Federal Registers - Table of Contents Federal Registers - Table of Contents
• Publication Date: 08/25/1994
• Publication Type: Proposed Rules
• Fed Register #: 59:43786-43796
• Title: Request by the Federal Aviation Administration (FAA) for an Alternate Standard for Emergency Egress in Air Traffic Control Towers (ATCTs)

DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Part 1960

[Docket No. F-01]

Request by the Federal Aviation Administration (FAA) for an Alternate Standard for Emergency Egress in Air Traffic Control Towers (ATCTs)

AGENCY: Occupation Safety and Health Administration (OSHA), Department of Labor.

ACTION: Proposed rule; Request for Comments.

SUMMARY: The FAA has requested approval from OSHA for an alternate standard regulating emergency egress in Air Traffic Control Towers (ATCTs). In this notice. OSHA has published the proposed alternate standard for public review and comments.

DATES: The last date for interested persons to submit comments is September 26, 1994.

ADDRESSES: Comments are to be sent to the Docket Office, Docket No. F-01, U.S. Department of Labor, Room N2625, 200 Constitution Avenue, N.W., Washington, DC 20210.

FOR FURTHER INFORMATION CONTACT: Mr. John Plummer, OSHA, U.S. Department of Labor, Director, Office of Federal Agency Programs, Room N3112, 200 Constitution Avenue, NW., Washington, DC 20210; Telephone: (202) 219-8151.

SUPPLEMENTARY INFORMATION: Section 19 of the Occupational Safety and Health Act (the Act) contains provisions to assure safe and healthful working conditions for Federal employees. Under that section, it is the responsibility of the head of each Federal agency to establish and maintain an effective and comprehensive occupational safety and health program which is consistent with the standards promulgated under section 6 of the Act. The Secretary of Labor (the Secretary), under section 19, is to report to the President certain evaluations and recommendations with respect to the programs of the various agencies, and the duties which section 24 of the Act imposes on the Secretary of Labor necessarily extend to the collection, compilation, and analysis of the occupational safety and health statistics from the Federal Government.

Executive Order 12196, Occupational Safety and Health Programs for Federal Employees, issued February 26, 1980, prescribes additional responsibilities for the heads of agencies, the Secretary, and the General Services Administrator. Among other duties, the Secretary is required to issue basic program element in accordance with which the heads of agencies shall operate their safety and health programs. These basic program elements are set forth in 29 CFR Part 1960. Although agency heads are required to comply with all standards issued under section 6 of the Act and to operate a program in accordance with the basic program elements, those elements contain numerous provisions which, by their terms, permit agency heads the flexibility necessary to implement their programs in a manner consistent with their respective missions, sizes, and organization. Thus, an agency head, after consultation with agency employees or their representatives and with appropriate safety and health committees may request the Secretary to consider approval of an alternate standard. Pursuant to 29 CFR 1960.17, when requesting an alternate standard the agency head must do the following:

(a) Any request by the head of the agency for an alternate standard shall be transmitted to the Secretary.

(b) Any such request for an alternate standard shall not be approved by the Secretary unless it provides equivalent or greater protection for affected employees. Any such request shall include:

(1) A statement of why the agency cannot comply with the OSHA standard or wants to adopt an alternate standard;

(2) A description of the alternate standard;

(3) An explanation of how the alternate standard provides equivalent or greater protection for the affected employees;

(4) A description of interim protective measures afforded employees until a decision is rendered by the Secretary of Labor; and

(5) A summary of written comments, if any, from interested employees, employee representative, and occupational safety and health committees.

This Notice is a request for comment on the proposed alternate standard submitted to OSHA by the FAA. This action is intended to assist the Secretary in assuring that ample opportunity has been given to allow affected employees, employee representatives and interested parties, such as occupational safety and health committees, to comment on the effectiveness of the proposed alternate standard and on its equivalence to appropriate OSHA standards. The Secretary also believes that review of this alternate standard by the scientific community and those National Committees responsible for developing comparable standards is essential so that workers in ATCTs are free from the hazards posed by inappropriate means of egress.

Alternate Standard

The FAA provided materials in support of the proposed alternate standard to 29 CFR 1910.36 (b)(8). FAA's request was based on the following:

* A number of specifications established in the existing alternate standard for ATCTs require types of construction beyond those mandated in OSHA regulations or in life safety and building codes.

* A licensed fire protection engineer has provided several alternate protection measures for ATCTs which were not included in the existing alternate standard.

* The existing alternate standard does not address important operational ATCT requirements (e.g., 360 degrees field of vision at the cab level) or their relationship with protective structural or procedural features.

Additionally, FAA describes the alternate as follows:

The revision to the existing alternate standard provides types of ATCT construction and methods of operation which enhance the fire detection and notification, fire resistance, smoke control, and emergency response features for ATCTs. These features provide early warning of the presence of fire or smoke, flame and smoke spread control, and automatic notification of emergency response units such that a level of fire safety equivalent to two means of egress are afforded ATCT occupants.

FAA contends that the alternate standard provides equivalent or greater protection for the affected employees because of enhancements such as, but not limited to:

* An ATCT stairway smoke control system;

* Fire resistant rated materials for stairway enclosures and openings;

* Self-closing or automatic fire doors;

* ATCT fire alarm system wiring in accordance with NFPA 72 reliability standards;

* Automatic smoke detection;

* Automatic fire detection, alarm, and signaling systems with automatic fire department and ATCT notification and ATCT cab annunciator panels with battery backup;

* Prohibition of storage of high hazard materials or use of more then minimal amounts of high hazard materials for specific duties;

* Occupancy above the level of exit discharge only be able-bodied persons;

* Prescribed quality and type of interior finish materials;

* Specified levels of fire resistant rated opening protective to base buildings.

Commenters are requested to comment on FAA's finding of equivalency as well as on the appropriateness of the enhancements.

Comments are requested on the following:

(1) Is an alternate standard necessary, or are technologies such that two means of egress are possible in ATCTs?

(2) Should an alternate standard be designed and formatted like equivalent OSHA standards?

(3) Does this alternate standard provide equivalent protection for affected employees as does the equivalent OSHA standard?

(4) What interim measures should be in effect while approval for this alternate standard is being considered?

(5) Should Chapter 12 be revised in accordance with the new Life Safety Codes (LSC)?

(6) Are there requirements set forth in Chapter 12 which are inappropriate?

(7) Should there be requirements proposed in Chapter 12 which go beyond the concept of allowing a single means of egress, e.g. width of steps, slopes of ladders, etc.?

Public Participation

Interested persons are invited to submit written data, views, and comments with respect to this alternate standard. These comments must be postmarked on or before (insert date 30 days after publication in the Federal Register), and submitted in quadruplicate to the Docket Office, Docket No. F-01, Room N2625, U.S. Department of Labor, 200 Constitution Avenue, NW., Washington, DC 20210. Comments limited to 10 pages or less also may be transmitted by facsimile to (202) 219-5046, provided the original and three copies are sent to the Docket Office thereafter.

Written submissions must clearly identify the provisions of the alternate standard which are being addressed and the position taken with respect to each issue. The data, views, and comments that are submitted will be available for public inspection and copying at the above address.

Signed at Washington, DC this 12th day of August, 1994.

Joseph A. Dear
Assistant Secretary of Labor.

Alternate Emergency Egress Standard for Airport Traffic Control Towers - Final Version

August 30, 1993.

Alternate Emergency Egress Standard for Air Traffic Control Towers (ATCT)

a. Scope and Application

1. General. Airport Traffic Control Towers (ATCTs) are unique structures used for the control of aircraft, usually over or near an airport facility. The distinctive mission of ATCTs requires ATCT designs that permit 360deg. visibility at the cab level and, in many cases, sufficient space for radar equipment and administrative activities related to ATCT operations.

2. This standard applies to all ATCTs.

3. Specific. This standard sets forth minimum fundamental requirements essential to providing a safe means of egress from fire and similar emergencies. Nothing in this standard shall be construed to prohibit a better type of building construction, more exits, or otherwise safer conditions than the minimum requirements specified herein.

4. Equivalent Protection. The use of alternative arrangements or construction, developed or approved by a licensed fire protection engineer, may be permitted by the authority having jurisdiction when it is shown that these features provide a level of safety to life equivalent to that required in this standard or, where this standard is silent on an issue, by other standards or codes.

b. Definitions

1. "Aisle" is a passageway between rows of desks, cabinets, equipment, etc, generally within a room or work area which leads to or connects with a corridor.

2. "Approved" refers to equipment listed or approved by a nationally recognized testing laboratory.

3. "ASTM" represents the American Society for Testing and Materials, who establishes flame spread characteristics for materials used in building construction and furnishing.

4. "ATCT" represents an airport traffic control tower and is an occupied structure containing equipment and supplies necessary for aircraft control and related activities.

5. "Authority Having Jurisdiction" is the Department of Labor, Occupational Safety and Health Administration. The Federal Aviation Administration (FAA) is responsible for implementing the requirements of this standard for FAA-owned or occupied ATCTs.

6. "Base Building" is a single or multiple level structure attached to an ATCT and which may house administrative, air traffic control, or facility management functions.

7. "Corridor" is an enclosed passageway which limits the means of egress to a single path of travel.

8. "Decorations" are curtains, hangings, draperies, mirrors, or other embellishments suspended from walls or ceilings.

9. "Draftstopping" is any building material installed to prevent the movement of air, smoke, gases, and flame to other areas of the building through large concealed passages such as attic spaces and floor assemblies with suspended ceilings or open-web trusses.

10. "Emergency action plan" is a plan for a workplace, or parts thereof, describing what procedures the employer and employees must take to ensure employee safety from fire or other emergencies.

11. "Emergency escape route" is the route that employees are directed to follow in the event they are required to evacuate the workplace or seek a designated refuge area.

12. "Exit" is that portion of a means of egress which is separated from all other spaces of the building or structure by construction or equipment as required in this standard to provide a protected way of travel to the exit discharge.

13. "Exit access" is that portions of a means of egress which leads to an exit.

14. "Exit discharge'; is that portion of a means of egress between the termination of an exit and a public way.

15. "Fire Partition" is a vertical assembly of material having protected openings and designed to restrict the spread of fire.

16. "Fire Resistive or Resistant" refers to the ability of materials or assemblies of construction to withstand exposure under standard fire test conditions for a prescribed temperature and period of time without structural failure.

17. "Fire Separation Assembly" is a continuous barrier, either horizontally or vertically oriented, with a fire resistance rating and protected openings, designed to restrict the spread of fire.

18. "Fire Separation Distance" is the distance in feed measured from the building face to the closest interior lot line, to the center line of a street or public way or to an imaginary line between two buildings on the same property.

19. "Firestopping" is approved noncombustible building material installed to prevent the movement of flame and gases to other areas of a building through small concealed passages in building components such as floors, walls, and stairs.

20. "Furnishings" are chairs, tables, plants, or other movable objects.

21. "Hazardous Areas" are areas of an ATCT possessing a degree of hazard greater than that normal to the facility, such as areas used for the storage of combustibles or flammable materials, or areas containing furnaces or boilers.

22. "High hazard contents" are contents classified as those which are liable to burn with extreme rapidity or from which poisonous fumes or explosions are to be feared in the event of fire (such as flammable or combustible liquids).

23. "Interior Finish" is the exposed interior surfaces of a building including, but not limited, to, walls and ceilings.

24. "Link" is a connecting passageway between at ATCT and a base building. Links are usually one story in height with direct access to the exterior.

25. "Listed" refers to equipment or material included in a list published by an organization acceptable to the "authority having jurisdiction" and concerned with product evaluation, that maintains periodic inspection of listed equipment or material and whose listing states either that the equipment or material meets appropriate standards or has been tested and found suitable for use in a specified manner.

26. "Means of Egress" is a continuous and unobstructed way of exit travel from any point in a building or structure to a public way and consists of three separate and distinct parts: the way of exit access, the exit, and the way of exit discharge. A means of egress comprises the vertical and horizontal ways of travel and shall include intervening room spaces, doorways, hallways, corridors, passageways, balconies, ramps, stairs, enclosures, lobbies, horizontal exit, courts, and yards.

27. "Noncombustible Construction" is construction in which the materials have been tested in accordance with ASTM E136 and conform to the criteria contained in Section 7 of that test method (e.g., gypsum wallboard).

28. "NRTL" is a Nationally Recognized Testing Laboratory.

29. "Opening Protectives" are the parts of an opening in a fire barrier that ensure the integrity of the protected barrier. Opening protective fire protection ratings for different fire barrier ratings are established in NFPA 101 - Life Safety Code.

30. "Protected Construction" is construction in which the structural members are protected from fire so that they can withstand exposure to fire for specified periods of time.

31. "Public way" is any street, alley, or other parcel of land open to the outside air leading to a public street, which has been deeded, dedicated, or otherwise permanently appropriated to the public for public use and which as a clear width and height of not less than 10 feet.

32. "Shaft" is an enclosed space extending through one or more stories of a building, connecting vertical openings in successive floors, or floors and the roof.

33. "Smokeproof enclosure" is an enclosed interior stairway designed to limit the infiltration of heat, smoke, and fire gases from a fire in any part of the building by either natural or mechanical means.

34. "Story" is that portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above.

35. "Structural elements" are the beams, columns, and other or similar supporting members of an ATCT.

36. "Type of Construction Classifications" are classifications which designate the fire resistance rating requirements of protection provided for certain types of construction, as follows:

First number represents: Exterior bearing walls.

Second number represents: Structural frame or columns and girders, supporting loads for more than one floor.

Third number represents: Floor construction. 37. "Type I Construction" is that type in which the structural members, including walls, columns, beams, floors, and roofs, are of approved noncombustible or limited-combustible materials and have fire resistance ratings not less than 443 or 332 (see NFPA 220, Table 3).

38. "Type II Construction" is that type not qualifying as Type I construction in which the structural members, including walls, columns, beams, floors, and roofs, are of approved noncombustible or limited-combustible materials and have fire resistance ratings not less than 222, 111, or 000 (see NFPA 220, Table 3).

39. "Type III Construction" is that type in which exterior walls and structural members that are portions of exterior walls are of approved noncombustible or limited-combustible materials, and interior structural members, including walls, columns, beams, floors, and roofs, are wholly or partly of wood of smaller dimensions than required for Type IV construction or of approved noncombustible, limited-combustible, or other approved combustible materials. In addition, structural members have fire resistance ratings not less than 221 or 200 (see NFPA 220, Table 3).

40. "Type IV Construction" is that type in which exterior and interior walls and structural members that are portions of such walls are of approved noncombustible or limited-combustible materials. Other interior structural members, including columns, beams, arches, floors, and roofs, are of solid or laminated wood without concealed spaces and comply with the provisions of NFPA 220 section 3-4.2 through 3-4.6. In addition, structural members have fire resistance ratings not less than 2HH (see NFPA 220, Table 3 and section 3-4 for additional information on Type IV construction). Interior columns, arches, beams, girders, and trusses of approved materials other than wood are permitted by NFPA 220 section 3-4.1 provided they are protected to provide a fire resistance rating of not less than 1 hour. Certain concealed spaces are permitted by NFPA 220 section 3-4.4.

41. "Vertical opening" is an opening through a floor or roof.

c. General Provisions

1. Existing ATCTs occupied at the time of adoption of this standard may remain in use provided:

(a) The occupancy classification remains the same. (b) No serious life safety hazard exists that would constitute an imminent threat.

2. Federally-owned or operated ATCTs shall be provided with protection of occupants and means of egress which meets the requirements of this chapter or shall have a plan established for bringing the structure into compliance with this chapter.

3. Compliance with this standard shall not be construed as eliminating or reducing the necessity for other provisions for safety of persons using a structure under normal occupancy conditions.

d. Protection of Employees During Construction and Repair Operations

1. No new ATCT under construction shall be occupied in whole or in part until all means of egress and fire protection features for that area of the structures are completed and ready for use.

2. No existing ATCT shall be occupied during repairs or alterations unless all existing means of egress and any existing fire protection features are continuously maintained, or in lieu thereof, other measures are taken which provide equivalent safety (e.g., contractor-provided fire watches).

3. No flammable or explosive substances or equipment used for repairs or alterations shall be introduced or stored in an ATCT while the ATCT is in operation, unless safeguards are provided to prevent any additional danger (e.g., contractor-provided fire watches, use of only those amounts of flammable substances in the ATCT necessary for the immediate task at hand).

e. Protection for Persons With Disabilities

1. Persons who are unable to use the stairway for emergency egress and who are permitted access to the ATCT shall be restricted to the level of exit discharge only.

2. Provisions must be made for employees who are temporarily unable to use the ATCT stairway.

3. Such provisions may include:

(a) requiring duties to be performed at the level of exit discharge only; or, (b) ensuring that pre-planned procedures have been established to facilitate the egress of persons with disabilities during emergencies.

f. Structural and Architectural Design Requirements

1. General. The structural elements of new ATCT facilities shall be noncombustible.

(a) The new ATCTs shall be of Type I, II, III, or IV construction as defined by NFPA 220, as follows:

Type of construction Height in feet, measured from grade to cab floor
I (443 or 332) Unlimited
III (222) 240
II (111) 100
II (000) 85
III (211) 65
IV (2HH) 65

Exception: Existing ATCTs may be constructed of protected combustible materials provided they meet the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems and the provisions of section c.1).

(b) The minimum fire resistance ratings of structural elements shall be as follows:

Structural element   Type of construction
I
(443)
I
(332)
II
(222)
II
(III)
II
(000)
III
(211)
IV
(2HH)
Exterior Walls Load-bearing 4 3 2 1 0 2 2
Nonload-bearing 0 0 0 0 0 (1)0 (1)0
Fire Separation Assemblies Exits 2 2 2 2 2 2 2
Shafts
(other than exits)
2 2 2 2 2 2 2
Hazardous Area Separations < = Not less than the fire resistance rating required by f.12 =>
Fire Partitions Exit Access Corridors < = Not less than the fire resistance rating required by f.4 =>
Tenent Space Separations 1 1 1 1 1 1 1
Other Nonload-bearing Partitions   (1)0 (1)0 (1)0 (1)0 (1)0 (1)0 0
Interior load-bearing, walls, loadbearing partitions, columns, girders, trusses (other than roof trusses), and framing Supporting more than 1 floor 4 3 2 1 0 (1)0 See Note a.(1)
Supporting 1 floor/roof only 3 2 1 1/2 1 0 (1)1  
Structural members supporting wall   3 2 1 1/2 1 0 (1)1 (1)1
< = Not less than the fire resistance rating of wall supported =>
Floor construction incl. beams   3 2 1 1/2 1 0 (1)1 See Note a.(1)
Roof construction including beams trusses and framing, arches and roof deck 15 feet height to lowest member 2 1 1/2 1 1 0 (1)1 See Note a.(1)
More than 15 feet, but less than 20 feet to lowest member 1 1 1 0 0 (1)0 See Note a.(1)
20 feet or more to lowest member 0 0 0 0 0 (1)0 See Note a.(1)
Footnote(1) May be combustible construction
Note a: See NFPA 220 for details

(c) Combustible Materials. Where an ATCT or part of an ATCT is required to be constructed of noncombustible construction, the use of combustible elements shall be permitted subject to the limitations of this section without altering the construction classification.

(1) Roofs, Floors, and Walls. Combustible elements in roofs, floors, and walls are permitted to be used for the following components:

A. Interior finish and trim materials as prescribed in section g.1. B. Fire retardant treated wood. C. Mastic and caulking materials applied to provide flexible seals between components of exterior wall construction.

D. Roof covering materials as prescribed in section f.1.(b). 2. Exterior Walls.

(a) Exterior walls of ATCTs shall be noncombustible.

Exception: Exterior nonloadbearing walls of existing ATCTs may be constructed of combustible materials if the structural elements of the ATCT are protected.

(b) Exterior walls of ATCTs shall be protected from weather damage.

3. Exterior Opening Protectives.

(a) Approved protected construction shall be provided for every opening that is less than 15 feet vertically above the roof of an adjoining building and within a horizontal fire separation distance of 15 feet of an adjacent building, unless the building's roof construction affords a fire resistance rating of not less than one hour.

4. Fire Separation Assemblies.

(a) Fire separation assemblies installed to enclose exits, floor openings, vertical shafts, and for separation of hazardous areas shall be constructed of approved materials consistent with the limitations for the type of construction and shall have not less than the fire resistance rating prescribed by section f.1.(b).

(b) Openings in exit enclosures other than unexposed exterior openings shall be limited to those necessary for exit access to the enclosure from normally occupied spaces and for egress from the enclosure. All opening protectives in fire separation assemblies shall have the minimum fire resistance rating as prescribed in section f.9.

(c) All vertical fire separation assemblies shall extend from the top of the fire resistance rated floor assembly below to the underside of the slab or deck above and shall be securely attached thereto. These walls shall be continuous through all concealed spaces such as the space above a suspended ceiling. The supporting construction shall be protected to afford the required fire resistance rating of the fire separation assembly supported. All hollow vertical spaces shall be firestopped at every floor level as required in section f.11.

Exception: Interstitial (crawl space) subjunction (immediately below the cab) levels do not require fire separation assemblies provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(d) Where exterior walls serve as a part of a required fire resistance rated enclosure, such walls shall comply with the requirements of section f.2 of exterior walls and the fire resistance rated enclosure requirements shall not apply.

5. Vertical Shafts.

(a) Vertical shafts include stairways; HVAC, mechanical, electrical, and plumbing chases; elevators; and dumbwaiters.

(b) Vertical shafts and their enclosures shall be constructed of materials permitted by f.1 for the type of construction of the ATCT. Vertical shaft walls which are exterior walls shall be constructed of materials approved for exterior walls.

(c) All vertical shafts in ATCTs shall be enclosed with fire separation assemblies having at least a 2-hour fire resistive rating.

Exception: Vertical shafts connecting fewer than four (4) stories may be enclosed by 1-hour rated construction.

(d) A vertical shaft that does not extend to the underside of the roof deck shall be enclosed at the top with a fire separation assembly having a fire resistance rating of not less than that required for the shaft enclosure walls.

(e) Shafts which do not extend to the bottom of the ATCT shall be enclosed at the lowest ATCT level with a fire separation assembly (e.g., fire resistant construction) having a fire resistance rating of not less than that required for the shaft enclosure walls, or the shaft shall terminate in a room having an occupancy related to the purpose of the shaft. The room shall be separated from the remainder of the ATCT by fire separation assemblies having a fire resistance rating with openings protected as prescribed in section f.9.

(f) Every shaft opening shall be protected by a normally closed, self-closing, or automatic closing door, cover, hatch, removable section, damper, or other device arranged to meet the requirements of f.9 or f.10.

6. Elevators and Dumbwaiters. Elevators and dumbwaiters shall conform to the requirements of the Safety Code for Elevators and Escalators (ASME A17.1 for new elevators and dumbwaiters and ASME/ANSI A17.3 for existing elevator and dumbwaiters) American Society of Mechanical Engineers and the American National Standards Institute, New York, New York.

Exception: For existing elevators, Phase II emergency in-car operation shall not be required.

7. Fire Partitions.

(a) Fire partitions for new ATCTs shall be noncombustible and have the minimum fire resistance rating prescribed by section f.1.(b) for the type of construction.

Exception: Existing partitions may be of combustible construction provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(b) All fire partitions must extend from the floor slab to the bottom of the slab above or shall connect with ceiling construction having a fire resistance rating of not less than that required for the fire partition walls.

(c) All opening protectives (e.g., doors, windows) in fire partitions shall have the minimum fire resistance rating as set forth in section f.9.

(d) Penetrations through assemblies shall comply with section f.11.(b). 8. Floor/Ceiling and Roof/Ceiling Assemblies. (a) All floor openings connecting two or more stories shall be protected by a vertical shaft enclosure that complies with section f.5.

(b) All penetrations of a floor/ceiling assembly shall be protected by a shaft enclosure that complies with section f.5.

Exception: A shaft enclosure shall not be required where cables, cable trays, conduits, tubes, or pipes penetrate a floor assembly and are protected with an approved through-penetration protection system tested in accordance with ASTM E814. The system shall have an "F" rating and a "T" rating of not less than 1 hour, but not less than the required fire resistance rating of the assembly being penetrated.

Exception: Hatch openings at the top of the shaft are permitted when a 1.5 hour fire rated assembly is provided at the hatch opening or when a protected enclosure around the shaft opening is a 1.5 hour fire rated assembly.

(c) All roof/ceiling assembly penetrations shall be protected in accordance with section f.1.(b).

9. Fire Door Assemblies. (a) Fire door assemblies shall provide a fire resistance rating in accordance with the following table:

Type of Assembly Required assembly rating hours) Minimum opening protection
Fire separation assemblies having a fire resistance rating greater than one hour 4 3
3 3
2 1 1/2
1 1/2 1 1/2
Fire separation assemblies:
Shaft and exit enclosure walls 1 1
Other fire separation assemblies 1 3/4
Fire partitions:
Exit access corridor enclosure wall 1 1/3
1/2 1/3
Other fire partitions 1 3/4

(b) Operation. Fire doors shall be self-closing and latching. Stairwell doors may be held open by approved devices that will meet all of the following requirements:

(1) The device shall release the door and the door shall automatically close and latch if the ATCT fire alarm is operated.

(2) The fire door shall be provided with appropriate hardware so that it can be instantly reopened manually by some simple and readily obvious operation (e.g., panic hardware, door knob). 10. Fire Dampers. Fire dampers shall be installed in accordance with the applicable provisions of NFPA 90A, Standard for the Installation of Air Conditioning and Ventilating Systems.

10. Fire Dampers. Fire dampers shall be installed in accordance wiht the applicable provisions of NFPS 90A, Standard for the Installation of Air Conditioning and Ventilating Systems.

11. Firestopping and Draftstopping.

(a) Firestops or draftstops shall be provided as specified herein in all walls, partitions, and other concealed spaces or openings, horizontal and vertical, to prevent the free passage of flame and the products of combustion and shall be sufficient to maintain the fire resistance rating of the wall, partition, or floor pierced.

(b) Wall and floor openings penetrated by materials (e.g., telephone and communication cables) where the materials are required to be frequently changed, added, etc., may be firestopped using mineral wool, firestop pillows, or other fire resistive material.

(c) Firestops shall be provided in any concealed space where there is the potential for fire, heat, or smoke passage, other than a properly enclosed service shaft, pass, or chase.

(d) Firestopping shall consist of approved noncombustible materials securely fastened in place. In open spaces of wood framing, firestops may be of approved noncombustible materials or of two-inch lumber installed with tight joints or the equivalent.

(e) The integrity of all firestopping and draftstopping materials shall be continuously maintained.

(f) Firestopping shall be installed in the locations specified in section f.11.(a), including:

(1) concealed wall spaces;

(2) connections between horizontal and vertical spaces;

(3) concealed spaces between stairway stringers at the top and bottom of the run; and

(4) ceilings and floor openings.

(g) Draftstopping shall be installed in ATCTs of Types III and IV construction in locations specified below:

(1) Floors. Where ceilings are suspended below solid wood joists or suspended or attached directly to the bottom of open-web wood floor trusses, the space between the ceiling and the floor above shall be divided by draftstopping installed so that horizontal areas do not exceed 1,000 square feet.

(2) Draftstopping materials shall not be less than half-inch gypsum board, 3/8-inch plywood or other approved materials adequately supported.

(3) Concealed roof spaces shall be provided with draftstopping such that no horizontal area exceeds 3,000 square feet.

Exception: Draftstopping is not required in a concealed space when ATCTs are equipped throughout with an automatic sprinkler system, provided that automatic sprinklers are also installed in combustible concealed spaces.

12. Hazardous Areas. Rooms or Areas designated as hazardous areas shall be separated from the remainder of the ATCT by fire separation assemblies as follows:

(a) Boiler and furnace rooms. Boiler and furnace rooms shall be separated by 1-hour fire resistance rated construction or provided with an automatic fire suppression system.

(b) Storage rooms.

(1) Storage rooms greater than 50 square feet in area shall be separated by 1-hour fire resistance rated construction.

(2) Storage rooms greater than 100 square feet in area shall be separated by 2-hour fire resistance rated construction.

(c) Engine generator rooms shall be separated from the remainder of the ATCT by 2-hour fire resistance rated construction.

(d) Other Electrical Equipment Rooms. Other electrical equipment rooms shall be separated by 1 hour fire resistance rated construction or provided with an automatic fire suppression system.

13. Connections to Base Buildings.

(a) The base building shall be separated from the ATCT by a fire separation assembly with a minimum fire resistance rating equivalent to the rating required of the stair shaft.

(b) The exit stairway of an ATCT which is directly connected to a base building, or is connected to a base building by a link, shall be a smokeproof enclosure or pressurized in accordance with this standard.

(c) ATCTs surrounded by a base building shall have the following:

A. At least one smokeproof or pressurized stairway.

B. ATCT stairways that discharge into a base building at the level of exit discharge with these considerations:

(a) Means of Egress on the level of exit discharge shall be free and unobstructed to the exterior of the building.

(b) Entire level of exist discharge is provided with automatic sprinkler protection, and any nonsprinklered areas are separated by fire rated construction equivalent to the rating required for the stair shaft.

(c) Smoke detectors shall be provided in all hazardous areas of the base building not separated by fire rated construction equivalent to the rating required for the stairway.

(d) Smoke detectors shall be provided on the base building side of openings between the ATCT and the base building.

C. Where the ATCT exist stairway does not discharge onto the level of exit discharge of the base building (as in an ATCT on top of a terminal) safe and continuous passageways, aisles, or corridors leading directly to base building exits shall be maintained and so arranged as to provide convenient access for each occupant to at least two exists by separate ways of travel, except as a single exit or limited dead ends are permitted by other provisions of this standard.

g. Interior Finishes

1. Interior Finish and Trim.

(a) All materials used for interior finish and trim shall be classified in accordance with ASTM E84. The classifications of interior finishes referred to in this section correspond to flame spread ratings on the flame spread test scale determined by ASTM E84 as follows: Class A flame spread, 0-25; Class B flame spread, 26-75; Class C flame spread, 76-200.

(1) Foam plastics shall not be installed as interior trim or finish.

(2) Interior wall and ceiling finish materials that have a smoke-developed rating greater than 450 when tested in accordance with ASTM E84 shall not be permitted.

(b) All materials used inside an exit stairway shall have fire hazard ratings of not more than 25 for flame spread and not more than 50 for smoke development.

(c) Other than in sprinklered ATCTs, all materials used for interior finish shall have fire hazard ratings of not more than 25 for flame spread and not more than 450 for smoke development and fuel contribution (Class A).

Exception: Carpeting may be used as wall covering in non-sprinklered areas provided the carpet type meets the requirements of the 80A120A8 ft room/corner fire test procedure described in NFPA 101, Section A-6-5.2.3 (1991 edition).

(d) In sprinklered ATCTs, all materials used for interior finish in enclosed rooms and spaces and in means of egress shall have fire hazard ratings of not more than 75 for flame spread and not more than 450 for smoke development.

Exception: Carpeting with a Class A flame spread classification may be used as wall covering provided it is used only in rooms protected by an approved automatic fire suppression system.

(e) Baseboards, chair rails, moldings, trim around openings and other interior trim, not in excess of 10 percent of the aggregate wall and ceiling areas of any room or space, shall be of Class A, B, or C materials.

(f) Paint, veneer, and other thin final finishing materials not over 0.035-inch thick and applied directly to a noncombustible base are permitted and may be used provided that such materials do not significantly increase the fire hazard ratings of the base material involved.

(g) Fire retardant paints. Fire retardant paints or solutions shall be re-applied as necessary to maintain the required flame retardant properties.

2. Interior Floor Finish.

(a) Finished floors or floor covering materials of a traditional type, such as wood, vinyl, linoleum, terrazzo, and other resilient floor covering materials, are exempt from the requirements of this section. Floor coverings judged by the authority having jurisdiction to represent an unusual hazard, such as carpet, shall meet the requirements of this section.

(b) Interior floor finish in means of egress shall be of not less than Class B materials in accordance with ASTM E648. Class B corresponds to a critical radiant flux of 0.22 watts/cm(2) as defined in ASTM E648. In all other areas the interior floor finish shall comply with the Department of Commerce FF-1 "pill test" (CPSC 16 CFR 1630).

(c) The requirement for rooms or enclosed spaces is based on the condition that the areas have partitions which extend from the floor to the ceiling. Where partitions do not satisfy this criterion, the room or space is considered part of the corridor.

3. Furnishings and Decorations.

(a) No furnishings, decorations, or other objects shall be so placed as to obstruct exits, access thereto, egress therefrom, or visibility thereof.

(b) No furnishings or decorations of an explosive or highly flammable character shall be used in any occupancy.

h. ATCT Console Construction

Consoles in the ATCT which are not constructed entirely of noncombustible materials shall comply with National Electrical Manufacturers Association Standard LD3, which incorporates a "Radiant Heat Resistance" test which measures the ability of the surface of high pressure decorative laminate to resist spot damage when subjected to a radiant heat source.

i. Electrical Requirements

All electrical wiring and equipment shall comply with the National Electrical Code, NFPA 70, 1993, National Fire Protection Association, Quincy, Massachusetts.

j. Means of Egress

1. General. Every ATCT shall be provided with exits of kinds, number, location, protective features, and capacity appropriate to the individual building or structure, with due regard to the unique character of ATCTs, the number of persons exposed, the fire protection available, and the height and type of construction of the building or structure, to afford all occupants convenient facilities for escape.

2. Occupancy and Use Requirements.

(a) ATCT structures are occupied by personnel and contain equipment and supplies necessary for aircraft control operations. ATCTs are designed to provide 360deg. visibility from the cab level.

(b) ATCTs may not be used for living or sleeping purposes.

(c) ATCTs may be occupied above the level of exit discharge by only able-bodied persons.

(d) No combustible materials shall be located in, under, or within the immediate vicinity of the ATCT except necessary furniture and equipment.

(e) High hazard contents shall not be permitted in the ATCT or the immediate vicinity thereof.

(f) ATCT exits shall be so arranged and maintained as to provide free and unobstructed egress from all parts of the building or structure at all times when it is occupied. No locks or fastening which prevents unimpeded escape from the inside of any building shall be installed.

3. General Limitations

(a) Permissible Means of Egress components. Means of egress shall consist only of the approved components as described in this section. Means of egress shall be constructed as components of the building or shall be permanently affixed thereto.

(b) Headroom. Means of egress shall be so designed and maintained as to provide adequate headroom, but in no case shall the ceiling height be less than 7 feet 6 inches nor any projection from the ceiling be less than 6 feet 8 inches from the floor.

Exception: In existing ATCTs where the headroom is less than that required in this section, signs reading "Low Clearance" shall be placed on both sides of the obstruction.

(c) Changes in elevation. Where changes in elevation exceed 21 inches in a means of egress, the difference in elevation shall be negotiated by stairs or ramps.

(d) Means of egress walking surfaces shall provide sufficient friction to prevent slipping under normal conditions.

4. Types and Location of Means of Egress

(a) Access to means of egress.

(1) Means of egress shall be so located and exit access shall be so arranged that exits are readily discernible and unobstructed at all times.

(2) In no case shall access to an exit be through a bathroom, or other room subject to locking, except where the exit is required to serve only the room subject to locking.

(3) Exit access shall be so arranged that it will not be necessary to travel toward any area of hazardous occupancy in order to reach the nearest exit, unless the path of travel is effectively shielded from the high hazard location by suitable partitions or other physical barriers.

(b) Discharge from exits.

(1) All exit discharges shall empty directly to the street, or to a yard, court, or other open space that gives safe access to a public way. The streets to which the exits discharge shall be of width adequate to accommodate all persons leaving the building. Yards, courts, or other open spaces to which exits discharge shall also be of adequate width and size to provide all persons leaving the building with ready access to the street.

(2) The exit discharge shall be so arranged as to make clear the direction of egress to the public way.

(c) Exterior ways of exit access.

(1) Access to an exit may be by means of any exterior balcony, porch, gallery, or roof that conforms to the requirements of this standard.

(2) Exterior ways of exit access shall have smooth, solid floors, substantially level, and shall have guards on the unenclosed sides.

(3) Where accumulation of snow or ice is likely because of the climate, the exterior way of exit access shall be maintained so that these accumulations of snow and ice will be regularly removed.

(4) A permanent, direct path of travel shall be maintained over the required exterior way of exit access. There shall be no obstruction by railings, barriers, or gates that divide the open space into sections.

(5) An exterior way of exit access, such as a courtyard, balcony, bridge, or porch shall be so arranged that there are no dead ends in excess of 20 feet.

(6) Any gallery, balcony, bridge, porch, or other exterior exit access that projects beyond the outside wall of the building shall comply with the requirements of this section (j.4.(c)) as to width and arrangement.

5. Occupant Load

(a) ATCTs may have an occupant load of 20 persons per floor and not more than 80 persons total provided that the type of ATCT construction is Type I, II, III, or IV.

(b) The occupant load shall be the maximum number of persons that may be in the space at any time.

(c) Where exits serve more than one floor, only the occupant load of each floor considered individually need be used in computing the capacity of the exits at the floor, provided that exit capacity shall not be decreased in the direction of exit travel.

6. Width and Capacity of Means of Egress

(a) The capacity of the means of egress for any floor, balcony, tier, or other occupied space shall be sufficient for the occupant load thereof.

(b) The minimum exit width shall not be less than 28 inches for existing ATCTs and not less than 36 inches for new ATCTs.

(c) Exit width shall be measured in the clear at the narrowest point of the means of egress.

(d) A door during its swing shall not reduce the width of the means of egress to one-half of the required exit width.

(e) When fully open, a door shall not project more than 7 inches into the required width of an aisle, corridor, passageway, or landing.

(f) Where a single way of exit access leads to an exit, its capacity in terms of width shall be at least equal to the required capacity of the exit to which it leads. Where more than one way of exit access leads to an exit, each shall have a width adequate for the number of persons it must accommodate.

(g) Means of egress shall be measured in inches per person. The ATCT egress capacity shall be 0.3 inch per person for stairways and 0.2 inch per person for level components.

(1) Level Egress Components. (including Class A Ramps). If an entry doorway has 28 inches clear width, a discharge doorway has 28 inches clear width, and a stairway is 30 inches wide, the egress capacity would be 100 persons, or the smallest of the three capacities.

Example:

28 in./0.2 = 140 persons for the entry doorway 28 in./0.2 = 140 persons for the discharge doorway 30 in./0.3 = 100 persons for the stairway (2) Inclined Egress Components (including Class B Ramps). For Class B ramps used for ascent, the width per person shall be increased by 10 percent beyond what is required for Class A ramps. Widths for Class B ramps used for descent shall be calculated the same as for Class A ramps.

(h) A ramp shall be designated as Class A or Class B based on the following table:

  Class A Class B
Minimum width 44 inches 30 inches
Maximum slope 1 in 10 1 in 8
Maximum height between landings 12 feet 12 feet

7. Number of Exits

(a) A single means of egress from an ATCT is permitted where:

(1) the exit is protected by a smokeproof enclosure as set forth in section j.13, or a pressurized enclosure as set forth in section j.13.(d).

(2) An automatic fire detection and alarm system is provided.

(3) ATCTs are not used for living or sleeping purposes.

(4) ATCTs are occupied by only able-bodied persons.

(5) No combustible materials are located in, under, or in the immediate vicinity of the ATCT except necessary furniture and equipment.

(6) The tower is subject to occupancy by no more than 20 persons per floor and not more than 80 persons total.

(7) Other requirements and exceptions specified in this standard for existing ATCTs are satisfied.

(b) Base buildings shall have as a minimum two exits remote from each other so arranged as to minimize the possibility that both may be blocked by any one fire or other emergency condition.

Exception: A single means of egress is permissible for those base buildings consisting of a single story, above ground and having less than 350 square feet gross floor area, and where all other requirements of this standard are met.

(c) Neither elevators nor ladders are acceptable as an approved exit component or a means of egress from an ATCT facility.

Exception: Ladders may be used for access to or egress from normally unoccupied roof areas.

8. Exit Access Passageways and Corridors

(a) Every corridor shall be not less than 44 inches in width.

Exception: Exit access passageways and corridors in existing ATCTs shall be no less than 28 inches provided they meet the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(b) Aisles shall not be less than 28 inches in width.

9. Means of Egress Doorways

(a) Every door which is required to serve as an exit shall be so designed and constructed that the way of exit travel is obvious and direct. Windows that, because of their physical configuration or design and the materials used in their construction, could be mistaken for doors shall be made inaccessible to the occupants by barriers or railings.

(b) Any door in a means of egress shall be of the side-hinged, or pivoted-swinging type. The door shall be so designed and installed that it is capable of swinging from any position to the full use of the opening in which it is installed. Doors shall swing in the direction of exit travel where serving a room or area with an occupant load of 50 or more, where used in an exit enclosure, and where serving a high hazard area.

Exception: Horizontal sliding doors may be used in means of egress provided they comply with the criteria established in NFPA 101 - Life Safety Code Section 5-2.1.14.

Exception: Revolving doors may be used in means of egress provided they comply with NFPA 101 - Life Safety Code Section 5-2.1.10.

(c) Every required exit doorway shall be of a size to permit the installation of a door not less than 36 inches in width.

(d) Exit doors shall be capable of opening at least 90 degrees and shall be mounted so as to provide a clear width of exit not less than 28 inches.

(e) A means of egress door shall be so arranged as to be readily opened from the side from which egress is to be effected at all times when the building is occupied. No lock or fastening to prevent free escape from the inside of an ATCT facility shall be installed.

(f) Doors shall latch upon closing except that a latch or other fastening device on a door shall be provided with a knob, handle, panic bar, or other simple type of releasing device.

(g) Doors required to be fire rated shall be marked by the manufacturer with a label indicating the fire resistive rating of the door and the approved testing laboratory. Door hardware shall be labeled appropriately.

(h) Automatic or self-closing doors shall operate so that in the event that the fire alarm is activated either manually or automatically, the "hold open device" automatically releases and the door automatically closes and latches.

(i) All doors shall be equipped with hardware which can be instantly reopened manually by some simple type of releasing device.

10. Stairways

(a) ATCT stairways serving an occupant load of more than 50 shall be not less than 44 inches in width. Stairways serving an occupant load of 50 or less may be 36 inches wide. Handrails may project from each side of a stairway at a distance of 3 1/2 inches into the required width. A stringer may project inside the measured width not more than 1 1/2 inches.

Exception: The width of a stairway may be 28 inches in existing ATCTs provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(b) Circular stairways are prohibited except in ATCT cabs where the circular stairway serves an occupant load of 10 or less and the minimum width of run is not less than 5 inches and the rise is not more than 9 inches.

Exception: The run of steps from the cab for existing ATCTs may be less than 5 inches (when measured 12 inches from the center column) provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(c) The maximum riser height of every step in an existing ATCT stairway shall not exceed 7 1/2 inches and the minimum run (tread depth) shall not be less than 10 inches. For stairways constructed after the effective date of this standard, the stair rise shall not be less than 4 inches and shall not exceed 7 inches and the minimum run shall be 11 inches.

Exception No. 1: Stairways serving an occupant load of less than 10 and stairways to roofs may be constructed with an 8-inch maximum rise and 9-inch minimum run.

Exception No. 2: Circular stairways as permitted by section j.10.(b) are excluded from this requirement.

Exception No. 3: The rise of steps from the cab for existing ATCTs may be greater than 7 1/2 inches and the run in existing ATCTs may be greater than 10 inches (when measured 12 inches from the center column) provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(d) The least dimension of a stair landing shall not be less than the required width of the stairway (36 inches for new ATCTs and 28 inches for existing ATCTs), except that the landing dimension in the direction of egress travel need not exceed 4 feet where the travel from one stair flight to the next stair flight is a straight run.

(e) There shall be not more than 12 feet vertically between landings.

Exception: Distances between landings in existing ATCTs serving an occupant load of 10 or less may be more than 12 feet provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(f) Exit stairs that continue beyond the floor of discharge shall be interrupted at the floor of discharge by partitions, doors, or other effective means.

11. Guards

(a) Means of egress such as stairs or landings that are more than 30 inches above the floor or the grade below shall be provided with guards at least 42 inches high to prevent falls over the open side.

Exception: Existing handrails meeting the requirements of section j.12 below shall be permitted to serve as guards.

(b) Guards shall have a pattern such that a sphere 4 inches in diameter cannot pass through the opening.

Exception: Guards in existing ATCTs may have an approved intermediate rail.

12. Handrails

(a) Handrails shall continue for the full length of each flight of stairs. At turns of stairs, inside handrails shall be continuous between flights and landings.

Exception: On existing stairs, the handrails are not required to be continuous between flights of stairs at landings provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(b) Handrails on stairs shall not be less than 34 inches nor more than 38 inches above the surface of the tread.

Exception No. 1: Handrails that form part of a guard shall be permitted to have a maximum height of 42 inches above the surface of the tread provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

Exception No. 2: Handrails in existing ATCTs shall not be less than 30 inches above the surface of the tread.

Exception No. 3: Additional handrails, beyond those required in this standard, are permitted at heights other than those stipulated provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(c) Handrails shall not project more than 3 1/2 inches into the required passageway, aisle, corridor, stair, or ramp width.

(d) The clear space between the handrail and the adjacent wall or surface shall not be less than 1 1/2 inches.

13. Smokeproof Enclosures

(a) A smokeproof enclosure shall consist of a continuous stairway enclosed by walls of fire resistive construction. The top of the enclosure shall be located within 50 feet travel distance from the most remote point of the cab for existing ATCTs and 20 feet travel distance from the most remote point of the cab for new ATCTs.

(b) The smokeproof enclosure shall be designed for natural or mechanical ventilation in compliance with NFPA 101 - Life Safety Code.

(c) Every ATCT shall have at least one exit which shall be a smokeproof enclosure. The enclosure construction meet the requirements of section f.5.(c) of this standard.

Exception: A pressurized stairway system may be used where the ATCT is protected by an automatic sprinkler system or is provided with equivalent levels of protection established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

(d) Pressurized Stairway Requirements. Smokeproof enclosures by stairway pressurization shall comply with the following:

(1) the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems); and

(2) the exist stairways are pressurized to a minimum of 0.15 inch of water column and a maximum of 0.35 inch of water column in the shaft relative to the building measured with all stairway doors closed under maximum anticipated stack pressures.

14. Exit Signs

(a) Exists shall be marked by a readily visible sign. Access to exists shall be marked by readily visible signs in all cases where the exit or pathway to an exit is not immediately visible to the occupants.

(b) Any door, passage, or stairway which is neither an exit nor a way of exit access, and which is so located or arranged as to be likely to be mistaken for an exit, shall be identified by a sign reading "Not an Exit" or similar designation, or shall be identified by a sign indicating its actual character, such as "To Basement," "Storeroom," "Linen Closet," or the like.

(c) Every required sign designating an exit or way of exit access shall be so located and of such size, color, and design as to be readily visible. No decorations, furnishings, or equipment which impair visibility of an exit sign shall be permitted, nor shall there be any brightly illuminated sign (for other than exit purposes), display, or object in or near the line of vision to the required exit sign of such a character as to so detract attention from the exit sign that it may not be noticed.

(d) Lettering of exit signs shall be at least 6 inches high with the principal strokes of letters not less than three-fourths of an inch wide.

(e) A sign reading "Exit," or similar designation, with an arrow indicating the directions, shall be placed in every location where the direction(s) of travel to reach the nearest exit is not immediately apparent.

(f) Every exit sign shall be suitably illuminated by a reliable light source of not less than 5 foot-candles, either internally or externally, on the illuminated surface.

Exception: Approved internally illuminated signs which evenly illuminate letters shall have a minimum luminance of 0.06 foot lambert.

15. Illumination of Means of Egress

(a) An emergency lighting system for means of egress shall be provided for every ATCT facility.

(b) In the absence of an emergency lighting system consisting of a prime mover-operated electric generator, electric battery-operated emergency lights shall be used which comply fully with the National Electrical Code, NFPA 70.

(c) Illumination of means of egress shall be continuous during the time the ATCT is occupied.

(d) The floors throughout the means of egress shall have an illumination of not less than 1 footcandle.

(e) Any required illumination shall be arranged so that failure of any single lighting unit will not leave any area in total darkness.

16. Emergency Power Requirements

(a) ATCTs more than 75 feet high shall have stand-by power in accordance with NFPA 70 - National Electrical Code and NFPA 110 - Emergency Standby Power Systems, Class I, Type 60 for the emergency lighting, automatic fire alarm system, electrical fire pump, central control station, mechanical equipment for smokeproof enclosures, and at least one elevator serving all floors except the cab which is transferable to any elevator.

(b) ATCTs less than 75 feet shall have emergency power for emergency lighting, automatic fire alarm systems, and mechanical equipment for smokeproof enclosures.

Exception: In existing ATCTs, emergency power to elevators is not required provided the ATCT meets the other criteria established in this standard (e.g., fire resistance rated protectives, fire detection and alarm systems).

17. Fire Escape Ladders and Exterior Stairs

(a) Fire escape ladders and exterior stairs shall not constitute any of the required means of egress in ATCTs.

(b) Although this standard contains provisions for fire escape ladders and exterior stairs on ATCTs, it does not recommend their use for several primary reasons:

(1) possible icing in cold conditions;

(2) fear of height by users;

(3) poor condition due to low maintenance;

(4) lack of protection from smoke and fire;

(5) lack of appropriate fall protection; and

(6) slow descent rate of users.

(c) Fire Escape Ladders.

(1) Fire escape ladders shall be permitted to be used only under the following conditions:

A. the ladders comply with OSHA requirement 29 CFR 1910.27, Fixed Ladders;

B. to provide access to unoccupied roof or maintenance areas; and

C. To provide a second means of escape from ATCTs only if fire conditions prevent the use of the primary means of egress or prevent other less dangerous means of escape or rescue.

(d) Fire Escape Exterior Stairs.

(1) Fire escape stairs shall be permitted in existing ATCTs but shall not constitute more than 50 percent of the required exit capacity.

(2) Fire escape stairs shall provide a continuous, unobstructed, safe path of travel to the exit discharge or a safe area of refuge.

(3) Fire escape stairs shall also comply with the other provisions of 1991 edition of NFPA 101 - Life Safety Code, Chapter 5-2.8 for fire escape stairs.

Exception: Existing noncomplying fire escape stairs may be continued to be used subject to the authority having jurisdiction.

18. Openings in exit enclosures shall be confined to those necessary for access to the enclosure from normally occupied spaces and for egress from the enclosure.

k. Fire Protection

1. General. Fire detection, alarm, and suppression equipment including detectors, manual and automatic alarms, and portable extinguishers shall be provided at ATCT facilities.

2. Automatic Fire Detection and Alarm Systems. In every ATCT, automatic fire detection and alarm systems shall be provided to warn occupants of the existence of fire.

(a) Fire detection and alarm systems. Fire detection and alarm systems shall be maintained and tested in accordance with the requirements of 29 CFR 1910.164(c) and NFPA 72.

(b) The fire alarm control panel which indicates the existence and location of a fire shall be installed in a constantly attended area in a location acceptable to the responding fire department, typically at the ATCT front entrance.

(c) The system shall be fully supervised at all times in accordance with the following styles of wiring per NFPA 72:

A. Initiating device circuits shall be Style D. B. Indicating appliance circuits shall be Style Z. C. If a multiplex system, signaling line circuits shall be Style 6 or 7.

Exception: Any style of wiring that complies with NFPA 72 shall be permitted if the ATCT is fully sprinklered.

(d) The fire detection and alarm system shall automatically notify the fire department providing service to the ATCT, or an effective plan for notifying the fire department shall be established.

(e) Alarms shall sound in all occupied spaces at a sound level of 15 dBA above the ambient sound pressure level to assure notification of all personnel in accordance with NFPA 72.

Exception: Alarm horns or bells are not required in ATCT cab or TRACON. An annunciator complying with k.2. (g), below, shall be provided.

(f) Manual fire alarm stations shall be provided in the path of escape. The stations shall be plainly marked, and lighted for ease of use in an emergency.

(g) When automatic sprinkler systems are employed, the systems shall be supervised by the alarm system.

(h) An annunciator panel to indicate the location of an actuated manual station, automatic detector, or waterflow switch shall be provided in the ATCT cab and TRACON which incorporates a silencing feature in accordance with NFPA 72 and Underwriters Laboratory. Additionally, annunciators shall resound an alarm indication at the annunciator after a period of 90 seconds if the system has not been reset or cleared.

(i) All detection and alarm equipment shall be listed by a Nationally Recognized Testing Laboratory (NRTL).

(j) Products of combustion (smoke) detectors shall be provided in all areas throughout an ATCT. Spacing of detectors shall not exceed the maximum distance indicated by tests performed by the approving laboratory for the particular device used.

(k) A secondary power source shall be provided for every fire detection and alarm system and shall operate automatically in the event of failure of the primary power source. Secondary power may be supplied by either an engine driven generator or by storage batteries of sufficient capacity.

(l) Detectors need not be provided in spaces above suspended ceilings where no combustibles are present.

(m) Detectors shall be installed below raised floors in accordance with the applicable provisions of NFPA 72.

(n) Detectors shall be installed in air handling systems downstream of air handlers with a capacity of greater than 2,000 cubic feet per minute. Upon activation of a detector, the associated air handling unit will be shut down.

3. Standpipe Systems. Standpipe systems, where required by local building code, shall conform to those local building codes.

4. Automatic Sprinkler, Halon 1301, Other Extinguishing Systems, and Portable Fire Extinguishers.

(a) Sprinkler Systems.

(1) Where automatic sprinklers are installed in an ATCT, sprinklers shall be provided in all areas or rooms.

(2) Sprinkler systems shall generally be of the wet type unless subject to freezing conditions. Waterflow and valve tamper supervision shall be annunciated with a listed alarm check valve or other listed waterflow detecting alarm device with the necessary attachments required to give an alarm. Installation shall comply with NFPA 13.

(3) All automatic sprinkler systems shall be continuously maintained in reliable operating condition at all times, and such periodic inspections and tests shall be made as are necessary to assure proper maintenance.

(b) Halon or Other Extinguishing Systems (see note in section k.3.(c)(4)).

(1) Halon 1301 extinguishing systems or other alternative extinguishing systems may be used in lieu of automatic sprinklers for existing ATCT computer or electronic equipment areas. Such areas include but are not limited to ATCT cabs, TRACON rooms, communications equipment rooms, and radar equipment rooms. However, a Halon 1301 or other alternative extinguishing system shall not be considered to be equivalent to an automatic sprinkler system for purposes of omitting the requirement for fire resistive construction as required in this standard unless it has automatic standby capacity.

(2) Halon 1301 or other alternative extinguishing systems shall be designed as an automatic sensing and actuating type with sufficient standby capacity.

(3) Halon 1301 systems shall be installed and maintained in accordance with the manufacturer's recommendation and NFPA No. 12A, 1973, Halogenated Fire Extinguishing Agent Systems - Halon 1301, National Fire Protection Association, Quincy, Massachusetts.

(4) Other alternative extinguishing systems shall be maintained in accordance with manufacturer's recommendations and the appropriate NFPA standard.

(c) Portable Fire Extinguishers.

(1) General.

A. Portable extinguishers shall be maintained in a fully charged and operable condition, and kept in their designated places at all times when they are not being used.

B. Extinguishers shall be conspicuously mounted where they will be readily accessible and immediately available in the event of fire. They shall be mounted along normal paths of travel.

C. Extinguishers shall not be obstructed or obscured from view. In large rooms and in certain locations where visual obstruction cannot be completely avoided, signs shall be provided to conspicuously indicate the location and intended use of extinguishers.

D. All extinguishers shall be marked conspicuously as to their intended use upon different classes of fire to ensure choice of the proper extinguisher.

(2) Inspection and Maintenance.

A. Extinguishers shall be inspected monthly, or at more frequent intervals when circumstances require, to ensure they are in their designated places, to ensure they have not been actuated or tampered with, and to detect any obvious physical damage, corrosion, or other impairments. Any extinguisher showing defects shall be given a complete maintenance check and repaired or replaced, as necessary.

B. At regular intervals, not more than 1 years apart, or when specifically indicated by an inspection, extinguishers shall be thoroughly examined and/or recharged or repaired to ensure operability and safety; or replaced as needed.

C. Extinguishers removed from the premises to be recharged or repaired shall be replaced by spare extinguishers during the period they are gone.

D. Each extinguisher shall have a durable tag securely attached to show the maintenance or recharge date and the initials or signature of the person who performs this service.

E. If, at any time, an extinguisher shows evidence of corrosion or damage, it shall be subjected to a hydrostatic pressure test, or replaced.

(3) Selection and Location.

A fire extinguisher of proper size and type shall be available within 75 feet from any point in a room. This requirement may increase the number of extinguishers over the quantity required in the table on Minimum Quantity and Type of Fire Extinguishers.

Minimum Quantity and Type of Fire Extinguisher (Note 1)
Room or area type Water, antifreeze and loaded stream Carbon Dioxide (CO(2)) Halon 1301
ATCT, All Occupied and Support Areas Note 2, 4   Note 4
Electronic Equipment Room Note 2, 4 Note 3, 4 Note 4
Mechanical Equipment Room Note 2, 4 Note 3, 4 Note 4
Telco Equipment Room Note 2, 4 Two 15 lb. Extinguishers Note 3, 4 Note 4
Engine Generator Room Note 2, 4 One 15 lb. Extinguisher Note 3, 4 Note 4
Electric Storage Area Note 2, 4 Note 3, 4 Note 3
General Storage Area Note 2, 4 One 15 lb. Extinguisher Note 3, 4  
Maintenance Shop Note 2, 4 One 15 lb. Extinguisher Note 3, 4  
Kitchen Note 2, 4 Multi- purpose   One 2A, 10B:C Halon Extinguisher
Office Space
ATCT Cab Note 2, 4 Note 3, 4 Note 4
TRACON Room Note 2, 4 Note 3, 4 Note 4
Note:
1. An extinguisher shall be available within 75 feet from any point in a room. This may increase the number of extinguishers over the quantity required in the above table. Multiple extinguishers of a lesser rating may not be substituted for one larger extinguisher
2. One 2 1/2 gallon extinguisher shall be provided per 300 square feed of floor area or portion thereof
3. One 15 lb. CO(2) extinguisher shall be required for each 1600 square feet of floor area or portion thereof
4. Halon 1301 or 1211 extinguishers may be used instead of CO(2) or water, antifreeze and loaded stream extinguishers in existing ATCTs. A Halon extinguisher rated 10 B:C may be substituted for a 15 lb. CO(2) extinguisher. A Halon extinguisher with 2A rating may be substituted for a water, antifreeze and loaded stream extinguisher with a 2 1/2 gallon capacity
5. Multipurpose dry chemical extinguishers are preferred for use on all types of fires. Multipurpose dry chemical extinguishers may be used instead of CO(2), or water, antifreeze and loaded stream extinguishers in ATCTs. A multipurpose dry chemical extinguisher rated 10 B:C may be substituted for a 15 lb. CO(2) extinguisher. A multipurpose dry chemical extinguisher with 2A rating may be substituted for a water, antifreeze and loaded stream extinguisher with a 2 1/2 gallon capacity

(4) Halogenated extinguishing agents are no longer in production. Existing supplies of Halon extinguishers may remain in use until they are either discharged or require repair.

(5) ATCTs constructed and occupied after the date this standard is promulgated shall not be equipped with halogenated fire extinguishers.

1. Fire Prevention and Evacuation Plan

1. Fire Prevention Plan. (a) Each ATCT shall develop a written fire prevention plan which shall include at a minimum the following:

(1) a list of all of the major workplace fire hazards and their proper handling and storage procedures, potential ignition sources (e.g., welding, smoking) and their control procedures, and the type of fire protection equipment or systems which can control a fire involving those hazards;

(2) names or job titles of personnel responsible for maintaining equipment and systems installed to prevent or control fire;

(3) names or job titles of personnel responsible for controlling fuel source hazards; and

(4) a list of extinguishers installed at the facility and their locations.

(b) Housekeeping. The employer shall control accumulations of flammable and combustible materials so that they do not contribute to a fire emergency. Housekeeping procedures shall be included in the written fire prevention plan.

(c) Training.

(1) The employer shall inform employees of the fire hazards of the materials and processes to which they are exposed.

(2) The employer shall review with each employee upon initial assignment and annually thereafter those parts of the fire prevention plan which the employee must know in the event of an emergency. The written fire prevention plan shall be kept in the workplace and be available for employee review.

(3) Employers shall train employees on the use of the various type of fire extinguishers used in their facility.

(4) Supervisors shall document employee fire prevention training in employee records.

2. Emergency Evacuation Plan.

(a) An emergency egress plan shall be developed and posted at each ATCT facility where it is available for employee review.

(b) This plan shall include actions employers and employees must take to ensure safety from fire and other emergencies. The plan shall include, at a minimum the following:

(1) emergency escape procedures and emergency escape route assignments;

(2) procedures to be followed by employees who remain to perform critical ATCT operations before they evacuate;

(3) procedures to account for all employees after emergency evacuation has been completed;

(4) rescue and medical duties for those employees who are to perform them; and

(5) names or job titles of persons or departments who can be contacted for further information or explanation of duties under the plan.

(6) This plan shall be posted in a place readily available to employees. A diagram of designated emergency egress routes shall be posted along the path of egress.

(c) Training.

(1) Before implementing the emergency action plan, the employer shall designate and train a sufficient number of persons to assist in the safe and orderly emergency evacuation of employees.

(2) The employer shall review the plan with each employee covered by the plan at the following times:

A. initially when the plan is developed;

B. whenever the employee's responsibilities or designated actions under the plan change; and

C. whenever the plan is changed.

D. The employer shall review with each employee upon initial assignment and annually thereafter those parts of the evacuation plan which the employee must know to protect the employee in the event of an emergency.

(d) Fire drills shall be held periodically. Fire drills shall be held often enough to ensure that each employee participates in at least one drill annually.

(e) Since all personnel may not be able to leave their positions during a fire drill, employees who were not able to participate shall be briefed on the emergency evacuation route and instructed to use this route the next time they leave the facility in order to familiarize themselves with the exit route. Supervisors shall document employee briefings in employee records.

(f) Ladders shall not be used during evacuation drills as their use during drills poses unnecessary risk.

Material Provided in Support of the Proposed Alternate Standard to 29 CFR 1910.36(b)(8)

A statement of why the agency cannot comply with the OSHA standard or wants to adopt an alternate standard.

The existing alternate standard was proposed by the Department of Transportation (DOT) and accepted by the Occupational Safety and Health Administration (OSHA) for Airport Traffic Control Towers (ATCTs) in 1982 in recognition of the characteristic structure of ATCTs and the unique FAA mission to control aircraft from these buildings. Contributing factors in the DOT pursuit of an alternate standard included the feasibility of using alternate life safety measures which provided an equivalent level of protection for ATCT occupants, the enormous expense and impracticality of adding a second exit to existing ATCTs or constructing ATCTs with two remote exits, and the need to minimize disruption of the commercial and private aviation activities.

DOT requests modification to the existing alternate standard for ATCTs for the reasons stated below.

* A number of specifications established in the existing alternate standard for ATCTs require types of construction beyond those mandated in OSHA regulations or in life safety and building codes.

* A licensed fire protection engineer has provided several alternative protection measures for ATCTs which were not included in the existing alternate standard.

* The existing alternate standard does not address important operational ATCT requirements (e.g., 360deg. field of vision at the cab level) or their relationship with protective structural or procedural features.

A description of the alternate standard. The revision to the existing alternate standard provides types of ATCT construction and methods of operation which enhance the fire detection and notification, fire resistance, smoke control, and emergency response features for ATCTs. These features provide early warning of the presence of fire or smoke, flame and smoke spread control, and automatic notification of emergency response units such that a level of fire safety equivalent to two means of egress are afforded ATCT occupants.

An explanation of how the alternate standard provides equivalent or greater protection for the affected employees.

Enhancements to the alternate standard include:

* an ATCT stairway smoke control system;

* fire resistant rated materials for stairway enclosures and openings;

* self-closing or automatic fire doors;

* ATCT fire alarm system wiring in accordance with NFPA 72 reliability standards;

* automatic smoke detection;

* automatic fire detection, alarm, and signalling systems with automatic fire department and ATCT notification and ATCT cab annunciator panels with battery backup;

* prohibition of storage of high hazard materials or use of more than minimal amounts of high hazard materials for specific duties;

* occupancy above the level of exit discharge only by able-bodied persons;

* prescribed quality and type of interior finish materials;

* specified levels of fire resistant rated opening protectives to base buildings.

These and other measures in the proposed revision to the alternate standard will provide equivalent or greater protection for ATCTs.

A description of interim protective measures afforded employees. Pending approval of the proposed alternate standard, DOT has completed standard design ATCT structural fire safety enhancements proposed by the Rolf Jensen Associates licensed fire protection engineer. These enhancements comply with the proposed alternate standard. Other ATCTs are currently under going review by the licensed fire protection engineer contractor and up-grades are scheduled for completion by December 1994. In the interim, DOT has initiated a program in which ATCT employees are trained in emergency response techniques (evacuation plan, fire response techniques, and fire extinguisher use), agreements are made with local fire and rescue response units to ensure prompt fire control and medical service response, smoke detectors and fire alarms are installed, and housekeeping material and storage practices are improved.

[FR Doc. 94-20473 Filed 8-24-94; 8:45 am]


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