Building Codes

OSHA 1910.23 Ladders

1910.23(b)(1) Ladder rungs, steps, and cleats are parallel, level, and uniformly spaced when the ladder is in position for use;
1910.23(b)(2) Ladder rungs, steps, and cleats are spaced not less than 10 inches (25 cm) and not more than 14 inches (36 cm) apart, as measured between the centerlines of the rungs, cleats, and steps, except that:
1910.23(b)(4) Ladder rungs, steps, and cleats have a minimum clear width of 16 inches (41 cm) (measured before installation of ladder safety systems) for fixed ladders
1910.23(b)(6) Metal ladders are made with corrosion-resistant material or protected against corrosion;
1910.23(b)(7) Ladder surfaces are free of puncture and laceration hazards;
1910.23(b)(8) Ladders are used only for the purposes for which they were designed;
1910.23(b)(11) Each employee faces the ladder when climbing up or down it;
1910.23(b)(12) Each employee uses at least one hand to grasp the ladder when climbing up and down it; and
1910.23(b)(13) No employee carries any object or load that could cause the employee to lose balance and fall while climbing up or down the ladder.
1910.23(d) Fixed ladders. The employer must ensure:
1910.23(d)(1) Fixed ladders are capable of supporting their maximum intended load;
1910.23(d)(2) The minimum perpendicular distance from the centerline of the steps or rungs, or grab bars, or both, to the nearest permanent object in back of the ladder is 7 inches (18 cm), except for elevator pit ladders, which have a minimum perpendicular distance of 4.5 inches (11 cm);
1910.23(d)(3) Grab bars do not protrude on the climbing side beyond the rungs of the ladder that they serve;
1910.23(d)(4) The side rails of through or sidestep ladders extend 42 inches (1.1 m) above the top of the access level or landing platform served by the ladder. For parapet ladders, the access level is:
1910.23(d)(4)(i) The roof, if the parapet is cut to permit passage through the parapet; or
1910.23(d)(4)(ii) The top of the parapet, if the parapet is continuous;
1910.23(d)(5) For through ladders, the steps or rungs are omitted from the extensions, and the side rails are flared to provide not less than 24 inches (61cm) and not more than 30 inches (76 cm) of clearance. When a ladder safety system is provided, the maximum clearance between side rails of the extension must not exceed 36 inches (91 cm);
1910.23(d)(6) For side-step ladders, the side rails, rungs, and steps must be continuous in the extension (see Figure D-2 of this section);
1910.23(d)(7) Grab bars extend 42 inches (1.1 m) above the access level or landing platforms served by the ladder;
1910.23(d)(8) The minimum size (cross-section) of grab bars is the same size as the rungs of the ladder.
1910.23(d)(9) When a fixed ladder terminates at a hatch (see Figure D-3 of this section), the hatch cover:
1910.23(d)(9)(i) Opens with sufficient clearance to provide easy access to or from the ladder; and
1910.23(d)(9)(ii) Opens at least 70 degrees from horizontal if the hatch is counterbalanced;
1910.23(d)(10) Individual-rung ladders are constructed to prevent the employee’s feet from sliding off the ends of the rungs (see Figure D-4 of this section);
1910.23(d)(11) Fixed ladders having a pitch greater than 90 degrees from the horizontal are not used;
1910.23(d)(12) The step-across distance from the centerline of the rungs or steps is:
1910.23(d)(12)(i) For through ladders, not less than 7 inches (18 cm) and not more than 12 inches (30 cm) to the nearest edge of the structure, building, or equipment accessed from the ladders;
1910.23(d)(12)(ii) For side-step ladders, not less than 15 inches (38 cm) and not more than 20 inches (51 cm) to the access points of the platform edge;
1910.23(d)(13) Fixed ladders that do not have cages or wells have:
1910.23(d)(13)(i) A clear width of at least 15 inches (38 cm) on each side of the ladder centerline to the nearest permanent object; and
1910.23(d)(13)(ii) A minimum perpendicular distance of 30 inches (76 cm) from the centerline of the steps or rungs to the nearest object on the climbing side. When unavoidable obstructions are encountered, the minimum clearance at the obstruction may be reduced to 24 inches (61 cm), provided deflector plates are installed (see Figure D-5 of this section).
Note to paragraph (d): Section 1910.28 establishes the employer’s duty to provide fall protection for employees on fixed ladders, and § 1910.29 specifies the criteria for fall protection systems for fixed ladders.

1910.28 Duty to have fall protection and falling object protection.

1910.28(b)(9) Fixed ladders (that extend more than 24 feet (7.3 m) above a lower level).
1910.28(b)(9)(i) For fixed ladders that extend more than 24 feet (7.3 m) above a lower level, the employer must ensure:
1910.28(b)(9)(i)(A) Existing fixed ladders. Each fixed ladder installed before November 19, 2018 is equipped with a personal fall arrest system, ladder safety system, cage, or well;
1910.28(b)(9)(i)(B) New fixed ladders. Each fixed ladder installed on and after November 19, 2018, is equipped with a personal fall arrest system or a ladder safety system;
1910.28(b)(9)(i)(C) Replacement. When a fixed ladder, cage, or well, or any portion of a section thereof, is replaced, a personal fall arrest system or ladder safety system is installed in at least that section of the fixed ladder, cage, or well where the replacement is located; and
1910.28(b)(9)(i)(D) Final deadline. On and after November 18, 2036, all fixed ladders are equipped with a personal fall arrest system or a ladder safety system.
1910.28(b)(9)(ii) When a one-section fixed ladder is equipped with a personal fall protection or a ladder safety system or a fixed ladder is equipped with a personal fall arrest or ladder safety system on more than one section, the employer must ensure:
1910.28(b)(9)(ii)(A) The personal fall arrest system or ladder safety system provides protection throughout the entire vertical distance of the ladder, including all ladder sections; and
1910.28(b)(9)(ii)(B) The ladder has rest platforms provided at maximum intervals of 150 feet (45.7 m).
1910.28(b)(9)(iii) The employer must ensure ladder sections having a cage or well:
1910.28(b)(9)(iii)(A) Are offset from adjacent sections; and
1910.28(b)(9)(iii)(B) Have landing platforms provided at maximum intervals of 50 feet (15.2 m).
1910.28(b)(9)(iv) The employer may use a cage or well in combination with a personal fall arrest system or ladder safety system provided that the cage or well does not interfere with the operation of the system.

1910.29 Fall protection systems and falling object protection-criteria and practices.

1910.29(g) Cages, wells, and platforms used with fixed ladders. The employer must ensure:
1910.29(g)(1) Cages and wells installed on fixed ladders are designed, constructed, and maintained to permit easy access to, and egress from, the ladder that they enclose (see Figures D-14 and D-15 of this section);
1910.29(g)(2) Cages and wells are continuous throughout the length of the fixed ladder, except for access, egress, and other transfer points;
1910.29(g)(3) Cages and wells are designed, constructed, and maintained to contain employees in the event of a fall, and to direct them to a lower landing; and
1910.29(g)(4) Platforms used with fixed ladders provide a horizontal surface of at least 24 inches by 30 inches (61 cm by 76 cm).
Note to paragraph (g): Section 1910.28 establishes the requirements that employers must follow on the use of cages and wells as a means of fall protection.
1910.29(i) Ladder safety systems. The employer must ensure:
1910.29(i)(1) Each ladder safety system allows the employee to climb up and down using both hands and does not require that the employee continuously hold, push, or pull any part of the system while climbing;
1910.29(i)(2) The connection between the carrier or lifeline and the point of attachment to the body harness or belt does not exceed 9 inches (23 cm);
1910.29(i)(3) Mountings for rigid carriers are attached at each end of the carrier, with intermediate mountings spaced, as necessary, along the entire length of the carrier so the system has the strength to stop employee falls;
1910.29(i)(4) Mountings for flexible carriers are attached at each end of the carrier and cable guides for flexible carriers are installed at least 25 feet (7.6 m) apart but not more than 40 feet (12.2 m) apart along the entire length of the carrier;
1910.29(i)(5) The design and installation of mountings and cable guides does not reduce the design strength of the ladder; and
1910.29(i)(6) Ladder safety systems and their support systems are capable of withstanding, without failure, a drop test consisting of an 18-inch (41-cm) drop of a 500-pound (227-kg) weight.

2018 International Building Code Chapter 10 Means of Egress

1011.1 General Stairways serving occupied portions of a building shall comply with the requirements of Sections 1011.2 through 1011.13. Alternating tread devices shall comply with Section 1011.14. Ship’s ladders shall comply with Section 1011.15. Ladders shall comply with Section 1011.16
Exception: Other than where required by Section 1011.12.1, in buildings without an occupied roof access to the roof from the top story shall be permitted to be by an alternating tread device, a ship’s ladder or a permanent ladder
1011.16 Ladders Permanent ladders shall not serve as a part of the means of egress from occupied spaces within a building. Permanent ladders shall be constructed in accordance with Section 306.5 of the International Mechanical Code. Permanent ladders shall be permitted to provide access to the following areas:
1. Spaces frequented only by personnel for maintenance, repair or monitoring of equipment
2. Nonoccupiable spaces accessed only by catwalks, crawl spaces, freight elevators or very narrow passageways
3. Raised areas used primarily for purposes of security, life safety or fire safety including, but not limited to, observation galleries, prison guard towers, fire towers or lifeguard stands
4. Elevated levels in Group U not open to the general public
5. Nonoccupied roofs that are not required to have stairway access in accordance with Section 1011.12.1
6. Where permitted to access equipment and appliances in accordance with Section 306.5 of the International Mechanical Code

2018 International Mechanical Code Chapter 3 General Regulations

Where equipment requiring access or appliances are located on an elevated structure or the roof of a building such that personnel will have to climb higher than 16 feet (4877 mm) above grade to access such equipment or appliances, an interior or exterior means of access shall be provided. Such access shall not require climbing over obstructions greater than 30 inches (762 mm) in height or walking on roofs having a slope greater than four units vertical in 12 units horizontal (33-percent slope). Such access shall not require the use of portable ladders. Where access involves climbing over parapet walls, the height shall be measured to the top of the parapet wall.
Permanent ladders installed to provide the required access shall comply with the following minimum design criteria:
1. The side railing shall extend above the parapet or roof edge not less than 30 inches (762 mm).
2. Ladders shall have rung spacing not to exceed 14 inches (356 mm) on center. The uppermost rung shall be not greater than 24 inches (610 mm) below the upper edge of the roof hatch, roof or parapet, as applicable.
3. Ladders shall have a toe spacing not less than 6 inches (152 mm) deep.
4. There shall be not less than 18 inches (457 mm) between rails.
5. Rungs shall have a diameter not less than 0.75-inch (19.1 mm) and be capable of withstanding a 300-pound (136 kg) load.
6. Ladders over 30 feet (9144 mm) in height shall be provided with offset sections and landings capable of withstanding 100 pounds per square foot (488 kg/m2). Landing dimensions shall be not less than 18 inches (457 mm) and not less than the width of the ladder served. A guard rail shall be provided on all open sides of the landing.
7.Climbing clearance. The distance from the centerline of the rungs to the nearest permanent object on the climbing side of the ladder shall be not less than 30 inches (762 mm) measured perpendicular to the rungs. This distance shall be maintained from the point of ladder access to the bottom of the roof hatch. A minimum clear width of 15 inches (381 mm) shall be provided on both sides of the ladder measured from the midpoint of and parallel with the rungs except where cages or wells are installed.
8.Landing required. The ladder shall be provided with a clear and unobstructed bottom landing area having a minimum dimension of 30 inches (762 mm) by 30 inches (762 mm) centered in front of the ladder.
9.Ladders shall be protected against corrosion by approved means.
10.Access to ladders shall be provided at all times. Catwalks installed to provide the required access shall be not less than 24 inches (610 mm) wide and shall have railings as required for service platforms.

ANSI-ASC A14.3-2008 – Fixed Vertical Ladders

1.4.1 Preferred Pitch. The preferred pitch of fixed ladders shall be considered to be within the range of 75 to 90 degrees from the horizontal.
1.4.3 Pitch Greater Than 90 Degrees. Ladders having a pitch in excess of 90 degrees from the horizontal shall not be permitted.
4.1.4.2 Ladder safety systems shall be used when the length of climb of a ladder or multiple section ladders exceeds 24 feet in a single length of climb and rest platforms shall be provided at maximum intervals of 150 feet.
4.1.5 All parts and surfaces of fixed ladder installations shall be free of sharp edges, burrs, or other details that may be hazardous to the person using the ladder.
4.1.6 A ladder safety system may be used in combination with a cage.
4.2.1.1 Live Loads Imposed by Persons. Live loads imposed by persons shall be as follows:
a. The minimum design live load shall be two loads of 250 pounds each concentrated between any two consecutive attachments. Each step or rung in the ladder shall be designed for a single concentrated live load of 250 pounds minimum.
4.2.2 Live Loads for Platforms. All platforms shall be designed for a uniform minimum live load of 100 pounds per square foot over the entire platform area; for the live loads resulting from ladders secured directly to the platforms; and for other live loads as indicated in 4.2.1.2.
5.1.1 Vertical Spacings: The vertical spacing of the first rung of climb shall be permitted to be adjusted within the range of 14 inches (from ground level, floor or roof) at the access level. All vertical spacing of the rungs from the center of first rung throughout the length of climb shall be 12 inches and uniform in the same length of climb.
5.1.2 Width. The minimum inside clear width of step surface for steps and rungs shall be 16 inches, and this width shall be uniform in the same length of climb.
c. In no case shall the minimum size (cross section) of steps and rungs be less than ¾ inch, as specified in 5.1.3.2 (a), regardless of the material used.
d. The size (cross section) of steps and rungs shall be uniform in the same length of climb.
e. Steps and rungs shall be parallel and level.
b. For ladders subject to unusually corrosive atmospheric exposures, 1-inch-diameter solid bar, or the equivalent in strength for square, rectangular, or other solid shapes, is required.
5.2.1.1 Various shapes may be used that provides for a uniform gripping surface for the hands of persons using the ladder, as long as the shape provides a power grip throughout the length of climb. Irregular shapes that do not provide for uniform power gripping shall not be used. (e.g. angle iron, I-beams configurations, etc.)
5.2.4.1 Steel Ladders. The spacing of supports for fastening the side rails to the structure, building, or equipment shall be 10 feet 0 inches for the size of side rails recommended in 5.2.2, and for the clear width of steps or rungs specified in 5.1.2. For additional design loads or attachment of ladder safety systems, or for variations in size (cross section) of side rails, the spacing of supports shall be adjusted in accordance with recognized design practice.
5.2.4.2 Ladders Constructed of Aluminum, Wood, and Other Materials. The maximum spacing of supports for fastening the side rails to the structure, building, or equipment shall be as required to adequately support the loads, subject to the same requirements specified for steel in 5.2.4.1.
5.3.1 Top Step or Rung. The top of a step or rung of a ladder shall be level with the top of the access/egress level or landing platform served by the ladder, except as required by 5.3.4.2 or as permitted in 6.2.1.2.
5.3.2.1 The side rails of through or side-step ladders shall extend 3 feet 6 inches above the top of the access/egress level or landing platform served by the ladder . For a parapet ladder, the access/egress level shall be the roof if the parapet is cut to permit passage through the parapet; if the parapet is continuous, the access/egress level shall be the top of the parapet.
5.3.2.2 For through ladder extensions, the steps or rungs shall be omitted from the extension and the extension of the side rails shall be flared to provide not less than 24 inches, or more than 30 inches, clearance between side rails.
5.3.2.3 For side-step ladders, the side rails and the steps or rungs shall be continuous in the extension.
5.3.3.1 Individual rung ladders, except those intended for manholes and terminations with hatches (see 5.3.4), shall be extended above the access/egress level or landing platform either by the continuation of the rung spacings as horizontal grab bars or by providing vertical grab bars that shall have the same lateral spacing as the vertical legs of the rungs.
5.3.3.2 Grab bars shall extend at least 3 feet 6 inches above the access/egress level or landing platform served by the ladder.
5.3.3.3 The minimum size (cross section) of the grab bars shall be the same as for ladder rungs.
5.3.4.1 Hatches shall meet the minimum inside clearances specified for wells in 6.2.2. In the case of the unusual hatch conditions, the clearance on the climbing side may be reduced to 24 inches from the centerline of the steps or rungs if the underside of the hatch opening is fitted with a deflector plate.
5.3.4.2 Counterbalanced hatch covers shall open at least 70 degrees from the horizontal. The springs or other counterbalance mechanisms for the hatch may project into the hatch opening provided they do not reduce the clear width of access/egress to less than 24 inches. The top rung of the ladder may also be located below the top of the hatch to provide required clearance for the hatch cover.
5.3.4.3 Hatch openings shall be provided with a means to facilitate access and exit from a fixed ladder (i.e. Grab Bars or other such items that can be grasped by the climber).
5.4.1.1 Ladders without cages or wells shall have a minimum perpendicular distance of 30 inches from the centerline of the steps and rungs to the nearest permanent object on the climbing side.
5.4.1.3 When unavoidable obstructions are encountered, the minimum clearance may be reduced to 24 inches if deflector plates are provided.
5.4.2.1 The perpendicular distance from the centerline of the steps and rungs, or grab bars, or both, to the nearest permanent object in back of the ladder shall be not less than 7 inches.
5.4.2.2 For a through ladder, the step-across distance from the centerline of the steps or rungs to the nearest edge of the structure, building, or equipment shall not be less than 7 inches or more than 12 inches, a landing platform shall be provided to reduce the distance to between 7 and 12 inches.
5.4.3.1 Ladders without cages or wells shall have a minimum clear width to the nearest permanent object of at least 15 inches on each side of the centerline of the ladder.
5.4.3.2 Side-step ladders at the point of access/egress to a platform shall have a step-across distance of 15 inches minimum and 20 inches maximum from the centerline of the ladder.
6.3.1.1 Platforms shall consist of a horizontal area on which a person may step while climbing a ladder, either for rest purposes or for access to another section of the ladder.
6.3.1.2 All platforms shall be provided with railing and toeboards, in accordance with ANSI A1264.1 – 2007.
6.3.2 Platform Size. The total depth of the platform shall provide a minimum space of 30 inches from the centerline of the ladder on the climbing side. The width of the platform shall be not less than 30 inches.
6.3.3 Ladder Access Protective Swing Gates shall be installed at each ladder opening on elevated platforms to provide fall protection on new fixed ladder installations. The ladder access swing gate shall be a hinged gate or equivalent that is self-closing and does not restrict the ladder access width clearances for entry and exit. The ladder access swing gate construction shall be capable of withstanding the guardrail strength test requirements.

OSHA 1910.25 Stairways

1910.25(a) Application. This section covers all stairways (including standard, spiral, ship, and alternating tread-type stairs), except for stairs serving floating roof tanks, stairs on scaffolds, stairs designed into machines or equipment, and stairs on self-propelled motorized equipment.
1910.25(b) General requirements. The employer must ensure:
1910.25(b)(1) Handrails, stair rail systems, and guardrail systems are provided in accordance with § 1910.28;
1910.25(b)(2) Vertical clearance above any stair tread to any overhead obstruction is at least 6 feet, 8 inches (203 cm), as measured from the leading edge of the tread. Spiral stairs must meet the vertical clearance requirements in paragraph (d)(3) of this section.
1910.25(b)(3) Stairs have uniform riser heights and tread depths between landings;
1910.25(b)(4) Stairway landings and platforms are at least the width of the stair and at least 30 inches (76 cm) in depth, as measured in the direction of travel;
1910.25(b)(5) When a door or a gate opens directly on a stairway, a platform is provided, and the swing of the door or gate does not reduce the platform’s effective usable depth to:
1910.25(b)(5)(i) Less than 20 inches (51 cm) for platforms installed before January 17, 2017; and
1910.25(b)(5)(ii) Less than 22 inches (56 cm) for platforms installed on or after January 17, 2017 (see Figure D-7 of this section);
1910.25(b)(6) Each stair can support at least five times the normal anticipated live load, but never less than a concentrated load of 1,000 pounds (454 kg) applied at any point;
1910.25(b)(8) Spiral, ship, or alternating tread-type stairs are used only when the employer can demonstrate that it is not feasible to provide standard stairs.
1910.25(b)(9) When paragraph (b)(8) of this section allows the use of spiral, ship, or alternating tread-type stairs, they are installed, used, and maintained in accordance with manufacturer’s instructions.
1910.25(e) Ship stairs. In addition to paragraph (b) of this section, the employer must ensure ship stairs (see Figure D-9 of this section):
1910.25(e)(1) Are installed at a slope of 50 to 70 degrees from the horizontal;
1910.25(e)(2) Have open risers with a vertical rise between tread surfaces of 6.5 to 12 inches (17 to 30 cm);
1910.25(e)(3) Have minimum tread depth of 4 inches (10 cm); and
1910.25(e)(4) Have a minimum tread width of 18 inches (46 cm).

OSHA 1910.28 Duty to have fall protection and falling object protection.

1910.28(b)(11)(iii) Each ship stairs and alternating tread type stairs is equipped with handrails on both sides.

2018 International Building Code Chapter 10 Means of Egress

A door is permitted to open at the top step of an interior flight of stairs, provided that the door does not swing over the top step
1011.1 General Stairways serving occupied portions of a building shall comply with the requirements of Sections 1011.2 through 1011.13. Alternating tread devices shall comply with Section 1011.14. Ship’s ladders shall comply with Section 1011.15. Ladders shall comply with Section 1011.16
1011.3 Headroom Stairways shall have a headroom clearance of not less than 80 inches (2032 mm) measured vertically from a line connecting the edge of the nosings. Such headroom shall be continuous above the stairway to the point where the line intersects the landing below, one tread depth beyond the bottom riser. The minimum clearance shall be maintained the full width of the stairway and landing
Exception: Other than where required by Section 1011.12.1, in buildings without an occupied roof access to the roof from the top story shall be permitted to be by an alternating tread device, a ship’s ladder or a permanent ladder
1011.15 Ship’s ladders Ship’s ladders are permitted to be used in Group I-3 as a component of a means of egress to and from control rooms or elevated facility observation stations not more than 250 square feet (23 m2) with not more than three occupants and for access to unoccupied roofs. The minimum clear width at and below the handrails shall be 20 inches (508 mm)
1011.15.1 Handrails of ship’s ladders Handrails shall be provided on both sides of ship’s ladders
1011.15.2 Treads of ship’s ladders Ship’s ladders shall have a minimum tread depth of 5 inches (127 mm). The tread shall be projected such that the total of the tread depth plus the nosing projection is not less than 8-1/2 inches (216 mm). The maximum riser height shall be 9-1/2 inches (241 mm)
1014.2 Height Handrail height, measured above stair tread nosings, or finish surface of ramp slope, shall be uniform, not less than 34 inches (864 mm) and not more than 38 inches (965 mm). Handrail height of alternating tread devices and ship’s ladders, measured above tread nosings, shall be uniform, not less than 30 inches (762 mm) and not more than 34 inches (864 mm)
Exceptions:
3. Handrails for alternating tread devices and ship’s ladders are permitted to terminate at a location vertically above the top and bottom risers. Handrails for alternating tread devices are not required to be continuous between flights or to extend beyond the top or bottom risers 1014.7Clearance Clear space between a handrail and a wall or other surface shall be not less than 1-1/2 inches (38 mm). A handrail and a wall or other surface adjacent to the handrail shall be free of any sharp or abrasive elements
Exceptions:
5. Along alternating tread devices and ship’s ladders, guards where the top rail serves as a handrail shall have height not less than 30 inches (762 mm) and not more than 34 inches (864 mm), measured vertically from the leading edge of the device tread nosing
4. In areas that are not open to the public within occupancies in Group I-3, F, H or S, and for alternating tread devices and ship’s ladders, guards shall not have openings that allow passage of a sphere 21 inches (533 mm) in diameter

OSHA 1910.23 Ladders

1910.23(d)(9) When a fixed ladder terminates at a hatch (see Figure D-3 of this section), the hatch cover:
1910.23(d)(9)(i) Opens with sufficient clearance to provide easy access to or from the ladder; and
1910.23(d)(9)(ii) Opens at least 70 degrees from horizontal if the hatch is counterbalanced;

OSHA 1910.28 Duty to have fall protection and falling object protection.

1910.28(b)(3)(v) Each employee is protected from falling through a hatchway and chutefloor hole by:
1910.28(b)(3)(v)(A) A hinged floor-hole cover that meets the criteria in § 1910.29 and a fixed guardrail system that leaves only one exposed side. When the hole is not in use, the employer must ensure the cover is closed or a removable guardrail system is provided on the exposed sides;
1910.28(b)(3)(v)(B) A removable guardrail system and toeboards on not more than two sides of the hole and a fixed guardrail system on all other exposed sides. The employer must ensure the removable guardrail system is kept in place when the hole is not in use; or

OSHA 1910.29 Fall protection systems and falling object protection-criteria and practices.

1910.29(b)(13) When guardrail systems are used around holes that serve as points of access (such as ladderways), the guardrail system opening:
1910.29(b)(13)(i) Has a self-closing gate that slides or swings away from the hole, and is equipped with a top rail and midrail or equivalent intermediate member that meets the requirements in paragraph (b) of this section; or
1910.29(b)(13)(ii) Is offset to prevent an employee from walking or falling into the hole;
1910.29(e) Covers. The employer must ensure each cover for a hole in a walking-working surface:
1910.29(e)(1) Is capable of supporting without failure, at least twice the maximum intended load that may be imposed on the cover at any one time; and
1910.29(e)(2) Is secured to prevent accidental displacement.

ANSI A14.3-2008 – Fixed Vertical Ladders

5.3.4.1 Hatches shall meet the minimum inside clearances specified for wells in 6.2.2. In the case of the unusual hatch conditions, the clearance on the climbing side may be reduced to 24 inches from the centerline of the steps or rungs if the underside of the hatch opening is fitted with a deflector plate.
5.3.4.2 Counterbalanced hatch covers shall open at least 70 degrees from the horizontal. The springs or other counterbalance mechanisms for the hatch may project into the hatch opening provided they do not reduce the clear width of access/egress to less than 24 inches. The top rung of the ladder may also be located below the top of the hatch to provide required clearance for the hatch cover.
5.3.4.3 Hatch openings shall be provided with a means to facilitate access and exit from a fixed ladder (i.e. Grab Bars or other such items that can be grasped by the climber).
2018 IBC Chapter 10 Means of Egress
1011.12.2 Roof access Where a stairway is provided to a roof, access to the roof shall be provided through a penthouse complying with Section 1510.2
Exception: In buildings without an occupied roof, access to the roof shall be permitted to be a roof hatch or trap door not less than 16 square feet (1.5 m2) in area and having a minimum dimension of 2 feet (610 mm)
1011.13 Guards Guards shall be provided along stairways and landings where required by Section 1015 and shall be constructed in accordance with Section 1015. Where the roof hatch opening providing the required access is located within 10 feet (3049 mm) of the roof edge, such roof access or roof edge shall be protected by guards installed in accordance with Section 1015
1015.7 Roof access Guards shall be provided where the roof hatch opening is located within 10 feet (3048 mm) of a roof edge or open side of a walking surface and such edge or open side is located more than 30 inches (762 mm) above the floor, roof or grade below. The guard shall be constructed so as to prevent the passage of a sphere 21 inches (533 mm) in diameter
Exception: Guards are not required where personal fall arrest anchorage connector devices that comply with ANSI/ASSE Z 359.1 are installed
2018 IMC Chapter 3 General Regulations
304.11 Guards.
Guards shall be provided where various components that require service and roof hatch openings are located within 10 feet (3048 mm) of a roof edge or open side of a walking surface and such edge or open side is located more than 30 inches (762 mm) above the floor, roof, or grade below. The guard shall extend not less than 30 inches (762 mm) beyond each end of components that require service. The top of the guard shall be located not less than 42 inches (1067 mm) above the elevated surface adjacent to the guard. The guard shall be constructed so as to prevent the passage of a 21-inch-diameter (533 mm) sphere and shall comply with the loading requirements for guards specified in the International Building Code.
Exception: Guards are not required where fall arrest/restraint anchorage connector devices that comply with ANSI/ASSE Z 359.1 are installed.

OSHA 1910.25 Stairways

1910.25(a) Application. This section covers all stairways (including standard, spiral, ship, and alternating tread-type stairs), except for stairs serving floating roof tanks, stairs on scaffolds, stairs designed into machines or equipment, and stairs on self-propelled motorized equipment.
1910.25(b) General requirements. The employer must ensure:
1910.25(b)(1) Handrails, stair rail systems, and guardrail systems are provided in accordance with § 1910.28;
1910.25(b)(2) Vertical clearance above any stair tread to any overhead obstruction is at least 6 feet, 8 inches (203 cm), as measured from the leading edge of the tread. Spiral stairs must meet the vertical clearance requirements in paragraph (d)(3) of this section.
1910.25(b)(3) Stairs have uniform riser heights and tread depths between landings;
1910.25(b)(4) Stairway landings and platforms are at least the width of the stair and at least 30 inches (76 cm) in depth, as measured in the direction of travel;
1910.25(b)(5) When a door or a gate opens directly on a stairway, a platform is provided, and the swing of the door or gate does not reduce the platform’s effective usable depth to:
1910.25(b)(5)(i) Less than 20 inches (51 cm) for platforms installed before January 17, 2017; and
1910.25(b)(5)(ii) Less than 22 inches (56 cm) for platforms installed on or after January 17, 2017 (see Figure D-7 of this section);
1910.25(b)(6) Each stair can support at least five times the normal anticipated live load, but never less than a concentrated load of 1,000 pounds (454 kg) applied at any point;
1910.25(b)(8) Spiral, ship, or alternating tread-type stairs are used only when the employer can demonstrate that it is not feasible to provide standard stairs.
1910.25(b)(9) When paragraph (b)(8) of this section allows the use of spiral, ship, or alternating tread-type stairs, they are installed, used, and maintained in accordance with manufacturer’s instructions.
1910.25(f) Alternating tread-type stairs. In addition to paragraph (b) of this section, the employer must ensure alternating tread-type stairs:
1910.25(f)(1) Have a series of treads installed at a slope of 50 to 70 degrees from the horizontal;
1910.25(f)(2) Have a distance between handrails of 17 to 24 inches (51 to 61 cm);
1910.25(f)(3) Have a minimum tread depth of 8.5 inches (22 cm); and
1910.25(f)(4) Have open risers if the tread depth is less than 9.5 inches (24 cm);
1910.25(f)(5) Have a minimum tread width of 7 inches (18 cm), measured at the leading edge of the tread (i.e., nosing).

OSHA 1910.28 Duty to have fall protection and falling object protection.

1910.28(b)(11)(iii) Each ship stairs and alternating tread type stairs is equipped with handrails on both sides.
2018 International Building Code Chapter 10 Means of Egress
A door is permitted to open at the top step of an interior flight of stairs, provided that the door does not swing over the top step
1011.1 General Stairways serving occupied portions of a building shall comply with the requirements of Sections 1011.2 through 1011.13. Alternating tread devices shall comply with Section 1011.14. Ship’s ladders shall comply with Section 1011.15. Ladders shall comply with Section 1011.16
1011.3 Headroom Stairways shall have a headroom clearance of not less than 80 inches (2032 mm) measured vertically from a line connecting the edge of the nosings. Such headroom shall be continuous above the stairway to the point where the line intersects the landing below, one tread depth beyond the bottom riser. The minimum clearance shall be maintained the full width of the stairway and landing
Exception: Other than where required by Section 1011.12.1, in buildings without an occupied roof access to the roof from the top story shall be permitted to be by an alternating tread device, a ship’s ladder or a permanent ladder
1006.2.2.1 Boiler, incinerator and furnace rooms Two exit access doorways are required in boiler, incinerator and furnace rooms where the area is over 500 square feet (46 m2) and any fuel-fired equipment exceeds 400,000 British thermal units (Btu) (422 000 KJ) input capacity. Where two exit access doorways are required, one is permitted to be a fixed ladder or an alternating tread device. Exit access doorways shall be separated by a horizontal distance equal to one-half the length of the maximum overall diagonal dimension of the room
1006.2.2.2 Refrigeration machinery rooms Machinery rooms larger than 1,000 square feet (93 m2) shall have not less than two exits or exit access doorways. Where two exit access doorways are required, one such doorway is permitted to be served by a fixed ladder or an alternating tread device. Exit access doorways shall be separated by a horizontal distance equal to one-half the maximum horizontal dimension of the room All portions of machinery rooms shall be within 150 feet (45 720 mm) of an exit or exit access doorway. An increase in exit access travel distance is permitted in accordance with Section 1017.1 Exit and exit access doorways shall swing in the direction of egress travel, regardless of the occupant load served. Exit and exit access doorways shall be tight fitting and self-closing
1011.14 Alternating tread devices Alternating tread devices are limited to an element of a means of egress in buildings of Groups F, H and S from a mezzanine not more than 250 square feet (23 m2) in area and that serves not more than five occupants; in buildings of Group I-3 from a guard tower, observation station or control room not more than 250 square feet (23 m2) in area and for access to unoccupied roofs. Alternating tread devices used as a means of egress shall not have a rise greater than 20 feet (6096 mm) between floor levels or landings
1011.14.1 Handrails of alternating tread devices Handrails shall be provided on both sides of alternating tread devices and shall comply with Section 1014
1011.14.2 Treads of alternating tread devices Alternating tread devices shall have a minimum tread depth of 5 inches (127 mm), a minimum projected tread depth of 8-1/2 inches (216 mm), a minimum tread width of 7 inches (178 mm) and a maximum riser height of 9-1/2 inches (241 mm). The tread depth shall be measured horizontally between the vertical planes of the foremost projections of adjacent treads. The riser height shall be measured vertically between the leading edges of adjacent treads. The riser height and tread depth provided shall result in an angle of ascent from the horizontal of between 50 and 70 degrees (0.87 and 1.22 rad). The initial tread of the device shall begin at the same elevation as the platform, landing or floor surface
Exception: Alternating tread devices used as an element of a means of egress in buildings from a mezzanine area not more than 250 square feet (23 m2) in area that serves not more than five occupants shall have a minimum tread depth of 3 inches (76 mm) with a minimum projected tread depth of 10-1/2 inches (267 mm). The rise to the next alternating tread surface shall not exceed 8 inches (203 mm)
1014.2 Height Handrail height, measured above stair tread nosings, or finish surface of ramp slope, shall be uniform, not less than 34 inches (864 mm) and not more than 38 inches (965 mm). Handrail height of alternating tread devices and ship’s ladders, measured above tread nosings, shall be uniform, not less than 30 inches (762 mm) and not more than 34 inches (864 mm)
3. Handrails for alternating tread devices and ship’s ladders are permitted to terminate at a location vertically above the top and bottom risers. Handrails for alternating tread devices are not required to be continuous between flights or to extend beyond the top or bottom risers 1014.7Clearance Clear space between a handrail and a wall or other surface shall be not less than 1-1/2 inches (38 mm). A handrail and a wall or other surface adjacent to the handrail shall be free of any sharp or abrasive elements
5. Along alternating tread devices and ship’s ladders, guards where the top rail serves as a handrail shall have height not less than 30 inches (762 mm) and not more than 34 inches (864 mm), measured vertically from the leading edge of the device tread nosing
4. In areas that are not open to the public within occupancies in Group I-3, F, H or S, and for alternating tread devices and ship’s ladders, guards shall not have openings that allow passage of a sphere 21 inches (533 mm) in diameter

OSHA 1910.25 Stairways

1910.25(a) Application. This section covers all stairways (including standard, spiral, ship, and alternating tread-type stairs), except for stairs serving floating roof tanks, stairs on scaffolds, stairs designed into machines or equipment, and stairs on self-propelled motorized equipment.
1910.25(b) General requirements. The employer must ensure:
1910.25(b)(1) Handrails, stair rail systems, and guardrail systems are provided in accordance with § 1910.28;
1910.25(b)(2) Vertical clearance above any stair tread to any overhead obstruction is at least 6 feet, 8 inches (203 cm), as measured from the leading edge of the tread. Spiral stairs must meet the vertical clearance requirements in paragraph (d)(3) of this section.
1910.25(b)(3) Stairs have uniform riser heights and tread depths between landings;
1910.25(b)(4) Stairway landings and platforms are at least the width of the stair and at least 30 inches (76 cm) in depth, as measured in the direction of travel;
1910.25(b)(5) When a door or a gate opens directly on a stairway, a platform is provided, and the swing of the door or gate does not reduce the platform’s effective usable depth to:
1910.25(b)(5)(i) Less than 20 inches (51 cm) for platforms installed before January 17, 2017; and
1910.25(b)(5)(ii) Less than 22 inches (56 cm) for platforms installed on or after January 17, 2017 (see Figure D-7 of this section);
1910.25(b)(6) Each stair can support at least five times the normal anticipated live load, but never less than a concentrated load of 1,000 pounds (454 kg) applied at any point;
1910.25(b)(7) Standard stairs are used to provide access from one walking-working surface to another when operations necessitate regular and routine travel between levels, including access to operating platforms for equipment. Winding stairways may be used on tanks and similar round structures when the diameter of the tank or structure is at least 5 feet (1.5 m).
1910.25(c) Standard stairs. In addition to paragraph (b) of this section, the employer must ensure standard stairs:
1910.25(c)(1) Are installed at angles between 30 to 50 degrees from the horizontal;
1910.25(c)(2) Have a maximum riser height of 9.5 inches (24 cm);
1910.25(c)(3) Have a minimum tread depth of 9.5 inches (24 cm); and
1910.25(c)(4) Have a minimum width of 22 inches (56 cm) between vertical barriers (see Figure D-8 of this section).

OSHA 1910.28 Duty to have fall protection and falling object protection.

1910.28(b)(11) Stairways. The employer must ensure:
1910.28(b)(11)(i) Each employee exposed to an unprotected side or edge of a stairway landing that is 4 feet (1.2 m) or more above a lower level is protected by a guardrail or stair rail system;
1910.28(b)(11)(ii) Each flight of stairs having at least 3 treads and at least 4 risers is equipped with stair rail systems and handrails as follows:

OSHA 1910.29 Fall protection systems and falling object protection-criteria and practices.

1910.29(f) Handrails and stair rail systems. The employer must ensure:
1910.29(f)(1) Height criteria.
1910.29(f)(1)(i) Handrails are not less than 30 inches (76 cm) and not more than 38 inches (97 cm), as measured from the leading edge of the stair tread to the top surface of the handrail (see Figure D-12 of this section).
1910.29(f)(1)(ii) The height of stair rail systems meets the following:
1910.29(f)(1)(ii)(A) The height of stair rail systems installed before January 17, 2017 is not less than 30 inches (76 cm) from the leading edge of the stair tread to the top surface of the top rail; and
1910.29(f)(1)(ii)(B) The height of stair rail systems installed on or after January 17, 2017 is not less than 42 inches (107 cm) from the leading edge of the stair tread to the top surface of the top rail.
1910.29(f)(1)(iii) The top rail of a stair rail system may serve as a handrail only when:
1910.29(f)(1)(iii)(A) The height of the stair rail system is not less than 36 inches (91 cm) and not more than 38 inches (97 cm) as measured at the leading edge of the stair tread to the top surface of the top rail (see Figure D-13 of this section); and
1910.29(f)(1)(iii)(B) The top rail of the stair rail system meets the other handrail requirements in paragraph (f) of this section.
1910.29(f)(2) Finger clearance. The minimum clearance between handrails and any other object is 2.25 inches (5.7 cm).
1910.29(f)(3) Surfaces. Handrails and stair rail systems are smooth-surfaced to protect employees from injury, such as punctures or lacerations, and to prevent catching or snagging of clothing.
1910.29(f)(4) Openings in stair rails. No opening in a stair rail system exceeds 19 inches (48 cm) at its least dimension.
1910.29(f)(5) Handhold. Handrails have the shape and dimension necessary so that employees can grasp the handrail firmly.
1910.29(f)(6) Projection hazards. The ends of handrails and stair rail systems do not present any projection hazards.
1910.29(f)(7) Strength criteria. Handrails and the top rails of stair rail systems are capable of withstanding, without failure, a force of at least 200 pounds (890 N) applied in any downward or outward direction within 2 inches (5 cm) of any point along the top edge of the rail.

2018 International Building Code Chapter 10 Means of Egress

1011.1 General Stairways serving occupied portions of a building shall comply with the requirements of Sections 1011.2 through 1011.13.
1011.2 Width and capacity. The required capacity of stairways shall be determined as specified in Section 1005.1, but the minimum width shall be not less than 44 inches (1118 mm). See Section 1009.3 for accessible means of egress stairways
Exceptions:
1. Stairways serving an occupant load of less than 50 shall have a width of not less than 36 inches (914 mm)
1011.3 Headroom Stairways shall have a headroom clearance of not less than 80 inches (2032 mm) measured vertically from a line connecting the edge of the nosings. Such headroom shall be continuous above the stairway to the point where the line intersects the landing below, one tread depth beyond the bottom riser. The minimum clearance shall be maintained the full width of the stairway and landing
1011.5 Stair treads and risers Stair treads and risers shall comply with Sections 1011.5.1 through 1011.5.5.3
1011.5.2 Riser height and tread depth Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. The riser height shall be measured vertically between the nosings of adjacent treads. Rectangular tread depths shall be 11 inches (279 mm) minimum measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread’s nosing.
Exceptions:
5. In Group I-3 facilities, stairways providing access to guard towers, observation stations and control rooms, not more than 250 square feet (23 m2) in area, shall be permitted to have a maximum riser height of 8 inches (203 mm) and a minimum tread depth of 9 inches (229 mm)
1. Solid risers are not required for stairways that are not required to comply with Section 1009.3, provided that the opening between treads does not permit the passage of a sphere with a diameter of 4 inches (102 mm)
1011.6 Stairway landings There shall be a floor or landing at the top and bottom of each stairway. The width of landings, measured perpendicularly to the direction of travel, shall be not less than the width of stairways served. Every landing shall have a minimum depth, measured parallel to the direction of travel, equal to the width of the stairway or 48 inches (1219 mm), whichever is less. Doors opening onto a landing shall not reduce the landing to less than one-half the required width. When fully open, the door shall not project more than 7 inches (178 mm) into a landing.
1011.7.2 Outdoor conditions Outdoor stairways and outdoor approaches to stairways shall be designed so that water will not accumulate on walking surfaces
1011.8 Vertical rise A flight of stairs shall not have a vertical rise greater than 12 feet (3658 mm) between floor levels or landings
1011.11 Handrails Flights of stairways shall have handrails on each side and shall comply with Section 1014. Where glass is used to provide the handrail, the handrail shall comply with Section 2407
1011.13 Guards Guards shall be provided along stairways and landings where required by Section 1015 and shall be constructed in accordance with Section 1015.
1014.1 Where required Handrails serving flights of stairways, ramps, stepped aisles and ramped aisles shall be adequate in strength and attachment in accordance with Section 1607.8. Handrails required for flights of stairways by Section 1011.11 shall comply with Sections 1014.2 through 1014.9. Handrails required for ramps by Section 1012.8 shall comply with Sections 1014.2 through 1014.8. Handrails for stepped aisles and ramped aisles required by Section 1029.16 shall comply with Sections 1014.2 through 1014.8
1014.2 Height Handrail height, measured above stair tread nosings, or finish surface of ramp slope, shall be uniform, not less than 34 inches (864 mm) and not more than 38 inches (965 mm). Handrail height of alternating tread devices and ship’s ladders, measured above tread nosings, shall be uniform, not less than 30 inches (762 mm) and not more than 34 inches (864 mm)
Exceptions:
1. Where handrail fittings or bendings are used to provide continuous transition between flights, the fittings or bendings shall be permitted to exceed the maximum height
1014.3 Handrail graspability Required handrails shall comply with Section 1014.3.1 or shall provide equivalent graspability
1014.3.1 Type I Handrails with a circular cross section shall have an outside diameter of not less than 1-1/4 inches (32 mm) and not greater than 2 inches (51 mm). Where the handrail is not circular, it shall have a perimeter dimension of not less than 4 inches (102 mm) and not greater than 6-1/4 inches (160 mm) with a maximum cross-sectional dimension of 2-1/4 inches (57 mm) and minimum cross-sectional dimension of 1 inch (25 mm). Edges shall have a minimum radius of 0.01 inch (0.25 mm)
1014.4 Continuity Handrail gripping surfaces shall be continuous, without interruption by newel posts or other obstructions
1014.6 Handrail extensions Handrails shall return to a wall, guard or the walking surface or shall be continuous to the handrail of an adjacent flight of stairs or ramp run. Where handrails are not continuous between flights, the handrails shall extend horizontally not less than 12 inches (305 mm) beyond the top riser and continue to slope for the depth of one tread beyond the bottom riser. The extensions of handrails shall be in the same direction of the flights of stairs at stairways and the ramp runs at ramps
1014.8 Projections. On ramps and on ramped aisles that are part of an accessible route, the clear width between handrails shall be 36 inches (914 mm) minimum. Projections into the required width of aisles, stairways and ramps at each side shall not exceed 4-1/2 inches (114 mm) at or below the handrail height. Projections into the required width shall not be limited above the minimum headroom height required in Section 1011.3. Projections due to intermediate handrails shall not constitute a reduction in the egress width. Where a pair of intermediate handrails are provided within the stairway width without a walking surface between the pair of intermediate handrails and the distance between the pair of intermediate handrails is greater than 6 inches (152 mm), the available egress width shall be reduced by the distance between the closest edges of each such intermediate pair of handrails that is greater than 6 inches (152 mm)
1014.9 Intermediate handrails Stairways shall have intermediate handrails located in such a manner that all portions of the stairway minimum width or required capacity are within 30 inches (762 mm) of a handrail. On monumental stairs, handrails shall be located along the most direct path of egress travel
1015.3 Height Required guards shall be not less than 42 inches (1067 mm) high, measured vertically as follows:
1. From the adjacent walking surfaces
2. On stairways and stepped aisles, from the line connecting the leading edges of the tread nosings
Exceptions:
3. At elevated walking surfaces for access to and use of electrical, mechanical or plumbing systems or equipment, guards shall not have openings that allow passage of a sphere 21 inches (533 mm) in diameter
4. In areas that are not open to the public within occupancies in Group I-3, F, H or S, and for alternating tread devices and ship’s ladders, guards shall not have openings that allow passage of a sphere 21 inches (533 mm) in diameter

OSHA 1910.28 Duty to have fall protection and falling object protection.

1910.28(b)(1)(i) Except as provided elsewhere in this section, the employer must ensure that each employee on a walking-working surface with an unprotected side or edge that is 4 feet (1.2 m) or more above a lower level is protected from falling by one or more of the following:
1910.28(b)(1)(i)(A) Guardrail systems;
1910.28(b)(3) Holes. The employer must ensure:
1910.28(b)(3)(i) Each employee is protected from falling through any hole (including skylights) that is 4 feet (1.2 m) or more above a lower level by one or more of the following:
1910.28(b)(3)(i)(A) Covers;
1910.28(b)(3)(i)(B) Guardrail systems;
1910.28(b)(3)(iii) Each employee is protected from falling into a stairway floor hole by a fixed guardrail system on all exposed sides, except at the stairway entrance. However, for any stairway used less than once per day where traffic across the stairway floor hole prevents the use of a fixed guardrail system (e.g., holes located in aisle spaces), the employer may protect employees from falling into the hole by using a hinged floor hole cover that meets the criteria in § 1910.29 and a removable guardrail system on all exposed sides, except at the entrance to the stairway.
1910.28(b)(3)(iv) Each employee is protected from falling into a safway floor hole or ladderway platform hole by a guardrail system and toeboards erected on all exposed sides, except at the entrance to the hole, where a self-closing gate or an offset must be used.
1910.28(b)(3)(v) Each employee is protected from falling through a hatchway and chutefloor hole by:
1910.28(b)(3)(v)(A) A hinged floor-hole cover that meets the criteria in § 1910.29 and a fixed guardrail system that leaves only one exposed side. When the hole is not in use, the employer must ensure the cover is closed or a removable guardrail system is provided on the exposed sides;
1910.28(b)(3)(v)(B) A removable guardrail system and toeboards on not more than two sides of the hole and a fixed guardrail system on all other exposed sides. The employer must ensure the removable guardrail system is kept in place when the hole is not in use; or
1910.28(b)(6) Dangerous equipment. The employer must ensure:
1910.28(b)(6)(i) Each employee less than 4 feet (1.2 m) above dangerous equipment is protected from falling into or onto the dangerous equipment by a guardrail system or a travel restraint system, unless the equipment is covered or guarded to eliminate the hazard.
1910.28(b)(6)(ii) Each employee 4 feet (1.2 m) or more above dangerous equipment must be protected from falling by:
1910.28(b)(6)(ii)(A) Guardrail systems;
1910.28(b)(7) Openings. The employer must ensure that each employee on a walking-working surface near an opening, including one with a chute attached, where the inside bottom edge of the opening is less than 39 inches (99 cm) above that walking-working surface and the outside bottom edge of the opening is 4 feet (1.2 m) or more above a lower level is protected from falling by the use of:
1910.28(b)(7)(i) Guardrail systems;
1910.28(b)(13) Work on low-slope roofs.
1910.28(b)(13)(i) When work is performed less than 6 feet (1.6 m) from the roof edge, the employer must ensure each employee is protected from falling by a guardrail system, safety net system, travel restraint system, or personal fall arrest system.
1910.28(b)(13)(ii) When work is performed at least 6 feet (1.6 m) but less than 15 feet (4.6 m) from the roof edge, the employer must ensure each employee is protected from falling by using a guardrail system, safety net system, travel restraint system, or personal fall arrest system. The employer may use a designated area when performing work that is both infrequent and temporary.
1910.28(b)(13)(iii) When work is performed 15 feet (4.6 m) or more from the roof edge, the employer must:
1910.28(b)(13)(iii)(A) Protect each employee from falling by a guardrail system, safety net system, travel restraint system, or personal fall arrest system or a designated area. The employer is not required to provide any fall protection, provided the work is both infrequent and temporary; and
1910.28(b)(15) Walking-working surfaces not otherwise addressed. Except as provided elsewhere in this section or by other subparts of this part, the employer must ensure each employee on a walking-working surface 4 feet (1.2 m) or more above a lower level is protected from falling by:
1910.28(b)(15)(i) Guardrail systems;
1910.28(c) Protection from falling objects. When an employee is exposed to falling objects, the employer must ensure that each employee wears head protection that meets the requirements of subpart I of this part. In addition, the employer must protect employees from falling objects by implementing one or more of the following:
1910.28(c)(1) Erecting toeboards, screens, or guardrail systems to prevent objects from falling to a lower level;

OSHA 1910.29 Fall protection systems and falling object protection-criteria and practices.

1910.29(b) Guardrail systems. The employer must ensure guardrail systems meet the following requirements:
1910.29(b)(1) The top edge height of top rails, or equivalent guardrail system members, are 42 inches (107 cm), plus or minus 3 inches (8 cm), above the walking-working surface. The top edge height may exceed 45 inches (114 cm), provided the guardrail system meets all other criteria of paragraph (b) of this section (see Figure D-11 of this section).
1910.29(b)(2) Midrails, screens, mesh, intermediate vertical members, solid panels, or equivalent intermediate members are installed between the walking-working surface and the top edge of the guardrail system as follows when there is not a wall or parapet that is at least 21 inches (53 cm) high:
1910.29(b)(2)(i) Midrails are installed at a height midway between the top edge of the guardrail system and the walking-working surface;
1910.29(b)(2)(iii) Intermediate vertical members (such as balusters) are installed no more than 19 inches (48 cm) apart; and
1910.29(b)(2)(iv) Other equivalent intermediate members (such as additional midrails and architectural panels) are installed so that the openings are not more than 19 inches (48 cm) wide.
1910.29(b)(3) Guardrail systems are capable of withstanding, without failure, a force of at least 200 pounds (890 N) applied in a downward or outward direction within 2 inches (5 cm) of the top edge, at any point along the top rail.
1910.29(b)(4) When the 200-pound (890-N) test load is applied in a downward direction, the top rail of the guardrail system must not deflect to a height of less than 39 inches (99 cm) above the walking-working surface.
1910.29(b)(5) Midrails, screens, mesh, intermediate vertical members, solid panels, and other equivalent intermediate members are capable of withstanding, without failure, a force of at least 150 pounds (667 N) applied in any downward or outward direction at any point along the intermediate member.
1910.29(b)(6) Guardrail systems are smooth-surfaced to protect employees from injury, such as punctures or lacerations, and to prevent catching or snagging of clothing.
1910.29(b)(7) The ends of top rails and midrails do not overhang the terminal posts, except where the overhang does not pose a projection hazard for employees.
1910.29(b)(9) Top rails and midrails are at least 0.25-inches (0.6 cm) in diameter or in thickness.
1910.29(b)(11) When guardrail systems are used around holes, they are installed on all unprotected sides or edges of the hole.
1910.29(b)(12) For guardrail systems used around holes through which materials may be passed:
1910.29(b)(12)(i) When materials are being passed through the hole, not more than two sides of the guardrail system are removed; and
1910.29(b)(12)(ii) When materials are not being passed through the hole, the hole must be guarded by a guardrail system along all unprotected sides or edges or closed over with a cover.
1910.29(b)(13) When guardrail systems are used around holes that serve as points of access (such as ladderways), the guardrail system opening:
1910.29(b)(13)(i) Has a self-closing gate that slides or swings away from the hole, and is equipped with a top rail and midrail or equivalent intermediate member that meets the requirements in paragraph (b) of this section; or
1910.29(b)(13)(ii) Is offset to prevent an employee from walking or falling into the hole;
1910.29(b)(14) Guardrail systems on ramps and runways are installed along each unprotected side or edge.
1910.29(k) Protection from falling objects.
1910.29(k)(1) The employers must ensure toeboards used for falling object protection:
1910.29(k)(1)(i) Are erected along the exposed edge of the overhead walking-working surface for a length that is sufficient to protect employees below.
1910.29(k)(1)(ii) Have a minimum vertical height of 3.5 inches (9 cm) as measured from the top edge of the toeboard to the level of the walking-working surface.
1910.29(k)(1)(iii) Do not have more than a 0.25-inch (0.5-cm) clearance or opening above the walking-working surface.
1910.29(k)(1)(iv) Are solid or do not have any opening that exceeds 1 inch (3 cm) at its greatest dimension.
1910.29(k)(1)(v) Have a minimum height of 2.5 inches (6 cm) when used around vehicle repair, service, or assembly pits. Toeboards may be omitted around vehicle repair, service, or assembly pits when the employer can demonstrate that a toeboard would prevent access to a vehicle that is over the pit.
1910.29(k)(1)(vi) Are capable of withstanding, without failure, a force of at least 50 pounds (222 N) applied in any downward or outward direction at any point along the toeboard.
1910.29(k)(2) The employer must ensure:
1910.29(k)(2)(i) Where tools, equipment, or materials are piled higher than the top of the toeboard, paneling or screening is installed from the toeboard to the midrail of the guardrail system and for a length that is sufficient to protect employees below. If the items are piled higher than the midrail, the employer also must install paneling or screening to the top rail and for a length that is sufficient to protect employees below; and
1910.29(k)(2)(ii) All openings in guardrail systems are small enough to prevent objects from falling through the opening.

2018 International Building Code Chapter 10 Means of Egress

1015.1 General Guards shall comply with the provisions of Sections 1015.2 through 1015.7.
1015.2 Where required Guards shall be located along open-sided walking surfaces, including mezzanines, equipment platforms, aisles, stairs, ramps and landings that are located more than 30 inches (762 mm) measured vertically to the floor or grade below at any point within 36 inches (914 mm) horizontally to the edge of the open side. Guards shall be adequate in strength and attachment in accordance with Section 1607.8
Exception: Guards are not required for the following locations:
1. On the loading side of loading docks or piers
2. On the audience side of stages and raised platforms, including stairs leading up to the stage and raised platforms
3. On raised stage and platform floor areas, such as runways, ramps and side stages used for entertainment or presentations
4. At vertical openings in the performance area of stages and platforms
5. At elevated walking surfaces appurtenant to stages and platforms for access to and utilization of special lighting or equipment
6. Along vehicle service pits not accessible to the public
7. In assembly seating areas at cross aisles in accordance with Section 1029.17.2 1015.2.1 Glazing Where glass is used to provide a guard or as a portion of the guard system, the guard shall comply with Section 2407. Where the glazing provided does not meet the strength and attachment requirements of Section 1607.8, complying guards shall be located along glazed sides of open-sided walking surfaces
1015.3 Height Required guards shall be not less than 42 inches (1067 mm) high, measured vertically as follows:
1. From the adjacent walking surfaces
2. On stairways and stepped aisles, from the line connecting the leading edges of the tread nosings
3. At elevated walking surfaces for access to and use of electrical, mechanical or plumbing systems or equipment, guards shall not have openings that allow passage of a sphere 21 inches (533 mm) in diameter
1015.6 Mechanical equipment, systems and devices Guards shall be provided where various components that require service are located within 10 feet (3048 mm) of a roof edge or open side of a walking surface and such edge or open side is located more than 30 inches (762 mm) above the floor, roof or grade below. The guard shall extend not less than 30 inches (762 mm) beyond each end of such components. The guard shall be constructed so as to prevent the passage of a sphere 21 inches (533 mm) in diameter
Exception: Guards are not required where personal fall arrest anchorage connector devices that comply with ANSI/ASSE Z 359.1 are installed
1015.7 Roof access Guards shall be provided where the roof hatch opening is located within 10 feet (3048 mm) of a roof edge or open side of a walking surface and such edge or open side is located more than 30 inches (762 mm) above the floor, roof or grade below. The guard shall be constructed so as to prevent the passage of a sphere 21 inches (533 mm) in diameter
Exception: Guards are not required where personal fall arrest anchorage connector devices that comply with ANSI/ASSE Z 359.1 are installed

2018 International Mechanical Code Chapter 3 General

Regulations

304.11 Guards. Guards shall be provided where various components that require service and roof hatch openings are located within 10 feet (3048 mm) of a roof edge or open side of a walking surface and such edge or open side is located more than 30 inches (762 mm) above the floor, roof, or grade below. The guard shall extend not less than 30 inches (762 mm) beyond each end of components that require service. The top of the guard shall be located not less than 42 inches (1067 mm) above the elevated surface adjacent to the guard. The guard shall be constructed so as to prevent the passage of a 21-inch-diameter (533 mm) sphere and shall comply with the loading requirements for guards specified in the International Building Code.
Exception: Guards are not required where fall arrest/restraint anchorage connector devices that comply with ANSI/ASSE Z 359.1 are installed.

ANSI A14.9 Disappearing Attic Stairways

5.2 Hardware. Hardware shall be made of aluminum, steel, wrought iron, malleable iron, or other material that is adequate in strength and durability for the purpose intended. Hardware should be free from edges that can cause injury when contacted with minor force.
5.3 Fasteners. Fasteners shall be applied in a tight and secure manner. Rivets through wood or plastic components shall be peened or set over the hardware or a standard riveting burr, or an equivalent washer. The head of the rivet, when used against wood, must afford an adequate bearing surface against the wood. Holes drilled in wood parts for fasteners shall not exceed the diameter of the fastener by more than 1/32 inch. All fasteners used at pivot points shall be rivets, nylock nuts, or equivalent to prevent unintentional disassembly.
6.1.1 Types of Stairways. Disappearing attic stairways shall be designated for use in household or commercial use. Household rated products are meant only for occasional use in a residential setting by one person at a time. Commercial rated products are designed for frequent use in stores, offices, possible roof access, etc., high traffic conditions by one or two people simultaneously, and extreme load conditions.
6.1.2 Duty Ratings. Duty ratings for residential stairways shall be 250 pounds, 300 pounds and 350 pounds. All commercial stairways shall be rated for a total 500 pound load.
6.2.1 Height. Disappearing attic stairways shall be rated for various installation heights from 7 to 12 feet.
6.2.2 Angle of Inclination. When properly installed, the slope of the rails shall be 66° or less.
6.2.3 Steps. Steps shall be a minimum of 3 inches deep for residential units and 5 inches deep for commercial units. The minimum inside clear width of the steps shall be 11 inches for residential units and 15 inches for commercial units. Metal steps shall be serrated, knurled or treated to provide a slip-resistant surface.
6.2.4 Step Spacing. Steps shall be spaced uniformly between 9 inches and 12 inches apart as measured along the leading edge of the side rail +/-1/4 inch. Steps shall be within +/- 2° of parallel.
6.2.6 Handrail. The stairway shall be equipped with at least one handrail to assist the user. The handrail should be made of wood 11/16 inch x 1-3/8 inch minimum or alternate materials of equivalent strength, and be set at least 1-1/2 inches from the rail. The handrail is necessary only on sections that have a grip obstruction behind the steps and rails of the unit. The handrail must begin within 12 inches of where the grip obstruction begins on the rails.