4.1 Working at height on somebody else's equipment

1 Four feet, not six

The single most common error a technician carries from a construction site into a plant is the trigger height. 1910.28(b)(1)(i): 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 guardrail systems, safety net systems, or personal fall protection systems such as personal fall arrest, travel restraint or positioning systems.

Four feet in general industry. Six feet is the construction number, from 1926.501(b)(1). A mezzanine edge, a tank top, a platform on a machine, the deck of a press, the top of a dust collector — all of them are four-foot decisions in a plant.

Holes get their own paragraph and their own two thresholds. 1910.28(b)(3)(i): each employee is protected from falling through any hole, including skylights, that is four feet or more above a lower level, by covers, guardrail systems, travel restraint systems or personal fall arrest systems. (b)(3)(ii): each employee is protected from "tripping into or stepping into or through" any hole that is less than four feet above a lower level, by covers or guardrail systems. There is no hole small enough or shallow enough to ignore.

And the specific hole that killed the crane mechanic has its own subparagraph. 1910.28(b)(3)(iv): each employee is protected from falling into a ladderway 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." A self-closing gate or an offset — not a chain, not a habit of watching your feet.

2 The surface you are standing on is somebody's equipment

1910.22(d) puts three duties on the employer for walking-working surfaces, and all three land on maintenance. (d)(1): surfaces are "inspected, regularly and as necessary, and maintained in a safe condition." (d)(2): hazardous conditions are corrected or repaired before an employee uses the surface again, and if the repair cannot be made immediately, "the hazard must be guarded to prevent employees from using the walking-working surface until the hazard is corrected or repaired." (d)(3): "When any correction or repair involves the structural integrity of the walking-working surface, a qualified person performs or supervises the correction or repair."

That third one is a limit on your own work. Cutting a section out of a grating, removing a handrail post to get a motor through, unbolting a platform leg to reach a bearing — each of those touches structural integrity, and each needs a qualified person performing or supervising it. It is also the paragraph that makes the temporary opening you created into your responsibility until it is closed.

1910.22(a)(3) is the housekeeping half, and maintenance work generates most of what it names: surfaces "maintained free of hazards such as sharp or protruding objects, loose boards, corrosion, leaks, spills, snow, and ice." An oil film from a hose you broke is a fall hazard on a mezzanine long after the repair is finished.

3 Ladders: the two paragraphs that catch a mechanic

1910.23(b) sets general ladder requirements, and two of its thirteen items are the ones that matter most in a plant. (b)(9): ladders are "inspected before initial use in each work shift, and more frequently as necessary, to identify any visible defects that could cause employee injury." (b)(10): any ladder with structural or other defects "is immediately tagged 'Dangerous: Do Not Use' or with similar language in accordance with § 1910.145 and removed from service until repaired in accordance with § 1910.22(d), or replaced."

The rest of (b) is a set of habits with paragraph numbers behind them: ladders are used only for the purposes for which they were designed, (b)(8); each employee faces the ladder when climbing up or down, (b)(11); each employee uses at least one hand to grasp the ladder, (b)(12); and no employee carries an object or load that could cause a loss of balance, (b)(13). That last one is a straightforward description of how a mechanic normally climbs, and the answer is a bucket on a rope or a bag on a shoulder strap.

From the portable ladder rules in (c), four that a maintenance department breaks weekly: ladders are not loaded beyond the maximum intended load, which under 1910.21(b) includes the employee and all tools, equipment and materials being carried, (c)(3); ladders are used only on stable and level surfaces unless secured or stabilized, (c)(4); no ladder is moved, shifted or extended while an employee is on it, (c)(6); the cap and top step of a stepladder are not used as steps, (c)(8); a portable ladder used to reach an upper landing has side rails extending at least three feet above the landing surface, (c)(11); and ladders are not placed on boxes, barrels or other unstable bases to gain height, (c)(13).

One requirement with a long horizon belongs to fixed ladders in plants, because maintenance is who climbs them. 1910.28(b)(9) requires fixed ladders extending more than 24 feet above a lower level to have a personal fall arrest system or a ladder safety system: on ladders installed before November 19, 2018 a cage or well is still acceptable for now, on ladders installed on or after that date it must be a fall arrest or ladder safety system, replacing any portion triggers the requirement in that section, and "on and after November 18, 2036, all fixed ladders are equipped with a personal fall arrest system or a ladder safety system."

4 Aerial lifts: 1910.67(c)(2), twelve short rules

Maintenance lives in boom lifts and scissor lifts. 1910.67(c)(2) covers extensible and articulating boom platforms, and it is short enough to know entirely.

• (i) "Lift controls shall be tested each day prior to use to determine that such controls are in safe working condition."
• (ii) Only trained persons shall operate an aerial lift.
• (iii) "Belting off to an adjacent pole, structure, or equipment while working from an aerial lift shall not be permitted."
• (iv) Employees shall always stand firmly on the floor of the basket, and "shall not sit or climb on the edge of the basket or use planks, ladders, or other devices for a work position."
• (v) A personal fall arrest or travel restraint system meeting Subpart I shall be worn and attached to the boom or basket when working from an aerial lift.
• (vi) Boom and basket load limits specified by the manufacturer shall not be exceeded.
• (vii) The brakes shall be set, outriggers positioned on pads or a solid surface, and "wheel chocks shall be installed before using an aerial lift on an incline."
• (viii) An aerial lift truck may not be moved when the boom is elevated in a working position with people in the basket, except for equipment specifically designed for that.
• (ix) Both platform (upper) and lower controls, with the lower overriding the upper, plainly marked as to function; lower level controls "shall not be operated unless permission has been obtained from the employee in the lift, except in case of emergency."
• (x) Climbers shall not be worn while performing work from an aerial lift.
• (xi) The insulated portion of an aerial lift shall not be altered in any manner that might reduce its insulating value.
• (xii) Before moving an aerial lift for travel, the booms shall be inspected to see that they are properly cradled and outriggers are in the stowed position.

Two of these read like commentary and are not. (iii) exists because reaching out of a basket and clipping to a structure converts a fall arrest system into a trap when the basket moves. And (iv) — standing firmly on the floor of the basket, no planks or ladders — is the paragraph that gets cited after a maintenance tech puts a step stool in a scissor lift to gain the last two feet.

The transformer test technician who died in Part 2, Chapter 3 was working from a scissor lift about 15 feet up, alone, on top of a high-voltage transformer (OSHA Accident Summary Nr 172460.015). The lift was not the failure. But working alone at height on equipment whose energy state was unverified is a combination that removes every second chance at once.

5 Pits, and the paragraph most plants have never read

1910.28(b)(8) is written for exactly the kind of opening a maintenance department works in. Fall protection is not required for a repair pit, service pit or assembly pit less than 10 feet deep, provided the employer does three things: limits access within six feet of the edge to authorized employees trained under 1910.30; applies floor markings at least six feet from the edge in contrasting colors, or places a warning line at least six feet from the edge plus stanchions "capable of resisting, without tipping over, a force of at least 16 pounds (71 N) applied horizontally against the stanchion at a height of 30 inches (76 cm)," or a combination of markings and warning lines; and posts readily visible caution signs meeting 1910.145 stating "Caution—Open Pit."

Where two or more pits in a common area are not more than 15 feet apart, contrasting floor markings at least six feet from the pit edge around the entire area of the pits satisfy the marking requirement. All three conditions have to be in place — the trained-access limit, the marking or warning line, and the sign. A pit with a faded stripe and no sign is a four-foot hole under 1910.28(b)(3).

6 The height question to ask at the pre-job walk

Height on a maintenance job is almost never the point of the job, which is why it is so often unplanned. Four questions cover it.

1. 1
   What surface will I be standing on, and is any edge or hole on it four feet or more above a lower level? A machine platform, a tank top and a dust collector deck all qualify.
2. 2
   Am I creating an opening? A removed grating, an opened hatch, a lifted cover — decide the guarding for the whole time it will be open, and remember that structural work on the surface needs a qualified person under 1910.22(d)(3).
3. 3
   If I need a lift, has anybody tested the controls today under 1910.67(c)(2)(i), and is my fall protection attached to the boom or basket rather than to something I reached out to?
4. 4
   How do the tools get up and down? Under 1910.23(b)(13) you may not carry anything that could cause you to lose balance, and under 1910.21(b) the ladder's maximum intended load includes everything you are carrying.