veloping a “Buy Quiet” web tool for use
when purchasing new equipment for the
workplace (for more information, visit
http://bit.ly/buyquiet). To get the quietest
equipment available, put a noise specification into the equipment purchase
requisition. This is a much better control
than simply giving people hearing protection and setting up a noise and hearing conservation program (HCP), and it
may be less expensive when considering
the costs of the HCP as well as potential
hearing loss claims.
Even our noise measurement process
has evolved since the inception of the
OSHA noise regulations, which have not
changed since the 1980s. We now know
that the noise dose is dramatically af-
fected by our measurement protocol and
whether we use a 3 or 5 dB doubling
rate. (The doubling rate is the rate of
increase of decibels that halves the al-
lowed time of noise exposure.) OSHA
uses a 5 dB doubling rate, but the rest of
the world (including ACGIH®) uses a 3
dB doubling rate. In addition, the thresh-
old at which a noise dosimeter begins
measuring noise is important for longer-
term, lower exposures, as research has
shown that the damage from noise can
begin at 70 dBA.
OSHA PEL OSHA Hearing Loss
Criterion: 80 dB
Exchange Rate: 5 dB
Threshold: 85 dB
Upper Limit: 115 dB
Table 1. Criteria for Setting Up a Noise Dosimeter
Protection in a Noisy World
If we can control noise exposures in the
workplace and ensure that employees
know the causes of hearing loss both
on and off the job, we can contribute to
better quality of life with age. It is imperative to help employees recognize this
hidden hazard.
Industrial hygienists can do much
to affect behavior. Our challenge is
not only to understand the hazards associated with noise, but to educate our
workforce about the dangers of noise
exposure and encourage them to be conscious of noise in their environment and
adopt safer behaviors.
ACGIH
Modified NIOSH*
Criterion: 90 dB
Exchange Rate: 5 dB
Threshold: 90 dB
Upper Limit: 115 dB
Criterion: 85 dB
Exchange Rate: 3 dB
Threshold: 80 dB
Upper Limit: 115 dB
Criterion: 80 dB
Exchange Rate: 3 dB
Threshold: 70 dB
Upper Limit: 130 dB
John C. Ratliff, CSP, CIH, MSPH, works in Industrial Hygiene and Environmental Health & Safety
for Kanto Corporation in Portland, Ore. He can be
reached at jratliff@kantocorp.com or (503) 978-1404.
Weighting: SPL:A Pk:Z
Time Constant: Slow
Alert Level 1: 90 dB
Alert Level 2: 0 dB
Weighting: SPL:A Pk:Z
Time Constant: Slow
Alert Level 1: 90 dB
Alert Level 2: 0 dB
Weighting: SPL:A Pk:Z
Time Constant: Slow
Alert Level 1: 85 dB
Alert Level 2: 0 dB
Weighting: SPL:A Pk:Z
Time Constant: Slow
Alert Level 1: 80 dB
Alert Level 2: 95 dB
*The author’s modified settings for incorporating NIOSH’s 1998 recommendations.
Table 2. Noise Exposure of a Materials Handler
Parameter
OSHA Hearing
Loss
ACGIH
Modified NIOSH
Peak (dBA)
Min (dBA)
147
69.9
115.6
86.4
86.3
1. American National Standards Institute/
American Society of Safety Engineers:
ANSI/ASSE A10.46-2007 Hearing
Loss Prevention for Construction and
Demolition Workers, American Society
of Safety Engineers, March 5, 2007.
2. Kujawa, Sharon G. and Liberman, M.
Charles: Adding Insult to Injury, Cochlear Nerve Degeneration after “
Temporary” Noise-Induced Hearing Loss.
The Journal of Neuroscience, 29(45):
14077-14085 (2009). www.jneurosci.
org/content/29/45/14077.full.
3. Niskar, et. al.: Estimated Prevalence
of Noise-Induced Hearing Threshold
Shifts Among Children 6 to 19 Years
of Age: The Third National Health and
Nutrition Examination Survey, 1988–
1994, United States. Pediatrics, Vol.
108 No. 1, pp. 40–43 (2001).
