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Rev: February 2014
Section 4. Hearing Protection and Hearing Conservation Program
(WAC 296-817-200), Noise Level Survey
Contents
4.1
Hearing Conservation Program ..................................................................................... 4-1
4.1.1
Intensity and Duration............................................................................................ 4-1
4.1.2
How the Ear Works................................................................................................ 4-2
4.1.3
Warning Signs ........................................................................................................ 4-2
4.2
Monitoring..................................................................................................................... 4-2
4.2.1
Noise Exposure ...................................................................................................... 4-2
4.2.2
Engineering Controls ............................................................................................. 4-2
4.2.3
Supervisor Responsibilities.................................................................................... 4-2
4.3
Hearing Protection Devices........................................................................................... 4-2
4.3.1
Ear Muffs ............................................................................................................... 4-2
4.3.2
Foam Ear Plugs ...................................................................................................... 4-3
4.4
Annual Hearing Tests .................................................................................................... 4-3
4.5
Recordkeeping............................................................................................................... 4-3
4.6
Noise Level Survey ....................................................................................................... 4-3
4.6.1
How to Use the Chart............................................................................................. 4-3
4.6.2
Noise Level Survey Chart ..................................................................................... 4-4
4.7
4.1
Noise Exposure with Hearing Protection ...................................................................... 4-5
Hearing Conservation Program
Hearing loss is not, and should not be considered, an inevitable part of your job or a natural part
of aging. With proper hearing protection, both on and off the job, your hearing can last your
entire lifetime. The TFREC has implemented the hearing conservation program to aid in
preventing hearing loss from noise exposure. The hearing conservation goal is to identify
employees whose job duties may expose them to noise greater than an average of 85 dB and
provide these employees with hearing protection, training and annual hearing tests.
4.1.1
Intensity and Duration
The amount of damage from noise depends upon two factors: the intensity of the noise,
measured in decibels (dB), and the duration of exposure. Sounds above 130 dB are painful and
most people will avoid these noise levels. However, sounds between 85 and 120 dB may not
cause physical pain, but they will damage hearing over time.
TFREC Occupational Illness and Injury Prevention Plan
SECTION 4: Hearing Protection, Page 4-1
Rev: February 2014
4.1.2
How the Ear Works
In order to understand how noise causes hearing loss, one needs to understand how the ear
works. Sound waves cause the eardrum to vibrate. These vibrations pass through three tiny bones
in the middle ear and on to the hair cells in the fluid-filled inner ear. The vibrations of the hair
cells are transmitted as nerve impulses to the brain which are translated as sound. Loud noise
damages the hair cells and, therefore, eliminates the nerve impulse to the brain.
4.1.3
Warning Signs
Early signs of hearing loss may include tinnitus, or ringing in the ear, temporary muffled hearing,
an inability to hear high-pitched noises such as children’s voices, inability to hear soft sounds or
an inability to distinguish one word from another.
4.2
Monitoring
Employees' noise exposure is determined through noise monitoring. Work areas should be tested
if you have to raise your voice to be heard two feet away. A copy of noise monitoring performed
at the TFREC is provided with this plan. If you feel other equipment or areas should be included
in the noise-monitoring program, contact Jerry Moreland.
4.2.1
Noise Exposure
With this noise monitoring data, determinations are made regarding job positions with a time
weighted average noise exposure of 85 dB or more. These positions will be included in the
hearing conservation program. Employees must be notified if the sound levels in their work areas
exceed 85 dB.
4.2.2
Engineering Controls
Noise levels can be minimized by engineering controls such as using sound barriers to isolate
noisy equipment from the work environment, by administrative controls such as limiting the time
an employee is exposed to loud noises, or by personal hearing protection devices. The noise
monitoring data should be used to determine when personal hearing protection should be used.
Though not required by law, it would be prudent to wear hearing protection for all exposures
above 85 dB regardless of the time exposed. Signs will be placed at the entrance to work areas
where the decibel reading is 115 or over. Hearing protection must always be worn in these areas.
4.2.3
Supervisor Responsibilities
Supervisors must determine which activities in their program will require hearing protection. The
supervisor should also help the employee select and effectively use proper hearing protection.
The employer must provide personal hearing protection devices at no cost to the employee.
4.3
Hearing Protection Devices
Hearing protection devices must fit properly in order to be effective. Listed below are some
guidelines for proper fit for various types.
4.3.1
Ear Muffs
•
Cups should fully enclose the entire ear without resting on the ear.
•
The headband should sit comfortably on the head.
•
Head gear must not interfere with the seal.
TFREC Occupational Illness and Injury Prevention Plan
SECTION 4: Hearing Protection, Page 4-2
Rev: February 2014
•
If fit is correct, a noticeable difference in sound level should detected between when
the muffs are off or on.
•
Use the same sound check on each ear.
4.3.2
4.4
Foam Ear Plugs
•
Roll plugs into a crease-free cylinder.
•
Pull outer ear upwards and outwards.
•
Insert properly rolled plug into ear.
•
Maintain pressure on the plug until it expands in the ear canal.
•
To check proper fit, put hands over ears. There should be little change in sound level
if your hands are on or off your ears.
•
If properly inserted the plug should be crease- and wrinkle-free when removed and
the compressed portion should be at least half of the plug.
Annual Hearing Tests
Annual hearing tests will be provided to all employees determined to have time weighted
exposure to sound levels averaging 85dB or above. If testing demonstrates a continued loss of
hearing in an individual, then the supervisor must re-evaluate the work environment of the
employee, must re-evaluate the type and proper fit of the hearing protection the employee is
using, and must ensure that the employee does wear hearing protection when required.
At the time of hire and annually thereafter, training will be provided to each employee having an
average noise level exposure of 85 dB or above.
4.5
Recordkeeping
Records of noise exposure measurements, hearing protection training, and audiometric testing
must be maintained by the employer and available to the employee.
4.6
Noise Level Survey
The noise survey chart details employee noise exposure without hearing protection and is set up
to enable supervisors to determine if employees in their program should be in a hearing
conservation program.
4.6.1
How to Use the Chart
If, for example, a supervisor wanted to know if an employee who operates the John Deere mower
should be in the hearing conservation program they could refer to the “exposure” column for that
piece of equipment and if the employee operated the mower more than 4 hours per day then the
employee should be in the hearing conservation program.
If the % dose is over 50% or if the TWA is 85dB or more for the number of hours indicated then
the employee should be included in the hearing conservation program.
TFREC Occupational Illness and Injury Prevention Plan
SECTION 4: Hearing Protection, Page 4-3
Rev: February 2014
4.6.2
Noise Level Survey Chart
Completed 8/99 with Quest Q-400 Noise Dosimeter
(dosimeter calibrated before and after each use according to manufacturer's directions).
EQUIPMENT
MAX
AVG Exposure (hr) %DOSE
OVERLEY BUILDING
#4 growth chamber
79
#3 growth chamber
79
#1 growth chamber
80
66
#2 growth chamber
92
88
6
56.6%
Supply fan #1
86
85
8
50%
Air Conditioning Compressor
94
90
4
50%
Refrigeration compressor room
88
87
7
57.9%
Cooling tower
81
Autoscrubber
81
Burnisher
83
BOILER ROOM
Boiler Room
108
83
8
37.9%
USDA BUILDING
Chiller
88
82
8
32.9%
Refrigeration compressor room
86
83
8
37.9%
Near growth chambers
83
Machine room
82
Walk-in cold rooms
79
SHOP
Arc welder
89
87
7
57.9%
Air Compressor
87
82
8
32.9%
Garage door opener
105
102
3/4
50%
Background noise
78
74
Vehicle engine noise
75
Fork lift
70
Metal chop saw
112
107
.38
50%
Table saw
115
109
.29
50%
Radial arm saw
123
107
FARM AND GROUNDS
Kubota 5400 with sprayer
87
86
7
50.4%
Weed Eater
94
92
4
64.5%
Blower
99
96
2
57.1%
John Deere mower
97
90
4
50%
Snow Blower
108
97
1.5
50%
Lawn edger
90
86
7
50.4%
Massey Ferguson 135
94
89
5
54.3%
with Parker sprayer (self-powered)
102
101
1
58.8%
Landini Tractor no implements
96
91
4
57.1%
Landini with Air-O-fan sprayer
98
91
4
57.1%
TFREC Occupational Illness and Injury Prevention Plan
TWA*
85.8 dB
85 dB
85 dB
86 dB
82.6 dB
81.5 dB
82.6 dB
86 dB
81.5 dB
85 dB
85 dB
85 dB
85.1 dB
86.9 dB
85.9 dB
85 dB
85 dB
85.1 dB
85.6 dB
86 dB
85.9 dB
85.9 dB
SECTION 4: Hearing Protection, Page 4-4
Rev: February 2014
EQUIPMENT
Large Cat.(army surplus)
Gyrette
Chain saw
Massey Ferguson 2135
MF 2135 with John Deere 509
Craftsman Lawn mower
Keith's ATV
John Deere 2350 Tractor
J.D.2350 with Woods Mower
Pathology truck mounted sprayer
MAX
103
93
103
98
98
98
102
95
100
112
AVG
100
88
101
91
93
92
71
90
92
94
Exposure (hr) %DOSE
1
50%
6
56.6%
1
58.8%
4
57.1%
3
56.6%
4
64.5%
4
4
2.3
50%
64.5%
50%
TWA*
85 dB
85.8 dB
86 dB
85.9 dB
85.8 dB
86.9 dB
85 dB
86.9 dB
85 dB
* TWA for hours in column 3
4.7
Noise Exposure with Hearing Protection
The following chart lists noise exposure for varying decibel levels and time durations with hearing
protectors that have a listed noise reduction rating (NRR) of 29.
Decibel level
85
90
95
100
110
4
58
63
68
73
83
5
59
64.5
70
74.6
84.7
Hours Exposed
6
61
66
71
75.9
*
7
62
67
72
77
*
8
63
68
73
78
*
* Above permissible exposure level.
TFREC Occupational Illness and Injury Prevention Plan
SECTION 4: Hearing Protection, Page 4-5