Noise Control Requirements, 101

OHS laws require you to protect workers from hazardous noise levels. The way it works: A competent person using ANSI- or CSA-approved instruments and techniques must measure noise levels and determine if they’re above the permissible exposure limit (PEL) for your particular jurisdiction. If so, you must implement reasonably practicable engineering controls, e.g., mufflers and insulation, to reduce the noise below the PEL. Only when it’s not reasonably practicable to engineer the problem away are you allowed to rely on PPE and hearing protection devices that meet CSA Z94.2-02 standards to protect workers. In many jurisdictions, you must also provide exposed workers audiometric tests to ensure they’re not suffering hearing loss.

The 7 Things You Must Know to Comply

To carry out these measures, there’s certain technical information in your jurisdiction’s OHS regulations that you need to know, including:

1. What is the PEL, typically expressed as dBA Lex, a weighted decibel measure over an 8-hour period?
2. What is the “action” or “investigation” level, i.e., the sound level that triggers the requirement to perform a noise assessment?
3. What’s the “exchange rate,” i.e., the amount by which you can increase the sound level as long as you cut the exposure time in half?
4. What, if anything, is the noise “impact or impulse” exposure limit?
5. What’s the ceiling rate or maximum sound level to which workers may be exposed?
6. When, if at all, must you ensure exposed workers get a baseline audiometric test and how often must it be repeated?
7. If audiometric testing is required, what’s the “standard threshold shift” (STS) level, i.e., the metric indicating that a worker exposed to hazardous sound has experienced or is developing hearing loss?

Of course, the answer to each of these questions varies depending on which jurisdiction you’re in. To spare you the trouble of looking it up yourself, we’ve summarized the key requirements of all the provinces and federal jurisdiction.

* Where required, noise measurements and assessments must be performed by a competent person