Interpretation ID: 3112yy
Vice President
Steward & Stevenson Services, Inc.
P.O. Box 1637
Houston, Texas 77251-1637
Dear Mr. Bates:
This responds to your letter of July 12, 1991. In the letter, you ask whether the National Highway Traffic Safety Administration (NHTSA) has regulations concerning the construction or testing of compressed natural gas (CNG) automotive fuel tanks.
I am pleased to have this opportunity to explain our regulations to you. Some background information on Federal motor vehicle safety laws and regulations may be helpful. NHTSA is authorized, under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., the Safety Act) to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. NHTSA, however, does not approve motor vehicles or motor vehicle equipment nor endorse any commercial products. 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.
Standard No. 301, Fuel System Integrity, (49 CFR 571.301) specifies requirements for the integrity of motor vehicle fuel systems. However, that standard does not apply to vehicles that use only fuel with a boiling point below 32 degrees Fahrenheit. Since CNG has a boiling point well below this level, vehicles manufactured to be fueled only by CNG are not covered by the standard. You should be aware, however, that NHTSA recently discussed the possibility of establishing a fuel system integrity standard for vehicles using CNG in an Advance Notice of Proposed Rulemaking (ANPRM). The ANPRM was published in the Federal Register on October 12, 1990 (55 FR 41561).
There are some requirements that are applicable to manufacturers of CNG automotive fuel tanks. Manufacturers of motor vehicle equipment are subject to the requirements in sections 151-159 of the Safety Act (15 U.S.C. 1411-1419) concerning the recall and remedy of products with defects related to motor vehicle safety.
Section 102(4) of the Safety Act (15 U.S.C. 1391(4)) defines, in relevant part, the term "motor vehicle equipment" as:
any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle . . .
Since your product would be manufactured for use as an automotive fuel tank, it would be considered "motor vehicle equipment" within the meaning of the Safety Act. If either your company, as the equipment manufacturer, or this agency were to determine that your product contained a defect related to motor vehicle safety, your company would have to notify purchasers of the defect and remedy the problem free of charge to the purchasers.
For your information, I am enclosing a copy of the ANPRM concerning possible fuel system integrity requirements for vehicles using CNG and an information sheet for new manufacturers of motor vehicles and motor vehicle equipment. If you have any further questions, please contact John Rigby of this office at 202-366-2992.
Sincerely,
Paul Jackson Rice Chief Counsel Enclosures
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