Noise and Hearing Conservation Program
Exposure to excessive noise in a workplace is a physical hazard. It is a serious and widespread problem in many New Brunswick workplaces. Exposure to excessive noise [>85 dBA] can cause short term (acute or reversible) or permanent hearing loss (chronic or irreversible) depending on the type of noise the employee is exposed to. Different types of work generate different types of noise.
It's important to know that overexposure to noise doesn't necessarily take a long time. Short periods of very high noise can cause overexposure and irreversible damage to the ear. Other health hazards from noise can cause a number of physiological and psychological effects. These effects can include:
- Interfering with speech, concentration and thought processes
- Disrupting sleep
- Fatigue and aggression
- Reduced immune response
High level noise may initially cause dull hearing and ringing in the ears. Regular high level noise exposures will lead to hearing loss and other adverse health effects. Low level noise can interfere with activities or concentration and causes similar stress and health effects as high level noise.
The three main types of noise are distinguished by how the noise changes over time.
- Continuous noise remains constant and stable over a period of time. For example, boilers in a powerhouse, fans, vibrating machines and compressors.
- Variable or intermittent noise fluctuates between quiet and loud in a given time period. For example, woodworking machines and sewing machines.
- Impulse or impact noise occurs in very high intensity and very short duration. For example, punch press, hammering and gun shots.
To prevent health hazards from excessive noise exposure, as an employer you must:
- Make sure when the employer or employee believes it is possible that the noise level may exceed 80 dBA, that the noise level is measured by a competent person according to the CSA Standard Z107.56-06 (R2011) "Procedures for the measurement of occupational noise exposure" or a standard offering equivalent or better protection.
- Make reports available to the committee or representative and to an officer on request.
- Ensure the exposure to noise is as low as possible, and does not exceed the following exposures:
- More than 85 dBA for 8 hours,
- More than 88 dBA for 4 hours, or
- More than 91 dBA for 2 hours. See regulation 91-191 for other exposure limits
- Consult with the committee or health and safety representative, if any, or with employees about the selection of types of hearing protective equipment used by employees.
- With the employee who uses the equipment, keep the equipment in sanitary condition, if hearing protective equipment is required
- Ensure any hearing protective equipment conforms to CSA standard CSA Z94.2-14 (R2019), "Hearing protection devices - Performance, selection, care and use" or a standard offering equivalent or better protection.
- Where noise levels exceed 85dBA ensure that the area is clearly marked by a sign that indicates the range of the noise levels measured and warns of the noise hazard.
To determine employee TWA (time-weighted average) exposure, an audio (or noise) dosimeter or a sound level meter can be used. It is important to note the differences, including advantages and disadvantages between both pieces of equipment. CSA has developed a standard that can be used as a guide to properly measure employee exposure to noise CSA Standard Z107.56-06 (R2011), "Procedures for the measurement of occupational noise exposure" or you can use a standard offering equivalent or better protection.
While the employer is ultimately responsible for all the provisions mentioned above, the supervisor has a vital role to play in the safety of their teams. As a supervisor, you must:
- Acquaint your employees with the hazards and control measures associated with their work
- Provide the information and instruction necessary to ensure their health and safety
- Enforce company safety rules, programs, codes of practice and , including ensuring employees comply with the requirements below.
As an employee, you must:
- Wear hearing protection, when required by the employer if you are exposed to noise levels such as:
- More than 85 dBA for 8 hours
- More than 88 dBA for 4 hours
- More than 91 dBA for 2 hours
- Know how to fit, use and care for hearing protectors.
Interpretations/Details
The two main types of hearing protection are muffs and plugs. They each have advantages and disadvantages but generally ear muffs provide better protection. (Reference: WorkSafeNB - Hearing Protection)
Plugs and muffs should have a Noise Reduction Rating (NRR) printed on the packaging. This rating is the protection provided in an ideal situation. In the real world, the protection may only be half of the printed NRR and this needs to be considered when determining if employees are adequately protected when working in noisy environments.
Hearing Conservation Code of Practice
The employer must establish and implement a hearing code of practice when noise exposure exceeds, or is believed to exceed, the noise exposure limits.
The code of practice must include:
- The noise level that employees will be exposed to,
- The location of the work area where the code of practice applies,
- The noise control measures that will be implemented, including engineering controls,
- The selection, use, and maintenance of hearing protective equipment,
- The methods and procedures that will be used to train employees about the hazards of excessive noise exposure, and the correct use of control measures and hearing protective equipment,
- That signs will be posted in the work area to identify noise hazards and the precautions required, and
- The requirements for hearing tests.
When employees are exposed to noise that exceeds the noise exposure limits, the employer will arrange a hearing test as soon as possible after employment starts (but not later than six months after the start of employment), and at least once every 24 months after the initial tests.
Hearing tests must be administered by:
- An audiologist who is registered as a member of the New Brunswick Association of Speech-Language Pathologists and Audiologists (NBASLPA), or
- A person who successfully completed a training course referred to in section 6 of CSA Standard Z107.6:16 (R2020), "Audiometric testing for use in hearing loss prevention programs", or a standard offering equivalent or better protection.
The employer must keep records of:
- The hearing test results of each employee and the results must be kept:
- While the employee is employed by the employer,
- Made available to an officer when requested, and
- Confidential and not released to anyone other than an officer without the written permission of the employee, or as required by law.
- The instruction and training provided to employees, and
- The noise level measurements.