What must the lower guard on a portable circular saw do when the saw is lifted out of the cut?
- Stay retracted until the operator releases the trigger
- Lock open so the operator can see the blade and the line
- Swing clear so the blade can coast to a stop in open air
- Return automatically and instantly to the covering position
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D. Return automatically and instantly to the covering position
The lower guard must cover the blade to the depth of the teeth and return automatically and instantly to the covering position when the saw is withdrawn. Wedging or pinning the guard open defeats it and exposes the coasting blade.
Reference: 29 CFR 1926.304(d)
How often must slings and other rigging equipment for material handling be inspected?
- Before use on each shift and as necessary during use
- Once a week by the crane operator's supervisor
- Once a month, with a tag showing the date
- Once a year by the sling manufacturer
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A. Before use on each shift and as necessary during use
Rigging equipment is inspected prior to use on each shift and as necessary during its use, and defective rigging is removed from service. Periodic documented inspections do not replace the check before each shift.
Reference: 29 CFR 1926.251(a)(1)
Below what oxygen concentration is the atmosphere in a confined space considered oxygen deficient?
- 16.0 percent
- 19.5 percent
- 20.9 percent
- 23.5 percent
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B. 19.5 percent
An atmosphere with less than 19.5 percent oxygen is oxygen deficient. Normal air is about 20.9 percent, and more than 23.5 percent is oxygen enriched, which is also hazardous because it makes materials burn faster.
Reference: 29 CFR 1926.1202