Engineering Out Noise

Under the OSHA Noise Standard 1910.95(b)(1), when the Permissible Exposure Limit (PEL) is exceeded, the employer is required to implement feasible engineering or administrative controls to bring employee exposures below the PEL.  Although engineering and administrative controls are required, OSHA has agreed not to enforce this stipulation and allow effective hearing protection to meet this requirement. However, the National Institute of Safety & Health (NIOSH) found that hearing protectors are largely ineffective as currently used in the workplace and as a result, millions of workers are exposed to high levels of noise resulting in hearing loss. In addition, noise can cause increased blood pressure, stress & anxiety, fatigue, headaches, sleep disturbance, and loss of productivity.
Employers who want to protect their employees from hearing loss should commit to implementing engineering and administrative controls. Four basic principles of noise control are:

  • Sound insulation prevents the transmission of noise by the introduction of a mass barrier. Common materials that have high-density properties include  brick, concrete, metal etc. 
  • Sound absorption is a porous material which acts as a ‘noise sponge’ by converting the sound energy into heat within the material. Common sound absorption materials include open cell foams and fiberglass.
  • Vibration damping is applicable for large vibrating surfaces. The damping mechanism works by extracting the vibration energy from the thin sheet and dissipating it as heat. A common material is sound-deadened steel.
  • Vibration isolation prevents transmission of vibration energy from a source to a receiver by introducing a flexible element or a physical break. Common vibration isolators are springs, rubber mounts, cork etc. 

Here are some suggestions on how to implement  a noise control program:

  • Conduct noise dosimeter testing to identify employees who are exposed to high noise levels.
  • Conduct sound level meter readings to identify sources of noise.
  • Make sure equipment and tools are working properly, repair noisy equipment, and include them on a preventative maintenance program. 
  • Use a sound level meter with an octave band analyzer to help identify internal sources of noise.
  • Replace metal parts with plastic parts or sound absorbing materials.
  • Move, isolate, and enclose noisy equipment.
  • Adjust pressure on air powered machinery
  • Use air powered tools with the lowest noise levels.
  • Require purchasing to only buy equipment that does not exceed 85 dBA. Use the Buy Quiet Program.
  • Use an acoustics professional to help reduce noise levels.
  • Budget funds to pay for lowering noise levels.

OSHA regulations have had limited effect in protecting workers from hearing loss. It is up to employers to go beyond providing hearing plugs and muffs and provide effective engineering and administrative controls. 

For more information on this topic and to discuss your company’s safety and industrial hygiene needs call OccuSafe at (214) 662-6005 or visit us at www.occusafeinc.comOccuSafe Industrial Hygiene & Safety, Inc. provides skills and expertise to recognize, evaluate and control hazards and injuries in the areas of industrial hygiene, occupational safety and health. OccuSafe services companies of all sizes in a range of industries.

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