Christian Havens

Noise Sample Report

July 27, 2016

Every year, thousands of construction workers suffer hearing loss from excessive noise exposure

on the job. Hearing loss impairs quality of life and increases the risk of injury – for instance, when a

worker cannot hear approaching vehicles or warning signals. In the United States, the Occupational

Safety and Health Administration (OSHA) set the permissible exposure limit (PEL, see final page for

chart) and action level for construction noise to 90 decibels (dBA) over an eight-hour period. However,

hearing loss usually results from prolonged exposer to noise above 85 dBA. That is why at Banks Gas

Services Inc. they are required by their parent company, Columbia Gas of Pennsylvania, to have a

written policy on noise control when operating above their action level of 85 dBA in a 8 hour period.

Which is every day for a natural gas company.

Hearing data a collected by the National Health Interview Survey (NHIS), a large household

survey in the U.S, reports that at least one in five (21.4%) construction workers self-reported some

hearing trouble due to their line of work in 2010. The graph below illustrates this data.

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Recently, a jobsite noise sample was conducted for 2 hours on one of the vacuum truck crews at

Banks Gas. In this noise sample, job tools such as jackhammers, air lances, clay spades, and the trucks

vacuum motor were all tested for sound levels. Each tool that was used operated at above 85 dBA.

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This chart highlights the different sound levels of equipment used in construction. The jackhammer,

according to the chart, operates at 96 dBA. This is a tool used daily by the majority of crews here at

Banks Gas Services Inc.

Due to the rules set by Columbia Gas of Pennsylvania, Banks Gas Services Inc. has created a

written program to protect their workers from hearing loss caused by high noise levels. As a company,

Banks Gas tries to follow the Hierarchy of Noise Control, established by the National Institute of

Occupational Safety and Health (NIOSH).

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However, anyone who has every worked in the construction industry is aware that it is

unrealistic and virtually impossible to eliminate all noise levels above the permissible exposure limit (see

final page). The most common way to try to protect workers from prolonged noise exposure is to

provide hearing protection, such as ear plugs or ear muffs. This is something Banks Gas provides and

requires all employees and jobsite personnel to utilize in a high risk situation.

Upon the completion of the two hour noise sample, conducted by Ben Rodgers, Safety Manager

at Banks Gas Services Inc., it was determined that in the two hour time frame of the sample, workers

were exposed to 94.46 dBA of continuous noise. Under the Permissible Exposure Limit set forth by

OHSH (see final page), if a jobsite does not exceed 100 dBA in two hours of operation, hearing

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protection is not required. However, when the data collected was used to find the 8 hour Time

Weighted Average (TWA), the situation changed. The following formula was used:

8-hr TWA= 90 + 16.61 log10 [(%dose)/100]

The 8 hour TWA was determined to be 105% of the 8 hour PEL. This Time Weighted Average

formula also determined that the crew being sampled would be exposed to 111% of the PEL at 16 hours,

a possible late day on the job. These things are the reason why Banks Gas provides all employees with

means of hearing protection.

The ear plugs supplied by Banks Gas Services Inc. to its employees have an NRR (Noise

Reduction Rating) of 32 dB. When wearing these ear plugs, the employee is then absorbing only 69.46

dB out of the original 94.46 dB, well under all levels of the Permissible Exposure Limits set forth by

OSHA. This was determined using the following formula:

dB-(NRR-7)

There are other, more costly ways to bring these numbers down. According to chart 3a, it is a

better option to try to substitute the noisy equipment for old fashioned shovel and digging bars. This,

however, would greatly lengthen the time spent on a single job and increase job difficulty.

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Overall, Banks Gas Services Inc. are following OSHA and Columbia Gas of Pennsylvania

guidelines and effectively protecting their workers from prolonged noise exposure, which can cause

hearing loss. Banks Gas values all employees and knows the importance of protecting them long term.

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