ID: 9211

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

Dear Mr. Schwarz:

This responds to your letter to Mr. John Messera of 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

ref:116 d:5/5/94

ID: nht71-1.10

DATE: 06/04/71

FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA

TO: Voevodsky Associates, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of May 19 concerning installation by vehicle manufacturers of your Cyberlite system as original equipment on motor vehicles.

You ask two questions:

"(1) Is the installation . . . of the Voevodsky-Cyberlite System . . . permissible under Motor Vehicle safety Standard No. 108?"

"(2) If the installation . . . is permissible . . . does a state have the authority to (a) require the system, (b) permit the system, or (c) prohibit the system.

Section 103 (d) of the National Traffic and Motor Vehicle Safety Act of 1966 in effect permits the States to regulate any aspect of performance that is not covered by a Federal motor vehicle safety standard. As discussed in your meeting with NHTSA representatives on May 13, Standard No. 108 permits the installation of additional lighting equipment that does not impair the effectiveness of the required lighting equipment. It does not appear that the Cyberlite system, with the performance characteristics and location on the vehicle as you have described it, would impair the effectiveness of other vehicle lamps, and its installation is considered permissible under Standard No. 108. Since Standard No. 108 does not prescribe requirements for this aspect of performance, the States are free to require, permit, or prohibit the use of your warning system.

Sincerely,

VOEVODSKY ASSOCIATES, INC.

May 19, 1971

Laurance R. Schneider National Highway Traffic Safety Agency

Dear Mr. Schneider:

On 13 May 1971 I met with Richard Dyson, Lewis Owen, and Mike Esposito and on 14 May 1971 I met with Robert H. Cannon, Jr. As a result of these meetings I was directed to write to you for an opinion from the National Highway Traffic Safety Agency on the following legal questions.

(1) Is the installation on motor vehicles of the Voevodsky-Cyberlite System as described in the submission under Docket No. 69-19; Notice 1, permissible under Motor Vehicle Safety Standard No. 108?

(2) If the installation on motor vehicles of the Voevodsky Cyberlite System is permissable under Motor Vehicle Safety Standard No. 108, does a state have the authority to (a) require the system, (b) permit the system, or (c) prohibit the system?

The Voevodsky - Cyberlite System is an intervehicular deceleration warning communications system in which a red or amber warning light is center mounted on the rear of the leading vehicle at the same height as existing stop lights to communicate a component of deceleration initiated by the driver of the leading vehicle to the driver of a following vehicle. A device for measuring the deceleration of the leading vehicle is rigidly attached to this vehicle. The warning light is pulsed in a controlled fashion at a rate which varies exponentially with a component of deceleration. This component of decelaration will take into account the intensity of break action, the deceleration caused by all other frictional forces including aerodynamic, which vary from vehicle to vehicle and lastly, the deceleration caused by the component of gravitational forces parallel to the slope of the road. The exponential variation compensates for the neural response of the following driver to the pulsed coded light. The "on" time per cycle of the light pulse is also shortened with increasing frequency rate to provide a redundant warning. In practice, the maximum delay time for the driver in the following vehicle to obtain the knowledge of the degree of deceleration of the lead vehicle is 1/2 second while the deceleration is minimum; and the minimum delay time is approximately 1/14 second when the deceleration is maximum, thereby defining the band width of the information system. A 50% increase in frequency of the light pulses from 1.0 pulses per second to 7.6 pulses per second for each 0.1 "g" increase in deceleration from 0 to 0.5 g's provides the desired exponential relationship and the 50% duty cycle provides the necessary information band width.

Sincerely yours,

Dr. John Voevodsky

cc: Robert H. Cannon,

Richard Dyson;

Mike Esposito;

Lewis Owen

ID: nht72-2.3

DATE: 07/24/72

FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA

TO: Weirich Associates

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of July 11, 1972, inquiring about the use of plastic for an automatically closing fuel cap for automobiles.

The National Highway Traffic Safety Administration (NHTSA) has the responsibility for promulgating standards that improve the safety performance of new motor vehicles to minimize injuries and fatalities associated with the use of motor vehicles. Among the standards that have been issued is Federal Motor Vehicle Safety Standard (FMVSS) No. 301, which specifies performance requirements for the fuel tank, fuel tank filler pipe, and fuel tank connections. Like other Federal Standards issued by the NHTSA, this standard is performance oriented and does not specify design requirements. This standard will shortly be amended to specify additional performance requirements including rear-end collisions and rollover. In addition, other proposals will also be issued to considerably improve fuel containment to minimize the possibility of fuel spillage resulting from additional vehicle impacts. The essential requirements pertain to demonstrations of safe fuel containment as the result of standardized vehicle crash tests. How the results are to be achieved, what materials can or cannot be used, or other design features, are left to the discretion of the motor vehicle manufacturer in order that there should be the maximum freedom for innovation and inventiveness to meet the specified safety performance. We have no restrictions in the use of plastics or other materials that meet a specified safety performance requirement.

In view of present rulemaking action to amend FMVSS No. 301, there has been much information assembled, which is part of the public record, concerning comments from manufacturers, the interested public, and from suppliers of components. Your components, including a self-closing fuel cap and a seal within the filler pipe are interesting developments having possible contribution to improved safety. We would be pleased to have more information concerning these developments and with your permission, we would like to have copies of descriptive information to put into our public record, Docket No. 70-20, for the public and for the motor vehicle industry to see.

We should mention also that the Bureau of Motor Carrier Safety, which regulates interstate commercial transportation of passengers and cargo, has regulations which include fuel caps. You may want to contact this organization for their current requirements. Their location is at the same address of NHTSA.

Relative to pollution, the current requirements for fuel evaporative emission controls have resulted in motor vehicles being equipped with fuel caps that either have no vents or which vent only after certain stress develops from positive or negative internal tank pressure. You may want to contact the Environmental Protection Agency concerning their regulations. The address is 1626 K Street, N.W., Washington, D.C.

We are enclosing a copy of FMVSS No. 301, a copy of a notice proposing additional requirements, and a copy of Public Law 89-563.

We appreciate your interest in motor vehicle safety.

SINCERELY,

WEIRICH ASSOCIATES

July 11, 1972

Department of Transporation

Bureau of Motor Vehicles

Gentlemen:

We have developed a closure for the gasoline tanks for automobiles that automatically closes after filling thereby preventing spillage in the event the present day cap is not replaced properly, or in some instances not put back in place.

The piece can also be made to include a seal inside the fill pipe which effectively closes in case of collision damage.

Our question is to inquire regarding the use of plastics in the manufacture of this type of closure. Does the government have any regulations in this regard?

We do believe the new closure will contribute to some degree in the prevention of pollution, and to a greater measure as a safety device.

May we please have your early reply?

Paul Weirich General Manager

ID: nht75-5.4

DATE: 11/20/75

FROM: AUTHOR UNAVAILABLE; Frank A. Berndt; NHTSA

TO: Wisconsin Trailer Co. Inc.

TITLE: FMVSR INTERPRETATION

TEXT: The Federal Highway Administration's Bureau of Motor Carrier Safety has forwarded to the National Highway Traffic Safety Administration (NHTSA) your September 17, 1975, petition to establish a ruling that trailers with a gross vehicle weight rating (GVWR) of 50 tons or less are required to establish load-carrying capacity at a speed of 50 mph. Heavier trailers would be required to display signs of their maximum rated speed if less than 50 mph.

The NHTSA has already issued a ruling in this area, a copy of which is enclosed for your information. It requires that the Gross Axle Weight Rating (GAWR) and GVWR on the vehicle certification plate be calculated on the basis of the vehicle's maximum attainable speed, or 60 mph, whichever is lower.

The NHTSA is also considering rulemaking to amend the definition of GAWR in conformity with this interpretation. Your letter will be considered as a comment on this rulemaking.

Sincerely,

Enclosure

September 17, 1975

Bureau of Motor Carrier Safety -- Department of Transportation;

Attention: Robert A. Kaye -- Director

Subject: Petition for Reconsideration of 49 CFR 393.75 Tires -- (Docket MC-56)

Dear Mr. Kaye:

We have been informed by Rogers Brothers Corporation, that the Bureau of Motor Carrier Safety ruling MC-56 will become effective on October 1, 1975.

We do not have a copy of this ruling, and I therefore cannot speak for it or against it. I can only assume from the information supplied to us, that this ruling will not allow trailers to have a rated capacity based on a speed of 20 miles per hour.

We at Wisconsin Trailer Company, have for many years, advocated a capacity rating on trailers based on a travel speed of 50 miles per hour. It is our opinion that the 50 mile per hour speed rating should apply to all trailers having a rated capacity of 50 tons or less. With the advent of powerful trucks and super highways, trucks and truck-trailer combinations are moving at a high rate of speed, and I feel that the laws have to be upgraded to these modern times.

We find many trailer manufacturers promoting and selling their products based on a 20 or 30 mile per hour travel speed. This practice, we feel, must be stopped, as it is an unsafe and highly dangerous practice. Most users of these trailers will travel at speeds up to 50 miles per hour, even though the trailer is only rated at a maximum speed of 30 miles per hour. Who is there to stop him from traveling 50 miles per hour with a trailer rated at 30 miles per hour? Since there isn't a law-enforcing agency actively enforcing the "misuse of products", it then must be up to the Federal government to properly rate the vehicle at a minimum speed of 50 miles per hour. There should not be a variable speed capacity rating on trailers up to 50 tons.

We strongly urge the Bureau of Motor Carrier Safety to establish a ruling in which all trailers, up to 50 tons, would have a rated capacity based on a minimum of 50 miles per hour.

It is my opinion that large capacity trailers should be allowed to have a rated capacity at a speed of 20 miles per hour. In these instances, it should be mandatory that a large sign, plainly visible from another moving vehicle, be placed on the sides and rear of the trailer, so that if there is a violation regarding the speed of the unit when fully loaded, it will be recognized by the proper authorities.

If we can be of any further assistance to you, please feel free to call upon us.

Yours very truly,

WISCONSIN TRAILER CO., INC. -- LeRoy E. Mueller, President

ID: nht75-6.23

DATE: 01/01/75 EST

FROM: RICHARD B. DYSON -- NHTSA ASSISTANT CHIEF COUNSEL

TO: ALLAN B. FREDHOLD -- GENERAL MANAGER K-B AXLE CO., INC.

TITLE: N40-30 (TWH)

ATTACHMT: LETTER DATED 4/16/75 FROM RICHARD B. DYSON -- NHTSA CHIEF COUNSEL TO GEOFFREY R. MYERS OF HALL AND MYERS; UNDATED LETTER FROM RICHARD B. DYSON -- NHTSA CHIEF COUNSEL TO ADDRESSEE UNKNOWN

TEXT: Dear Mr. Fredhold:

This responds to K-B Axle Company's March 4, 1975, request for guidance 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 some 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 its 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 performance 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 road 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 all 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. Your 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 to 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 other 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,

ID: nht90-3.17

TYPE: Interpretation-NHTSA

DATE: July 13, 1990

FROM: Barry Felrice -- Associate Administrator for Rulemaking, NHTSA

TO: Brian Gill -- Senior Manager, Certification Department, American Honda Motor Co., Inc.

TITLE: None

ATTACHMT: Letter dated 3-16-90 to B. A. Kurtz from B. Gill with enclosure

TEXT:

This responds to your request that this agency determine that the new antitheft device proposed to be installed on the MY 1991 Honda Acura NS-X car line, represents a de minimis change in the system that was the basis for the agency's previous granting o f a theft exemption for the car line beginning in MY 1991, and that therefore the Acura NS-X vehicles containing the new device would be fully covered by that exemption.

As you are aware, the Acura NS-X car line was granted an exemption, pursuant to 49 CFR Part 543, from antitheft marking because Honda showed that the antitheft device to be used in lieu of marking on the car line was likely to be as effective as parts ma rking. This exemption was issued on February 5, 1990, and appeared in the Federal Register on February 9, 1990 (55 FR 4746).

The agency granted the exemption from theft marking because the agency found that based on substantial evidence, the agency believed that the antitheft device is "likely to be as effective in reducing and deterring motor vehicle theft as compliance with the parts-marking requirements of the theft prevention standard (49 CFR Part 541)." In the granting of the exemption from theft marking, the agency stated that it believed that the device will provide the types of performance listed in 49 CFR Part 543.6 (a)(3): Promoting activation; attracting attention to unauthorized entries; preventing defeat or circumventing of the device by unauthorized persons; preventing operation of the vehicle by unauthorized entrants; and ensuring the reliability and durabili ty of the device.

In your letter, it was stated that beginning from MY 1991, Honda plans improvements in the antitheft device that is standard equipment on the Acura NS-X in two ways: First, the new antitheft system would be armed by using the auto door lock system contr ol to lock either door. Honda states that in the system that was the subject of the exemption from the theft prevention system, it was necessary to use the control on the driver's door in order to arm the system. According to the attachment provided in your letter, this change would make it possible to arm the theft deterrent system by locking either door even if the other door is left unlocked. Second, the radio would now be included in the alarm system. Thus, the alarm system will be activated if the radio terminal or the coupler is disconnected, or if the radio's wiring is cut.

After reviewing the proposed changes to the componentry and performance of the antitheft device on which the exemption was based, the agency concludes that the changes are de minimis. While the new device has enhanced componentry and provides some aspec ts of performance not provided by the original device, it also continues to provide the same aspects of

performance provided by the original device and relies on essentially the same componentry to provide that performance. Therefore, it is not necessary for Honda to submit a petition to modify the exemption pursuant to 49 CFR Part 543.9(c)(2).

If Honda does not implement the new antitheft device as described in your letter, or delays implementation until after MY 1991, we request that Honda notify the agency of such decisions.

It is my understanding that, in a May 16, 1990, telephone conversation between Brian Tinkler of Honda and Dorothy Nakama of NHTSA's Office of Chief Counsel, Mr. Tinkler confirmed that Honda was not requesting confidential treatment of any information pro vided in your letter. Therefore, a copy of your letter, and this response, will be placed together in NHTSA's public docket.

ID: nht92-8.16

DATE: March 26, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Larry J. French -- President and CEO, Magnascreen

TITLE: None

ATTACHMT: Attached to letter dated 1/24/92 from Larry J. French to Office of the Chief Counsel, NHTSA (OCC 6921)

TEXT:

This responds to your letter inquiring about a recent amendment to Safety Standard No. 111, Rearview Mirrors. (49 CFR S571.111) You explained that your company is developing electronically controlled dimmable (day/night) rearview mirrors for motor vehicles and requested that the agency assess your reading of section S11 of the standard. We are pleased to have this opportunity to interpret our standard for you.

By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approval of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, the manufacturer is responsible for certifying that its vehicles or equipment comply with applicable standards. The following letter represents our opinion based on the facts presented in your letter.

Safety Standard No. 111 specifies requirements for the performance and location of rearview mirrors. Section S11, which was recently amended to better address new mirror designs, specifies requirements for mirror construction. (See 56 FR 58513, November 20, 1991.) The section states in relevant part that:

All single reflectance mirrors shall have an average reflectance of at least 35 percent. If a mirror is capable of multiple reflectance levels, the minimum reflectance level in the day mode shall be at least 35 percent and the minimum reflectance level in the night mode shall be at least 4 percent. A multiple reflectance mirror shall either be equipped with a means for the driver to adjust the mirror to a reflectance level of at least 35 percent in the event of electrical failure or achieve such reflectance level automatically in the event of electrical failure.

You asked whether an alternate power source can be used to achieve the specified fail-safe operation (i.e., adjusting the mirror to a reflectance level of at least 35 percent in the event of electrical failure). While your letter did not specify what you meant by "alternate power source," we assume that it means an electrical power source other than the one intended to normally operate the mirror. Examples of an alternate electrical power source include solar energy or a self-contained battery system.

We interpret the term "electrical failure," as used in section S11 of Standard No. 111, to include any type of electrical failure. This would include electrical failure related to an alternate power source as well as electrical failure related to the primary power source. Therefore, unless adjustment of

the mirror to a reflectance level of at least 35 percent occurred even in situations where there was electrical failure related to the alternate power source, the alternate electrical source could not be used to provide the fail-safe operation required by section S11.

The preamble to the final rule amending Standard No. 111 explained that the agency wanted to assure that multiple reflectance mirrors are capable of providing adequate images at all times during this vehicle's operation, including electrical failure situations where the mirror is unpowered. The agency noted that situations can occur where the mirror would be unpowered even though the vehicle could be operational, citing connector faults and circuit board faults. See 56 FR 58515.

To comply with section S11 in situations where a mirror is unpowered as a result of electrical failure, a mirror would either have to default automatically to the high reflectance mode (as in the case of an opposite polarity fail-safe liquid crystal mirror described in the preamble) or be capable of being manually adjusted to the high reflectance mode. We do not have enough information about your proposed mirror to determine whether it would comply with the amendments in the case of electrical failure related to the alternate power source.

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.

ID: nht90-4.44

TYPE: Interpretation-NHTSA

DATE: October 15, 1990

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: W. Marshall Rickert -- Motor Vehicle Administrator, Maryland Department of Transportation

TITLE: None

ATTACHMT: Attached to letter dated 7-31-90 from W.M. Rickert to Chief Counsel, NHTSA (OCC 5076); Also attached to Maryland Vehicle Law, sections 22-103 and 104, page 320 (text omitted); Also attached to Maryland Vehicle Inspections procedures regarding m irrors and vehicle glazing, pages 227 and 228 (text omitted)

TEXT:

Thank you for your letter seeking this agency's opinion as to whether the State of Maryland may amend its motor vehicle regulations to permit the installation of aftermarket tinting on motor vehicle windows, for individuals who may desire this for medica l reasons. I am pleased to have this opportunity to describe the legal principles that relate to your question.

The National Highway Traffic Safety Administration ("NHTSA") is responsible for issuing Federal motor vehicle safety standards that impose requirements for specific levels of safety performance for new motor vehicles and motor vehicle equipment. Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR S571.205), which has been in effect since 1968, imposes a minimum level of light transmittance of 70 percent in all areas requisite for driving visibility (which includes all windows on pa ssenger cars). The purpose of this requirement is to ensure adequate visibility through the windows, thereby reducing the risk of a motor vehicle crash.

Although Federal motor vehicle safety standards apply directly only to new vehicles and equipment, Federal law also imposes limits on the addition of tinting materials to motor vehicle glazing after vehicles have been purchased by consumers. Pursuant to section 108(a)(2) of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1397(a)(2), manufacturers, distributors, dealers, or motor vehicle repair businesses may not "render inoperative" any equipment or element of design installed in complianc e with a Federal safety standard. Thus, those businesses may not install tinting that reduces the light transmittance of windows covered by Standard 205 to a level below the Federal requirement of 70 percent, since that would make the windows "inoperati ve" within the meaning of Standard 205.

This Federal prohibition is similar to that imposed by section 22-104 of the Maryland Vehicle Law, which provides:

A person may not willfully or intentionally remove or alter any safety device or equipment that has been placed on any motor vehicle . . . in compliance with any law, rule, regulation, or requirement of . . . the United States or of this State . . . unle ss the removal or alteration is permitted by rule or regulation adopted by the (Maryland Motor Vehicle) Administrator.

The "render inoperative" provision of Federal law does not apply to actions by individual vehicle owners. Therefore, each State may regulate the extent to which aftermarket tinting may be applied by vehicle owners to their own vehicles. Thus, although section 22-104 appears to preclude aftermarket tinting by any person if the result would be to reduce the level of light transmittance below 70 percent, Maryland may amend its rules or regulations to permit such tinting by individuals, for medical or any other reasons deemed valid by the State. However, Maryland has no authority to grant any exemptions, including medical exemptions, from the "render inoperative" prohibition of Federal law that applies to commercial entities. Hence, regardless of any p rovisions of Maryland law, no manufacturer, distributor, dealer, or motor vehicle repair business may legally install window tinting film on a vehicle, unless the vehicle continues to comply with the Federal light transmittance requirements.

In adopting Standard 205, NHTSA determined that a minimum light transmittance of 70 percent is necessary to meet the need for motor vehicle safety. This is the same level of light transmittance contained in the Safety Code of the American National Stand ards Institute. If, as your letter suggests, Maryland is considering permitting vehicle owners to modify their vehicles such that their windows will have a lower level of light transmittance, we would urge you to carefully consider the safety consequenc es of such an exemption.

Please let me know if you need any further information on this subject.

ID: 86-2.37

TYPE: INTERPRETATION-NHTSA

DATE: 04/23/86

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Delta Radio Co.

TITLE: FMVSS INTERPRETATION

TEXT:

Delta Radio Co. P.O. Box 531 Spring Valley, N.Y. 10977

Gentlemen:

The enclosed publicity on the "Attention Getter" motorcycle accessory lighting device has come to our attention. It is represented as "Approved by the NHTSA". We do not know whether that is your characterization or that of the publication in which it appeared. The National Highway Traffic Safety Administration does not "approve" or endorse products. Upon request, it will provide an interpretation of whether a lighting device is regulated, permitted, or not permitted by the Federal motor vehicle safety standard on lighting. If a device is deemed permitted by the standard, in no sense should that be construed as "approved by NHTSA".

As a matter of fact, we have never been asked for an opinion of the "Attention Getter" but its installation could be viewed as impairing the effectiveness of lighting equipment required by the Federal standard (Motor Vehicle Safety Standard No. 108), and prohibited by paragraph S4.1.3 of that standard. A stop lamp is required to be steady-burning in use, and not flash as does your device, and its intensity must not exceed the maximum limits imposed by SAE Standard J586c, which is incorporated by reference into Standard No. 108. The fact that "Attention Getter"s intensity goes from "normal intensity to extra bright" raises the possibility that the maxima may be exceeded.

If you have any questions regarding your further responsibilities under the National Traffic and Motor Vehicle Safety Act, I shall be happy to answer them.

Sincerely,

Erika Z. Jones Chief Counsel

Subject: Advertisement for "Attention Getter" Date: Mar 14 1986 Motorcycle Taillight Flasher From: George L. Reagie Associate Administrator, TSP

To: Erica Z. Jones Chief Counsel, NHTSA

The attached advertisement was sent to us by Mr. Niel Tolhurst, Assistant Manager of Motorcycle Safety and Recreation for American Honda Motor Company. Mr. Tolhurst questioned the reference to "Approved by the NHTSA" in relationship to the "Attention Getter" motorcycle tail light flasher.

Since NHTSA does not approve or endorse products, I wanted to bring the advertisement to your attention so that appropriate action might be taken with the manufacturer of the product to correct the erroneous information.

Attachment

October 31, 1985

Administrator

National Highway Traffic Safety Administrator U. S. Department of Transportation 400 Seventh Street SW Washington, D.C. 20590

Dear Sir:

Enclosed is a sketch of a proposed motorcycle rear turn signal lamp positioning for some models of motorcycles. Reference is made to part 571.108, Title 49 of the CFR.

Table IV of the above cited reference specifies a minimum 9 inch horizontal separation distance. As indicated by dimension "A" this distance is 12 inches. This table also specifies that minimum edge to edge separation distance between lamp and tail or stop lamp is 4 inches. Dimension "B" indicated as 5.00 inches satisfies this requirement.

Your timely confirmation that our interpretation of this standard is correct will allow us to initiate tooling orders for 1987 model vehicles.

I will be happy to answer any questions you may have concerning the attached sketch and provide any additional information required. I may be reached at

Please receive this information as "Confidential business information" as described in 5 U.S.C. 552(6)(4). The release of details from the correspondence may provide vehicle styling information that could benefit our competitors.

Sincerely,

rn Enc.

ID: 2703y

Mr. W. Marshall Rickert
Motor Vehicle Administrator
Maryland Department of Transportation
6601 Ritchie Highway
Glen Burnie, MD 21062

Dear Mr. Rickert:

Thank you for your letter seeking this agency's opinion as to whether the State of Maryland may amend its motor vehicle regulations to permit the installation of aftermarket tinting on motor vehicle windows, for individuals who may desire this for medical reasons. I am pleased to have this opportunity to describe the legal principles that relate to your question.

The National Highway Traffic Safety Administration ("NHTSA") is responsible for issuing Federal motor vehicle safety standards that impose requirements for specific levels of safety performance for new motor vehicles and motor vehicle equipment. Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR 571.205), which has been in effect since 1968, imposes a minimum level of light transmittance of 70 percent in all areas requisite for driving visibility (which includes all windows on passenger cars). The purpose of this requirement is to ensure adequate visibility through the windows, thereby reducing the risk of a motor vehicle crash.

Although Federal motor vehicle safety standards apply directly only to new vehicles and equipment, Federal law also imposes limits on the addition of tinting materials to motor vehicle glazing after vehicles have been purchased by consumers. Pursuant to section 108(a)(2) of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1397(a)(2), manufacturers, distributors, dealers, or motor vehicle repair businesses may not "render inoperative" any equipment or element of design installed in compliance with a Federal safety standard. Thus, those businesses may not install tinting that reduces the light transmittance of windows covered by Standard 205 to a level below the Federal requirement of 70 percent, since that would make the windows "inoperative" within the meaning of Standard 205.

This Federal prohibition is similar to that imposed by section 22-104 of the Maryland Vehicle Law, which provides: A person may not willfully or intentionally remove or alter any safety device or equipment that has been placed on any motor vehicle . . . in compliance with any law, rule, regulation, or requirement of . . . the United States or of this State . . . unless the removal or alteration is permitted by rule or regulation adopted by the [Maryland Motor Vehicle] Administrator.

The "render inoperative" provision of Federal law does not apply to actions by individual vehicle owners. Therefore, each State may regulate the extent to which aftermarket tinting may be applied by vehicle owners to their own vehicles. Thus, although section 22-104 appears to preclude aftermarket tinting by any person if the result would be to reduce the level of light transmittance below 70 percent, Maryland may amend its rules or regulations to permit such tinting by individuals, for medical or any other reasons deemed valid by the State. However, Maryland has no authority to grant any exemptions, including medical exemptions, from the "render inoperative" prohibition of Federal law that applies to commercial entities. Hence, regardless of any provisions of Maryland law, no manufacturer, distributor, dealer, or motor vehicle repair business may legally install window tinting film on a vehicle, unless the vehicle continues to comply with the Federal light transmittance requirements.

In adopting Standard 205, NHTSA determined that a minimum light transmittance of 70 percent is necessary to meet the need for motor vehicle safety. This is the same level of light transmittance contained in the Safety Code of the American National Standards Institute. If, as your letter suggests, Maryland is considering permitting vehicle owners to modify their vehicles such that their windows will have a lower level of light transmittance, we would urge you to carefully consider the safety consequences of such an exemption.

Please let me know if you need any further information on this subject.

Sincerely,

Paul Jackson Rice Chief Counsel

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