Hearing Protection in Noisy Industrial Environments

This document outlines the required safety measures and guidelines for hearing protection in noisy industrial environments, aiming to prevent occupational hearing loss. It addresses noise exposure assessment, control measures, hearing protection device (HPD) selection and use, audiometric testing, and training requirements. These measures are crucial for protecting workers from the harmful effects of noise and ensuring compliance with safety regulations.

Noise Exposure Assessment

Employers must conduct noise monitoring to identify employees exposed to noise levels at or above an 8-hour time-weighted average (TWA) of 85 decibels (dBA). This level is often referred to as the action level, triggering the requirements for a hearing conservation program. [12]

Monitoring should be repeated whenever changes in production, processes, equipment, or controls increase noise exposures, potentially affecting more employees or rendering existing hearing protection inadequate. [6]

Employers must use calibrated instruments to ensure accurate noise exposure measurements. [13]

Hierarchy of Controls

Before providing hearing protection devices, employers should implement a hierarchy of controls to reduce noise levels, if reasonably possible: [2]

• Eliminate the hazard
• Engineering controls
• Substitution of equipment
• Administrative controls

[2] [2] [2] [2] Hearing Protection Devices (HPDs)

HPDs are required when noise levels are at or above 85 dBA, especially when engineering or administrative controls are not feasible or do not reduce noise exposure to acceptable levels. [2] [2]

Selection:

Employers must provide a variety of suitable HPDs, allowing employees to choose based on comfort and suitability for the work environment. HPDs must meet CSA Standard Z94.2 requirements. [7] [2]

Types of Hearing Protectors:

• Earplugs: Inserted into the ear canal; can be premolded, moldable, or custom molded.
• Semi-insert earplugs: Held over the ear canal by a rigid headband.
• Earmuffs: Consist of sound-attenuating material and soft ear cushions that fit around the ear.

[4] [4] [4]

Fit Testing:

HPDs must be fit-tested according to CSA Standard Z94.2-14 (R2019) to ensure proper fit and adequate protection. [5]

Attenuation Evaluation:

Employers must evaluate the attenuation provided by HPDs in specific noise environments, using methods described in Appendix B of OSHA 29 CFR 1910.95. HPDs must attenuate employee exposure to at least an 8-hour TWA of 90 dBA; for employees with a standard threshold shift (STS), attenuation to 85 dBA or below is required. [7] [9] [9]

Proper Use and Care:

The effectiveness of hearing protection is greatly reduced if HPDs do not fit properly, are not inserted or worn correctly, are worn only periodically, or are removed even for a short period. HPDs should not be modified, and music earphones or headsets are not substitutes. [4]

Audiometric Testing

Audiometric testing is a critical component of a hearing conservation program, helping to identify and prevent hearing loss. It involves: [8]

• Baseline Audiogram: Established within 6 months of an employee's first exposure at or above the action level (85 dBA). Testing should be preceded by at least 14 hours without exposure to workplace noise, or hearing protectors may be used as a substitute.
• Annual Audiogram: Obtained at least annually after the baseline audiogram.
• Evaluation of Audiogram: Each annual audiogram is compared to the baseline to determine if a standard threshold shift (STS) has occurred. A retest may be conducted within 30 days of the annual audiogram.
• Follow-up Procedures: Employees must be informed in writing within 21 days if an STS has occurred. Employees not using hearing protectors must be fitted with them, trained, and required to use them. Employees already using protectors should be refitted and retrained, and provided with greater attenuation if necessary.

[6] [6] [6] [11] [11] [11] Audiometric tests must meet specific requirements, including pure-tone, air-conduction threshold examinations at minimum frequencies of 500, 1000, 2000, 3000, 4000, and 6000 Hz. Tests should be conducted in rooms meeting the requirements of Appendix D: Audiometric Test Rooms. [11] [11]

Audiometers must be calibrated regularly, with functional checks before each day's use, acoustic calibration at least annually, and exhaustive calibration at least every two years. [11] [11] [11]

Worker Education and Training

Workers required to wear HPDs must receive education and training covering: [10]

• Why use hearing protection
• When to wear protective equipment
• How to select and wear HPDs
• Responsibility for HPD care
• Proper HPD care (storage, cleaning, etc.)
• Company policy requirements for noise control and hearing conservation

[10] [10] [10] [10] [10] [10] Training should be repeated regularly, at least once every two years. [10]

Hazard Communication

Warning signs should be posted at every approach to areas where noise levels exceed: [10]

• 80 dBA: "Warning" and the range of noise levels
• 85 dBA: "Warning" and requirement to wear single hearing protection
• 105 dBA: "Warning" and requirement to wear double hearing protection

[10] [10] [10] Hearing Conservation Program

A written hearing conservation program is required if noise exposure exceeds 85 dBA. The program should include: [15]

• Methods for assessing worker noise exposure
• Methods of noise control (engineering and administrative)
• Selection, use, and maintenance of hearing protectors
• Worker training on noise hazards and proper use of controls and HPDs
• Maintenance of exposure records
• Requirements for audiometric tests
• Schedule for reviewing the hearing conservation plan

[14] [14] [14] [14] [14] [14] [14] The program should be reviewed and revised at least every three years. [15]

Special Considerations for Workers with Hearing Aids

Workers who use hearing aids may require special consideration in noisy environments. Hearing aids are not hearing protectors and may amplify background noise. The following steps should be considered: [1]

• Reduce noise exposure at the source whenever possible.
• Perform detailed noise exposure measurements.
• Perform a job safety analysis to determine hearing requirements.
• Investigate noise engineering and administrative controls.
• Provide alternative methods for alarms (sound and light).
• Determine if the worker can wear both hearing aids and hearing protection without reducing protection.
• Determine if removing hearing aids will reduce worker safety.
• Consult with a medical professional or audiologist.
• Perform audiograms to monitor for changes in hearing (every 6 months for those with hearing loss).
• Use other communication methods (written text, Bluetooth, FM communication).
• Provide education and training for persons who are hearing impaired.
• Use flashlights to guide hearing-impaired individuals during emergencies.

[3] [3] [3] [3] [3] [3] [3] [3] [3] [3] [3] [3] Recordkeeping

Maintain accurate records of employee exposure measurements, audiometric test results, and hearing protector attenuation evaluations. [12]

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