ID: nht92-2.21

DATE: November 18, 1992

FROM: L. J. Sharman

TO: NHTSA, Department of Transportation

TITLE: None

ATTACHMT: Attached to letter dated 3-23-93 from John Womack to L. J. Sharman (A40; Std. 302)

TEXT: Recently, two questions have arisen concerning the procedure to be followed when conducting the flammability test method specified in Motor Vehicle Safety Standard No. 302. Each of the questions, the writers answer and rationale are given on the attached sheets. I am writing to request an advisory opinion as to whether these answers are correct, if not what the correct interpretation should be.

Thank you for your prompt attention to this matter.

QUESTIONS CONCERNING THE FLAMMABILITY TEST PROCEDURE SPECIFIED IN MVSS-302

QUESTION 1.

MVSS-302, in Section S5.3(e), states that the timing for each specimen be started when the flame from the burning specimen reaches a point 1.5 inches from the open end of the specimen and, in Section S5.3(f), is stopped when the flame progresses to a point 1.5 inches from the clamped end of the specimen. Further, the Standard, in Section S5.2.2, states the specimen is oriented so that the surface closest to the occupant compartment air space faces downward on the test frame. The question that has been raised is whether the timing is started and stopped when the flame reaches the designated points on the surface of the specimen closest to the occupant compartment air spaces (the surface facing down during the test), or when the flame reaches the designated points on the surface of the specimen facing away from the occupant compartment air space (the surface facing up during the test).

ANSWER

Timing of the flame should start when the flame from the burning specimen reaches the 1.5 inch point on the surface facing up during the test and stopped when the flame progresses to a point 1.5 inches from the clamped end of the specimen on the surface facing up during the test.

RATIONALE

The Standard states that the bunsen burner and the specimen are positioned so that the center of the bottom edge of the open end of the specimen. While the Standard does not specify how far above the cabinet floor the specimen must be located, the bunsen burner and flame height specified above effectively define this distance. At that height, it is extremely difficult if not impossible to observe the flame front underneath the specimen. If the intent of the standard was to observe the flame front test cabinet floor or some other means of

observing the flame front. Since NHTSA did not make such requirements, the logical location points for starting and stopping the timing are on the surface facing up during the test.

QUESTION 2.

MVSS-302, in Section S5.3(f), states that the flame progression be measured to a point 1.5 inches rom the clamped end of the specimen under test. The standard does not specify actions to be taken after timing has stopped. Some laboratories put out the flame using a small amount of water from a spray bottle. The question has been raised as to whether using a small amount of water from a spray bottle to put out the flame is an acceptable procedure.

ANSWER

The use of a small amount of water from a spray bottle is believed to be acceptable.

RATIONALE

The primary concern with the use of water to put out the flame is whether the water would affect the humidity in the test chamber and, therefore, the test results. MVSS 302 states in Section S5.1.2 that prior to testing each specimen be conditioned at a temperature of 70 degrees F. and a relative humidity of 50 percent, and the test be conducted under those ambient conditions. The Standard does not specify the humidity limits within which the test must be conducted. Considering the short time the specimen is in the chamber before burning and the small amount of water used it is believed that the humidity would not be significantly affected and therefore the procedure to be both acceptable and a good safety precaution.

ID: NCC-231206-001 - Steptoe VanHool FMVSS 217 Emergency Exit Requirements 11-25-2024 signed

November 25, 2024 

David H. Coburn Steptoe LLP 

1330 Connecticut Avenue, NW 

Washington, DC 20036-1795 

Dear Mr. Coburn: 

This responds to your letter dated December 5, 2023, on behalf of Belgium-based bus manufacturer Van Hool NV regarding the emergency exit identification requirements under 49 C.F.R. § 571.217 S5.5.1 for buses other than school buses. You asked whether the requirements under S5.5.1 to designate emergency exits and provide concise operating instructions for these exits may be satisfied by pictograms, without the use of text. This letter responds to that request. 

In responding, the National Highway Traffic Safety Administration (NHTSA) notes that the contents of this letter do not have the force and effect of law and are not meant to bind the public in any way. This letter is only intended to provide clarity regarding existing requirements under the law at the time of signature. 

Section 5.5.1 requires in pertinent part: 

For buses other than school buses…each emergency exit door shall have the designation “Emergency Door” or “Emergency Exit,” and every other emergency exit shall have the designation “Emergency Exit” followed by concise operating instructions describing each motion necessary to unlatch and open the exit, located within 16cm of the release mechanism. 

S5.5.1 provides explicit designation requirements. The use of quotations in the standard indicates that the exact words “Emergency Door” or “Emergency Exit” are necessary for compliance and that a pictogram by itself will not suffice. Thus, a pictogram may not be provided in lieu of text. This position aligns with NHTSA’s earlier interpretation in Letter to Vincent P. Schulze (June 22, 1998).1 

With regard to the “concise operating instructions” required by the standard, S5.5.1 does not set forth explicit language that must be used, nor does it otherwise expressly prohibit the use of pictograms, symbols, icons or similar. The standard requires only that the instructions “describ[e] each motion necessary to unlatch and open the exit.” It further provides examples of operating instructions as follows: “(1) Lift to Unlatch, Push to Open; and (2) Lift Handle and Push out to Open.”

1 Available at www.nhtsa.gov/interpretations/17175drn (declining the use of a symbol in lieu of words for emergency egress windows). 

While the text examples provided in the standard are not exhaustive given the breadth of variation in vehicle emergency exit design, NHTSA emphasizes the need to ensure that passengers can quickly access both the emergency exit and the instructions for the exit’s release mechanism. The agency has noted that “[i]n an emergency, persons are used to finding an emergency exit where they see a label with the designation ‘Emergency Exit.’”2 Moreover, the standard “nowhere draws any distinction between markings designating an exit as an emergency exit and markings setting forth operating instructions for the emergency exit.”3 This interpretation suggests that both the emergency exit designation and the operating instructions were intended to be text-based. 

Diluting the emergency egress marking requirements would be consequential to motor vehicle safety.4 At present, the agency has no data to support that a particular set of pictograms5 will be easily and universally understood by bus passengers in the United States. That U.N. Regulation No. 1076 allows for safety sign pictograms and has been accepted in the European Union7 does not inform or guarantee that an American audience will understand and accept the same pictograms. 

As you acknowledged, NHTSA intends its policies to both promote international harmonization and avoid unnecessary design restrictions. If a manufacturer wishes to produce vehicles with pictorial emergency egress markings not currently permitted under Standard 217, it may elect to file a petition for rulemaking on the issue. 

I hope this information is helpful. If you have any further questions, please feel free to contact Evita St. Andre of my staff at this address or (617) 494-2767. 

Sincerely,
ADAM RAVIV
Adam Raviv Chief Counsel

Dated: 11/25/24
Ref: Standard No. 217 

2 Letter to John G. Sims (Jan. 26, 1990), available at www.nhtsa.gov/interpretations/nht90-124.
3 Id.
4 See Denial of a Petition for Forest River Inc., 86 FR 56351 (Oct. 8, 2021) (misplacement of the emergency egress labels by 9cm).
5 Van Hool submitted that NHTSA may require that pictograms used to comply with S5.5.1 adhere to either the International Organization for Standardization (ISO) standard 3864-1:2011, paragraph 6.5, or the American National Standards Institute (ANSI) standard Z535.
6 U.N. Regulation 107, “Concerning the Adoption of Harmonized Technical United Nations Regulations for Wheeled Vehicles, Equipment and Parts which can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for Reciprocal Recognition of Approvals Granted on the Basis of these United Nations,” Revision 8 (Feb. 14, 2023), available at unece.org/sites/default/files/2023-02/R107r8e.pdf
7 Framework Regulation (EU) 2018/858 of the European Parliament and of the Council (May 30, 2018), available at
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:02018R0858-20230730&qid=1699805899877

ID: aiam2157

Dear Ms. Freeston: This is in response to your letter of February 10, 1976, in which yo request our opinion concerning the applicability of Federal Motor Vehicle Safety Standard No. 302 to mattresses.; You are correct in saying that the amendment to S4.2 of Standard No 302, promulgated on March 31, 1975 (40 FR 14318), extends the coverage of the standard to '(a)ny portion of a single or composite material which is within 1/2 inch of the occupant compartment air space...' S4.1 of the standard provides, however, that '(t)he portions described in S.4.2 of the following components shall meet the requirements (of the standard)....' S4.1 then lists the components to which the standard applies. While mattress covers are included in the listing, mattresses are not. Consequently, Standard No. 302 does not apply to mattresses as such.; You should be aware that a notice of proposed rulemaking was als issued on March 31, 1975 (40 FR 14340) proposing that any material within 1/2 inch of the occupant compartment air space meet the requirements of the standard. Should this proposal be adopted, mattresses would fall within the purview of Standard No. 302. I have enclosed a copy of the proposed rule for your further information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: aiam0792

Dear Mr. Mulvey: Thank you for your letter of June 28, 1972, inquiring about th applicability of Federal Motor Vehicle Safety Standard No. 302 to safety glazing.; Safety glazing is not included in the list of motor vehicle interio materials to which Standard No. 302 applies. However, if your plastic material is used as all or part of a component of vehicle occupant compartments included under S4.1 of the standard, then, it is required to meet the requirements of Standard No. 302. A copy of this standard is enclosed for your reference.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs;

ID: 17893a.df

Mr. Bobby Puett
President
Diversified Testing Laboratories, Inc.
336 West Front Street
P.O. Box 4004
Burlington, North Carolina 27215

Dear Mr. Puett:

This responds to your letter concerning the test procedures in Federal Motor Vehicle Safety Standard No. 302, Flammability of Interior Materials. I apologize for the delay in my response.

You explain that you tested a lightweight coated fabric both with and without support wires and had dramatically different test results. You state that when you tested the fabric without the support wires, the fabric burned at a rate of 15 inches per minute and failed the test (the standard limits the burn rate to not more than 4 inches per minute). In addition, the testing specimen bent slightly during the test. You explain further that when you tested the fabric with support wires and a U-shaped frame as specified in Standard 302, the fabric "ignited but self-extinguished upon contact with the second cross wire from the end of the frame" and passed the test. You express concern over the variation in test results and ask when to use a frame with support wires and where to place the support wires during testing.

Section S5.1.3 of Standard 302 states, in relevant part, that:

A specimen that softens and bends at the flaming end so as to cause erratic burning is kept horizontal by supports consisting of thin, heat resistant wires, spanning the width of the U-shaped frame under the specimen at 1-inch intervals. A device that may be used for supporting this type of material is an additional U-shaped frame, wider than the U-shaped frame containing the specimen, spanned by 10--mil wires of heat resistant composition at 1-inch intervals, inserted over the bottom U-shaped frame.

The National Highway Traffic Safety Administration cannot specify, outside of the context of a compliance test, whether it will use support wires to test your material. As a matter of policy, a decision to use wires is made only in the context of compliance testing. The agency decides to use wires based on observations made in previously-conducted compliance tests of the specimen, or on the agency's knowledge of or testing experience with components that are highly similar to a test specimen. We note that the test condition noted in S5.1.3 should be read as a whole. Thus, the supplemental supports are only to be used if the specimen (1) softens and bends at the flaming end (2) so as to cause erratic burning. The agency does not use support wires in situations of erratic burning alone.

If you have any questions, please contact Nicole Fradette at this address or by phone at (202) 366-2992.

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:302
d.11/24/98

ID: aiam4692

"Dear Mr. Higgins: This responds to your letter on behalf o Skill-Craft Enterprises, which is designing and manufacturing a fiberglass seat to be installed in the bed of a pickup truck. You were interested in learning which of the Federal motor vehicle safety standards would apply to this product. You indicated that you believed Standards No. 207, 209, 210, and 'possibly 302' would apply to this seat. I am enclosing a December 1, 1986 interpretation letter from this office to Mr. Scott Muirhead, which explains the application of NHTSA's safety standards and regulations to seats in the cargo bed of a pickup. You will see that this letter specifically addresses the applicability of Standards No. 207, 208, 209, and 210 to such seats. I am also enclosing an information sheet for new manufacturers that briefly describes our laws and regulations, and explains how to get copies of those laws and regulations. You also asked whether Standard No. 302, Flammability of Interior Materials, would apply to your client's product. That standard applies only to new vehicles in areas located in the 'occupant compartment air space,' which the standard defines as 'the space within the occupant compartment that normally contains refreshable air.' I am enclosing a copy of a February 15, 1983 interpretation to Mr. H. Nakaya in which the agency explained that the determination of whether any particular area is within the 'occupant compartment air space' turns on whether people can and do ride in the area in question. Given that your client's product is a seat, it is designed and intended so that people will ride in it. Hence, the area around the seat would be an area where people could and would ride, and would be considered within the 'occupant compartment air space.' Section S4.1 of Standard No. 302 expressly lists seat cushions, seat backs, and seat belts as items of equipment that must meet the flammability resistance requirements of section S4.3. Based on the above, we conclude that a seat installed as original equipment in the bed of a pickup would be required to comply with Standard No. 302. If the seat will be sold exclusively as an item of aftermarket equipment, Standard No. 302 would not directly apply to it. Nevertheless, other Federal laws indirectly affect your client's manufacture and sale of such a seat in the aftermarket. Section 108(a)(2)(A) of the Act states: '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 ...' This section requires manufacturers, distributors, dealers or motor vehicle repair businesses (i.e., any person holding him or herself out to the public as being in the business of repairing motor vehicles or motor vehicle equipment for compensation) to ensure that any aftermarket installations of additional equipment or vehicle modifications its addition would not negatively affect the compliance of any component or design on a vehicle with applicable Federal safety standards. Section 109 of the Act specifies a civil penalty of up to $1,000 for each violation of this 'render inoperative' provision. Your client should also be aware of an additional aspect of the Safety Act. As a manufacturer of motor vehicle equipment, your client is also subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects relating to motor vehicle safety. I have enclosed an information sheet that briefly describes those responsibilities. In the event that your client or NHTSA determines that the seats contain a safety related defect, it would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. If you have any further questions or need additional information on this subject, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Stephen P. Wood Acting Chief Counsel Enclosures";

ID: 571.205 Plexiglass Barriers (002)

Mr. Mike Collingwood

Illinois Department of Transportation

2300 South Dirksen Parkway, Room 305

Springfield, IL 62764                       

August 11, 2020

Dear Mr. Collingwood:

This responds to your two inquiries to the National Highway Traffic Safety Administration (NHTSA) about the installation of barriers in school buses to minimize the spread of the Coronavirus Disease 2019 (COVID-19). In your June 16, 2020 email, you ask about the installation of “plexiglass barriers” installed to the right of, and behind, the driver’s seating position. In a later email, you ask about the installation of clear plastic “soft shields” that would be installed to the immediate right of and behind the driver, and/or installed throughout the passenger compartment by attachment to the interior roof of the school bus and to the seat backs of the passenger seats. As explained below, NHTSA’s regulations would permit the installation of the barriers, subject to the requirements discussed in this letter.

Please note that our answer below is based on our understanding of the specific information provided in your email. This interpretation letter does not have the force and effect of law and is not meant to bind the public in any way. This letter is intended only to provide clarity to the public regarding existing requirements under the law, and represents the opinion of the agency on the questions addressed in your email at the time of signature.

Background 

NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act, 49 U.S.C. Chapter 301) to issue Federal motor vehicle safety standards (FMVSS) that set performance requirements for new motor vehicles and new items of motor vehicle equipment. The Safety Act requires manufacturers to self-certify that their vehicles and equipment conform to all applicable FMVSS in effect on the date of manufacture. NHTSA also investigates safety- related defects.

Based on your description of the barriers and the photos you provided, the plexiglass material of the barrier and transparent flexible material of the shield would be motor vehicle “glazing” that must comply with FMVSS No. 205, “Glazing materials.” FMVSS No. 205 applies to glazing installed in motor vehicles prior to first purchase and to aftermarket glazing for use in motor vehicles. The standard incorporates by reference an industry standard, the “American National Standards Institute American National Standard for Safety Glazing Materials for Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land Highways-Safety Standard” (ANSI/SAE Z26.1-1996). FMVSS No. 205 and ANSI/SAE Z26.1-1996 specify performance requirements for various types of glazing, called “Items,” and specify the locations in vehicles in which each item of glazing may be used. As motor vehicle glazing, the transparent material of the barrier or shield must meet the requirements of FMVSS No. 205 and be certified as meeting that standard by the prime glazing manufacturer, and, if applicable, the manufacturer or distributor who cuts the glazing into components for use in motor vehicles or items of motor vehicle equipment. If an entity, in assembling the barrier or shield, cuts the glazing, it must ensure the glazing meets the requirements of FMVSS No. 205, and must certify its compliance pursuant to S6.3 of FMVSS No. 205.1 Anyone who assembles and markets an aftermarket barrier or shield would be a manufacturer of motor vehicle equipment and be responsible for ensuring the product is free from safety-related defects. If the assembler or NHTSA finds the product to contain a safety-related defect, the assembler would be responsible for conducting a recall campaign as required under 49 U.S.C. §§ 30118-30120. 

Discussion 

Plexiglass Barriers. You ask about plexiglass barriers installed in school buses to the right of and just behind the driver. Assuming the barriers are comprised of plexiglass (or similarly rigid transparent material), NHTSA would consider them to be “interior partitions.”2 This classification is important as it, along with the location of the glazing in the vehicle, determines which types of glazing may be used.

Depending upon where the glazing is placed, it may be considered “requisite for driving visibility” and subject to heightened requirements. On buses, the windows deemed requisite for driving visibility are windows to the immediate right or left of the driver and the front windshield.3 (Any portion of glazing that the driver would have to see through to view the windows requisite for driving visibility would also be considered requisite for driving visibility.) You describe the barriers as being located to the right of the driver and immediately behind the driver. Of these locations, only the first would be considered requisite for driving visibility on buses.

Glazing for interior partitions on buses in areas requisite for driving visibility must be of one of the following types of glazing: Items 1, 2, 4, 4A, 10, 11A, 11C, 14, 15A, or 15B. This means the part of the barrier to the right of the driver must be of the items listed above.  Interior partitions in areas not requisite for driving visibility have additional compliance options, and may also be made of one of following types of glazing: Items 3, 5, 11B, 12, 13, 16A, or 16B. This means the part of the partition immediately behind the driver may be any of the above items.

1On the other hand, if the entity only assembles the barrier using pre-cut glazing that has been certified by a glazing manufacturer, it is not required to certify the glazing.

2 See letter to Ms. Lee Ann Sparks, (June 4, 2020) available at https://isearch.nhtsa.gov/files/571-205- Driver%20Shield%20for%20Buses%20and%20Vans_final%20signed%20(002).htm.

3 In a letter to Cris Morgan (January 14, 2009), NHTSA concluded that low-level glazing on doors to the right or left of the driver are considered windows that are requisite for driving visibility. Therefore, glazing through which the driver would view these windows would be considered requisite for driving visibility. https://isearch.nhtsa.gov/files/08-004149--19%20Nov%2008--sa.htm.

Soft Shields. You ask about “soft shields” installed in school buses that would be installed to the right of and behind the driver or installed in the passenger compartment by attachment to the interior roof of the school bus and to the seat backs of the passenger seats. Based on photos of the soft shields, and assuming they are comprised of flexible transparent material, NHTSA would consider them to be “flexible curtains.” Again, this classification is important for FMVSS No. 205, as it, along with the location of the glazing in the vehicle, determines which types of glazing may be used.

The photos you provide show that the shields would be installed to the right of the driver or immediately behind the driver, and/or installed between each row of seats by attachment to the interior roof of the school bus and to the seat backs of the passenger seats. Of these locations, only the location to the right of the driver would be considered requisite for driving visibility.

Glazing for flexible curtains on buses in areas requisite for driving visibility must be of one of the following types of glazing: Items 1, 2, 4, 4A, 6, 10, 11A, 11C, 14, 15A, or 15B. This means the soft shield to the right of the driver must be of the items listed above. However, although these Items of glazing are permitted for use as flexible curtains, the only appropriate Item for the pliable plastic shown in the photos may be Item 6. Some of the requirements for certain Items may necessitate a level of rigidity that a soft plastic cannot provide. Some Items of glazing, such as Item 6, have requirements that were designed specifically for flexible plastics.

Glazing for flexible curtains in buses in areas not requisite for driving visibility must be one of the following types of glazing: Items 1, 2, 3, 4, 4A, 5, 6, 7, 10, 11A, 11B, 11C, 12, 13, 14, 15A, 15B, 16A, or 16B. Accordingly, the part of the flexible curtain for any location behind the driver and in the passenger compartment must be of these items. Of these permissible Items of glazing, Items 6, 7, and 13 may be the only appropriate ones for the soft, pliable plastic shown in the photos you provide. Soft, pliable glazing may not be able to meet the requirements for certain Items of glazing because they do not provide a level of rigidity that is necessary for meeting some of the requirements. However, Items 6, 7, and 13, have requirements that were designed specifically for flexible plastics.

Other requirements. There may be additional requirements applying to the installation of the partition or curtain (“glazing”) depending on the entity installing it. If the glazing is installed on a new bus prior to first vehicle sale for purposes other than resale, the installer must ensure that, with the glazing installed, the vehicle complies with FMVSS No. 205 and all other applicable FMVSS, and must certify the vehicle as complying with all FMVSS affected by the installation. If the glazing is installed as aftermarket equipment by a manufacturer, distributor, dealer, rental company, or motor vehicle repair business, that entity would be subject to 49 U.S.C. 30122, which prohibits the entity from knowingly making 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 FMVSS.

In both cases, the entity installing the glazing must ensure that installation of the partition does not: (1) take the vehicle out of compliance with or make inoperative systems installed pursuant to FMVSS No. 222, “School bus passenger seating and crash protection;” (2) impact the vehicle’s compliance with or make inoperative systems installed pursuant to FMVSS No. 302, “Flammability of interior materials;” (3) prevent the driver and passengers from readily accessing emergency exits installed in compliance with or make inoperative systems installed pursuant to FMVSS No. 217, “Bus emergency exits and window retention and release;” (4) obstruct the driver’s view of the mirrors and/or rearview image required under FMVSS No. 111, “Rear visibility;” or (5) impede the driver’s ability to see through the windows needed for driving visibility. Visibility is particularly important for school buses, as not only are school buses engaged in the transportation of children, they also make frequent stops. Installers should ensure that installation of a partition or curtain, particularly one situated in an area requisite for driving visibility, does not create glare or otherwise reduce the driver’s ability to see embarking and disembarking students and other road users.

Regarding how the installation of the glazing affects compliance with FMVSS No. 222’s head protection requirements, S5.3.1 of FMVSS No. 222 establishes head protection requirements for “contactable surfaces” within the head protection zone defined by S5.3.1.1. The head protection zone is determined based on seating references points. This means that each seat in a school bus has its own head impact protection zone. As an example, a partition that is installed directly behind the driver is likely to fall within the head protection zone for the seat directly behind the driver. Partitions installed to the right of the driver may also partially fall within the head protection zones for the seat directly behind the driver.

If the partition is installed prior to first purchase, the installer must ensure that the vehicle will meet FMVSS No. 222 with the glazing installed. If the head impact protection requirements cannot be met for that first row of seats with the partition installed, the installer might have to remove the first row and move the FMVSS No. 222 restraining barrier rearward such that the bus provides proper compartmentalization for what would be the new (reconfigured) first row. This modification would ensure that the partition is no longer within the head protection zone of any of the school bus seats.

If the partition is installed after first purchase by an entity subject to the make inoperative provision in 49 U.S.C. 30122, the installer may not knowingly make inoperative any part of a device or element of design installed on or in the school bus pursuant to FMVSS No. 222. School buses are required to have passenger seating systems designed to afford impact protection to occupants. Installation of the partition may affect this element of design (compartmentalization) for the front row of seats by impairing the seat’s head impact protection. To avoid this result, the installer may need to remove the first row of seats and move the FMVSS No. 222 restraining barrier rearward such that the bus provides proper compartmentalization for what would be the new (reconfigured) first row.

Entities modifying their own school buses are not subject to Federal restrictions on “making inoperative” the safety systems on their vehicles. However, NHTSA recommends that owners not degrade the safety systems provided on their vehicles. Thus, we recommend that schools take measures to ensure that students will not occupy seats that have compromised head protection zones. For example, if a school installs a partition that will be in the head impact zone, the school can mitigate risk by not allowing students to sit in those first-row seats.

It appears from the photos you sent that the flexible curtain is a “soft shield” made from pliable plastic. Even though the curtains would likely fall within the head protection zones when installed forward of each passenger seat, it does not appear to have an adverse effect on school bus compliance with FMVSS No. 222’s head protection requirements.

In addition to the above, please note that the installation of the barrier may be subject to State laws or regulations. School bus operators should contact their local highway safety office for information governing how school children should be transported.

I hope this information is helpful. If you have any further questions, please feel free to contact Callie Roach of my staff at this address or at (202) 366-2992.

Sincerely,

JONATHAN CHARLES MORRISON

Digitally signed by JONATHAN CHARLES MORRISON

Date: 2020.08.11 15:21:29

-04'00'

Jonathan C. Morrison

Chief Counsel

Dated: 8/11/20

Ref: FMVSS No.205

ID: aiam5312

"Dear Mr. Carver: This responds to your letter of January 8, 1994 asking two questions concerning a recent amendment to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413, November 2, 1992). Your questions and the response to each follow. 1. There's some confusion here in our engineering department regarding the interpretation of the 'Daylight Opening' and 'Unobstructed Opening' as it applies to the new side emergency door specification in FMVSS 217. Page 2 shows the allowable obstruction and the context in which 'Daylight Opening' and 'Unobstructed Opening' are used. Page 3 shows some measurements of our seats placed according to the '30 cm minimum' shown on page 2. Page 4 shows four different interpretations of the 'Unobstructed Opening' area. Depending on the interpretation, between 9 and 15 people may be accommodated by a side emergency door. My question is this: of the four possibilities shown, which definition of the 'Unobstructed Opening' area is correct? Mr. Hott indicated definition 4. The term 'daylight opening' is defined in the Final Rule as 'the maximum unobstructed opening of an emergency exit when viewed from a direction perpendicular to the plane of the opening.' An obstruction in this context would include any obstacle or object that would block, obscure, or interfere with, in any way, access to that exit when opened. In determining the 'maximum unobstructed opening of an emergency exit,' we would subtract, from the total area of the opening, the area of any portions of the opening that cannot be used for exit purposes as a result of the obstruction. The area measurements would be taken when viewed from a direction perpendicular to the plane of the opening. Your question specifically concerns how the 'maximum unobstructed opening' of a side door is measured when the opening is partially obstructed by a seat. In the case of the illustrated door exit, occupants would use the exit by movement along the floor. This would be considered in determining the extent of an obstruction. None of the four examples you enclosed with your letter correctly illustrates the area that would be credited for the illustrated exit. The following regions would not be credited for this exit: (1) the area visually obstructed by the seat, (2) your region A2, an area bounded by a horizontal line tangent to the top of the seat back, a vertical line tangent to the rearmost portion of the top of the seat, the upper edge of the door opening, and the edge of the door forward of the seat, (3) your region A5, an area bounded by the seat back, a horizontal line tangent to the top of the seat back, and the edge of the door forward of the seat, and (4) your region A8, an area bounded by the seat leg, the floor, the lower edge of the seat bottom, and the edge of the door forward of the seat. Because the seat would make the last three regions unusable as exit space for a person traveling along the floor of the bus towards the exit, they would not be credited for that exit. You should be aware that the agency published a notice of proposed rulemaking to amend Standard No. 217 on December 1, 1993 (58 FR 63321). The notice proposed two alternate means for determining the maximum amount of area that will be credited for all types of emergency exits on school buses. The agency is currently reviewing the comments received in response to this notice. I am enclosing a copy of this notice. 2. Here is an excerpt from FMVSS 217 S5.5.3(a): 'Each school bus ....shall have the designation 'Emergency Door' or 'Emergency Exit' as appropriate, .... For emergency exit doors, the designation shall be located at the top of, or directly above, the emergency exit door on both the inside and outside surfaces of the bus..... For emergency window exits, the designation shall be located at the top of, or directly above, or at the bottom of the emergency window exit on both the inside and outside surfaces of the bus.' I've seen a two-sided sticker used by other bus manufacturers. It is applied on the inside surface of a window and the same image 'Emergency Door' or 'Emergency Exit' can be read from both inside and outside the bus. Is it permissible for us to use this sort of decal, assuming it meets all other (i.e., FMVSS 302)? The answer to your question is yes. The agency addressed this issue in an October 2, 1978, letter to Mr. E.M. Ryan of Ward Industries, Inc. I am enclosing a copy of this letter. I hope you find this information helpful. If you have any other questions, please contact Walter Myers of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures";

ID: aiam5144

"Dear Mr. Sharman: This responds to your letter of November 18, 1992 regarding the test procedure in Standard No. 302, Flammability of Interior Materials. Your questions and the answer to each follows. Question 1. MVSS-302, in Section S5.3(e), states that the timing for each specimen be started when the flame from the burning specimen reaches a point 1.5 inches from the open end of the specimen and, in Section S5.3(f), is stopped when the flame progresses to a point 1.5 inches from the clamped end of the specimen. Further, the Standard, in Section S5.2.2, states the specimen is oriented so that the surface closest to the occupant compartment air space faces downward on the test frame. The question that has been raised is whether the timing is started and stopped when the flame reaches the designated points on the surface of the specimen closest to the occupant compartment air space (the surface facing down during the test), or when the flame reaches the designated points on the surface of the specimen facing away from the occupant compartment air space (the surface facing up during the test). You suggest that the timing should be started and stopped when the flame reaches the designated points on the surface facing up during the test. As explained below, NHTSA disagrees. Section S4.3(a) of Standard No. 302 states: When tested in accordance with S5, material described in S4.1 and S4.2 shall not burn, nor transmit a flame front across its surface, at a rate of more than 4 inches per minute. However, the requirement concerning transmission of a flame front shall not apply to a surface created by the cutting of a test specimen for purposes of testing pursuant to S5. Any surface not created by the cutting of the test specimen, including the surface oriented downward pursuant to S5.2.2, is required to comply with the burn-rate requirement of S4.3(a). Surfaces created by the cutting of the test specimen were excluded from this requirement in a final rule published on March 31, 1975 (40 FR 14318). The reasons for the exclusion were stated in the notice as follows: (C)utting certain materials to the prescribed thickness produces a tufted surface upon which a flame front may be propagated at a faster rate than it would be upon the surface of the material before cutting, thereby creating an artificial test condition. Because of this exclusion, the surface facing upward pursuant to S5.2.2 is not required to comply with the burn-rate requirement of S4.3(a) if the surface was created by cutting the material to be tested to the prescribed thickness. In addition, I note that S5.3(b) requires the test specimen to be placed in the center of the cabinet. Therefore, it should not be any more difficult to observe the progress of the flame on the surface facing down than the surface facing up. Question 2. MVSS-302, in Section S5.3(f), states that the flame progression be measured to a point 1.5 inches from the clamped end of the specimen under test. The standard does not specify actions to be taken after timing has stopped. Some laboratories put out the flame using a small amount of water from a spray bottle. The question has been raised as to whether using a small amount of water from a spray bottle to put out the flame is an acceptable procedure. You are correct that Standard No. 302 does not specify a procedure to extinguish the flame after the test. Therefore, spraying a specimen with a small amount of water to extinguish the flame would be acceptable. However, please bear in mind that S5.1.2 states Prior to testing, each specimen is conditioned for 24 hours at a temperature of 70 F. and a relative humidity of 50 percent, and the test is conducted under those ambient conditions. After spraying a specimen in the test cabinet, it would be necessary to ensure that the ambient conditions in the cabinet conform to those specified in S5.1.2 before conducting any additional tests. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel";

ID: aiam0835

Dear Mr. Bronte: This is in reply to your letter of August 31, 1972, concerning Moto Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.' You ask whether the Standard applies to the shower and matching window curtains you manufacture and sell to manufacturers of mobile homes, trailers, and campers, and whether mobile homes must comply with the requirements of the Standard.; Because Standard No. 302 applies to motor vehicles, the components o vehicle occupant compartments listed in S.4.1 of the Standard are subject to the Standard only when they are installed in a vehicle included under a vehicle class to which the Standard is applicable. Standard No. 302 applies to passenger cars, multipurpose passenger vehicles, trucks, and buses. It does not apply to trailers, the vehicle category which includes mobile homes and other towed recreational vehicles, but it does apply to those campers that are constructed on new chassis. Since the only vehicles you list that must meet the requirements of the Standard and that use your curtains are campers constructed on new chassis, the Standard applies only to the curtains used in such campers.; Yours truly, Richard B. Dyson, Assistant Chief Counsel