Pasar al contenido principal

Los sitios web oficiales usan .gov
Un sitio web .gov pertenece a una organización oficial del Gobierno de Estados Unidos.

Los sitios web seguros .gov usan HTTPS
Un candado ( ) o https:// significa que usted se conectó de forma segura a un sitio web .gov. Comparta información sensible sólo en sitios web oficiales y seguros.

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



Displaying 341 - 350 of 2067
Interpretations Date

ID: nht73-4.18

Open

DATE: 05/08/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: National Tire Dealers & Retreaders Association, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of March 21, 1973, in which you ask how retreaded tires are to be tested to the strength requirements (plunger-energy) of Standard No. 117 (S5.1.1, incorporating by reference S4.2.2.4 of Standard No. 109). You appear to believe testing to the requirement is precluded because Standard No. 117 contains no requirement that the cord material be labeled onto the tire, and the plunger-energy requirements specify different performance levels for differing cord materials.

While Standard No. 117 does not require the generic name of the cord material to be labeled onto the retreaded tire, we expect that it will be found on most tire casings and will be available to the retreader on all post "DOT" casings, and on many pre-DOT casings as well. If a retreaded tire is not labeled with its cord material, the strength test can still be conducted. It is not necessary to know the cord material before the plunger-energy values are obtained. Once they are obtained, a sample can be removed from the tire, from which the material can be determined.

March 21, 1973

Mr. Michael Pescoe, Counsel National Highway Traffic Safety Administration

We would like to forward to you a question on Federal Retread Standard 117 raised by one of the companies in the industry: "As specified in S4.2.2.4 Tire Strength, each tire shall meet the requirement for minimum breaking injuries specified in Table 2, when tested in accordance with S5.3 of Safety Standard 109. My question is, the labelling specification S6.3 has no provision for fabric identification. Without cord type the Plunger Energy test, as specified in F.M.V. S.S. 109, cannot be performed because of the different minimum force values for different types of cord. In other words the minimum force is 1650 lbs. for a Rayon tire with a cross section of 6 inches or above. While the specification is 2600 lbs. for Nylon and Polyester cord with the same cross section width. Cord identification is required for testing in compliance with M.V.S.S. 117. What do we do now?"

As soon as we receive your answer, we will forward it on to the company that requested it.

Phillip P. Priedlander, Jr. Director of Communications

ID: nht90-1.92

Open

TYPE: INTERPRETATION-NHTSA

DATE: 03/30/90

FROM: MICHAEL LOVE -- MANAGER SAFETY COMPLIANCE PORSCHE

TO: JERRY CURRY -- NHTSA

TITLE: 49 CFR PART 543 EXEMPTION

ATTACHMT: ATTACHED TO LETTER DATED 05/31/90 FROM BARRY FELRICE -- NHTSA TO MIKE LOVE -- PORSCHE, A 35 PART 543; LETTER FROM BARRY FELRICE -- NHTSA TO STEPHEN WOOD -- NHTSA ACTING CHIEF COUNSEL ENTITLED PORSCHE'S MODIFIED ANTITHEFT EXEMPTION, LETTER DATED 04/12/90

TEXT: On January 25, 1989, Porsche submitted petitions for exemption from the Vehicle Theft Prevention Standard under 49 CFR Part 543 for its 1990 (MY) 911 and 928 models. NHTSA granted the petitions on May 26, 1989, on condition that any modifications to the alarm systems require Porsche to re-petition the NHTSA unless the modifications could be characterized as de minimus.

Porsche is planning to make the modifications set forth below to the alarm systems of MY 1991 911 and 928 model lines. For the following reasons, the changes described below should be considered de minimus:

1) The alarm control unit will be integrated with the central locking and interior light control units in order to save space and simplify the vehicle electrical system.

2) The system changes will be virtually transparent to the operator. The system will still be armed by locking either door with the key.

3) All of the same points of entry (i.e., door, hood, hatch, etc.) will be monitored by the system and the engine disabling and alarm features are the same. The system will be as protected and tamper resistant as the current system.

4) The new system will also monitor the glove box for opening. If the glove box is opened while the alarm is armed, the alarm will be set off (this is important for convertibles).

5) The system will have improved diagnostic capability in order to enhance serviceability.

6) The system will have the capability to accept other inputs (such as motion sensors) if they are desired in the future.

Based on the above, we believe that the alarm systems as modified contains all of the functions and features on which NHTSA based its decision to grant the exemptions. For that reason, we respectfully request a ruling from you that the planned modificat ions are de minimus and thus, obviating the need for a formal petition.

If you have any questions, please call me at (702) 348-3198.

ID: nht76-4.38

Open

DATE: 02/25/76

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: State of Connecticut

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letters of June 24, 1975, and May 30, 1975, regarding Federal Motor Vehicle Safety Standards Nos. 217 and 205. Please excuse our delay in answering your questions.

In your letter of June 24, 1975, you asked whether Standard No. 217 applies to school buses, and if so, whether Connecticut's regulations concerning emergency exits for school buses are in conflict with the Federal standard. By notice published in the Federal Register on January 27, 1976 (41 FR 3871) Federal Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release, 49 CFR 571.217, was amended to specify requirements for emergency doors for school buses, pursuant to the provisions of Section 202 of the Motor Vehicle and Safety Amendments of 1974 (Pub. L. 93-492, 88 Stat. 1484, 15 U.S.C. 1392).

Since Standard No. 217, as amended, applies to school buses, effective October 26, 1976, any State regulations which differ are voided by @ 103(d) of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1392(d)). The Connecticut regulations are, therefore, preempted by Standard No. 217, since @ 103(d) requires the State regulations to be "identical" to the Federal standard.

It should be noted, however, that while the State of Connecticut may not issue a regulation which differs from similarly applicable Federal Motor Vehicle Safety Standard requirements, Connecticut (or any of its political subdivisions) may in its own contracts for school bus purchases require more stringent specifications, as long as the Federal minimum requirements are met.

In your letter of May 30, 1975, you asked whether Lucite AR and other similar rigid plastics are allowed for use as side windows of buses under Standard No. 205, even though S5.1.2.1 does not list the use for "Item 12" rigid plastics.

"Item 12" is a classification created by the NHTSA for rigid plastics which comply with all the tests required of "Item 5" rigid plastics as defined in ANS Z26, with the exception of the test for resistance to undiluted denatured alcohol. Paragraph S5.1.2.1, Item 12 - Rigid plastics, provides that "Item 5" safety plastic materials may be used in motor vehicles only in the locations specified, at levels not requisite for driving visibility. These locations include "Standee windows in buses" and "readily removable windows". However, there is no provision in S5.1.2.1 which allows the use of "Item 12" plastic materials for fixed, side windows in buses.

Standard No. 205 defines readily removable windows in buses having a GVWR of more than 10,000 pounds to include pushout windows and windows mounted in emergency exits that can be manually pushed out of their location in the vehicle without the use of tools, whether or not one side remains hinged to the vehicle. Rigid plastics can only be used for side windows in buses if the side window is a readily removable window as defined by S5.1.1.4 or a standee window.

I hope this letter clarifies your questions concerning Standard Nos. 217 and 205. Please contact us if we can be of any further assistance.

YOURS TRULY,

STATE OF CONNECTICUT DEPARTMENT OF MOTOR VEHICLES

June 24, 1975

Richard Dyson Assistant Chief Counsel U.S. Department of Transportation National Highway Traffic Safety Administration

This is in regard to your recent reply to Mr. W. G. Milby, Staff Engineer from the Blue Bird Body Company in Fort Valley, Georgia concerning Connecticut regulations for emergency exits on school buses.

I have no question with the response that State regulations must be identical to Federal standard or are considered void. I can understand the reasoning behind this decision and agree with it completely. The interpretation I would have is; Does Motor Vehicle Safety Standard #217 apply to school buses, and if it does; are Connecticut regulations concerning emergency doors and emergency windows in conflict with Motor Vehicle Safety Standard #217?

I am attaching for your information copies of those sections of Connecticut regulations concerning emergency exits from the "MINIMUM REQUIREMENTS FOR TYPE I SCHOOL BUS CONSTRUCTION AND EQUIPMENT and all correspondence pertaining to this subject.

Thank you for your cooperation and assistance in this regard.

John L. O'Connell Pupil Transportation Administrator

ATTACHMENTS

BLUE BIRD BODY COMPANY

May 19, 1975

Richard Dyson Assistant Chief Counsel U.S. Department of Transportation NHTSA

The State of Connecticut recently adopted new school bus specifications which will become effective on school buses manufactured after January 1, 1976. In two areas these specifications are more restrictive than FMVSS 217 Bus Window Retention and Release.

In section 14-275B-16 (d) and 14-275B-17 (a), (see attached copies), the Connecticut specifications call for emergency exit release forces of between 5 and 15 pounds and 5 and 20 pounds respectively. Since these forces are different than those required by FMVSS 217, this imposes an additional constraint on school bus manufacturers for that state. Also, we are concerned that latch forces as low as 5 pounds could result in inadvertent opening of emergency exits.

We are in receipt of a copy of a letter which you sent to Mr. Donald L. Gibson, dated November 29, 1974, with file reference N40-30 (KK). In that letter you state:

"The federal requirements must be regarded as conclusive with regard to parking brake performance and emergency braking capability in order to maintain the uniformity necessary in a federal regulatory scheme. If states were permitted to impose additional requirements in an area regulated by a federal safety standard, manufacturers would be confronted with an impossible task of compliance. This reasoning formed the basis of the recent decision rendered in a case brought by the Motorcycle Industry Council, Inc., against the State of California in the United States District Court for the Eastern District of California concerning the preemption of a California State requirement that motorcycle lamps be wired to operate when the engine is running. The court held that the California requirement is preempted by the Federal Motor Vehicle Standard 108 since the NHTSA intended to cover all aspects of performance directly involving motorcycle headlamps."

It appears to us that this current conflict between the new Connecticut regulations and FMVSS 217 is similar to the matter which you addressed in your letter quoted above.

In the light of such conflicting specifications, what is our responsibility as a school bus manufacturer.

W. G. Milby Staff Manager

cc: JOHN O'CONNELL; DAVE PHELPS

MINIMUM REQUIREMENTS FOR TYPE I SCHOOL BUS CONSTRUCTION AND EQUIPMENT PAGES 9 AND 10 the release mechanism should be turned to open the emergency door shall be painted on the outside of the emergency door in black on the national school bus yellow background. The emergency door shall have a horizontal opening of at least 30 inches and a vertical opening of at least 48 inches measured from the floor level. No steps shall lead to the emergency door. The emergency door or exit shall be devised so as to be opened from the inside and the outside.

(b) The passage to the emergency door shall be kept clear of obstructions. For rear doors the horizontal clearance of 30 inches shall be maintained for a distance of at least twelve inches inside the bus. When the emergency door is in the left side, a minimum horizontal clearance of 30 inches and a vertical clearance of 48 inches shall be maintained between it and the center aisle.

(c) The upper and lower portion of the central rear emergency door shall be equipped with approved safety glass, the exposed area of which shall be not less than four hundred (400) square inches in the upper portion and not less than three hundred (300) square inches in the lower portion. The left side emergency door shall be equipped with safety glass in the upper portion and the lower portion shall be of at least the same gauge metal as the body outer panels. The emergency door shall be hinged on the right side if it is in the rear end of the bus and on the front side if it is in the left side and shall open only outward. Control from the driver's seat shall not be permitted.

(d) The emergency door shall be equipped with a slide-bar, cam-operated latch which shall be a minimum stroke of one inch. The latch shall be equipped with a suitable electric plunger-type switch connected with a distinctive audible signal automatically operated and located in the driver's compartment which shall clearly indicate the unlatching of this door and no cutoff switch shall be installed in the circuit. The switch shall be enclosed in a metal case, and wires leading from the switch shall be concealed in the body. The switch shall be so installed that the plunger contacts the farthest edge of the slide bar in such a manner that any movement of the slide bar will immediately close the circuit and activate the signal. The door latch shall be equipped with an interial handle which shall be capable of quick release upon application of a force between 5 and 15 pounds but shall be protected against accidental release. It shall lift up to release the latch. The outside handle shall be installed in a vertical position when latched so as to minimize hitching and shall be a non-detachable device.

(e) An audio alarm shall indicate to the driver when any door is in the locked position while the ignition switch is in the "on" position.

Sec. 14-275b-17. Emergency Windows. (a) A rear emergency window at least 16 inches height and as wide as practicable shall be provided in any where the emergency door is not in the rear. The rear window shall be designed so as to be opened from either the inside the outside. It shall be hinged at the top and be equipped a linkage or mechanism that will automatically hold the (Illegible Word) window against the force of gravity at a hinge opening angle 60 + 5 degrees measured from the closed window position. Such linkage or mechanism shall not prevent the window from (Illegible Word) a full 90 degrees due to gravitational forces should the bus be inverted. A positive latch on the inside shall provide (Illegible Word) quick release upon application of a force between 5 and 20 pounds but offer protection against accidental release. The outside handle shall be non-detachable and designed to minimize hitching.

(b) Labeling shall indicate in 1/2 inch letters on the inside the window operates and in letters at least two inches in height the words "Emergency Exit" above on the inside and directly below on the outside. clearly indicate to the driver the unlatching of the rear emergency window or the opening of any push-out emergency windows and no cutoff switch shall be installed in the (Illegible Word)

(d) If there is a space between the top of the rear divan seat the inside lower edge of the rear emergency window, such space shall be covered by a material of sufficient strength to sustain 600 pounds weight.

Sec. 14-275b-18. Exhaust System and Muffler. The exhaust system shall include the exhaust manifold and gaskets, piping leading from the flange of the exhaust manifold to and including the muffler(s). The system shall not extend into the body and shall be attached to the chassis. The tail pipe(s) shall be non-flexible sixteen gauge steel or equivalent and shall extend beyond the rear end of the chassis frame but not beyond the rear limit of the bumper. The complete exhaust system shall be tight and free from leaks and shall be properly insulated from the electrical wiring or any combustible part of the bus. It shall not pass within twelve inches of the fuel tank or its connections except that the exhaust system may come within four inches of the tank or its connections if a suitable heat baffle is installed between the exhaust system and such tank or connections. The size of the in the exhaust system shall not be reduced below that at the engine manifold.

BLUE BIRD BODY COMPANY

June 10, 1975

John O'Connell Pupil Transportation Adm. Department of Motor Vehicles

On May 19, 1975, I wrote Mr. Richard Dyson, Assistant Chief Counsel for NHTSA with regard to the emergency exit requirements in the new Connecticut School Bus Specifications VS Federal Standard 217, Bus Window Retention and Release per our earlier telephone conversation.

Attached please find a copy of the reply to that letter from Mr. James C. Schultz, Chief Counsel for NHTSA. I think it would be good for us to discuss this reply and so after you have had a few days to review this letter I will plan to call you.

Look forward to talking to you shortly.

W. G. Milby Staff Engineer

c: DAVE PHELPS

ID: 003059 bts

Open

    Mr. Joe Masci
    Pollak Switch Products Division
    300 Dan Road
    Canton, MA 02021

    Dear Mr. Masci:

    This responds to your May 2, 2003, faxed letter and your telephone conversations with Mr. Otto Matheke of my staff concerning the application of Federal Motor Vehicle Safety Standard (FMVSS) No. 209, Seat belt assemblies, to a seat belt tension sensor (BTS). You stated that the BTS is used in conjunction with a passenger weight classification system to prevent misclassification of children seated in child safety seats. Your letter asked several questions as to how a seat belt assembly using a seat belt tension sensor would be tested for compliance with Federal standards. Each of your questions is addressed below.

    1. General Applicability of FMVSS No. 209.

    You asked if the BTS would be considered part of the seat belt assembly under FMVSS No. 209, or if it would be considered an anchorage under FMVSS No. 210, Seat belt assembly anchorages, which is a vehicle standard. S3 of FMVSS No. 210 defines a seat belt anchorage as:

    [A]ny component, other than the webbing or straps, involved in transferring seat belt loads to the vehicle structure, including, but not limited to, the attachment hardware, seat frames, seat pedestals, the vehicle structure itself, and any part of the vehicle whose failure causes separation of the belt from the vehicle structure.

    Accordingly, FMVSS No. 210 applies to fixed attachment points on the vehicle structure and the associated hardware. FMVSS No. 209 applies to seat belt assemblies, defined as:

    [A]ny strap, webbing, or similar device designed to secure a person in a motor vehicle in order to mitigate the results of any accident, including all necessary buckles and other fasteners, and all hardware designed for installing such seat belt assembly in a motor vehicle. (S3 of FMVSS No. 209)

    In your phone conversation, you stated that the BTS is sold to manufacturers of seat belt assemblies and may be placed in a variety of positions on the assembly. As a component of the seat belt assembly, the BTS would be subject to the requirements of FMVSS No. 209. However, because the BTS may be incorporated into a seat belt system in a variety of ways, we are unable to determine whether the BTS could ever be considered a seat belt anchorage under FMVSS No. 210.

    2. FMVSS No. 209 Strength requirements

    In your letter you included a diagram properly identifying the components of a Type 2 seat belt assembly and asked for verification of the strength requirements for each labeled component. The strength requirements for FMVSS No. 209 are contained in: S4.2, webbing; S4.3, hardware; and S4.4, assembly performance.

    Under S4.2(b), webbing in the pelvic restraint portion of a Type 2 seat belt assembly must have a breaking strength of not less than 22,241 N (5,000 pounds). The upper torso portion of a Type 2 seat belt assembly must have a minimum breaking strength of 17,793 N (4,000 pounds). The testing procedure for both portions of webbing is contained in S5.1(b).

    S4.3(c) requires that attachment hardware bolts used to secure the pelvic restraint of a seat belt assembly must be able to withstand a force of at least 40,034 N (9,000 pounds) when testing in accordance with S5.2(c)(1). Other attachment hardware designed to receive the ends of two seat belt assemblies shall withstand a tensile force of at least 26,689 N (6,000 pounds) when tested under S5.2(c)(2).

    S4.4 sets forth the strength requirements of a Type 2 seat belt assembly in subsection (b). Under S4.4(b)(1), each structural component in the pelvic restraint must withstand a force of not less than 11,120 N (2,500 pounds). This includes the BTS, if it is located along the pelvic portion of the pelvic restraint. S4.4(b)(2) requires that each structural component in the upper torso restraint portion of the seat belt assembly be able to withstand a force of not less than 6,672 N (1,500 pounds). This includes a torso guide loop and retractor if the design permits only upper torso restraint forces on the restraint. Under S4.4(b)(3), any structural component that is common to both the pelvic and upper torso restraints must withstand a force of not less than 13,345 N (3,000 pounds). This would include any buckle or portion of the BTS that would be subject to forces from both the pelvic and upper torso restraints. The seat belt assembly performance for a Type 2 seat belt assembly is tested by the procedure specified in S5.3(b).

    3. Procedure for Testing Assembly Performance

    In your letter you asked what would be the proper method of attaching and orienting an assembly with a BTS under the test procedures in S5.3. Under S5.3, each end of the pelvic or torso portion of the belt assembly is attached to an anchorage bar to form a loop over rollers on a testing machine. (See FMVSS No. 209 Figure 5, enclosed.) The anchor points are such that the webbing is parallel in two sides of the loop. The attaching bolts are either aligned with or at an angle of 45 or 90 degrees to the webbing, whichever results in an angle nearest to 90 degrees between webbing and attachment hardware.

    You stated that you believe the appropriate testing method for an assembly with the "BTS installed between the fixed anchor on the pelvic-only side of the belt and the belt webbing" would be to utilize the procedure in S5.3(a)(2) for a "nonthreaded anchorage." Such a determination would be governed by the specific application of the belt assembly and not by the presence of a BTS. S5.3(a)(2) declares that testing will be performed in accordance with the installation instructions provided with belts designated for use in specific models of vehicles. In such an instance, the anchorages of the vehicle-specific assembly would be installed for testing so as to produce the maximum angle in use indicated by the installation instructions. From your letter and phone conversations, the BTS is sold to seat belt assembly manufacturers for eventual use in a variety of vehicle models. As such, the "nonthreaded anchorage" procedure would only be appropriate in those instances where the BTS is incorporated into a seat belt assembly that is designed for a specific vehicle and is accompanied by instructions for installation specific to that vehicle.

    For the assembly you specified, compliance testing would require the attaching bolts to be set according to the general set-up procedure. The attaching bolts would be positioned under S5.3(a)(2) such that the angle between the webbing and the attachment hardware is as close to 90 degrees as possible.

    4. Minimum Force Requirements for Assembly Performance

    In your letter you asked if the force minimums listed for the Type 2 belt component strength requirements apply to each component individually or to the test loop as a whole. The answer is that these force requirements apply to the components and not to the test loop. Under S4.4(b) of FMVSS No. 209, for a Type 2 belt, the structural components in the pelvic restraint must withstand a force of not less than 11,120 N (2,500 pounds), the structural components in the upper torso restraint must withstand a force of not less than 6,672 N (1,500 pounds), and structural components that are common to the pelvic and upper torso restraints must withstand a force of not less than 13,345 N (3,000 pounds). The test procedure for Type 2 belt assembly components requires a tensile force equal to that of the appropriate minimum be applied to the components (S5.3(b)). Therefore, in compliance testing of the pelvic restraint portion of a Type 2 seat belt assembly, a force of 22,240 N (5,000 pounds) would be applied to the test loop. The application of the 22,240 N (5,000 pounds) would be required so that the components would experience a tensile force of 11,120 N (2,500 pounds); the minimum required.

    We note that in a letter to Mr. Douglas Kubehl, dated March 16, 1992, we took the position that under S4.4(b) and the corresponding procedure in S5.3(b), the minimum force requirement would be applied to the test loop. However, we have reconsidered that interpretation and conclude that it was incorrect. The previous interpretation would result in Type 2 seat belt assembly components being tested to much lower force requirements than components in a Type 1 seat belt assembly. However, it is our understanding that all manufacturers of Type 2 seat belt assemblies have built and tested their products in a manner consistent with this revised interpretation, so this revision will not cause any seat belt assemblies (or the vehicles in which they are installed) to become noncompliant. To the extent a manufacturer has relied upon our previous interpretation, we will only pursue an enforcement action for noncompliance with the standard prospectively.

    5. Manual Belts Subject to the Requirements of FMVSS No. 208

    In your letter, you ask if you are correct in understanding that the strength requirements of S4.4 do not apply if the requirements of S5.1 of FMVSS No. 208 are met instead. Your understanding is correct. Under S4.6 of FMVSS No. 209, manual seat belt assemblies subject to the requirements of S5.1 of FMVSS No. 208, Occupant crash protection, would not be required to meet the requirements of S4.2(a)-(f) and S4.4 of FMVSS No. 209. [1] This includes the FMVSS No. 209 strength requirements for seat belt assembly components.

    You further ask, "how frequently do vehicle manufacturers opt for the 208 test option over the static component strength tests in 209?" A seat belt assembly subject to FMVSS No. 209 must comply with that standard, and be certified by its manufacturer as conforming to that standard. We do not collect or maintain data on how vehicle manufacturers certify with respect to their seat belt assemblies, although NHTSA may examine a manufacturer's certification in connection with any prospective or pending enforcement action. As such, we do not know with what frequency manufacturers opt for the FMVSS No. 208 compliance option.

    I hope you find this information helpful. If you have any further questions, please contact Mr. Chris Calamita of my staff at (202) 366-2992.

    Sincerely,

    Jacqueline Glassman
    Chief Counsel

    Enclosure
    ref:209
    d.7/16/03




    [1] Excepted from this provision are seat belts that are subject to S4.1.2.1(c)(2) of FMVSS No. 208, which cross references FMVSS No. 209. S4.1.2.1(c)(2) does not apply to vehicles manufactured on or after September 1, 1986.

2003

ID: 86-2.23

Open

TYPE: INTERPRETATION-NHTSA

DATE: 04/18/86

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Carol Dingledy

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your letter to Steve Kratzke of my staff, asking several questions about the effects of an amendment to the buckle force requirements in Standard No. 213, Child Restraint Systems (49 CFR @ 571.213). Buckles used on child restraints manufactured on or after February 16, 1986, must release with a minimum of 9 pounds force and a maximum of 14 pounds force. Buckles used on child restraints manufactured between January 1, 1981, and February 15, 1986, were required to release with a minimum of 12 pounds applied force and a maximum of 20 pounds applied force. Buckles used on child restraints manufactured before January 1, 1981, were required to release with a maximum of 20 pounds applied force. You asked with which buckle release force requirements replacement buckles provided by your company should comply. Assuming that the replacement buckles are to be installed by you or dealers, distributors, or repair businesses, the answer is that the buckles may, at your option, comply with either the release force requirements applicable to child restraint buckles as of the date of manufacture of the child restraint or with the current buckle release force requirements.

Standard No. 213, like all of our safety standards applicable to items of motor vehicle equipment, does not apply to the equipment after its first purchase in good faith for purposes other than resale. This general rule is, however, limited by the provisions of section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)), which specifies: "No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative . . . any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard . . . ." Please note that these prohibitions do not apply to the child restraint owner rendering inoperative some element of design installed on his or her child restraint. Hence, replacement buckles that are sold to and installed by child restraint owners are not required to comply with the provisions of Standard No. 213.

However, if you as a manufacturer, or any dealers, distributors, or repair businesses were to remove complying buckles from a child restraint and replace them with buckles that did not comply with Standard No. 213, this would violate section 108(a)(2)(A). This result arises because buckles with the specified release force levels were installed on an item of motor vehicle equipment (the child restraint system) in compliance with an applicable Federal motor vehicle safety standard (Standard No. 213). Section 109 of the Safety Act (15 U.S.C. 1398) specifies that each violation of section 108(a)(2)(A) subjects the violator to a potential $ 1,000 civil penalty.

Assuming that you or your dealers and distributors will be installing the replacement buckles, section 108(a)(2)(A) gives you an option of which release force requirements the replacement buckles must meet. In connection with several other standards that have been amended, the National Highway Traffic Safety Administration has stated its opinion that a manufacturer, distributor, dealer, or repair business does not knowingly render inoperative an element of design by replacing components installed in satisfaction of a safety standard with other components used in newer items of the same type in satisfaction of the same standard, even if the newer version of the standard imposes less stringent performance requirements. See, for example, the enclosed opinion issued when Standard No. 121, Air Brake Systems, was amended; 42 FR 26279, May 23, 1977. In this context, this opinion means that child restraint manufacturers may install replacement buckles that either:

1. comply with the requirements of Standard No. 213 as of the date the child restraint was manufactured; or

2. comply with the current requirements of Standard No. 213.

If you have any further questions, please let me know.

Sincerely,

Enclosure

ATTACH.

COSCO INC.

OCC 0062

Steve Kratsky -- NHTSA, Office of Chief Counsel

January 16, 1986

Dear Mr. Kratsky,

I am interested in receiving clarification about the FMVSS 213 amendment for reduction of pressure required to operate buckles on child restraints. This amendment, effective February 16, 1986, will require child restraints to have buckles with a release pressure of not less than 9 or more that 14 pounds, instead of the original 12 pounds minimum.

My questions regarding the provision of replacement buckles for child restraints are as follows:

1. Which type buckle will need to be provided for child restraints manufactured prior to January 1, 1981?

2. Must we provide 12 pound minimum pressure buckles for child restraints manufactured between January 1, 1981 and February 16, 1986 so they will continue to be in compliance with the FMVSS 213 standard in effect at time of manufacture?

3. Must we provide buckles meeting the amendment requirements for child restraints manufactured between January 1, 1981 and February 16, 1986 so they will be in compliance with the current FMVSS 213 standard as amended?

Thank you for your assistance.

Sincerely,

Carol Dingledy -- Communications Supervisor

ID: nht91-3.36

Open

DATE: May 1, 1991

FROM: Cliff Chuang -- Chief Design Engineering, Prospects Corporation

TO: Legal Counsel -- NHTSA

TITLE: Re Require Confirmation For The Interpretation Of New FMVSS Standard number 118

ATTACHMT: Attached to letter dated 7-1-91 from Paul Jackson Rice to Cliff Chuang (A38; Std. 118)

TEXT:

We have received the new FMVSS #118 published on April 16, 1991. Our company is currently developing advanced power window and power sunroof control systems for the automotive industry. Several of our interpretations to the new standard #118 need to be confirmed in writing by your office.

First, the new FMVSS #118 section S5 (a) says: "Notwithstanding S4, power window, partition or roof panel systems which, while closing, reverse direction when they meet a resistive force of 22 pounds or more from a solid cylinder of 4 to 200 mm in diameter and open to at least 200 mm, may close: ... "

Our interpretation of "22 pounds or more" is that 22 pounds is set as the MINIMUM level of the resistive force for the control system to reverse the window moving direction from closing to opening. Most motors that are currently used in the vehicle power window systems have a maximum force of around 65 pounds. Assume the motor has to give X pounds of force to move the window upward in a normal closing, if an obstruction occurs, naturally the motor will provide more force in order to continue to move the window upward. The force level can change very rapidly when the obstruction occurs. When the total force reaches the minimum level of (X + 22) pounds, or exceeds the minimum level and reaches anywhere between (X + 22) pounds and the maximum force (i.e., 65 pounds), if the control system has the capability to immediately reverse the window moving direction from closing to opening to at least 200 mm, then this control system complies with FMVSS #118 S5.

Second, the new FMVSS #118 section S5 (b) says: "The 4 to '200 mm dimension cited in S5 (a) is measured from the window or panel's leading edge to the daylight opening."

Our interpretation is that this 4 mm daylight opening can-be seen from inside the passenger compartment. We attached diagram Fig.-l (for window), Fig.-2 and Fig.-3 (for sunroof) to explain our understanding.

Please examine our interpretations and confirm them in writing as soon as possible. Your confirmation will have significant impact on our system development. I am looking forward to hearing from you soon.

Fig.-1 -- Window Diagram (graphics omitted) Fig.-2 -- Sunroof Diagram (graphics omitted)

Fig.-3 -- Sunroof Diagram (graphics omitted)

ID: nht81-1.10

Open

DATE: 02/05/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Richard A. Rechlicz

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your December 18, 1980, letter asking several questions about the application of Standard No. 217, Bus Window Retention and Release, to school buses.

First, you refer to paragraphs (a) and (b) of S5.2.3.1 and question which paragraph establishes the minimum safety level. Since paragraph (a) was first proposed and subsequently modified by the addition of paragraph (b), you believe that paragraph (a) defines the minimum level of safety while paragraph (b) meets or exceeds that level of safety. This reading of the standard is not completely accurate. Paragraph (a) of that section was the first part of the section to be proposed. Before the rule became effective, however, the proposal was amended to include paragraph (b). Accordingly, both paragraphs must be read together as defining the minimum mandatory safety performance requirement.

Second, you ask for our opinion of the preemption clause in the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1392(d)). You state that your interpretation is that no State or local government may adopt a safety standard applicable to the same aspect of performance as a Federal standard unless it is identical to the Federal standard. An exception exists for standards applicable to vehicles purchased for the State's or the local government's own use. This is an accurate reading of the preemption clause, however, a major area of contention frequently arises around what constitutes the same aspect of performance as a Federal standard.

Third, you ask whether the Federal government, through Standard No. 217, has preempted States from regulating unobstructed openings for purposes of emergency exists. As you are aware, the standard states that the emergency exit opening must be of a certain size. Further, the standard specifies the location of one of the seats at the forward-most side of the emergency exit. These are the agency's only requirements relating to the unobstructed emergency exit opening. With respect to whether a State could regulate further in this area, it would depend upon the type of regulation the State adopted. For example, a regulation that governed the size of the opening or the location of the forwardmost seat would probably be preempted. However, a regulation that required an aisle leading to the side emergency door would not likely be preempted, since the Federal government does not regulate aisles in buses.

Your fourth question asks us to comment on whether a Wisconsin statute requires aisles in school buses. The agency does not issue interpretations of State statutes. You should contact appropriate State officials for this information.

Finally, you recite a Wisconsin definition of emergency door zone which states that it is "the area inside the vehicle required by FMVSS 217 to be unobstructed at the emergency exit . . . " You then ask whether there are any such zones on buses constructed with side emergency exits. The agency, as stated above, requires an unobstructed opening at each exit (S5.2.3.1). If Wisconsin defines this as a zone, then such a zone exists in buses for purposes of the Wisconsin statute.

SINCERELY,

RICHARD A. RECHLICZ

ATTORNEY AND COUNSELOR

December 18, 1980

United States Department of Transportation National Highway Traffic Safety Administration

Attn: Frank Berndt, Chief Counsel

RE: Standard 217, Bus Window Retention and Release File No. 80-82

Dear Mr. Berndt:

Please be advised that the undersigned has been retained by and represents a corporation engaged in the manufacture of school buses throughout the United States, for the purpose of investigation certain issues that relate to standard 217, Bus Window Retention and Release and the Wisconsin Administrative Code Chapter MVD 17 entitled Transporation of School Children.

For your information, I have enclosed a copy of the Wisconsin Administrative Code MVD 17.

The purpose of this correspondence is to request a written legal opinion from your offices on the issues raised in this correspondence as they relate to standard 217 and MVD 17.

First, as I understand the legislative history of standard 217, S5.2.3.1 was first issued with only subsection (a). Later, as a response to and after opposition was voiced by certain west coast bus manufacturers using the "California window" due to rear mounted engines, NHTSA promulgated subsection (b). Thus, the present standard allows the manufacturer to choose either subsection (a) or subsection (b). Is it correct that subsection (a) established the minimum degree of safety and that subsection (b) either meets or exceeds that minimum standard?

Second, please advise as to the NHTSA position on the supremacy clause, 15USC section 1392(b). It was my belief that with respect to the directive of Congress to the NHTSA to address itself to the safety standards itemized in 15 USC 1395(i), where the NHTSA issued a safety standard thereon, the State could not adopt "any safety standard applicable to the same aspect of performance of said vehicle or item of equipment which is not identical to the Federal standard." (State owned and used vehicles excepted).

Third, and I believe this relates to question 2, as I read Standard 217, especifically 217 S5.2.1, it is my impression that all buses with a GVWR of 10,000 pounds or more "shall meet the unobstructed openings requirements by providing side exits and at least one rear exit that conforms to S5.3 through S5.5". Has the federal government pre-empted the field as to what is unobstructed for the openings? For this example, please refer to the spec drawing enclosed: if the manufacturer meets the requirements of S5.4.2.1(b), can the State initiate a rule that the seating arrangement as shown in the drawing for the side door obstructs the opening? (Assume also that the seating arrangement meets federal specifications as to distance.)

Fourth, it is my belief that nowhere in the Wisconsin Administrative Code MVD 17, is there a requirement that buses must have aisles. From your reading of that chapter alone, and I suggest that the word aisle is used only in MVD 17.13(1) and 17.25(2)(b), do you find anywhere that MVD 17 either

(1) defines aisle? or

(2) requires aisles in school buses?

Again, I request the opinion on this aspect only from your reading of the provision, not from other outside factors.

Finally, MVD 17.06(3) defines "emergency door zone" as "the area inside the vehicle required by FMVSS 217 to be unobstructed at the emergency exit. . ." From a reading of this definition alone, could you please advise as to whether there are any emergency door zones on a bus that is manufactured with exists meeting FMVSS 217 S5.2.3.1(b) ("California window" and side door exit).

I understand that responses to all of these issues raised in this correspondence will require a considerable amount of time by your offices. Please realize that it is important that we have a response from your offices on each question.

Accordingly, if there is any question that is not clear to you as stated, please call.

Furthermore, I would request that you acknowledge receipt of this correspondence.

Your prompt and immediate attention to this correspondence is appreciated as we are currently experiencing certain time restraints.

I thank you in advance for your consideration and courtesies. Seasons greetings to you and your family.

ENC.

cc: THOMAS BUILT BUS, INC. ATTN: BRYCE HUNT; RODDY LIGON, JR.; WILLIAM G. LADEWIG, ATTY AT LAW;

NOTE:

THE SEAT JUST FORWARD OF THE SIDE EMERGENCY DOOR CAN NOT EXTEND BEYOND LEADING VERTICAL EDGE OF DOOR OPENING.

APPLIES TO:

"S" MODELS WITH SIDE EMERGENCY DOOR AND WITHOUT REAR EMERGENCY DOOR.

ALL GAUGES TO CONFORM TO AMERICAN IRON A STEEL INSTITUTE (AISI) SPECIFICATIONS

THOMAS BUILT BUSES, INC. HIGH POINT, N.C.

TITLE

SEAT LOCATION - SIDE EMERGENCY DOOR FMVSS #217

(Graphics omitted)

ID: aiam1854

Open
Mr. Allan B. Fredhold, General Manager, K-B Axle Co., Inc., 5010 Triggs Street, Los Angeles, CA 90022; Mr. Allan B. Fredhold
General Manager
K-B Axle Co.
Inc.
5010 Triggs Street
Los Angeles
CA 90022;

Dear Mr. Fredhold: This responds to K-B Axle Company's March 4, 1975, request for guidanc in assisting K-B's customers in meeting their certification responsibilities under Standard No. 121, *Air brake systems*.; Standard No. 121 specifies air brake performance requirements (and som equipment requirements) which newly-manufactured trucks, buses, and trailers must be capable of meeting. For example, the standard specifies that if a truck or bus, in the loaded and unloaded condition, is stopped six times from 60 mph on certain test surfaces, it must be capable of stopping at least once in 258 feet without leaving a 12-foot wide lane and without uncontrolled wheel lockup.; Many manufacturers incorrectly assume that this requirement means that in order to certify that it has this capability, each vehicle produced must actually be tested from 60 mph on a test track. In fact the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1391, et. seq.) specifies the manufacturer's certification responsibility, which is to exercise 'due care' that the vehicle or item of equipment is *capable* of meeting all requirements.; NHTSA has made clear in the past, and has emphasized in it implementation of Standard No. 121, that a manufacturer is free to use whatever method is reasonably calculated to fulfill his responsibility to exercise due care. To cite a simple example, if a safety standard specifies that a certain safety device be no less than 8 inches above the ground, it would not be necessary to measure the height of each safety device on each vehicle produced to assure in the exercise of due care that it complies.; Standard No. 121, of course, establishes more complex performanc requirements, and they would be affected by the addition of your 'tag' or 'pusher' axles. Most final- stage manufacturers and alterers feel confident that they can meet such requirements as minimum air tank volume when they add a third axle. In more complex areas, however, they require some reasonable basis on which to certify, in the exercise of due care, that the vehicle still is capable of stopping within the required distance, and that the brake actuation and release times still meet the minimum performance levels of the standard.; As noted earlier, the standard and our statute do not require roa testing as the basis of certification. NHTSA, in a preamble to Standard No. 121 recognized:; >>>What constitutes due care in a particular case depends on al relevant facts, including such things as the time to elapse before a new effective date, the availability of test equipment, the limitations of current technology, and above all the diligence evidenced by the manufacturer.<<<; Road testing would be one method of exercising due care. You customers, of course, may not have the capability to conduct road testing.; As a supplier of the added component, you are in a good position t develop engineering data on the effect your axle has when added to a 121 vehicle. For example, you could add your axle to a 121 chassis with a representative body and conduct a road test to see that the vehicle with the added axle and gross vehicle weight would still meet the stopping distance requirements. You might also test the actuation and release times on this vehicle to see that the axle addition does not cause non-conformity. This experimentation would permit you to make general statements about the conditions under which your axle could be added to a 121-type chassis without causing non- conformity.; Although retardation force is not a requirement for a vehicle othe than a trailer, you suggest use of dynamometer data as a basis of certification. Such information would be a valid basis of certification if it is shown that a reasonable correlation exists between the retardation forces you specify and the actual ability of the modified truck to stop.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: aiam4097

Open
Ms. Carol Dingledy, Communications Supervisor, Cosco Inc., 2525 State Street, Columbus, IN 47201; Ms. Carol Dingledy
Communications Supervisor
Cosco Inc.
2525 State Street
Columbus
IN 47201;

Dear Ms. Dingledy: This responds to your letter to Steve Kratzke of my staff, askin several questions about the effects of an amendment to the buckle force requirements in Standard No. 213, *Child Restraint Systems* (49 CFR S571.213). Buckles used on child restraints manufactured on or after February 16, 1986, must release with a minimum of 9 pounds force and a maximum of 14 pounds force. Buckles used on child restraints manufactured between January 1, 1981, and February 15, 1986, were required to release with a minimum of 12 pounds applied force and a maximum of 20 pounds applied force. Buckles used on child restraints manufactured before January 1, 1981, were required to release with a maximum of 20 pounds applied force. You asked with which buckle release force requirements replacement buckles provided by your company should comply. Assuming that the replacement buckles are to be installed by you or dealers, distributors, or repair businesses, the answer is that the buckles may, at your option, comply with either the release force requirements applicable to child restraint buckles as of the date of manufacture of the child restraint *or* with the current buckle release force requirements.; Standard No. 213, like all of our safety standards applicable to item of motor vehicle equipment, does not apply to the equipment after its first purchase in good faith for purposes other than resale. This general rule is, however, limited by the provisions of section 108(a)(2)(A) of the Safety act (15 U.S.C. 1397(a)(2)(A)), which specifies: 'No manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative...any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard....' Please note that these prohibitions do not apply to the child restraint owner rendering inoperative some element of design installed on his or her child restraint. Hence, replacement buckles that are sold to and installed by child restraint owners are not required to comply with the provisions of Standard No. 213.; However, if you as a manufacturer, or any dealers, distributors, o repair businesses were to remove complying buckles from a child restraint and replace them with buckles that did not comply with Standard No. 213, this would violate section 108(a)(2)(A). This result arises because buckles with the specified release force levels were installed on an item of motor vehicle equipment (the child restraint system) in compliance with an applicable Federal motor vehicle safety standard (Standard No. 213). Section 109 of the Safety Act (15 U.S.C. 1398) specifies that each violation of section 108(a)(2)(A) subjects the violator to a potential $1,000 civil penalty.; Assuming that you or your dealers and distributors will be installin the replacement buckles, section 108(a)(2)(A) give you an option of which release force requirements the replacement buckles must meet. In connection with several other standards that have been amended, the National Highway Traffic Safety Administration has stated its opinion that a manufacturer, distributor, dealer, or repair business does *not* knowingly render inoperative an element of design by replacing components installed in satisfaction of a safety standard with other components used in newer items of the same type in satisfaction of the same standard, even if the newer version of the standard imposes less stringent performance requirements. See, for example, the enclosed opinion issued when Standard No. 121, *Air Brake Systems*, was amended, 42 FR 26279, May 23, 1977. In this context, this opinion means that child restraint manufacturers may install replacement buckles that either:; >>>1. comply with the requirements of Standard No. 213 as of the dat the child restraint was manufactured, or; 2. comply with the current requirements of Standard No. 213.<<< If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel

ID: aiam5353

Open
Mr. Randolph Schwarz 141 North Madison Drive South Plainfield, NJ 07080; Mr. Randolph Schwarz 141 North Madison Drive South Plainfield
NJ 07080;

"Dear Mr. Schwarz: This responds to your letter to Mr. John Messera o NHTSA, requesting an interpretation of Federal Motor Vehicle Safety Standard No. 116, Motor vehicle brake fluids. Your letter has been referred to my office for a response. As a consumer retrofitting your vehicle with DOT 5 brake fluid, you had several questions concerning the possible effects that an ingredient in the brake fluid might have on elastomers used in brake systems. Your questions are answered below. You mentioned 'seal swelling additives' added to DOT 5 brake fluid, that contact various elastomers in the brake system. Your first question was, when brake fluid manufacturers combine additives with brake fluid, should consumers be concerned with the combined fluids' compatibility with various elastomers used in braking systems? Standard No. 116 defines, at S4. Definitions, brake fluid as a liquid designed for use in a motor vehicle hydraulic brake system where it will contact elastomeric components made of: styrene and butadiene rubber (SBR), ethylene and propylene rubber (EPR), polychlorophene (CR) brake hose inner tube stock, or natural rubber (NR). In order to minimize failures in hydraulic braking systems, Standard No. 116 specifies minimum performance standards for brake fluids. These performance standards include tests for styrene and butadiene rubber cups, the most common type of elastomer in a hydraulic brake system. The brake fluid manufacturer must certify that the brake fluid complies with Standard No. 116. (See S5.2.2(d).) While DOT 5 brake fluid must meet Standard No. 116, the specific ingredients in the fluid are not regulated by the standard. The brake fluid manufacturer is expected to be aware that in addition to SBR, its brake fluid may contact EPR, CR, and NR elastomers in the brake system. Thus, the brake fluid manufacturers must ensure that contact between the fluid and the above stated elastomers would not result in a safety-related defect under the National Traffic and Motor Vehicle Safety Act. Sections 151-159 of the Safety Act concern the recall and remedy of products with defects related to motor vehicle safety. In the event that the brake fluid manufacturer or NHTSA determines that the brake fluid contains a safety related defect, the brake fluid manufacturer would be responsible for notifying purchasers of the defective brake fluid and remedying the problem free of charge. Your second question was whether DOT 5 brake fluid's compliance with Standard No. 116 ensures compatibility with elastomers. The answer is yes, for SBR elastomers. Further, besides Standard No. 116, the brake fluid manufacturer is subject to sections 151-159 of the Safety Act, that were previously discussed. At this time, NHTSA is not aware of safety related defects resulting from other ingredients used with brake fluid. Your third question was whether Standard No. 116 only addresses SBR compatibility with brake fluid. Standard No. 116, at S4, addresses brake fluid that contacts four elastomer types. However, the tests specified in the standard are only of the most commonly used SBR cups. Your fourth question was, if Standard No. 116 only mentions SBR elastomer, would it be advisable to add other elastomers to the specification, or to discuss elastomer compatibility on the brake fluid container? Information discussing the elastomer compatibility of the brake fluid, or other ingredients, may be voluntarily placed on brake fluid containers. Standard No. 116 specifies information that brake fluid containers must carry. However, Standard No. 116 does not prohibit manufacturers from noting on brake fluid containers, compatibility of the silicone brake fluid, or other ingredients, with various elastomers. Finally, you asked what Standard No. 116 specifies as the maximum viscosity for DOT 5 brake fluid, at -40 degrees Fahrenheit. Standard No. 116 specifies, at S5.1.3(c), that the maximum viscosity is 900 centistokes (cSt). I hope that this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, John Womack Acting 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.

Go to top of page