Skip to main content
Search Interpretations

Interpretation ID: nht95-1.43

TYPE: INTERPRETATION-NHTSA

DATE: February 2, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: Jane L. Dawson -- Specifications Engineer, Thomas Built Buses, Inc.

TITLE: NONE

ATTACHMT: Attached to 8/8/94 letter from Jane L. Dawson to NHTSA Chief Counsel

TEXT: Dear Ms. Dawson:

This responds to your letter of August 8, 1994, regarding the test procedure in Standard No. 210, Seat Belt Assembly Anchorages. I apologize for the delay in our response. Your letter asks whether a seat manufacturer can certify that a passenger seat c omplies with Standard No. 210 with the seat attached to a 1/2" steel plate test fixture rather than with the seat attached to a typical 14 gauge school bus floor. If the seat manufacturer can certify using 1/2" steel plate, your letter also asks whether the final stage school bus manufacturer must retest using a typical 14 gauge school bus floor to certify that the vehicle complies with Standard No. 210.

By way of background information, each of this agency's safety standards specifies the test conditions and procedures that this agency will use to evaluate the performance of the vehicle or equipment being tested for compliance with the particular safety standard. The National Highway Traffic Safety Administration precisely follows each of the specified test procedures and conditions when conducting its compliance testing. However, as your letter recognizes, manufacturers are not required to test thei r products only in the manner specified in the relevant safety standard, or even to test the product at all, as their basis for certifying that the product complies with all relevant standards. A manufacturer may choose any means of evaluating its produ cts to determine whether the vehicle or equipment will comply with the safety standards when tested by the agency according to the procedures specified in the standard.

Section S2 of Standard No. 210 states that the standard applies to "passenger cars, multipurpose passenger vehicles, trucks, and buses." The standard does not apply to seats as items of equipment. Therefore, it is the vehicle manufacturer rather than th e seat manufacturer that is required to certify compliance with the standard. More specifically, the vehicle manufacturer must certify that the vehicle, with the seat installed, complies with Standard No. 210. Of course, one of the bases for the vehicl e manufacturer's certification may be test results and other information provided by the seat manufacturer.

If the agency testing shows that an apparent noncompliance exists in a vehicle or item of equipment, the manufacturer is asked to show the basis for its certification that the vehicle or equipment complies with the relevant safety standard or standards. If in fact there is a noncompliance, the manufacturer is subject to civil penalties unless it can establish that it exercised "reasonable care" in the design and manufacture of the product (through actual testing, computer simulation, engineering analys is, or other means) to ensure compliance, but nevertheless did not have reason to know that the vehicle or item of equipment did not in fact comply with the safety standards (49 U.S.C. 30112(b) (2) (A)).

Standard No. 210 includes strength requirements for seat belt anchorages. The test procedure requires the specified force to be applied through body blocks at specified angles and for specified periods of time. As you state in your letter, the procedur e allows the agency to replace the seat belt webbing with "material whose breaking strength is equal to or greater than the breaking strength of the seat belt assembly." If substitute material is used, the test procedure requires the material to "duplica te the geometry, at the initiation of the test, of the attachment of the originally installed seat belt assembly." This provision was included to ensure that the material was strong enough to pass the load to the anchorage during the test and, therefore, that the strength of the test anchorage rather than the seat belt was tested.

Your letter asks whether a seat manufacturer may base its certification on a test performed with the seat attached to a 1/2" steel plate test fixture rather than with the seat attached to a typical 14 gauge school bus floor. This, in effect, is a reques t for a determination of whether a vehicle manufacturer's reliance on the fact that the seat belt anchorages did not fail when a 1/2" steel plate test fixture is used would constitute "reasonable care" in assuring that the completed vehicle complied with the standard. This agency has long said that it is unable to judge what efforts would constitute "reasonable care" in advance of the actual circumstances in which a noncompliance occurs. What constitutes "reasonable care" in a particular case depends on all relevant facts, including such things as the limitations of current technology, the availability of test equipment, the size of the manufacturer, and, above all, the diligence exercised by the manufacturer. However, I would like to say that attac hment of a seat or anchorage to stronger material (whether 1/2" steel plate or some other material) than the material used in the construction of the vehicle in which it will actually be installed would not appear to provide a manufacturer with informati on on whether or not the anchorage, when attached to the vehicle structure, will withstand the specified loads.

You should also note that, while the exercise of "reasonable care" may relieve a manufacturer of liability for civil penalties in connection with the manufacture and sale of noncomplying vehicles, it does not relieve a manufacturer of the responsibility to notify purchasers of the noncompliance and remedy the noncompliance without charge to the purchasers, if either the manufacturer or this agency determines that vehicles do not comply with all applicable safety standards.

I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.

Sincerely,

Philip R. Recht