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![]() Where do you find noise exposure limits in Canadian legislation? Back to top Please contact Northwest Territories or Nunavut for further information. * In both territories, the Mine Health and Safety Regulations reference the 3 dBA exchange rate and the maximum impulse level of 140 dB. Employers must follow the “hierarchy of controls”, which uses engineering controls and work practices to protect workers and places restrictions on the use of hearing protection devices (HPDs) by workers. The Ontario Noise regulation requires that the employer must make sure that no worker is exposed to a sound level greater than a time-weighted average exposure limit of 85 dBA measured over an 8-hour work day. Even when the equivalent exposure is less than 85 dBA, if a worker is exposed at any time at sound levels equal to or above 90 dBA, the employer is required to take the protective measures.ĥ. These jurisdictions also do not allow unprotected exposures for sound levels that exceed 90 dBA. dBA Lex means the level of a worker's total exposure to noise in dBA is averaged over an entire workday and adjusted to an equivalent eight-hour exposure. The regulations in these jurisdictions indicate that over an exposure limit of 85 dBA Lex or an “at any time” sound level limit of 90 dBA, the employer is required to provide hearing protection, train workers, and implement audiometric testing. The regulations in these jurisdictions do not specify a value but reference the ACGIH TLVs.Ĥ. The exact figures vary slightly, but generally the regulations in which the exchange rate is 5 dB permit 10,000 impulses at a peak pressure level of 120 dB 1,000 impulses at 130 dB 100 impulses at 140 dB, and none above 140 dB.ģ. A common approach is to limit the number of impulses at a given peak pressure over a workday. Noise regulations in several jurisdictions treat impulse noise separately from continuous noise. The equivalent sound exposure level (L ex) takes impulse noise into account in the same way as it does that for continuous or intermittent noise. When a 3 dB exchange rate is used, generally, there is no separate regulation for impulse/impact noise. For more information about continuous, impulse and impact noise, please see Noise - Basic Information.Ģ. What are the noise exposure limits in Canadian jurisdictions? Back to top Jurisdictionġ. The table below shows the criterion levels (i.e., maximum permitted exposure levels for 8 hours) and the exchange rates used in different Canadian jurisdictions. This is precisely the case if the 3 dBA exchange rate is used. It follows, then, that the allowable time should be halved for every 3 dBA increase in sound level. ![]() They argue that it is logical that if the sound level is doubled, then the allowable exposure time should be cut in half. Most experts recognize the 3 dB rule as more logical. With the 5 dBA exchange rate, it is one hour. For example, the maximum permitted duration for a 100 dBA noise exposure in the 3 dBA exchange rate is 15 minutes. The 3 dBA exchange rate is more stringent. There are two types of exchange rates currently in use: 3 dBA exchange rate or the "3 dB rule," and 5 dBA exchange rate or the "5 dB rule." These two exchange rates, with criterion levels of 85 dBA and 90 dBA, give two different sets of exposure guidelines, as Table 1A and 1B show. The allowed maximum exposure time is calculated by using an exchange rate, also called a "dose-trading relation" or "trading ratio." The exchange rate is the amount by which the permitted sound level may increase if the exposure time is halved. This criterion level is 85 dBA in most jurisdictions, but it is 87 dBA for organizations that follow the Canadian federal noise regulations.Īs the sound level increases above the criterion level, Lc, the allowed exposure time must be decreased. The criterion level, often abbreviated as Lc, is the steady noise level permitted for a full eight-hour work shift. Noise Exposure Limits when Criterion Level = 90 dBA ![]() Noise Exposure Limits when Criterion Level = 85 dBA The OELs depend on two key factors that are used to prepare exposure-duration tables: the criterion level and the exchange rate. ![]() They are often displayed in exposure-duration tables like Table 1A and Table 1B. Occupational exposure limits (OELs) for noise are typically given as the maximum duration of exposure permitted for various noise levels. What are the occupational exposure limits for workplace noise? Back to top You are here: Noise - Occupational Exposure Limits in Canada ![]()
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