showing the effects of aging on a specific fire retardant additive. The evidence available to the NHTSA does not, however, indicate that it is necessary to use flame-retardant treatments that display these undesirable characteristics in order to comply with the standard.

Finally, while you present arguments against the retention of a 4-inch-per-minute rate, your petition lacks significant substantive arguments for the 12-inch-per-minute rate you wish to substitute. At no point do you show how a 12-inch-per-minute burn rate will allow sufficient time for the driver to stop the vehicle, and if necessary for occupants to leave it, before injury occurs. Based on the Administration's findings, such a 12-inch-per-minute rate will not provide the necessary escape time.

Your request for changes in the test cabinet and test procedure is presently being evaluated, and you will be notified when a decision concerning them has been made.

Sincerely,