Canadian Standards Association (CSA) Hearing Protection Device Ratings

ORIGIN: Moldex® Technical Services Department


You will see the CSA Class rating on some of our literature. This is a method of rating hearing protection devices that are used in Canada. It is a simple system which is based on the same laboratory tests that are performed on our hearing protectors to obtain NRRs in the United States. The system provides guidance to the user for choosing the appropriate hearing device for a certain level of noise exposure.

Each hearing protection device is rated A, B, or C. The A and B Class may also have an L associated with it. Therefore, the following Classes of hearing protectors are A, AL, B, BL, or C.

The L classification associated with Class A or B (i.e. AL or BL) means that the hearing protection device attenuates at least 20dBA when tested at 125Hz. This is an important factor when choosing hearing protection for low frequency noise.

Lex, 8h (dBA) Recommended Class
< 90 C
> 90 (up to and including 95) B or BL
> 95 (up to and including 105) A or AL
> 105 Dual*

* Dual hearing protection shall be used. A minimum of a Class B earmuff and a Class A earplug shall be used. See Z94.2-14 for details.

As always, these ratings, just like NRR, are to be used by the end user as a guide to selecting the proper hearing protection device. The Classes are based on laboratory tests and actual noise reduction achieved by any individual depends upon many factors including proper use of the device, training, maintenance, etc.

To view individual Moldex product’s CSA Class please navigate to that product’s information page.  The CSA Class is listed to the right of the NRR in the packaging table.

WARNING: The information contained in this Tech Brief is dated and was accurate to the best of Moldex’s knowledge, on the date above. It is not meant to be comprehensive, nor is it intended to be used in place of the warning/use instructions that accompany Moldex respirators. Outside of the USA, check with all applicable and local government regulations.

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