Transcript Hearing Conservation Program Part-1

HEARING
CONSERVATION
(PART 1)
Noise Assessment, Interpretation of
Results and Noise Reduction Options
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Copyright © 2012 CNA.
Part 1 Learning Objectives
• Understand different ways to evaluate
workplace noise exposures.
• List three possible methods for a person to
lower their noise exposure.
• Describe when hearing protection maybe
worn voluntary and when is wearing
mandatory.
Separate OSHA Noise Regulations
Federal OSHA
• General Industry, 29CFR1910.95
• Construction, 29CFR1926.52 Occupational
noise exposure and 1926.101 Hearing
protection
Facts About Hearing Loss
• More than 40 million Americans have hearing
loss.
• About 40% of the hearing-impaired are under
age 65.
• About 20% of people by age 55 have some form
of hearing loss.
• About 15% of college graduates have a level of
hearing loss equal to or greater than their
parents; a significant cause is listening to loud
music.
Causes of Hearing Loss
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Age
Disease (middle or inner-ear)
Trauma
Drugs
Noise Exposure
Noise Exposure Monitoring
Serves Various Purposes
1. Interfere with communication or recognition of
warning signals
2. Understand which employees should be
included in a hearing conservation program
3. Prioritizing noise control efforts
4. Identify specific noise sources
5. Evaluate noise control efforts
Two Ways to Monitor Noise
Exposure
• Noise Measurements
(area)
• Noise Exposure
(personal)
– Sound Level Meter
– Noise Dosimeter
– Impulsive or Impact
Noise
Area Noise Measurements
• Measure and map the
noise levels around the
plant in a grid layout and
at various machines.
• Contour map the high
noise sources. Measure
the distance away from
the noise source.
Personal Exposure Monitoring
• Sound Level Meter
– Estimate exposures at
various locations and at
various sound levels
– Good for a steady-state
sound level
• Noise Dosimeter is more
effective when:
– Worker moves around the
plant
– Intermittent high noise
exposures
What if you are exposed to
too much noise?
Hearing loss makes it hard to:
• Talk with family, friends and
coworkers.
• Hear warning signals.
• Enjoy music, nature, voices and
other sounds.
Management Requirements
• Exposures between 85 to <90dBA- 8Hr TWA
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Notify the employees of their noise exposures
Implement audiometric testing of employees
Provide personal hearing protection devices
Inform your employees about your Hearing
Conservation Program
Maintain related record keeping requirements
• Exposures at 90dBA and greater- 8 Hr TWA
Proactive Measures
• Before remodeling or building, determine if
noise can be engineered out with design
plans.
• Have noise-level testing done after
remodeling and installation of new equipment.
• Purchase equipment with lowest noise levels.
Power Tool Database
This is an example of the information of the sound
levels under load and free spinning.
Employees Must Wear
Hearing Protectors
• For any period exceeding 6 months from the
time they are first exposed to 8-hr TWA noise
exposure of 85dBA or above until they receive
their baseline audiogram. Employers have up to
12 months if using a Mobile Audiometric
Testing Company.
• If they have incurred standard threshold shifts
that demonstrate they are susceptible to noise.
• If they are exposed to noise over the
permissible exposure limit of 90dBA over an 8hour TWA.
Noise Exposure Reduction
• Engineering Controls
• Administrative Procedures
• Personal Protective Equipment (hearing protection)
Engineering Controls
• Preventive Maintenance
– Repair/Replace
• Process Change
– Block Noise
o Enclosure
o Path-barrier
– Vibration Noise Damping
Administrative Procedures
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Employee Responsibility
Management Responsibility
Scheduling when Fewest Exposed
Worker Rotation
Training
Posting Warning Signage
Enforcement
Provide Hearing Protectors
• Types of Hearing Protectors
• Listed Noise Reduction Rating
(NRR)
• Selection of Hearing Protection
• When Dual Protection is Required
Calculate Effective Noise
Reduction of Hearing Protection
A common method used for
single protection (either
muffs or plugs) is as follows:
1. Subtract 7 from the NRR.
2. Subtract that revised
NRR from the Worker’s
TWA exposure, as follows:
Estimated Exposure (dBA)
= TWA (dBA) - (NRR - 7)
Example
• Worker’s TWA = 100 dBA.
• Ear muff’s NRR = 19 dB
Estimated Exposure =
[100 - (19 - 7)] = 88 dBA.
The worker’s equivalent noise
exposure is 88 dBA.
Calculate Effective Noise Reduction
When Wearing Dual Hearing Protection
When dual protection is worn use
the following:
1. Select the higher rated of the two
protectors (NRRhigher).
2. Subtract 7 dB from that protector’s
NRR.
3. Add just 5 dB to the field-adjusted
NRR to account for the use of the
second hearing protector.
Estimated Exposure (dBA) =
TWA (dBA) - [(NRRhigher- 7) + 5]
Example:
• Worker’s TWA noise
exposure was 100 dBA.
• Earmuff NRR = 19 dB
Estimated Exposure =
[100 - (19-7) + 5] = 83 dBA
If the earmuff is worn
correctly, then the worker’s
equivalent noise exposure
is 83 dBA.
Training and Education
• Provide training not only initially but annually
• Explain health effects of noise on hearing
• Communicate purpose of hearing protectors
and instructions on selection, fitting, use and
care
• Communicate purpose of audiometric testing,
and provide an explanation of the test
procedures
Questions?