The construction noise standard is shorter and older than its general-industry counterpart, and the differences trip up people who learned the rules in a plant.
The limits. Protection against the effects of noise exposure must be provided when sound levels exceed those in Table D-2, measured on the A-scale at slow response (29 CFR 1926.52(a)). The table runs from 90 dBA for 8 hours through 92 for 6 hours, 95 for 4 hours, down to 115 dBA for a quarter hour or less.
Controls first. When employees are subjected to levels exceeding the table, feasible administrative or engineering controls must be used; only if those fail to reduce levels within the table is personal protective equipment provided and used (29 CFR 1926.52(b)). Subpart E repeats the point: wherever it is not feasible to reduce levels or durations to Table D-2, ear protective devices must be provided and used (29 CFR 1926.101(a)), and inserted devices must be fitted or determined individually by competent persons (29 CFR 1926.101(b)).
The program. In all cases where sound levels exceed the table's values, a continuing, effective hearing conservation program must be administered (29 CFR 1926.52(d)(1)). The construction rule does not spell out the program's contents the way 1910.95 does — no action level, no audiometric testing schedule in the text — which is why many contractors adopt the general-industry program as the practical definition of "effective."
A gas-powered cut-off saw runs well above 100 dBA. On Table D-2 that is a one- to two-hour allowance, and the standard's first instruction is to make it quieter, not to hand out plugs.