5.4 PPE, Fire Protection, Cranes, and Confined Spaces

Personal Protective Equipment (PPE) is the last line of defense in OSHA's Hierarchy of Controls (Elimination → Substitution → Engineering controls → Administrative controls → PPE). A frequent trap: PPE is the least preferred control, not the first. Subpart E governs construction PPE, and the employer generally pays for required PPE (with narrow exceptions like ordinary safety-toe boots and prescription glasses an employee takes home).

Head protection hard hats meet ANSI Z89.1. Classes by electrical rating: Class G (General, tested to 2,200 V), Class E (Electrical, 20,000 V), and Class C (Conductive, no electrical protection). Eye/face protection meets ANSI Z87.1. Hearing protection is required when noise reaches the action level of 85 dBA (8-hr TWA); the PEL is 90 dBA. Above 90 dBA, feasible engineering/administrative controls must be used first.

Respirator use requires a written program, medical evaluation, and fit testing before use.

Fire Protection (Subpart F): Provide a fire extinguisher rated at least 2A within 100 feet of travel for each 3,000 sq ft of protected building area. Know the extinguisher classes: A (ordinary combustibles), B (flammable liquids), C (energized electrical), D (combustible metals), K (cooking oils). A common combination unit is an ABC dry chemical extinguisher. Flammable liquids over 25 gallons must be stored in approved cabinets/rooms.

Cranes and Derricks (Subpart CC): Crane operators must be certified by an accredited organization. A qualified rigger must rig loads during assembly/disassembly and hoisting personnel. Conduct an annual comprehensive inspection plus daily/shift inspections. The power-line clearance default is 20 feet for lines up to 350 kV during crane operation (more conservative than the 10-ft general electrical rule — note the difference).

Rigging/sling capacity appears as a numeric. A sling's safe working load drops as the angle from horizontal decreases. Tension factor = 1 ÷ sin(angle). At 60° the factor ≈ 1.16; at 45° ≈ 1.41; at 30° ≈ 2.0 — meaning a 1,000 lb load on a two-leg bridle at 30° puts ~1,000 lb tension in each leg. Flatter sling angles dramatically increase leg tension; never sling below 30°.

Confined Spaces in Construction (Subpart AA, 1926 Subpart 1200-series, effective 2015): A confined space is large enough to enter, has limited entry/exit, and is not designed for continuous occupancy. A permit-required confined space (PRCS) additionally has a hazardous atmosphere, engulfment potential, inwardly converging walls, or another serious hazard. Examples: manholes, tanks, sewers, crawl spaces, pits.

Atmospheric testing order before entry is tested verbatim: test (1) oxygen, (2) flammable gases/vapors, (3) toxic air contaminants — in that sequence. Safe oxygen range is 19.5% to 23.5%; below 19.5% is oxygen deficient, above 23.5% is oxygen enriched (fire risk). The lower explosive limit (LEL) must stay below 10%. PRCS entry requires an entry permit, an attendant outside, an entry supervisor, and rescue provisions — never rely on the attendant entering to rescue.

PPE Hierarchy and Selection (Subpart E)

OSHA's hazard-control hierarchy is: elimination → substitution → engineering controls → administrative controls → PPE — PPE is the last line of defense. Construction PPE: hard hats (ANSI Z89.1), safety glasses/face shields (Z87.1), hearing protection when noise exceeds the 90 dBA 8-hour PEL (action level 85 dBA), respirators (requiring a written program, medical eval, and fit testing), and hi-vis apparel. The employer pays for most required PPE.

Fire Protection (Subpart F)

Provide fire extinguishers rated for the hazard: Class A (ordinary combustibles), B (flammable liquids), C (energized electrical), D (combustible metals), K (cooking). General rule: a rated extinguisher within 100 ft of travel for Class A and within 50 ft for Class B. Control hot work (welding/cutting) with a permit, a fire watch, and 35-ft clearance of combustibles. Store flammable liquids in approved safety cans/cabinets.

Cranes (Subpart CC) and Confined Spaces (1926 Subpart AA)

Cranes: operators must be certified; a signal person and rigging by qualified persons are required; keep 10 ft clearance from energized lines up to 50 kV; do not exceed the load chart. Confined spaces in construction (Subpart AA): a permit-required confined space has limited entry/exit plus a hazard (atmospheric, engulfment). Required: atmospheric testing (O2 19.5–23.5%, LEL <10%, toxics), an attendant, entry permit, and rescue provisions.

Common Exam Traps

• Trap: PPE is the first control. It is the last resort after engineering/administrative controls.
• Trap: Using a Class A extinguisher on an energized electrical fire. Use Class C.
• Trap: Worker pays for required PPE. The employer generally pays.
• Trap: Entering a permit space without atmospheric testing or an attendant.

Rigging, Load Charts, and Sling Angles

Crane and hoisting items often test rigging math. As a sling's angle from horizontal decreases, the tension in each leg increases sharply — at 30° the leg tension is roughly double the vertical load, which can overload the sling even though the total weight is unchanged. Inspect slings before use, never exceed the rated capacity marked on the tag, and pad sharp edges. Combined with the load chart and clearances from energized lines, these are the recurring crane-safety exam points.