You're using an outdated browser. This website will not display correctly and some features will not work.
Learn more about the browsers we support for a faster and safer online experience.

Important: This version of the e-Laws website will be upgraded to a new version in the coming weeks.
You can try the beta version of the new e-Laws at


filed December 15, 2006 under Occupational Health and Safety Act, R.S.O. 1990, c. O.1

Skip to content


ontario regulation 565/06

made under the

occupational health and safety act

Made: November 29, 2006
Filed: December 15, 2006
Published on e-Laws: December 19, 2006
Printed in The Ontario Gazette: December 30, 2006

Amending Reg. 851 of R.R.O. 1990

(Industrial Establishments)

1. Subsection 132 (1) of Regulation 851 of the Revised Regulations of Ontario, 1990 is amended by striking out “section 20 of the Act” and substituting “section 33 of the Act”.

2. Section 139 of the Regulation is revoked and the following substituted:

139. (1) In this section,

“dBA” means a measure of sound level in decibels using a reference sound pressure of 20 micropascals when measured on the A-weighting network of a sound level meter;

“decibel” means a unit of measurement of sound pressure level that is equal to 20 times the logarithm to the base 10 of the ratio of the pressure of a sound, divided by the reference pressure of 20 micropascals;

“equivalent sound exposure level” is the steady sound level in dBA which, if present in a workplace for eight hours in a day, would contain the same total energy as that generated by the actual and varying sound levels to which a worker is exposed in his or her total work day, determined in accordance with the formula set out in subsection (2).

(2) The formula for determining the equivalent sound exposure level is as follows:

Insert regs\Graphics\Source Law\2006\565\565FG1ae.tif


  Lex,8 is the equivalent sound exposure level in 8 hours,

Σ is the sum of the values in the enclosed expression for all activities from i = 1 to i = n,

i is a discrete activity of a worker exposed to a sound level,

ti is the duration in hours of I,

SPLi is the sound level of i in dBA,

n is the total number of discrete activities in the worker’s total workday.

(3) Every employer shall take all measures reasonably necessary in the circumstances to protect workers from exposure to hazardous sound levels.

(4) The protective measures shall include the provision and use of engineering controls, work practices and, subject to subsection (7), personal protective equipment.

(5) Any measurement of sound levels in the workplace that is done in order to determine what protective measures are appropriate shall be done without regard to any use of personal protective equipment.

(6) Without limiting the generality of subsections (3) and (4), every employer shall ensure that no worker is exposed to a sound level greater than an equivalent sound exposure level of 85 dBA, Lex,8.

(7) Except in the circumstances set out in subsections (8) and (9), the employer shall protect workers from exposure to a sound level greater than the limit described in subsection (6) without requiring them to use and wear personal protective equipment.

(8) If this subsection applies, workers shall wear and use personal protective equipment appropriate in the circumstances to protect them from exposure to a sound level greater than the limit described in subsection (6).

(9) Subsection (8) applies if engineering controls are required by subsections (3) and (4) and,

(a) are not in existence or are not obtainable;

(b) are not reasonable or not practical to adopt, install or provide because of the duration or frequency of the exposures or because of the nature of the process, operation or work;

(c) are rendered ineffective because of a temporary breakdown of such controls; or

(d) are ineffective to prevent, control or limit exposure because of an emergency.

(10) A clearly visible warning sign shall be posted at every approach to an area in the workplace where the sound level, measured as described in subsection (5), regularly exceeds 85 dBA.

3. (1) Subject to subsection (2), this Regulation comes into force on the day it is filed.

(2) Section 2 comes into force on July 1, 2007.