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
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ID: aiam5620OpenMr. Joseph J. Smith Assistant Chief Maintenance Officer New York City Transit Authority 25 Jamaica Avenue Brooklyn, NY 11207; Mr. Joseph J. Smith Assistant Chief Maintenance Officer New York City Transit Authority 25 Jamaica Avenue Brooklyn NY 11207; "Dear Mr. Smith: This responds to your inquiry about whether Federa Motor Vehicle Safety Standard No. 302, Flammability of Interior Materials (49 CFR 571.302), applies to air conditioning return air filters. You state that these filters are placed on top of the air conditioning evaporator coil and are separated from the bus interior by a louvered panel. You were concerned that the filters may be subject to Standard No. 302 because they may be considered located in the 'occupant compartment air space.' As explained below, Standard No. 302 does not apply to air conditioning return filters. By way of background information, NHTSA is authorized to issue Federal Motor Vehicle Safety Standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. Instead, Congress has established a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. Since Standard No. 302 is a vehicle standard, the manufacturer of the vehicle, and not the manufacturer of the individual component, is responsible for certifying compliance with Standard No. 302. The agency periodically tests new vehicles and items of equipment for compliance with the standards. Standard No. 302 specifies burn resistance requirements for materials used in the occupant compartment of new motor vehicles. Section S4.1 lists the components in vehicle occupant compartments that the vehicle manufacturer must certify as complying with the flammability resistance requirements of paragraph S4.3. The components listed include seat cushions, seat backs, seat belts headlining, convertible tops, arm rests, all trim panels including door, front, rear, and side panels, compartment shelves, head restraints, floor coverings, sun visors, curtains, shades, wheel housing covers, engine compartment covers, 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. Section S4.1 represents a complete listing of all components in new vehicles that must comply with the flammability resistance requirements. Any component not identified in section S4.1 is not subject to those requirements. Therefore, an air conditioning return filter is not subject to those requirements. Please note that there are other NHTSA requirements that could affect the manufacture and sale of products related to motor vehicles. A motor vehicle or equipment manufacturer incorporating air conditioning filters in its vehicles or equipment would be subject to 49 U.S.C. 30118-30121 to ensure that its vehicles or equipment do not contain any safety related defect. If the manufacturer or NHTSA determines that a safety related defect exists, the manufacturer would be responsible for notifying purchasers of the defective vehicle or equipment and remedying the problem free of charge. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam4932OpenDeborah K. Nowak-Vanderhoef, Esq. General Motors Corporation Legal Staff New Center One Building 3031 West Grand Boulevard P.O. Box 33122 Detroit, MI 48232; Deborah K. Nowak-Vanderhoef Esq. General Motors Corporation Legal Staff New Center One Building 3031 West Grand Boulevard P.O. Box 33122 Detroit MI 48232; "Dear Ms. Nowak-Vanderhoef: This responds to your request for a interpretation of Standard No. 209, Seat Belt Assemblies (49 CFR 571.209). Specifically, you asked if General Motors Corporation (GM) could include the term 'dynamically-tested' in the label required by S4.6(b) of Standard No. 209. The answer is that GM may do so. Prior to September 1, 1992, S4.6(b) of Standard No. 209 requires a dynamically tested manual belt to be labeled with the following statement: 'This dynamically-tested seat belt assembly is for use only in (insert specific seating position(s), e.g., front right) in (insert specific vehicle make(s) and model(s)). However, a November 4, 1991 final rule, published at 56 FR 56323, amended S4.6(b) by deleting the term 'dynamically-tested' from the required label, effective September 1, 1992. GM would like to continue to include the term 'dynamically-tested' on its labels. NHTSA has often addressed the issue of whether additional information may be provided along with information that is required to be labeled on the product in the context of our safety standards that apply to tires. NHTSA has consistently stated that additional information may be included on tires, provided that the additional information 'does not obscure or confuse the meaning of the required information, or otherwise defeat its purpose.' See, e.g., our May 31, 1988 letter to Mr. Garry Gallagher of Metzeler Motorcycle Tire. This is the same test we would apply in any of our safety standards for additional information that is provided along with required labeling information. Applying this test to the situation at hand, the purpose of the labeling requirements in Standard No. 209 is to minimize the likelihood of improper installations of dynamically-tested manual belts, by specifying the particular vehicles and seating positions in which the belts are designed to be installed. GM's proposed labels would provide the information about the particular vehicles and seating positions in which the belts are designed to be installed on the label of these belts. The only difference between GM's proposed labels and the exact language specified in S4.6(b) of Standard No. 209 would be that GM's proposed labels would describe the belts as 'dynamically-tested seat belt assemblies,' instead of 'seat belt assemblies.' We do not see how this additional description of the belts, which is accurate and consistent with the agency's use of the term 'dynamically-tested,' would obscure or confuse the meaning of the required information or otherwise defeat its purpose. Therefore, GM's proposed labeling would be permitted under the provisions of S4.6(b) of Standard No. 209 that take effect September 1, 1992. Enclosed with your letter was a petition for reconsideration that you asked be considered if the agency determined that the current language of S4.6(b) of Standard No. 209 prohibited the additional information to be provided on the GM labels. Since NHTSA has concluded that Standard No. 209 permits the additional information, we are disregarding that petition for reconsideration and will take no action on it. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0422OpenMr. J. A. Shuman, Safety and Environment Manager, International Harvester Company, Motor Truck Division, 401 North Michigan Avenue, Chicago IL 60611; Mr. J. A. Shuman Safety and Environment Manager International Harvester Company Motor Truck Division 401 North Michigan Avenue Chicago IL 60611; Dear Mr. Shuman: This is in reply to your letter of March 18, 1971, petitioning fo reconsideration of the 'Defect Reports' regulations (Docket No. 69-31, Notice 2). Your letter was received on March 22, 1971, which is more than 30 days after publication of the regulation. Accordingly, pursuant to NHTSA procedural rules (49 CFR S 553.35), it has been treated as a petition for rulemaking.; You request that the requirements specified in A 573.4(b), that defec information reports be submitted not more than 5 working days after a defect in a vehicle has been determined to be safety related, be changed to require the report to be submitted not later than 15 days after the determination has been made. You state as the basis for this requested change that the information required pursuant to S 573.4(c)(3) and S 573.4(c)(7) cannot be provided by International Harvester within 5 days due to computer run-out times, but can be provided within 15 days. Section 573.4(b) of the regulation provides, as you point out, that information required pursuant to S 573.4 that is not available within 5 days may be submitted as it becomes available. This provision deals with the issue you raise, and no amendment to the regulation is called for.; With reference to your statement that the figures you intend to repor pursuant to S 573.5(c)(6) and (c)(7) will be identical, the regulation requires different kinds of information to be reported. Only if the information required by SS 573.5(c)(6) and (c)(7) is in fact identical may it be reported as such. The requirements are not intended necessarily to fit within the framework of manufacturers' presently existing data gathering procedures, and may require some manufacturers to change these procedures to provide the specific information.; Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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ID: aiam5270OpenMr. Herman Myburgh Executive Vice-President Allvan Corporation; Mr. Herman Myburgh Executive Vice-President Allvan Corporation; FAX 1-615-459-0289 Dear Mr. Myburgh: This responds to your FAX o November 8, 1993, asking for an interpretation of the conspicuity mounting height requirement of Standard No. 108 as it applies to your curtainsided trailer. You state that there are no retroreflective tapes that can be affixed to the curtain material itself and ask whether the conspicuity material may be placed on the frame rail. The answer is yes. As you note, in that location the material will be located within the range of mounting heights specified in recent amendments to Standard No. 108. For your information, submissions to the docket during the course of this rulemaking indicate that there are conspicuity materials that can be affixed to curtain materials. Some trailer manufacturers may prefer this avenue to compliance. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0588OpenMr. J. Michael Hartstein, Vice President, Campact Corporation, 3807 Wilshire Boulevard, Los Angeles, CA 90010; Mr. J. Michael Hartstein Vice President Campact Corporation 3807 Wilshire Boulevard Los Angeles CA 90010; Dear Mr. Hartstein: This is in reply to your letter of December 29, 1971, concerning th use of glazing materials in the Kangaroo Camper which your company manufacturers (sic). You ask whether Motor Vehicle Safety Standard No. 205, 'Glazing Materials' (49 CFR S 571-205) applies to this item.; Because it is impossible for a person to ride in the Kangaroo campe while the vehicle is in motion, we would not consider this item to be a 'camper' within the meaning of Standard No. 205, and the standard does not apply to this product.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0072OpenMr. E. C. Dix, Sales Manager, Bert's Truck Equipment, Inc., Highway 2, East Grand Forks, MN 56721; Mr. E. C. Dix Sales Manager Bert's Truck Equipment Inc. Highway 2 East Grand Forks MN 56721; Dear Mr. Dix: Thank you for your letter of April 18, 1968, in which you provide certification information, and presented extra axle modification problems.; Enclosed is a copy of the Federal Motor Vehicle Safety Standards wit chassis-cab information from the Federal Register.; Your certification of compliance concerns compliance of the vehicle a the time of your installation or modification. It does not extend to subsequent additions or modifications by others.; With respect to an old truck body mounted on a chassis-cab which i manufactured on or after January 1, 1968, you are required to bring the lighting into compliance. (See Federal Standard 108 applicable for January 1, 1968.(sic); With regard to lighting requirements for trucks, the corner lights, o side marker and clearance lamp requirements are also provided in the foregoing, enclosed standard.; Your letter is being referred to the engineers responsible fo standards preparation, and the information is appreciated.; Sincerely, Joseph R. O'Gorman, Acting Director, Office of Performanc Analysis, Motor Vehicle Safety Performance Service; |
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ID: aiam4898OpenMr. Garth C. Bates, Jr. Vice President Steward & Stevenson Services, Inc. P.O. Box 1637 Houston, Texas 77251-1637; Mr. Garth C. Bates Jr. 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 th 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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ID: aiam0567OpenMr. David G. Holden, President, Triple H Frame Company, Coffeyville, KS 67337; Mr. David G. Holden President Triple H Frame Company Coffeyville KS 67337; Dear Mr. Holden: This is in reply to your letter of December 1, 1971, stating that yo are an incomplete vehicle manufacturer, and asking for clarification of provisions of section 568.4 of Title 49, Code of Federal Regulations ('Vehicles Manufactured in Two or More Stages'), that refer to 'standards.' You indicated in a phone conversation of December 17, 1971, with Michael Peskoe of this office that you manufacture travel trailer and mobile home frames, which may be equipped by you with both tires and a trailer hitch before being sent to the subsequent manufacturer for completion.; The reference to 'standards' in S 568.4, as you were informed o December 17, is to the Motor Vehicle Safety Standards (49 CFR 571.101 *et seq*., formerly 571.21 *et seq*.) which apply to motor vehicles manufactured for sale in the United States. Copies of the standards, as you were also informed, may be purchased as indicated in the enclosed 'Notice of Publications Change.'; You stated on December 17 that you planned to include the statement o 568.4(a)(7)(iii) as part of your certification label. Based on the information you have provided, this choice appears to be consistent with the requirements of Part 568. This is because the only motor vehicle safety standard presently applicable to trailers and mobile homes is Standard No. 108, 'Lamps, Reflective Devices, and Associated Equipment.' It appears quite possible that conformance to this standard would not be substantially determined by the design of the incomplete vehicle you manufacture.; We are pleased to be of assistance. Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4877OpenMr. Stephen Mamakas AIR Inc. 1517 West 9 Street Brooklyn, NY 11204; Mr. Stephen Mamakas AIR Inc. 1517 West 9 Street Brooklyn NY 11204; "Dear Mr. Mamakas: This responds to your letter asking what Federa standards apply to the 'repair' of deployed air bags. I am pleased to have this opportunity to explain our laws and regulations to you. Section 103 of the National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1392) authorizes this agency to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. We have exercised this authority to issue Standard No. 208, Occupant Crash Protection (49 CFR 571.208). Standard No. 208 requires, among other things, that passenger cars provide automatic crash protection. Light trucks will also be required to provide automatic crash protection, beginning with the 1995 model year. Vehicles equipped with automatic crash protection protect their occupants by means that require no action by vehicle occupants. The compliance testing of vehicles to the requirement of Standard No. 208 is determined in a dynamic crash test. That is, a vehicle must comply with specified injury criteria (as measured on a test dummy) when tested by this agency in a 30 mph barrier crash test. The two types of automatic crash protection currently offered on new passenger cars are automatic safety belts (which help to assure belt use) and air bags (which supplement safety belts and offer some protection even when safety belts are not used). Automatic crash protection will save thousands of lives and prevent tens of thousands of serious injuries each year. Note that the automatic crash protection requirement applies to the performance of the vehicle as a whole, instead of setting requirements for the air bag as an individual item of equipment. This approach permits vehicle manufacturers to 'tune' the performance of the air bag to the crash pulse and other specific attributes of each of their vehicle models. However, this approach also means that the Federal standards do not specify specific performance attributes for air bags such as inflated dimensions, actuation time, and the like. Hence, there are no specific performance attributes with which repaired air bags must comply. The only Federal requirement that might affect your planned operation would be the 'render inoperative' prohibition in section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A)). That section provides that, 'No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle . . . in compliance with an applicable Federal motor vehicle safety standard ...' In this case, air bags are a 'device or element of design' installed in passenger cars in compliance with Standard No. 208. Hence, your repair business would violate Federal law if it were to remove, deploy, disable, or otherwise 'render inoperative' air bags installed in passenger cars. However, your letter gives no indication that your company intends to perform repairs or other operations on air bags that have not yet deployed. Instead, your letter asks only about performing repairs on air bags that have already deployed. Deployed air bags have been 'rendered inoperative' by the forces that caused deployment, not by anything a repair business does after that deployment. Thus, it seems unlikely that any repairs your company performs on deployed air bags would violate the 'render inoperative' section of Federal law. Although there is no Federal law prohibiting the sort of repairs you asked about, your planned 'repair' of deployed air bags gives rise to a host of safety concerns. You will need to contact the manufacturer of each vehicle on which you repair an air bag to learn the exact formula and amount of gas generant in the inflator canister for each air bag. This would be necessary to ensure that the 'repaired' air bag will inflate at the time and in the manner intended by the original manufacturer. Additionally, you will need to replace the crash sensors, the inflation mechanism, and other electronic parts. Again, you will need to contact the vehicle manufacturer to obtain specifications for the performance of these electronic components. You will also need to refold and lubricate the fabric of the air bag in the same manner as the original air bag. If you fail to exactly duplicate the equipment and procedures used in the original air bag, your company could significantly reduce or even eliminate the protection that would have been provided by the original air bag. This, in turn, could expose your company to substantial liability under State laws for such repairs. You may wish to consult a private attorney for more information in this regard. I hope this information is helpful. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0137OpenMr. William O. Green, Jr., Payne, Barlow and Green, Attorneys-at-Law, 2496 Austell Road, Austell, GA 30001; Mr. William O. Green Jr. Payne Barlow and Green Attorneys-at-Law 2496 Austell Road Austell GA 30001; Dear Mr. Green: Thank you for your letter of January 23, 1969, to William Haddon, Jr. M.D., requesting information on Federal standards for child restraint devices.; I am enclosing a copy of Federal Motor Vehicle Safety Standard No. 209 Seat Belt Assemblies - Passenger Cars, Multipurpose Passenger Vehicles, Trucks and Buses' which includes requirements for a Type 3 seat belt assembly for persons weighing not more than 50 pounds and capable of sitting upright by themselves.; The technical requirements of the present standard No. 209 wer previously included in Standards for Seat Belts for Use in Motor Vehicles (15 CFR Part 9, 31 F.R. 11528)' which was incorporated by reference in the initial Standard No. 209. I am also enclosing copies of these previous documents.; We are in the process of developing a standard for child car seats an I am enclosing a copy of a recently issued Notice of Proposed Rule Making on this subject. It is important to note that this is only a *proposed* regulation and the requirements may be modified somewhat when the final rule is published. However, this proposed rule indicates those safety features which are considered to be important for a child car seat.; There are no other existing Federal standards on child restrain systems for use in motor vehicles.; Sincerely, Clue D. Ferguson, Director, Office of Standards o Crash-Injury Reduction, Motor Vehicle Safety Performance Service; |
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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.