Elective and Optional Topics — OSHA 30 practice questions

A contractor plans permit space entries in a new sewer wet well. Which arrangement for rescue is acceptable?

1. Call the local fire department at the time of an emergency and expect help
2. Evaluate and select a rescue service, and inform it of the space hazards
3. Designate two of the entrants to pull each other out if anything goes wrong
4. Rely on the attendant to enter and perform the rescue wearing a harness

Answer: B — Evaluate and select a rescue service, and inform it of the space hazards

B) Correct — the employer must evaluate prospective rescuers for capability and timeliness, give them access to the space to plan, and inform them of the hazards. A) Assuming a response without evaluating capability is exactly what the standard prohibits. C) Entrants inside the same hazardous atmosphere cannot be the rescue plan. D) The attendant may perform non-entry retrieval but is not the entry rescue team.

Two slings are attached to a load in a basket hitch. As the crew shortens the slings and the angle between the sling legs and the horizontal decreases, what happens?

1. Tension in each sling leg rises and the hitch capacity drops
2. Tension in each leg drops because the legs are now shorter and stiffer
3. Tension is unchanged, because the weight of the load has not changed at all
4. Tension rises only if the load is unbalanced from side to side on the hook

Answer: A — Tension in each sling leg rises and the hitch capacity drops

A) Correct — as the horizontal sling angle gets smaller, the tension in each leg increases sharply for the same load, so the rated capacity of the hitch falls. B) Shorter legs are exactly what flattens the angle and raises tension. C) The load weight is constant but its distribution into the legs is not. D) Angle effects apply even to a perfectly balanced load.

Fuel-gas and oxygen cylinders in storage must be separated by:

1. 5 ft or by a 5-ft, 30-minute fire-rated barrier
2. 10 ft or by an equivalent fire-rated barrier
3. 20 ft minimum
4. 50 ft minimum

Answer: B — 10 ft or by an equivalent fire-rated barrier

Off-by-one trap. 20 ft is excessive; 10 ft / 1/2 hour barrier is the rule.

Hand and power tools are covered in 29 CFR 1926 Subpart:

1. I
2. J
3. M
4. L

Answer: A — I

Subpart I = Tools – Hand and Power. J is welding, M is falls, L is scaffolds.

Rigging slings (chain, wire rope, synthetic) must be:

1. Inspected only when broken
2. Replaced annually regardless of condition
3. Inspected only by the manufacturer
4. Inspected by a competent person before each shift / use

Answer: D — Inspected by a competent person before each shift / use

Pre-use inspection by competent person.

In a permit-required confined space, the oxygen range considered acceptable is:

1. 16.5–25%
2. 19.5–23.5%
3. 20.0–21.0%
4. Any oxygen level is acceptable

Answer: B — 19.5–23.5%

Off-by-one trap. 19.5–23.5%.

A rough-terrain forklift on a sloped site rolls over. The operator is fatally injured after being thrown from the cab. Which control would MOST likely have prevented the fatality?

1. A backup alarm loud enough to be heard above the ambient site noise
2. Wearing the seat belt so he stayed inside the protective structure
3. A hard hat carrying a rating for lateral as well as top impact
4. A spotter walking ahead of the machine to check the intended travel path

Answer: B — Wearing the seat belt so he stayed inside the protective structure

B) Correct — rollover protective structures only work if the operator is restrained inside the protected zone, which is why seat belt use is required on equipment so equipped. A) Backup alarms address struck-by hazards behind the machine, not rollover. C) A hard hat is PPE that cannot protect an ejected operator crushed by the machine. D) A spotter helps with travel path hazards but does not keep an operator in the seat.

A helper stands near a shielded metal arc welder without eye protection and later reports painful, gritty eyes. What does this MOST likely indicate?

1. Metal fume fever from breathing the smoke coming off the welding process all day
2. A foreign body left in the eye from grinding earlier in the same shift
3. Photokeratitis from the ultraviolet light given off by the welding arc itself
4. Heat stress from standing close to the hot metal for an extended period

Answer: C — Photokeratitis from the ultraviolet light given off by the welding arc itself

C) Correct — arc flash burns the corneal surface through ultraviolet exposure, and symptoms typically appear hours later, which is why bystanders need shielding or filtered eyewear too. A) Metal fume fever produces flu-like symptoms, not eye pain. B) A foreign body is possible but the classic delayed bilateral presentation near an arc points to UV. D) Heat stress causes systemic symptoms, not corneal irritation.

A fire watch has been assigned for torch cutting near combustible wall framing. Which statement about the fire watch is MOST accurate?

1. The fire watch may leave for other work as soon as the cutting torch is shut off
2. The fire watch may also serve as the welder's helper handling the leads
3. He must be equipped and trained, and must stay on after the work has stopped
4. A fire watch is not needed if a charged hose line is close to the work

Answer: C — He must be equipped and trained, and must stay on after the work has stopped

C) Correct — the fire watch's value is the delayed-ignition period; the watch must be equipped, trained, able to sound an alarm, and stay after the work stops. A) Most hot work fires are discovered well after the torch is off. B) A person handling leads cannot devote attention to watching for fire. D) Nearby hose lines do not eliminate the need for someone watching.

Which requirement applies specifically to powder-actuated tools?

1. They may be used on any base material as long as the lowest charge is chosen
2. Only trained operators may use them, and loading waits until just before use
3. They may be left loaded between fastenings so the work moves along faster
4. They must be supplied through a ground fault circuit interrupter protected circuit

Answer: B — Only trained operators may use them, and loading waits until just before use

B) Correct — operators must be trained on the particular tool and carry evidence of that training, and a loaded tool must not be left unattended or carried loaded. A) Firing into unsuitable material such as brittle masonry or thin steel can drive a fastener straight through. C) A loaded tool is a live firearm-equivalent hazard. D) Powder-actuated tools are not electrically powered, so GFCI protection does not apply.

Scaffold inspection?

Inspected by competent person before each shift + after any incident. Visual + structural. Tagged if defective.

Fire classes?

A: ordinary combustibles (wood, paper). B: flammable liquids. C: electrical. D: combustible metals. K: cooking oils. Match extinguisher to class.

Rigging inspection?

Daily visual inspection by competent person. Slings (chain, wire rope, synthetic). Document deficiencies. Don't use compromised rigging.

What are the three main types of scaffolds, and what is the minimum safety factor for scaffold capacity?

Supported, suspended, and aerial lifts. Each scaffold and component must support its own weight plus at least 4 times the maximum intended load; suspension ropes must support 6 times the intended load.