The Honorable Bob Clement
U.S. House of Representatives
Washington, DC 20515-4205

Dear Congressman Clement:

Thank you for your letter of October 3, 1995, enclosing correspondence from Mr. Dale Allen Pommer concerning his attempts to have a third seat belt installed in the back seat of his 1983 Chevrolet S-10 Blazer. Mr Pommer has been told that this cannot be done because of safety laws. You requested comments on Mr. Pommer's letter. As explained below, there is no Federal prohibition against the modification Mr. Pommer would like done to his vehicle. However, Federal law does place some limits on how the modification is done. The installation of additional seat belts must be done in a way that does not compromise the performance of the existing seat belts.

Some background information about the agency may be useful. NHTSA has the authority to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. Federal motor vehicle safety standards are minimum standards, and may be exceeded by manufacturers. Federal law prohibits the manufacture or sale of any new motor vehicle or new item of motor vehicle equipment which does not conform to all applicable Federal motor vehicle safety standards in effect at the time of manufacture.

After the first retail sale, there is a limit on the modifications that can be made by certain businesses to vehicles. Manufacturers, distributors, dealers, and repair businesses are prohibited from "knowingly making inoperative" any device or element of design installed on or in a motor vehicle in compliance with an applicable safety standard (49 USC '30122). In general, the "make inoperative" prohibition would require a business which modifies motor vehicles to ensure that it does not remove, disconnect, or degrade the performance of safety equipment installed in compliance with an applicable safety standard.

A safety belt is an item of motor vehicle equipment and all safety belts sold in the United States must be certified as

complying with Standard No. 209, Seat Belt Assemblies, regardless of whether the belts are installed as original equipment in a motor vehicle or sold as a replacement part. Standard No. 209 sets forth strength, elongation, webbing width, durability, and other requirements for seat belt assemblies. The additional belt which might be added to Mr. Pommer's vehicle must comply with the requirements of Standard No. 209.

In addition to Standard No. 209, the agency has issued two additional safety standards which apply to new vehicles and affect safety belts: Standard No. 208, Occupant Crash Protection, which sets forth requirements for occupant protection at the various seating positions in vehicles, and Standard No. 210, Seat Belt Assembly Anchorages, which establishes strength and location requirements for seat belt anchorages. The 1983 Chevrolet S-10 Blazer would have been required to have, at a minimum, a lap belt at each rear designated seating position.

A "designated seating position" is defined by NHTSA regulations as:

any plan view location capable of accommodating a person at least as large as a 5th percentile adult female, if the overall seat configuration and design and vehicle design is such that the position is likely to be used as a seating position while the vehicle is in motion...Any bench or split- bench seat ...having greater than 50 inches of hip room (measured in accordance with SAE Standard J1100(a)) shall have not less than three designated seating positions.

Since the 1983 Chevrolet S-10 Blazer had a rear bench seat with 49.5 inches of hip room, that seat was required to have a minimum of two lap belts.

The "make inoperative" prohibition discussed earlier would not prohibit a business from adding a third seat belt to Mr. Pommer's vehicle. In addition, the anchorages would not have to comply with Standard No. 210. However, in adding the third seat belt, it is possible that the existing belts and

anchorages would have to be relocated. The businesses contacted by Mr. Pommer may be concerned that the belts and anchorages could not be removed and replaced without "making inoperative" the compliance of those belts and anchorages.

I hope this information has been helpful.


Samuel J. Dubbin Chief Counsel

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