Noise exposure in the workplace: changes coming soon in Québec

On June 16, 2023,² significant changes in Québec’s regulation will come into effect. Target values for noise exposure levels have been lowered to better align provincial and federal standards. For all so-called “continuous” noise, the permissible sound level for a maximum daily duration of eight hours will drop from 90 to 85 dB(A), while the coefficient of equivalence, aka the exchange rate, will go from Q=5 to Q=3. For impulsive noise, the instantaneous peak sound pressure level must not exceed 140 dB(C).

What does this mean in practice?

Let’s take a worker who is working an 8-hour shift in a production plant where 10 noise sources each generate 80 dB(A). The total noise level would then be 90 dB(A). To comply with the new regulation, employers have two options that don’t require hearing protection or noise mitigation for each noise source:

1. Shut down 7 of the 10 noise sources, thereby reducing the total noise level by 5 dB(A) to reach the target value of 85 dB(A) and allowing workers to work an eight-hour shift.
2. Keep the 10 sources of noise operating, whereby workers can not be exposed to the 90 dB(A) noise levels for more than 2.5 hours.

As for the change in the exchange rate, it simply needs to be understood that when the noise level increases by 3 dB(A), the exposure time will be reduced by half, as shown in the following table.

Impulsive noise, which is short-lived noise (usually less than one second) that reaches very high levels, is represented by the C-weighted peak sound pressure level. The new regulation stipulates that impulsive noises must not exceed 140 dB(C).

In addition, every five years, employers will be required to assess work areas that represent noisy activities from one or more workers. Given BBA’s knowledge of ISO-9612(2009) and CSA Z107.56-13(2014) standards, it has the technical means and expertise required to measure noise exposure. If noise limits are exceeded, employers will have one year to take the necessary actions to comply with the standards.

Hearing protection devices, such as earbuds or earmuffs, may seem like a quick and inexpensive solution. However, they must comply with the CSA Z94.2-14 standard, offer a sufficiently high noise reduction rating and, above all, be adapted to the tasks employees are assigned.

In most industrial sectors, spoken communication is necessary to ensure processes are carried out properly. Also, sirens and safety announcements or backup signals must be audible at all times. So, if workers are wearing these devices, they may not be able to hear these sounds and will be exposed to high risks for accidends.

Finally, employers are responsible for keeping an up-to-date safety log to record work situations that may exceed limits, interventions that are carried out and in situ noise assessment reports.

In Québec, employers must prepare for major changes for noise exposure levels in the workplace as soon as summer 2023. BBA is dedicated to drawing on its vast acoustics and vibration expertise to help improve worker protection and promote reasonable noise levels at work.

We will soon be publishing articles related to BBA’s technical capabilities in providing noise diagnostics and mitigation solutions for both existing operations or projects in the design phase.

To learn more, feel free to email the Acoustics and Vibrations team:

Romuald.veros@bba.ca

Vincent.simard@bba.ca – Sabine.butler@bba.ca – Annabelle.Paré@bba.ca

¹ Annual 2021 statistics, final CNESST version

² Exposition au bruit, CNESST

Gazette officielle du Québec, June 16, 2021

Calculette permettant d’évaluer le niveau d’exposition quotidienne au bruit – CNESST

Réduire le bruit en milieu de travail – CNESST