Construction Health and Safety Technician (CHST) Practice Test 2026 – All-in-One Study Guide for Exam Success!

To calculate the percentage of OSHA permissible noise exposure represented by the construction employee's exposure, we start by determining the total noise exposure in terms of an equivalent continuous noise level (LEQ). The OSHA permissible exposure limit for noise is 90 dBA for an 8-hour workday.

First, we need to convert the different noise levels and their respective durations into a single equivalent level using the formula for noise exposure. This is done through a process where noise levels above the threshold of 90 dBA are considered to accumulate quicker due to the logarithmic nature of sound levels.

The exposure contributions can be accounted as follows:

1. For the duration at 92 dBA, it is above the threshold, so we use the formula \( N = 10^{(L-W)/10} \), where \( W \) is the standard of 90 dBA.

2. For the duration at 95 dBA, we also apply the formula.

3. For the duration at 90 dBA, it equals the threshold and adds no additional risk.

By calculating the total equivalent sound exposure, we derive a cumulative effect that is greater than the permitted daily exposure of 90 dBA over 8 hours. Once everything is summed and