Noise in Road Construction

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Noise in Road Construction
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What this presentation covers

• Hearing loss rates and claims facts
• Noise levels of construction equipment
• Control methods to reduce harmful noise exposures
• Resources

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Hearing loss is expensive!
In Washington State,

• Hearing loss is 1/3 of all costs of permanent
  impairments.
• Hearing loss is the most expensive occupational
  disease for road construction workers.
• Incidence rate is 10 times higher for Road
  Construction risk class than for all other risk
  classes.
• Hearing loss claims rate is highest of all
  construction risk classes.

The result is higher industrial insurance
premiums paid by road construction contractors.
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Noise and hearing loss

• Noise is measured in units called decibels (dB).

Threshold of pain
Construction noise levels are often above 85 dBA
Jet take-off (200)
(A-weighting is a standard of sound measurement
used to evaluate continuous noise levels
designated as dBA)
Chipping hammer
Jackhammer
Bulldozer
Freeway noise
City traffic

• Scientific studies have shown that hearing loss
  can occur when 8-hour average noise exposure
  exceeds 85 decibels.

Normal conversation (3)
Urban residence

• (If two people 3 feet apart must shout to be
  heard, the background noise is too loud - above
  85 dBA.)

Soft whisper (5)
Threshold of hearing
For more information on noise and hearing, see
WISHA Noise Exposure Hearing Loss
Noise level (dBA)
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Some Common Noise Levels in Construction
Source Center to Protect Workers Rights
Decibels (dBA)
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Sample Noise Level Measurements
Saw Operator 95 dBA (7-hour sample)
Source OSHA case files
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Sample Noise Level Measurements
Jackhammering 102 dBA (7.5-hour sample)
Source OSHA case files
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Sample Noise Level Measurements
Breaking pavement 112 dBA (7-hour sample)
Source OSHA case files
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Sample Noise Level Measurements
Lateral drilling
97 dBA (6.5-hour sample)
104 dBA (7-hour sample)
Source OSHA case files
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Sample Noise Level Measurements
Sandblasting 125 dBA (4-hour sample) 109 dBA
(inside hood)
Source OSHA case files
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Sample Noise Level Measurements
Dumping concrete 96 dBA (4-hour sample)
Source OSHA case files
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Noise Sources in Road Work
Several factors influence the noise levels to
which workers are exposed

• Type and condition of equipment being operated
• Other equipment running at the same time
• Enclosed or partially enclosed spaces (e.g.,
  underpass)
• Traffic around work site

Underpass
Underpass work
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When is hearing protection required?

• At noise exposures of 85 dBA TWA8 and higher,
  you must use a hearing protection device.
• Wherever the noise exposure is 90 dBA TWA8 and
  higher, feasible controls must be used to reduce
  your exposure.

Time-weighted average during an 8-hour period
High Noise Exposures Rules of Thumb You need
protection

• If you have to shout at someone 3 feet away to be
  heard
• When using electric, gasoline, or air powered
  tools
• When sitting in an open cab of dozers, rollers,
  some cranes, earth moving or road building
  equipment

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What are some methods to controlnoise exposures?

• Substitute quieter process or equipment
• Eliminate or minimize at the source
• Isolate/enclose the process or operator
• Increase distance from the source
• Change work practices
• Implement a hearing conservation program

The most desirable methods of controlling a noise
problem are to use quieter process/equipment,
eliminate the noise at the source, or to block
the noise from reaching you. Using hearing
protection devices (ear plugs, muffs) isn't
considered a control of the noise hazard. There
are many drawbacks and using them will not always
be effective.
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What are some methods to controlnoise exposures?
Substitute quieter process or equipment
New quieter generators have sound-proofing and
produce only 75 dBA at 1 meter and 65 dBA at 7
meters under load.
Replacing a large jackhammer with a middle range
one reduced the noise level by 10 dBA.
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What are some methods to controlnoise exposures?
Eliminate/minimize at the source

• Install silencers/mufflers
• Retrofit old equipment
• Operate equipment as designed per
  manufacturers instructions
• Damp noisy equipment and parts
• install sound-absorbing material or vibration
  isolation systems
• Maintain equipment properly
• replace worn, loose, or unbalanced machine parts
  that cause vibration
• keep machine parts well lubricated to reduce
  friction
• adjust belts and valves, tighten bolts

Acoustically treated operator cabins on
earth-moving equipment have noise levels of 75
dBA or below.
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What are some methods to controlnoise exposures?
Isolate/enclose the process or operator

• Noise enclosures
• Noise barriers
• higher and wider than noise source
• may be simple walls or curtains of acoustic
  materials
• ½-inch plywood can provide a 10dB noise reduction
• place close to noise source or to you
• Include acoustic panels or baffles to
  walls/ceilings
• Minimize leaks
• e.g., cover joints with 1/8-inch thick neoprene
  strip or duct tape

A portable screen set up around a power pack
reduced the noise level from 98 to 90 dBA at 1
meter.
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What are some methods to controlnoise exposures?
Isolate/enclose the process or operator (conti
nued)
Note if the source of noise is equipment
operated by you, a barrier placed close can
increase your noise exposure by reflecting the
noise back toward you. Be sure to line the
barrier with sound absorbing material to reduce
the reflected noise.
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What are some methods to controlnoise exposures?
Increase the distance between the noise source
and you

• Every doubling of the distance between you and
  the noise source results in as much as a 6 dB
  decrease in noise level thats a four-fold
  reduction!

(This is true if there is no reflected noise. The
reduction will be less if there are walls or
partitions between you and the noise source.)

• Keep noisy equipment away from walls or other
  surfaces that will reflect noise toward you.
• Combine distancing and barriers to further reduce
  noise exposure. Using both methods results in
  greater noise reduction than would be achieved
  from either method alone.

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What are some methods to controlnoise exposures?
Change work practices

• limit time exposed job rotation, rescheduling
  work
• limit use of noisy equipment
• rest breaks
• turn off equipment not in use

Hearing Conservation Program Chapter 296-817 WAC

• baseline and annual audiometric testing
• monitoring of noise exposure levels
• hearing protection devices (HPDs)
• training and education
• maintenance of employee exposure and hearing loss
  records

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Summary
Hearing loss is expensive!
Many construction noise levels are high and
require controls to reduce workers exposures.
Control methods

• Substitute quieter process or equipment
• Eliminate or minimize at the source
• Isolate/enclose the process or operator
• Increase distance from the source
• Change work practices
• Implement Hearing Conservation Program

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WISHA Consultation Services

• Safety Health program review and worksite
  evaluation

• By employer invitation only
• Free
• Confidential
• No citations or penalties
• Letter explains findings
• Follow-up all serious hazards

For additional assistance, you can call one of
our consultants. Click below for local L I
office locations http//www.lni.wa.gov/wisha/cons
ultation/regional_consultants.htm
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Web Resources

• WISHA Noise Exposure Hearing Loss
• NIOSH Noise and Hearing Loss Prevention
• OSHA Construction - Noise and Hearing
  Conservation
• National Hearing Conservation Association
• MSHA Noise Control Manual Surface Mining
  Equipment
• Institute of Noise Control Engineering of the USA

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• Thank you for taking the time to learn about
  safety and health and how to prevent future
  injuries and illnesses.