Revised on
01/26/17 02:27pm
SafetyNet #
112

Hearing Conservation

Contact information

Noise survey and evaluation is mandated under Cal-OSHA regulations (8 CCR 5096 and 5097). These regulations require employers to monitor noise exposure levels in a manner that will accurately identify employees who are exposed to noise at or above an 8-hour time-weighted average of 85 decibels (dBA). In order to comply with Cal-OSHA regulations, UC Davis requires employees exposed at or above a time-weighted average of 85 dBA to participate in the Hearing Conservation and Medical Surveillance Program. This program includes an annual audiogram examination and evaluation provided by Employee Health. The Program also provides annual hearing protection training and requires hearing protection be used by employees. Additionally, Cal-OSHA regulates the exposure time of employees for noise levels between 90-115 dBA.

EH&S recommends hearing protection (earplugs, muffs, etc.) be made available to employees for use at their discretion for areas above 80 dBA, and strongly recommends hearing protection be used in all areas above 85 dBA. At levels exceeding 90 dBA, steps must be taken to reduce the level of noise exposure to employees.

So, how loud is loud? The following is a list of various sounds, their decibel levels, and the Cal-OSHA recommended exposure time to each.
 

SOUND DECIBEL LEVEL

(dBA)

TIME PERMITTED

Rustling leaves

20

No limit

Whispering

25

No limit

Library

30

No limit

Refrigerator

45

No limit

Average home

50

No limit

Normal conversation

60

No limit

Clothes dryer

60

No limit

Washing machine

65

No limit

Dishwasher

65

No limit

Car

70

No limit

Vacuum cleaner

70

No limit

Mixer

70

No limit

Electric sewing machine

70

No limit

Busy traffic

75

No limit

Mini-bike

80

No limit

Alarm clock

80

No limit

Noisy restaurant

80

No limit

Office tabulator

80

No limit

Outboard motor

80

No limit

Passing snowmobile

80

No limit

Average factory

85

16 hours

Electric shaver

85

16 hours

Screaming child

90

8 hours

Passing motorcycle

90

8 hours

Convertible ride on freeway

95

4 hours

Subway train

100

2 hours

Diesel truck

100

2 hours

Woodworking shop

100

2 hours

Pneumatic drill

100

2 hours

Boiler shop

100

2 hours

Jackhammer

100

2 hours

Helicopter

105

1 hour

Power mower

105

1 hour

Snowmobile (drivers seat)

110

30 minutes

Inboard motor

110

30 minutes

Sandblasting

110

30 minutes

Live rock music

90-130

8-0.3 hours

Auto horn

120

7.5 minutes

Propeller aircraft

120

7.5 minutes

Air raid siren

130

3.75 minutes

THRESHHOLD OF PAIN

140

Danger Level

Gunshot

140

Danger Level

Jet engine

140

Danger Level

Rocket launching

180

Danger Level

Source: Better Hearing Institute, 1998, Your Guide to Better Hearing, Washington, D.C.