Many areas within animal care facilities are inherently noisy. Excessive noise can result from the animals, particularly pigs, dogs, goats, and primates, or the equipment in use such as cage washers, high-pressure air cleaning equipment, and wet vacuum systems. Exposure to loud noise can result in loss of hearing. Noise-induced hearing loss is permanent and cannot be treated medically. This type of hearing loss is usually noticed by a reduced response to frequencies above 2,000 hertz (Hz). Since normal human speech is in the 2,000 to 4,000 Hz range noise-induced hearing loss is debilitating at work and in daily life.

 

OSHA limits employee noise exposure to 90 decibels (dB) averaged over an eight-hour work shift measured on the A-scale and slow response with a standard sound level meter. If noise levels exceed 85dB then the employer must implement a hearing conservation program for exposed employees. The American Conference of Governmental Industrial Hygienists (ACGIH) recommends a more conservative threshold of 85dB as an eight-hour time-weighted average (TWA). Monitoring, annual audiometric testing, hearing protection, training and record-keeping, are required under the HCP.

 

A quick and useful method of checking areas for excessive noise is the "conversation test." Standing one to three feet apart attempt a normal conversation with another person in the noisy area. If conversation is difficult or impossible then the noise might be excessive. Have the areas evaluated by a qualified person knowledgeable in occupational noise, measuring techniques, data analysis, and control alternatives.

 

Control of excessive noise falls into three categories: engineering controls, administrative controls and personal protective equipment. Under the OSHA standard engineering controls are used first to control the hazard. This can include purchase of newer, quieter equipment, shielding, or installation of acoustical sound-deadening treatments on walls and ceilings. Administrative controls entail limiting the time an employee spends in the noise hazard area or assigning more than one employee to split the time to complete the task. The last line of defense for preventing excessive noise exposure is using personal protective equipment such as ear plugs or ear muffs.

 

From: Careful, Watch Your Step! By the Safety Guys