Noise is a common problem in construction. But until now, it has not received the attention it de-serves. Most electrical contractors might even dismiss this hazard as nonexistent unless they were working in particularly noisy environments. To our surprise, a recent National Institute on Occupational Safety and Health (NIOSH) study has revealed the magnitude of the problem and captured the watchful eye of the Occupational Safety and Health Administration (OSHA). OSHA has placed noise on its priority list. An “Advanced Notice of Proposed Rulemaking for Hearing Conservation in the Construction Industry” was listed on the regulatory agenda released on November 30, 2000.
Under OSHA’s current rules, a permissible exposure limit to noise is set at 90 decibels or dBAs. This is a time-weighted average exposure limit for an eight-hour day. As the level increases, the exposure time must be reduced. At 105 dBA exposure must be less than 1 hour. No exposure above 115 dBA is allowed. To put these sounds in perspective, normal conversation is about 60 dBA and chain saw sounds are as high as 125 dBA. Sources of exposures on construction job sites in general include rock drilling, up to 115 dBA; abrasive blasting, 105 to 112 dBA; heavy equipment operation, 95 to 110 dBA; demolition, up to 117 dBA; and needle guns, up to 112 dBA.
An electrical contractor’s concern comes from the tools and equipment used on a daily basis. Over 421,000 construction workers are exposed to noise levels over 85 dBA. The average noise levels on job sites range from 93.1 dBA to 107.7 dBA. A common source is tools and equipment. For workers other than heavy equipment operators, this noise comes from the use of electric or pneumatic power tools. Overexposure occurs even when the tools are used for short periods.
Overexposure obviously causes hearing loss. But there are other problems, such as hypertension and elevated blood pressure levels. Balance is also affected, which may lead to deadly falls. On job sites, communication is reduced, affecting the safety of all operations. Alarms or other warning devices become ineffective if they can’t be heard.
To protect workers, the current OSHA rules require employers to take action. The general industry rule (29 CFR 1910.95) prescribes specific actions. When noise levels exceed 85 dBA an effective hearing conservation program must be implemented, which includes noise monitoring, audiometric tests, audiogram evaluations, hearing protection, training, and recordkeeping.
In contrast, the construction rule (29 CFR 1926.52) does not provide specific mandates. It only states that an employer needs to have an effective hearing conservation program. The permissible exposure limit is set at 90 dBA. When noise exceeds this limit, it must be reduced through feasible administrative and engineering controls. Hearing protection is prescribed by the construction personal protective equipment standard found in 29 CFR 1926.101.
OSHA intent is to expand the current construction rule to include requirements similar to the general industry rule. In the absence of that rule, construction may still need to implement a comprehensive program. In a letter of interpretation issued on August 4, 1992, OSHA identified seven elements they look for in an effective construction hearing conservation program:
* monitoring of employee noise exposures;
* the institution of engineering, work practice, and administrative controls for excessive noise;
* the provision of each overexposed employee with an individually fitted hearing protector with an adequate noise reduction rating;
* employee training and education regarding noise hazards and protection measures;
* baseline and annual audiometry;
* procedures for preventing further occupational hearing loss by an employee whenever such an event has been identified, and
* record keeping.
Electrical contractors should evaluate daily noise exposure and implement appropriate controls. A number of actions can be taken to reduce levels below the exposure limit. Try to divert the flow of sound energy away from employees. Maintain equipment properly and change operating procedures to reduce exposure periods. Where possible, use acoustical shields and barriers. Make sure employees wear proper hearing protection as needed. Finally, monitor OSHA regulatory activities. The National Electrical Contractors Association helps members accomplish this by issuing news items as needed.
O’CONNOR is with Intec, a producer of safety manuals with training videos and software for contractors, Based in Alexandria, Va., he can be reached at (703) 628-4326, or by e-mail at email@example.com.