ID: nht93-3.6

DATE: April 19, 1993

FROM: John Womack -- Acting Chief Counsel, U.S. Department of Transportation, NHTSA

TO: Donald L. Anglin -- Consulting Editor, MacMillan/McGraw-Hill Publishing, Automotive and Technical Writing

TITLE: None

ATTACHMT: Attached to letter date 12-30-92 from Donald L. Anglin to William A. Boehly (OCC 8223)

TEXT: This responds to your letter in which you asked whether removing the self-adjusters on a motor vehicle's drum brakes constitutes a violation of the "anti-tampering" provisions of several Federal laws, including the National Traffic and Motor Vehicle Safety Act. I am pleased to have this opportunity to explain this agency's regulations. You will need to contact the Environmental Protection Agency for an interpretation of the Clean Air Act.

By way of background information, the National Traffic and Motor Vehicle Safety Act ("Safety Act") requires this agency, the National Highway Traffic Safety Administration (NHTSA), to promulgate motor vehicle safety standards that specify performance requirements for new motor vehicles and items of motor vehicle equipment. Among the standards issued by NHTSA are Standard No. 105, HYDRAULIC BRAKE SYSTEMS and Standard No. 121, AIR BRAKE SYSTEMS. Standard No. 105 specifies requirements for hydraulic service brake and associated parking brake systems, and applies to new passenger cars, multipurpose passenger vehicles, trucks, and buses equipped with hydraulic brake systems. Standard No. 121 establishes performance and equipment requirements for braking systems on vehicles equipped with air brake systems, and applies to almost all new trucks, buses, and trailers equipped with air brake systems.

NHTSA recently amended these standards to require vehicles to be equipped with automatic brake adjusters. (57 FR 47793, October 20, 1992) This rule takes effect on October 20, 1993 for vehicles equipped with hydraulic brakes and on October 20, 1994 for vehicles equipped with air brakes. Until these effective dates, a vehicle is not required to be equipped with automatic brake adjusters.

You specifically asked about the agency's "anti-tampering" provisions. While the agency has no provision called this, the Safety Act does include a provision known as the "rendering inoperative" provision which is set forth in section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section prohibits manufacturers, distributors, dealers, and repair shops from knowingly "rendering inoperative," in whole or in part, any device or element of design installed on or in a vehicle in compliance with an applicable safety standard.

For vehicles manufactured on or after the effective date of the new requirements for automatic adjusters, manufacturers, distributors, dealers and repair businesses will be prohibited by section 108(a)(2)(A) from rendering the devices inoperative. For vehicles manufactured before that time, such an entity should ensure that removal of the adjusters does not otherwise render inoperative the compliance of the vehicle with a safety standard.

I hope this information is helpful. If you have any questions about NHTSA's safety standards, please feel free to contact Marvin Shaw at this address or by

telephone at (202) 366-2992.

ID: nht78-1.28

DATE: 01/26/78

FROM: AUTHOR UNAVAILABLE; Howard J. Dugoff; NHTSA

TO: Howard Sturtz, M.D.

COPYEE: RALPH NADER

TITLE: FMVSS INTERPRETATION

TEXT: Mr. Ralph Nader forwarded to me your letter dated November 23, 1977, concerning your difficulty in determining whether your 1977 Ford Econoline van is equipped with an energy absorbing steering column.

Ford Econoline vans are equipped with conventional steering columns that are not energy absorbing. Federal Motor Vehicle Safety Standards No. 203, Steering Control Impact protection, and No. 204, Steering Control Rearward Displacement, are currently only applicable to passenger cars, so manufacturers are not required to have energy absorbing steering columns on van vehicles. Ford has not voluntarily equipped its vans with such steering systems.

The National Highway Traffic Safety Administration shares your concern in this subject. As a matter of fact, the agency has initiated high priority rulemaking proceedings to extend the applicability of several passenger car standards, including Standards 203 and 204, to both vans and light trucks.

Please let me know if you would like further information on automotive safety matters.

Sincerely,

ATTACH.

November 23, 1977

Ralph Nader -- Washington, D.C.

Dear Mr. Nader:

I am an orthopedic surgeon and am most interested in automobile safety. I belong to various organizations regarding automotive safety. Recently, I bought a Ford Van after prolonged investigation, believing that it was safer because of a supposed impact absorbing front end. However, the brochure did not indicate whether the steering column was energy absorbing. I have checked with the dealer, a local assembly plant, as well as "Ford Listens Better." A copy of this latter letter is enclosed. I have not to date received a reply. I have also checked with various organizations, none of which will provide me with an answer. I was hoping that perhaps you could "stimulate" the Ford Motor Company to provide me with some concrete information. I suspect that vans, being considered trucks, do not have the safety features such as an energy absorbing steering wheel that automobile drivers enjoy. Apparently, the automotive industry believes that truck drivers are expendable.

Any help that you can give me in this matter would be most appreciated.

Sincerely,

Howard Sturtz, M.D.

Enclosure

October 11, 1977

Ford Listens Better P.O. Box 1973 Dearborn, Michigan

Gentlemen:

I own a 1977 Ford Econoline Van in the 250 series. I have been most unsuccessful in determining whether the van has an energy absorbing steering wheel. I have been unable to get an answer from Ford other than the usual brochure on the van which does not include this information. I have also inquired from the National Safety Council and other agencies without success. I would appreciate it if you can inform me as to the type of steering column in the van and what the results might be in a front-end collision.

Sincerely,

Howard Sturtz, M.D.

ID: nht72-6.61

DATE: DECEMBER 28, 1972

FROM: TATSUO KATO -- ENGINEERING REP, NISSAN MOTOR CO., LTD.

TO: LAWRENCE SCHNEIDER -- NHTSA

COPYEE: J. W. CARSON

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED FEBRUARY 16, 1973 FROM E.T. DRIVER, NHTSA, TO TATSUO KATO, NISSAN MOTOR CO.

TEXT: This is to request the answer to the following questions regarding MVSS 124 which we explained at a meeting held in the Office of NHTSA, on Friday, December 8, 1972.

1. We are using a two-barrel, down draft type carburetor with a linkage as shown in the attached schematic drawing (see Figure 1). We have designed the accelerator control system that has at least two sources of energy capable of returning the throttle to the idle position, that is, whenever the driver removes the opposing actuating force, the primary valve of the carburetor is closed by sources of energy of spring A and B and the secondary valve is done by spring A, B and C. Although in the event of failure of the spring C, the secondary valve is usually returned to the initial closed position by the lever L which is actuated by the torsion spring A and B as explained at the meeting, there is a possibility of slightly opening the secondary valve because of endplay by the tolerance of the production so that engine speed might slightly increase more than engine idle speed specified in our manuals.

Under the aforementioned situation, may be understand that the increase of engine idle speed resulting from the endplay caused by failure of the spring C will not be included in the scope of "Overspeed" which is stated in S2 of MVSS 124, that is, in the case of malfunctions, tolerance to the idle speed will be accepted by NHTSA.

If the tolerance is accepted, we would like to know the acceptable range (if possible, by rpm = revolution per minute of engine) of the increase of engine idle speed.

2. It is difficult to decide the components of accelerator control system which we have to consider a severence or disconnection which is specified in MVSS 124, S5.2, "The throttle shall return to the idle position from any accelerator position or any speed of which the engine is capable whenever any one component of the accelerator control system becomes disconnected or severed!'

Under the abovementioned situation, in case of our model PL610, we do not consider breakage of parts such as mounting brackets or mounting bolts as a portion of severence or disconnection, but we do only the portion with the mark X in the attached drawing. (see Figure 2). May we understand the definition of the portion of severence or disconnection as mentioned above?

Your prompt reply would be greatly appreciated.

Attachments

CONDITION OF FULL THROTTLE

In case of breakage of Spring "C" secondary valve is returned - by Linkage L.

Condition of Secondary Valve with possibility of opening.

(Graphics omitted)

FIGURE 2 SIDE VIEW

Graphics omitted)

FIGURE 2 FRONT VIEW

Graphics omitted)

ID: nht75-6.26

DATE: 06/02/75

FROM: JAMES B. GREGORY -- NHTSA ADMINISTRATOR

TO: DAVID E. MARTIN -- DIRECTOR AUTOMOTIVE SAFETY ENGINEERING GENERAL MOTORS CORPORATION

TITLE: N40-30

TEXT: Dear Mr. Martin:

This responds to your December 17, 1974, and March 31, 1975, letters asking whether your proposed inertia seatback latch meets the requirements of Federal Motor Vehicle Safety Standard No. 207, Seating Systems.

After carefully examining the mechanism, considering General Motors' arguments in its favor, and meeting twice with GM representatives, we have decided that the proposed inertia latch would not comply with S4.3.1 of FMVSS 207 unless an emergency release were added to enable someone to override the automatic locking mechanism when necessary.

We agree with GM that the proposed seatback latch is an improvement in some respects over current designs. The latch provides added convenience for rear seat occupants since under normal circumstances they may fold the seat forward by simply pushing on the seatback. We also recognize that there may be a safety advantage in certain circumstances requiring fast exit from the vehicle in that the passenger will not have to fumble for a latch, which, though readily accessible, is neither in the same location nor operated in a similar manner in all cars. Your proposed design also avoids a serious problem of some current latches: namely, that they will not release if even light pressure is applied against the seatback in a forward direction. The National Highway Traffic Safety Administration is seriously considering action on this problem.

Despite these advantages, GM's proposed inertia latch would satisfy neither the intent nor the wording of S4.3.1 of FMVSS 207 because it would not release when the vehicle is upside down or upright at a pitch attitude exceeding a 32% downgrade. Such vehicle positions are not uncommon in accident situations and GM's own figures indicate that "100 rear seat occupants per year could be hindered in leaving the vehicle under circumstances which would make prompt egress important." S4.3.1 requires that "the control for releasing the (self-locking seatback) device shall be readily accessible to the occupant of the seat . . . and . . . to the occupant of the designated seating position immediately behind the seat." Under normal conditions the seatback itself would be the control for your latch and it is certainly readily accessible. When the vehicle is nose down or inverted, however, the seatback would not perform this function and there would consequently be no readily accessible control for releasing the self-locking device.

Because it is often important for passengers in post-accident situations immediately to leave or be removed from a vehicle, for any number of reasons including fire, serious bleeding or hazardous vehicle location, it seems especially important that a seatback release control operate under these circumstances. Adding an emergency latch lock override to the inertia latch design would avoid this problem while retaining the previously mentioned advantages of your design.

Sincerely,

ID: nht91-5.11

DATE: July 31, 1991

FROM: Wayne Trueman -- Plant Manager, BX-100

TO: Barry Felrice -- Associate Administrator of Rulemaking, U.S. D.O.T.

TITLE: None

ATTACHMT: Attached to letter from Paul Jackson Rice to Wayne Trueman (A38; Std. 121); Attached to letter dated 9-24-91 from Wayne Trueman to Marvin Shaw

TEXT:

Once again please allow me to take this opportunity to thank you and your staff for the prompt response you gave to my previous inquiries to your office.

Currently, our BX-100 Brake Equalizers are being specified by numerous customers for installation on their new equipment (tractor and trailer) orders at the factory. There have been several inquiries by school districts from several states in reference to having these units retrofitted onto their current stock of school buses or included into the specification for their new bus orders. However, current California law requires that written approval be obtained from the chassis manufacturer prior to making any "Brake System Modifications ". (ref. California Highway Patrol Title 13, Section #1246c. - copy attached).

What we are trying to determine now is: 1. Whether or not a similar written authorization requirement exists for some or all other states in reference to school buses.

2. Are there any special regulations pertaining to school buses that need to be considered prior to installing or retrofitting product into their air brake systems.

Or are the remaining states simply subject to compliance with current FMVSS 121 regulations?

The effectiveness of the BX-100 Brake Equalizer has been documented by independent test labs, customer conducted tests and testing done with a "Minnetonka Warehouse" VC200 de-accelerotometer. I am enclosing a copy of the tests done at Nevada Automotive Test Center, and two "G" Force graphs done from the information obtained with the deaccelerometer. These and other tests have been done on a variety of air brake equipped vehicles both before and after installation of the BX-100 Brake Equalizers. The results consistently indicate shorter stopping distance with less application pressure, and increased driver control which allows the vehicle to stop in a straight line.

Once again, I would like to thank you in advance for your assistance on this matter. If we are successful in penetrating this market, the test and actual end user results, indicate that we will be instrumental in avoiding accidents and saving many lives.

Attachment A

California Highway Patrol Title 13 Section 1246C School Bus Brakes (text omitted)

Attachment B

Nevada Automotive Test Center Final Report for BX-100 International, Inc.

Brake Test Evaluations for the BX-100 Brake Equalizer Authorization: Purchase Order No: Verbal NATC Project No: 20-17-404 October 1989 Prepared by: Gene Smith Test Engineer

Nevada Automotive Test Center P.O. Box 234, Carson City, Nevada 89702 Telephone No. (702) 882-3261

(Text and graphics omitted)

ID: nht95-6.12

TYPE: INTERPRETATION-NHTSA

DATE: August 14, 1995 EST

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Isaias Rios -- Product Engineering Department, Rines de Acero K-H, S.A. de C.V.

TITLE: NONE

ATTACHMT: ATTACHED TO 6/29/95 LETTER FROM ISAIAS RIOS TO MARVIN SHAW (OCC 11007)

TEXT: Dear Mr. Rios:

This responds to your letter of June 29, 1995, to Marvin Shaw of this office requesting information on obtaining a certification from the U.S. that the wheels you supply to automobile manufacturers in Mexico comply with Federal Motor Vehicle Safety Standard (FMVSS) Nos. 110 and 120.

You explained in your letter and in telephone conversations with Walter Myers of this office that your company supplies steel and aluminum passenger car wheels to automobile manufacturers located in Mexico. You stated that Nissan Mexicana requires from you a certificate demonstrating compliance with FMVSS Nos. 110, Tire Selection and Rims, and 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars. Your letter asked how to obtain such a certification and for information on other responsible U.S. government agencies and approved test labs.

On July 21, Mr. Myers telefaxed you copies of two interpretative letters previously issued by this office, one to Mr. Ralph Trimarchi dated February 11, 1985, and one to Mr. Jay D. Zeiler dated November 20, 1977. We explained in those letters that U.S. law requires motor vehicle and equipment manufacturers to self-certify their products and that the U.S. government does not test or certify products prior to first retail sale. Rather, this agency, the National Highway Traffic Safety Administration (NHTSA), randomly tests vehicles and equipment for compliance with the FMVSSs. Mr. Myers also telefaxed you copies of FMVSS Nos. 110 and 120 on July 24, 1995.

We would like to advise you of another issue. 49 Code of Federal Regulations (CFR) Part 566 (copy enclosed) requires manufacturers of motor vehicle equipment to which an FMVSS applies (referred to in the regulation as "covered equipment," such as wheels) to submit its name, address, and a brief description of the items of equipment it manufactures to NHTSA. NHTSA requires that information from an equipment manufacturer even though the equipment manufacturer does not directly sell its products in the U.S. but supplies them to foreign vehicle manufacturers who sell their vehicles in the U.S. (see enclosed copy of NHTSA letter to Mr. K. Nakajima, dated January 6, 1972). Therefore, if your company has not already done so, please submit the information required by Part 566 to the Administrator of NHTSA within thirty days after receipt of this letter. No forms or prescribed format is required. A standard letter is sufficient.

I hope this information is helpful to you. Should you have any further questions or need any additional information, please feel free to contact Mr.

Myers at this address or by telephone (202) 366-2992 or telefax (202) 366-3820.

ID: nht95-3.86

TYPE: INTERPRETATION-NHTSA

DATE: August 11, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Isaias Rios -- Product Engineering Department, Rines de Acero K-H, S.A. de C.V.

TITLE: NONE

ATTACHMT: ATTACHED TO 06/29/95 LETTER FROM ISAIAS RIOS TO MARVIN SHAW (OCC 11007)

TEXT: Dear Mr. Rios:

This responds to your letter of June 29, 1995, to Marvin Shaw of this office requesting information on obtaining a certification from the U.S. that the wheels you supply to automobile manufacturers in Mexico comply with Federal Motor Vehicle Safety Stand ard (FMVSS) Nos. 110 and 120.

You explained in your letter and in telephone conversations with Walter Myers of this office that your company supplies steel and aluminum passenger car wheels to automobile manufacturers located in Mexico. You stated that Nissan Mexicana requires from you a certificate demonstrating compliance with FMVSS Nos. 110, Tire Selection and Rims, and 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars. Your letter asked how to obtain such a certification and for information on other resp onsible U.S. government agencies and approved test labs.

On July 21, Mr. Myers telefaxed you copies of two interpretative letters previously issued by this office, one to Mr. Ralph Trimarchi dated February 11, 1985, and one to Mr. Jay D. Zeiler dated November 20, 1977. We explained in those letters that U.S. law requires motor vehicle and equipment manufacturers to self-certify their products and that the U.S. government does not test or certify products prior to first retail sale. Rather, this agency, the National Highway Traffic Safety Administration (NHT SA), randomly tests vehicles and equipment for compliance with the FMVSSs. Mr. Myers also telefaxed you copies of FMVSS Nos. 110 and 120 on July 24, 1995.

We would like to advise you of another issue. 49 Code of Federal Regulations (CFR). Part 566 (copy enclosed) requires manufacturers of motor vehicle equipment to which an FMVSS applies (referred to in the regulation as "covered equipment, such as wheel s) to submit its name, address, and a brief description of the items of equipment it manufactures to NHTSA. NHTSA requires that information from an equipment manufacturer even though the equipment manufacturer does not directly sell its products in the U.S. but supplies them to foreign vehicle manufacturers who sell their vehicles in the U.S. (see enclosed copy of NHTSA letter to Mr. K. Nakajima, dated January 6, 1972). Therefore, if your company has not already done so, please submit the information r equired by Part 566 to the Administrator of NHTSA within thirty days after receipt of this letter. No forms or prescribed format is required. A standard letter is sufficient.

I hope this information is helpful to you. Should you have any further questions or need any additional information, please feel free to contact Mr. Myers at this address or by telephone (202) 366-2992 or telefax (202) 366-3820.

ID: nht95-3.89

TYPE: INTERPRETATION-NHTSA

DATE: August 14, 1995 EST

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Isaias Rios -- Product Engineering Department, Rines de Acero K-H, S.A. de C.V.

TITLE: NONE

ATTACHMT: ATTACHED TO 6/29/95 LETTER FROM ISAIAS RIOS TO MARVIN SHAW (OCC 11007)

TEXT: Dear Mr. Rios:

This responds to your letter of June 29, 1995, to Marvin Shaw of this office requesting information on obtaining a certification from the U.S. that the wheels you supply to automobile manufacturers in Mexico comply with Federal Motor Vehicle Safety Stand ard (FMVSS) Nos. 110 and 120.

You explained in your letter and in telephone conversations with Walter Myers of this office that your company supplies steel and aluminum passenger car wheels to automobile manufacturers located in Mexico. You stated that Nissan Mexicana requires from you a certificate demonstrating compliance with FMVSS Nos. 110, Tire Selection and Rims, and 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars. Your letter asked how to obtain such a certification and for information on other resp onsible U.S. government agencies and approved test labs.

On July 21, Mr. Myers telefaxed you copies of two interpretative letters previously issued by this office, one to Mr. Ralph Trimarchi dated February 11, 1985, and one to Mr. Jay D. Zeiler dated November 20, 1977. We explained in those letters that U.S. law requires motor vehicle and equipment manufacturers to self-certify their products and that the U.S. government does not test or certify products prior to first retail sale. Rather, this agency, the National Highway Traffic Safety Administration (NHT SA), randomly tests vehicles and equipment for compliance with the FMVSSs. Mr. Myers also telefaxed you copies of FMVSS Nos. 110 and 120 on July 24, 1995.

We would like to advise you of another issue. 49 Code of Federal Regulations (CFR) Part 566 (copy enclosed) requires manufacturers of motor vehicle equipment to which an FMVSS applies (referred to in the regulation as "covered equipment," such as wheels ) to submit its name, address, and a brief description of the items of equipment it manufactures to NHTSA. NHTSA requires that information from an equipment manufacturer even though the equipment manufacturer does not directly sell its products in the U .S. but supplies them to foreign vehicle manufacturers who sell their vehicles in the U.S. (see enclosed copy of NHTSA letter to Mr. K. Nakajima, dated January 6, 1972). Therefore, if your company has not already done so, please submit the information r equired by Part 566 to the Administrator of NHTSA within thirty days after receipt of this letter. No forms or prescribed format is required. A standard letter is sufficient.

I hope this information is helpful to you. Should you have any further questions or need any additional information, please feel free to contact Mr.

Myers at this address or by telephone (202) 366-2992 or telefax (202) 366-3820.

ID: nht69-2.27

DATE: 10/03/69

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Harbors Trailers Inc.

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letters of August 12 and September 4, 1969 in which you asked several questions about the responsibilities under the National Traffic and Motor Vehicle Safety Act of companies that assemble bodies to chassis. I have taken the liberty of restating your questions.

What does a person who assembles truck bodies to chassis certify, and on what basis: Such an assembler is a manufacturer" under the Act, and the vehicles that he assembles must be certified by him as conforming to all applicable standards. The primary responsibility for conformity of the chassis-cab, however, falls on the manufacturer of it (generally a major automotive manufacturer), and under the regulations that manufacturer is required to affix to label to the chassis-cab listing the standards to which it conforms. Under section 108(b)(2) of the Act, such a certification protects subsequent persols in the chain of distribution from liability from noncenformity of while they have no knowledge. Thus, the body assembler is directly responsible for conformity of the finished vehicle with (1) any applicable standard to which the chassis-cab manufacturer has not certified, and (2) any other standards conformity to which is affected by what the assembler does to the vehicle. His certification must be for all standards, in the language specified in the certification regulations, but he can rely on the interim certification of the chassis-cab manufacturer for the standards it covers, as long as he does not know of any nonconformity.

What are the applicable standards? The applicable standards for a vehicle manufactured by assembling a body to a chassis-cab are those in effect on the date on which the chassis-cab was completed. This date appears on the label that the chassis-cab manufacturer must affix to the chassis-cab.

What is the vehicle identification number that must appear on the assembler certification label? At present there is not a safety standard relative to a vehicle identification number for vehicles other than passenger cars. The vehicle identification number to be affixed to the completed vehicle under the certification regulations, therefore, should be a number assigned to the vehicle by the assembler, by which he can identify the vehicle on request of an investigating agency such as the Federal Highway Administration.

Is there any requirement for certification of truck bodies separately from the assembled vehicles? No. A truck body is not a "motor vehicle" within the meaning of the Act and the regulations, and therefore is not covered by the present Certification Regulations (49 CFR Part 367). Although it is "motor vehicle equipment", such equipment is only required by the Act to be certified where there is a safety standard applicable directly to it; and there are none at present for truck bodies. When the body is assembled to the chassis, the completed vehicle must be certified in accordance with the Certification Regulations, as explained above.

I am enclosing a copy of the current standards and regulations. We are pleased to be of assistance.

ID: nht70-1.43

DATE: 02/25/70

FROM: AUTHOR UNAVAILABLE; F. C. Turner; NHTSA

TO: FWD Corporation

TITLE: FMVSS INTERPRETATION

TEXT: RE: PETITION FOR RULEMAKING

This is in reply to your letter of October 16, 1969, requesting an exception from Paragraph S3.1 of Federal Motor Vehicle Safety Standard No. 205 ("Glazing Materials - Passenger Cars, Multipurpose Passenger Vehicles, Motorcycles, Trucks and Buses"), to allow the use of Lemen and Plexiglas in certain specified locations in twenty-one (21) fire fighting vehicles to be delivered to the city of New York.

You state the purpose of your request is to provide better protection for occupants of these fire fighting vehicles from objects thrown at them when, for example, the vehicles are enroute to a fire. Further, you state the use of these materials would eliminate replacing safety glass, which can be broken when hit by small objects. Because you are requesting a change in an existing standard your letter has been treated as a petition for rulemaking to amend Standard No. 205, pursuant to the provisions of 49 CFR @@ 353.31, 353.33. For the reasons stated below, your petition is denied.

It is not completely clear from your letter and the enclosed drawing where the interior or canopy partitions in which you wish to use Lexen and Plexiglas are located. Standard No. 205 presently permits the use of rigid plastics in interior partitions of fire fighting vehicles if these materials meet the requirements for plastics designated AS4 and AS5 (the latter can only be used when not requisite for driving visibility) in American Standards Association Test Z26.1-1966, July 15, 1966. We understand that Plexiglas meets these requirements and may therefore be used in this location. We also understand, however, that Lexen does not, failing specifically to meet certain chemical and abrasion resistance requirements applicable to AS4 and AS5 rigid plastics under the Standard. If our understanding regarding Lexen is correct, we believe its failure to meet these minimum requirements renders its unsuitable for use in areas of motor vehicles where a possible loss of transparency may affect the safe operation of the vehicle.

With reference to glazing in side and door windows of fire fighting vehicles, Standard No. 205 allows the use of glazing specified AS1, AS2, and AS10 in ASA Test-226.1-1966 and also allows the use of AS11 and AS3 glazing at levels not requisite for driving visibility. This glazing may be either laminated, tempered, or bullet resistant safety glass meeting the applicable requirements. Plastics meeting AS4 and AS5 requirements, while appropriate for certain locations such as partitions, are not considered appropriate for use in side and door windows as they do not possess chemical and abrasion resistance qualities necessary for exterior glazing and which the types of safety glass specified above possess. The occupant protection which you desire can be provided by using AS10 (and AS11 where appropriate) bullet resistant glass which contains both structural advantages over normally used safety glazing and satisfactory chemical and abrasion resistance for use in side and door windows.