Interpretation ID: nht93-6.13

DATE: August 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Han Dinh -- Project Manager, United States Postal Service

TITLE: None

ATTACHMT: Attached to letter dated 6/17/93 from Han Dinh to Steven P. Wood (OCC 8783)

TEXT:

This responds to your letter requesting information about the conversion of postal vehicles to operate on compressed natural gas (CNG). You explained that you are deciding which specifications to apply to the CNG pressure vessels on the converted vehicles. You ask whether we would recommend the American Gas Association's voluntary standard, NGV-2, or the Department of Transportation standard for cylinders which transport CNG.

By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1381 et seq.; Safety Act) to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. NHTSA does not approve or certify any vehicles or items of equipment. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. NHTSA also investigates safety- related defects in motor vehicles and items of motor vehicle equipment.

At present, NHTSA has not issued any standard applicable to CNG cylinders or vehicles using CNG as a fuel. However, as you know, NHTSA has undertaken rulemaking on a safety standard for CNG tanks and vehicles. (58 FR 5323, January 21, 1993.) In response to our January 1993 proposal, the agency received over 55 comments, which we are currently analyzing. We expect our next regulatory decision in early 1994. Given that this rulemaking has not been completed, NHTSA is unable to recommend to you a particular course of action with respect to the NGV-2 and DOT standards at this time.

If NHTSA were to issue a safety standard for CNG cylinders and vehicles, the standard would apply to new products, and have applicability to vehicle conversions as follows.

The cylinder regulation would be an equipment standard. Thus, all cylinders manufactured after the effective date of the standard would be required to comply with its requirements, whether they are placed on new vehicles or on vehicles converted to CNG fuel.

The fuel system regulation would apply to new vehicles as manufactured by original equipment manufacturers or as converted prior to the first sale of the vehicle. Once the vehicle is sold, if the vehicle is converted by a commercial converter, the CNG fuel system regulation would apply if the vehicle was manufactured after the effective date of the standard and thus would have been regulated if it had originally been a CNG vehicle. With this in mind, I have enclosed a discussion that sets forth the implications under Federal law of converting gasoline-powered vehicles to use propane or other gas (such as CNG). That discussion addresses S108 (a)(2)(A) of the Safety Act, which prohibits

vehicle manufacturers, distributors, dealers and repair businesses from "knowingly rendering inoperative, in whole or in part, any device or element of design installed . . . in compliance" with any FMVSS.

In addition, please be aware that manufacturers of CNG tanks and vehicles are subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. In the event that NHTSA or the manufacturer of the tank or vehicle determines that the product contains a safety-related defect, the manufacturer would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge.

Our sister agency in the Department, the Federal Highway Administration (FHWA), has operational and equipment requirements for commercial vehicles used in interstate commerce. For further information about FHWA requirements, you can contact that agency's Chief Counsel's office at (202) 366-0650.

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