Loud noise at work can damage hearing. Approximately 22 million U.S. workers are exposed to hazardous noise at work. To minimize occupational noise-induced hearing loss, the National Institute for Occupational Safety and Health (NIOSH) recommends that workers should not be exposed to noise at a level that amounts to more than 85 decibels (dBA) for 8 hours. To create a more healthful workplace, NIOSH recommends an approach based on the hierarchy of control.
The Hierarchy of Control
Occupational safety and health professionals use the hierarchy of control (shown in the figure below) to determine how to implement feasible and effective controls. This approach groups actions by their likely effectiveness in reducing or removing the noise hazard.
In most cases, the preferred approach is to eliminate the source of hazardous noise. When elimination is not possible, substitution of the loud equipment for quieter equipment may be the next best alternative to protect workers from hazardous noise. If the hazardous noise cannot be controlled through elimination of the source or substitution of quieter equipment, engineering controls may be installed to reduce noise to safer levels or remove noise at the source.
Engineering controls require physical changes to the workplace such as redesigning equipment to eliminate noise sources and constructing barriers that prevent noise from reaching a worker. If it is not possible to remove the hazard through elimination, substitution or engineering controls, the next step is to reduce noise exposure through the use of administrative controls. For example, an employer may change an employee’s work schedule to avoid too much noise.
Personal protective equipment (PPE), such as ear plugs or other hearing protection devices, is the last option in the hierarchy of control. PPE is generally less effective than elimination, substitution, and engineering controls because they rely on human actions to reduce noise. Used in combination with other levels of control, such as administrative controls, PPE may provide worker protection when engineering controls do not adequately remove the noise hazard.
NIOSH encourages occupational safety and health professionals, employers, and workers to learn more about controls for hazardous noise exposure. Consult a workplace safety and health professional to determine solutions for your work setting and employees.
Occupational safety and health professionals and employers can take the following actions to reduce noise in the workplace. Consider these solutions when creating your hearing loss prevention program:
- Buy Quiet – select and purchase low-noise tools and machinery
- Maintain tools and equipment routinely (such as lubricate gears)
- Reduce vibration where possible
- Isolate the noise source in an insulated room or enclosure
- Place a barrier between the noise source and the employee
- Isolate the employee from the source in a room or booth (such as sound wall or windows)
To learn more about these strategies and review case studies, visit the Industrial Noise Control Manual, DHHS (NIOSH) Publication No. 79-117.
NIOSH and its partners have led efforts to promote Buy Quiet initiatives including the development of a NIOSH Power Tools Database to make noise data available to tool buyers, users, and manufacturers of powered hand tools. NIOSH held a Buy Quiet Workshop in 2012 and is continuing to develop additional web tools and guidance for use by organizations when implementing Buy Quiet programs. To learn more, visit our Buy Quiet website.
Join us to help promote Buy Quiet by raising awareness among workers and employers. Be part of a nationwide effort to reduce noise-induced hearing loss. Read about it on the NIOSH Science Blog and contact the NIOSH Division of Applied Research and Technology, Engineering and Physical Hazards Branch, Hearing Loss Prevention Team at 513-841-4221 to learn more.