NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
| Interpretations | Date |
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ID: aiam3343OpenMr. H. Miyazawa, Director, Automotive Lighting, engineering Department, Stanley Electric Co., Ltd., 2-9-13, Nakameguro, Meguro-ku, Tokyo 153, Japan; Mr. H. Miyazawa Director Automotive Lighting engineering Department Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 Japan; Dear Miyazawa: This responds to your August 4, 1980, letter asking whether severa vehicle components would be required to comply with Standard No. 302, *Flammability of Interior Materials.* In particular you ask whether a headlining lamp, a courtesy lamp installed on a door panel, or various pilot indicator lamps and meters installed in the front panel must comply with the requirements.; As you stated in your letter, Section S4.1 of the standard lists th components required to comply with the standard. Further, that section states that materials designed to absorb energy on contact by occupants must comply with the standard. Since the components that you mention are not listed in S4.1 and since they do not appear to be designed to absorb energy on contact by an occupant, we conclude that they are not required to comply with the standard.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0669OpenMr. Louis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Environmental Activities Staff, General Motors Technical Center, Warren, MI, 48090; Mr. Louis C. Lundstrom Director Automotive Safety Engineering General Motors Environmental Activities Staff General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom: This is in reply to your letter of March 28, 1972, in which you as whether, for purposes of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials,' you may consider the 'occupant compartment' for van and panel-type trucks to be 'the front area of the vehicle extending rearward to the rearmost point on any occupant seat.'; We would consider a reasonable interpretation of the phrase 'occupan compartment,' when applied to van and panel-type trucks which have no physical barrier between the occupant and cargo compartments, to be that area forward of a vertical plane perpendicular to the longitudinal centerline of the vehicle, and tangent to the rearmost point of any occupant seat in its rearmost position. This interpretation appears to be substantially the same as that expressed in your letter.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1035OpenMr. Donald W. Taylor, Engineering Liaison Representative, Volvo of America Corporation, Rockleigh, NJ, 07647; Mr. Donald W. Taylor Engineering Liaison Representative Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Taylor: This is in reply to your letter of February 9, 1973, regarding th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials'. You ask whether both the face and the under-surfaces of a single or composite material must meet the burn- rate requirement of Paragraph S4.3, and whether it is necessary to subject both surfaces to the flammability test in Paragraph S5.; Under Paragraph S5.2.2 of the standard, test specimens for eac component are to be tested 'so as to provide the most adverse results'. This means that the relevant test result is the most adverse one achieved in any horizontal orientation, either upward- or downward-facing. Accordingly, while every surface of a test specimen must meet the burn-rate requirement, the way you determine which positioning of the test specimen produces the most adverse results is within your own discretion.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3341OpenMr. H. Miyazawa, Director, Automotive Lighting, Engineering Department, Stanley Electric Co., Ltd., 2-9-13, Nakameguro, Meguro-ku, Tokyo 153, Japan; Mr. H. Miyazawa Director Automotive Lighting Engineering Department Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 Japan; Dear Mr. Miyazawa: This responds to your August 4, 1980, letter asking whether severa vehicle components would be required to comply with Standard No. 302, *Flammability of Interior Materials*. In particular you ask whether a headlining lamp, a courtesy lamp installed on a door panel, or various pilot indicator lamps and meters installed in the front panel must comply with the requirements.; As you stated in your letter, Section S4.1 of the Standard lists th components required to comply with the standard. Further, that section states that materials designed to absorb energy on contact by occupants must comply with the standard. Since the components that you mention are not listed in S4.1 and since they do not appear to be designed to absorb energy on contact by an occupant, we conclude that they are not required to comply with the standard.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1231OpenMr. Kesao Nishiki, Program Supervisor, International Research & Marketing, The Plaza, 2 West 59th Street, New York, NY, 10010; Mr. Kesao Nishiki Program Supervisor International Research & Marketing The Plaza 2 West 59th Street New York NY 10010; Dear Mr. Nishiki: This is in reply to your letter of May 24, 1973, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials'. We apologize for the delay in answering your letter, but we did not receive your letter of the above date and the copy we later received does not include the diagram that was apparently attached to your original letter.; You ask whether the weather strip assembly 'used for the sealin between the car body and the door panel' must meet the requirements of the standard. We are unable to answer this question without additional information regarding the placement of the weather strip assembly and its attachment, if any, to the door panel. If you would provide us with this information, we will try to give you a prompt reply.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5306OpenMr. Andrew Tweddle AV Technology Corp. 2340 Alger Troy, MI 48083; Mr. Andrew Tweddle AV Technology Corp. 2340 Alger Troy MI 48083; Dear Mr. Tweddle: This responds to your request for an interpretatio whether AV Technology's armored vehicle is subject to the Federal Motor Vehicle Safety Standards (FMVSSs). As explained below, a vehicle manufactured to U.S. Army contract specifications, and sold to the Army, is not subject to the FMVSSs. In your letter, you explained that AV Technology is in the process of responding to a Department of the Army draft specification for an armored security vehicle. AV Technology proposes to offer its Dragoon ASV, an armored security vehicle, with a weapon carrying capability. Your letter states that the Dragoon ASV would be built to U.S. Army specification MIL-STD-1180. In a telephone conversation with Dorothy Nakama of my staff, you stated that the Dragoon ASV would also be built to other applicable military specifications. The FMVSSs' applicability to vehicles manufactured for and sold to the U.S. military, is addressed at 49 CFR 571.7(c): (c) Military vehicles. No standard applies to a vehicle or item of equipment manufactured for, and sold directly to, the Armed Forces of the United States in conformity with contractual specifications. You stated the Dragoon ASV would be manufactured to all applicable military specifications, specified by the Army. The Army is part of the 'Armed Forces.' Thus, when manufactured to Army contractual specifications, and sold to the Army, the Dragoon ASV is not subject to the FMVSSs. If you have any questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0611OpenMr. K. Krueger, Technical Development, Liaison Engineer, Volkswagen of America, Inc., Englewood Cliffs, NJ, 07632; Mr. K. Krueger Technical Development Liaison Engineer Volkswagen of America Inc. Englewood Cliffs NJ 07632; Dear Mr. Krueger: This is in reply to your letter of December 6, 1971, in which you as several questions regarding the test procedures of Standard No. 302, 'Flammability of Interior Materials,' and list certain components asking whether they are subject to the standard. While we indicated to you in our letter of February 17, 1972, that we are considering amendments to the standard which affect the questions you raise, we are responding, because of the limited time remaining before the standard becomes effective, to your questions based on the standard as presently written, indicating where appropriate, those areas where modifications may be made.; The three questions you raise regarding the test procedures of th standard are restated in part below, followed by our response.; >>>1. How is a part whose largest dimension is less than one inch an which is subject to the requirements of S4.1 to be tested under S5? You state that many small parts of Volkswagens would fall through the wire grid if required to be tested.; If a component fits the criteria of S4.1, it is required to meet th standard's requirements regardless of its size. In testing, however, manufacturers are not required to follow the procedures set forth in the standard, but may modify those procedures as long as results obtained can be correlated sufficiently that the manufacturer can show he exercised due care in attempting to meet the requirements. In the case of components that are too small to be supported by the wire grids, we believe manufacturers would be free to space the wire grids so that, at the very least, the component can be supported, and still avail themselves of a due care defense. One other alternative, although not as easily correlated to the standard, would be to test samples of the material of which the component is manufactured in sizes large enough to be supported by the test device as described in the standard.; 1(a). If the specimen held in the frame offers less than 1.5 inches o material from its open end to its clamped end, does it have to be tested under MVSS 302?; The answer to this question is similar to the one above. There is n exemption for small components in the standard. However, minor modifications to the test procedure may be made without jeopardizing the ability of a manufacturer to demonstrate, should the need arise, that he has exercised due care. In this case, we believe that a manufacturer could begin timing before the flame had traveled 1.5 inches, or again, could test larger samples of the material of which the component is made.; 1.(b). If a small specimen held in the frame offers less than 2 inche of material for progression of the flame after timing has begun, and if the material stops burning before it has burned for 60 seconds from the start of timing, does it meet the requirements of S4.3?; The provisions of S4.3 that you refer to are intended to reflect th performance of samples described in the test procedures of S5. These requirements are intended to provide an exemption for self-extinguishing materials, and not to exempt small samples that are consumed by fire before two minutes elapse. The standard establishes burn-rate requirements, and manufacturers should keep this in mind in determining whether particular components comply. If your component is such that it is consumed by fire because of its size before the two-minute period, then we would expect modifications to the procedure, of a nature described above, to be made in order that a determination of the burn rate of the material is obtained.; 2. 'We do not understand the applicability requirements of S4.1 specifically the latter part of the paragraph which states, ' . . ., and any other interior materials, including padding and crash-deployed elements, that are designed to absorb energy on contact by occupants in the event of a crash.'' You then list certain components and ask whether they fall within the quoted language.; This provision is presently under review by NHTSA, and may be modifie in the amendment to be published in the near future. Any such change may also affect the problems you appear to have in testing very small components, as indicated by your previous questions. However, as presently written, the phrase refers to those components which are in fact designed to be energy absorbing. This determination must be made by the manufacturer, based upon the design of his vehicles. It does not appear to us that any of the components you list would necessarily fall within the quoted language.; The list you provide includes numerous gaskets, or gasket-typ components such as (a) windshield gasket, (b) side door insulating rubber, (c) door gaskets, (h) rubber boots at base of gear shift and hand brake levers, (l) gaskets for sliding sun roof, and (m) gasket between steering column and firewall. If these items are not within the above-quoted language of S4.1, we would not consider them to be covered by any other language of that paragraph.; With reference to the open truck compartments in Type 2, Type 3, an Type 411 vehicles (your paragraph (d)), we consider areas in passenger vehicles where occupants can ride, such as the rear of station wagons, to be within the occupant compartment, and the components listed in S4.1 that appear in these areas must meet the requirements.; With reference to paragraph (e), we would consider the battery cover if it is part of the floor, to be a floor covering within S4.1 However, we do not consider electric cables (f) to be within any of the enumerated items of S4.1. In addition, the brake fluid reservoir (g) would only be included if it is within the 'any other interior materials . . .' language of S4.1.<<<; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0872OpenMr. L. A. Ferguson, Project Engineer, Frigiking Division, Cummins Engine Company, Inc., 10858 Harry Hines Boulevard, Dallas, TX, 75220; Mr. L. A. Ferguson Project Engineer Frigiking Division Cummins Engine Company Inc. 10858 Harry Hines Boulevard Dallas TX 75220; Dear Mr. Ferguson: This is in reply to your letter of September 28, 1972, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials', to the plastic air discharge chambers or combination air chamber-unit housings of the air-conditioning units you manufacture for use in motor vehicles. You ask whether this equipment must meet the requirements of the standard.; The portion of an item of a motor vehicle equipment that forms part o a component listed in the standard will normally be subject to the standard. From the photographs of your equipment that you submitted, we would consider an air discharge chamber or combination air chamber-unit housing that forms part of the surface of a front or side panel to be incorporated into the panel and therefore subject to the standard. The air discharge chamber or combination chamber-unit housing of your roof-mounted equipment is not a part of the 'headlining,' and accordingly would not be subject to the standard.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0561OpenMiss Vicki Morin, Project Director, National Association of Auto Trim Shops, Auto Trim News, 129 Broadway, Lynbrook, NY, 11563; Miss Vicki Morin Project Director National Association of Auto Trim Shops Auto Trim News 129 Broadway Lynbrook NY 11563; Dear Miss Morin: This is in reply to your letter of December 15, 1971, concerning Moto Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.'; You ask whether the standard applies to new cars manufactured afte September 1, 19072, or to any car sold after that date as well. The standard applies to passenger cars, multipurpose passenger vehicles, trucks, and buses manufactured on or after September 1, 1972. Vehicles manufactured before September 1, 1972, which would not be required to comply with the standard, may still be sold after that date.; Your second question is whether the standard applies only to ne vehicles, or whether it also applies to the aftermarket. As the standard applies only to vehicles manufactured on or after its effective date, replacement or aftermarket materials are not subject to its requirements.; A copy of the standard, as well as a copy of a proposed amendment, ar enclosed in accordance with your request.; We are pleased to be of assistance. Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1393OpenMr. Lee Moses, Trailer Coach Association, 3855 East LaPalma Avenue, Anaheim, CA, 92806; Mr. Lee Moses Trailer Coach Association 3855 East LaPalma Avenue Anaheim CA 92806; Dear Mr. Moses: This is in response to your telephone request of February 6, 1974 concerning the application of Standard No. 302, *Flammability of Interior Materials.*; The standard applies to passenger cars, multipurpose passenge vehicles, trucks, and buses. It does not apply to trailers, the vehicle category which includes mobile homes and other towed recreational vehicles, but it does apply to motor homes and to those campers that are constructed on new chassis. Accordingly, any of the components listed in paragraph S4.1 that are installed in the occupant compartments of the motor vehicles to which the standard is applicable must meet the standard's requirements.; You also asked whether a State may have a motor vehicle safety standar applicable to vehicles covered by a Federal standard that differs from the requirements of the Federal standard. The answer is no. Under the preemption provision of the National Traffic and Motor Vehicle Safety Act, section 103(d), 15 U.S.C. 1392(d), State motor vehicle requirements, if any, have to be identical to the requirements of the Federal standard. Any differing requirements would be void.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.