OSHA 29 CFR 1910.15(a) – Occupational Noise Exposure Limits

Hearing loss due to high noise levels is a common problem in many industrial facilities. Without the use of proper PPE, hearing loss can occur quickly. This is a serious concern as hearing loss is permanent and once the damage is done there’s no way to reverse it. Due to this risk, OSHA strictly enforces standard 29 CFR-1910.95(a).

This directive discusses the effects of noise and limits exposure based on the dBA. The table below indicates the maximum allowable exposure time to different noise levels. Sound levels that exceed these levels should first be addressed by proper engineering controls such as isolating the source of the sound from personnel or replacing the cause of the sound with something like an engineered compressed air nozzle. When such controls aren’t feasible, proper PPE must be worn to protect the operator.

OSHA Chart

Hearing loss can occur in as little as 30 minutes when exposed to sound levels 110 dBA or greater. Operators have a tendency not to use PPE as directed, if an OSHA inspector comes to your facility and notices that the sound levels exceed the maximum allowable level without protection hefty fines will be soon to follow. In this example from the United States Department of Labor, a company was fined a total of $143,000 for failing to protect their employees.

SoundMeter_new_nist225
Model 9104 Digital Sound Level Meter

In order to identify the places or processes in your facility that are causing the problems, you’ll need a tool to measure the sound level. EXAIR’s easy to use Digital Sound Level Meter allows you to measure and monitor the sound level pressure in a wide variety of industrial environments. The source of the loud noise can then be identified and isolated so that corrective action can be taken. For compressed air related noise, EXAIR manufactures a wide variety of engineered compressed air products that can reduce the sound level dramatically. In many cases, EXAIR products are capable of reducing noise levels by as much as 10 dBA. Since the dBA scale is logarithmic, this equates to cutting the sound level in half!

sound-level-comparison
Drilled pipes and open ended tubes are the common culprit for excessive noise levels. Replacing them with an engineered solution often eliminates the need for hearing protection.

If there’s processes within your facility that are above these limits and you’d like to eliminate relying on proper PPE, give an Application Engineer a call. We’ll help walk you through the selection process and make sure that when the OSHA inspector comes knocking you’re prepared!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

Sound – It Adds Up! How to Calculate Decibel Levels

Keeping noise levels in check and at safe levels is very important to ensure employee safety and well being.  OSHA (the Occupational Safety and Health Administration) through standard 29 CFR-1910.95(a) has studied the situation and set Maximum Allowable Noise Exposure limits in Hours per Day based on the Sound Level, in dBA, of exposure.

For existing processes, a Digital Sound Meter is a valuable tool to measure the sound level to ensure that the source of loud noises can be quickly identified and isolated for immediate corrective action.

For new processes, or changes to an existing process, it is important to estimate the sound level prior to installation and start-up, so that precautions can be taken as needed.

For example, let’s say we are going to add a blow off station to clean off a part on a conveyor to improve the process and increase the throughput.  A typical set-up might be a 12″ Super Air Knife (model 110012) blowing off the top and a pair of Super Air Nozzles (model 1100) to blow off the sides.

SAK and ASAN
12″ Super Air Knife and Super Air Nozzle

If we look at the performance data for the (2) different blow off devices, we find that the Super Air Knife is rated at 69 dBA and the nozzles at 74 dBA, when operated at 80 PSIG of compressed air supply.

SAK and ASAN

When asked, “what is the sound level for (1) of the knives, and (2) of the nozzles” a little Acoustic Engineering is in order. The decibel scale is logarithmic, and determining the total sound level when all (3) devices are in operation is not as easy as adding up the three sound level values (which would equal 218 dBA, way off the charts!).  Thankfully, both the actual sound level and the numerical value are determined another way.  I’ll spare you a lot of the math but the equation is as below.

Capture

… where SL1, SL2, SL3, … are the sound levels in dBA of the each sound makers, for as many that are being combined (in our example SL1 = 69, SL2 = 74 and SL3 = 74)

Plugging in the numbers into the equation, the combined sound level works out to be a quiet 77.65 dBA — well within the OSHA limit for exposure for a full 8 hour period.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can make your process better and quieter, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Digital Sound Level Meter Identifies Harmful Noise in the Workplace

slm-newlabel EXAIR offers the model 9104 Digital Sound Level Meter.  It is an easy to use instrument for measuring and monitoring the sound level pressures in and around equipment and other manufacturing processes.

Sound meters convert the movement of a thin membrane due to the pressure waves of sound into an electric signal that is processed and turned into a readable output, typically in dBA.  The dBA scale is the weighted scale that most closely matches the human ear in terms of the sounds and frequencies that can be detected.

 

To protect workers in the workplace from suffering hearing loss OSHA has set limits to the time of exposure based on the sound level.  The information in the OSHA Standard 29 CFR – 1910.95(a) is summarized below.

OSHA Noise Level

The Digital Sound Meter can be used to monitor and measure sound levels of manufacturing processed such as blowoffs for cooling or drying.  Many blowoffs, especially open or drilled pipes are very inefficient and can be identified as a source of excessive noise, outside the OSHA exposure ranges.  Once the noise violators are identified, a review can be done and the implementation of engineered solutions such as Super air Nozzles or Super Air Knives can be investigated. Keeping harmful noise levels in check benefits everyone involved.

The EXAIR Digital Sound Level Meter is an accurate and responsive instrument that measures the decibel level of the sound and displays the result on the large optionally back-lit LCD display. There is an “F/S” option to provide measurement in either ‘slow’ or ‘fast’ modes for stable or quickly varying noises. The ‘Max Hold’ function will capture and hold the maximum sound level, and update if a louder sound occurs.

Certification of accuracy and calibration traceable to NIST (National Institute of Standards and Technology) is included.

There is an informative Video Blog, presented by @EXAIR_LE that can be found here.

If you have questions about the Digital Sound Level Meter, or would like to talk about any of the quiet EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Calibration – Keep Your Meters True

EXAIR offers meters to measure the level of physical parameters such as sound and static. Each meter has sensitive electrical circuitry and a periodic calibration is recommended to ensure the meter readings are tried and true.

The model 9104 Digital Sound Level Meter is an easy to use instrument that measures and monitors the sound level pressure in a wide variety of industrial environments. The source of loud noises can be quickly identified so that corrective measures can be taken to keep sound levels at or below OSHA maximum allowable exposure limits.

The sound meter comes from the factory with an NIST (National Institute of Standards and Technology) certificate of accuracy and calibration.  As a good practice, EXAIR recommends a yearly calibration of the instrument, and we offer a service that calibrates the unit to the same NIST standards and provide a written report of the calibration.

The model 7905 Static Meter allows easy one-hand static measurements.  It is useful in both locating sources of high static charge and checking the reduction of static after treatment with an EXAIR Static Elimination product.  The unit is sensitive and responsive, and indicates the the surface polarity of objects up to +/- 20 kV when measured from 1″ away.

It is also recommended that the Static Meter be calibrated on a yearly basis.  EXAIR offers (3) levels of calibration service.  The first two provide calibration in accordance with MIL Standards using accepted procedures and standards traceable to NIST.  The third calibration service conforms to the same Mil Standard, as well as ISO/IEC standards.

Annual calibration service of your EXAIR Digital Sound and Static Meter, along with proper care and storage, will keep your meter performing tried and true for many years, providing accurate and useful measurements.

To initiate a calibration service, give us a call and an Application Engineer will issue an Returned Good number, and provide instructions on how to ship the meter to EXAIR.

If you have questions regarding calibration services for your meters or would like to talk about any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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OSHA 29 CFR 1910.95 – Standard on Occupational Noise Exposure

Last week, the EXAIR Blog featured an article about the OSHA Standard 1910.242(b) – Reduction of Air Pressure below 30 psi for Cleaning Purposes.  This week, we will review another OSHA standard that affects many of you in manufacturing and other industries.

OSHA 29 CFR 1910.95 – Standard on Occupational Noise Exposure discusses the effects of noise and sets limits for exposure.  Occupational noise can cause hearing loss, and also interfere with concentration and communication, disrupting the job performance. Below is a summary from the standard of the Permissible Noise Exposure (OSHA Table G-16)

OSHA Noise Level

From the chart, the time an employee can be exposed to loud noise is greatly reduced as the sound level goes up.   The use of hearing protection is helpful but relies on the operator to use consistently and correctly.  Ear plugs or ear muffs can be uncomfortable and hot, leading to possible reduced usage.  OSHA can come on site, and if violations to the sound level exposure limits are found, they can impose fines and mandate corrective action be taken place.

The recommended course of action when an operator is subjected to sound exceeding those in the chart above is to enable feasible administrative or engineering controls. Engineering controls is the arena in which EXAIR can be a great resource.

The first step in understanding and addressing any sound level issues is to measure the sound. The easy to use Digital Sound Meter, model 9104 shown below, allows for accurate testing of noise levels throughout the facility.  Noisy areas can be quickly identified, leading to review, design and implementation of the engineering controls.

SoundMeter_new_nist225

Some of the worst offenders for noise violations is compressed air usage.  A prime example would be inefficient blowoffs, used for cooling, drying, or cleaning.  Open pipe, copper tube or drilled pipe are a few of the common culprits.  Not only do they consume excessive amounts of compressed air, they can produce noise levels above 100 dBA.

EXAIR manufactures a wide variety of engineered products that utilize compressed air and deliver it in a controlled manner.  This allows for the most efficient use of compressed air and keeps the sound levels much lower than the inefficient methods.  A Super Air Knife can replace a drilled pipe, reducing sound by as much as 20 dBA, while using 50-70% less compressed air.  An engineered Super Air Nozzle can replace an open pipe or copper tube and reduce sound levels down to 74 dBA, and even down to 58 dBA for the smallest available nozzles.

EXAIR has been providing Intelligent Compressed Air Products since 1983.

If you have questions regarding noise limits and how to solve any issue with an EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Reduce Noise Exposure with Super Air Nozzles

News from the CDC that those of us involved with industrial safety are paying close attention to is the release of their NIOSH (National Institute for Occupational Safety and Health) division’s Hazard Evaluation Program Noise Measurement Database, which contains data obtained through Health Hazard Evaluation surveys performed between 1996 and 2012. It includes hundreds of personal noise exposure measurements (how much noise was received by individuals) and almost as many area noise measurements (how much noise was made.) A comparison of these measurements, of course, is valuable in determining if appropriate measures are being taken to abate the exposure, which is key: there are an awful lot of industrial processes where there’s nothing that can be done about the generation of noise…they’re just simply LOUD. So, they focus on what they can do to limit exposure: Use engineering controls (retrofit open line with engineered nozzles, build sound barriers) , use administrative controls (relocating personnel away from the sound), use personal protective equipment, and spending as little time as possible near the source.

Regardless of what people can get used to, the area noise associated with compressed air use CAN be reduced, while still maintaining the efficiency of the operation. Here’s the deal:

*The most basic form of air blow off is a piece of pipe, tubing, or hose connected to a source of compressed air. When it’s opened to the atmosphere, the compressed air exits with a great deal of force. This makes quite a racket, and the only way to quiet it down is to reduce the air supply pressure. Then you get less force, however, and it might not get the job done.

*Engineered air nozzles, such as EXAIR’s Super Air Nozzles, solve this problem by design:

air nozzle flow

The compressed air supply (black arrow) uses the Coanda effect when it exits the series of holes recessed in the array of fins (dark blue arrows.) This serves to entrain an enormous amount of air from the surrounding environment (light blue arrows,) which not only results in a high volume flow rate at minimal consumption, but also makes the resultant air flow very quiet.

EXAIR Super Air Nozzles are quiet, efficient, and easy to get…we maintain inventory of anything you see in the Catalog, all available for same day shipment. If you’d like to know how EXAIR products can be easy on your ears…and your wallet…give me a call!

Russ Bowman
Application Engineer
(513)671-3322 local
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(513)671-3363 fax
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Common Sense…Of Hearing

When I was eight years old, on one very special Saturday morning every month, my Dad would take me and my brother to downtown Cincinnati, where we’d have breakfast and visit the Carew Tower, which, until earlier this year, was the tallest building in the city. We always went to the observation deck, regardless of the weather. Those trips were among the greatest father/sons moments in history, I’m convinced. I got to see my Dad, a simple country man who was completely out of his element in this urban setting, approach a beggar and slip him some change. With that, I learned about discreet charity and unpretentious humility. One particularly unforgettable morning, over pancakes at our usual diner stop, my Dad noticed that Johnny Bench was sitting two booths down, and encouraged my brother and me to go say hi. Now, this was 1975, when the Big Red Machine was invincible, and Mr. Bench was the Most Important Man In The World. He made me feel like the Most Important Kid In The World that morning, so I thank him…and my Dad…for that.

My Dad was a master of finding, and exploiting, the proverbial silver lining…see, the reason he was making these exciting monthly treks to the Big City was because he was losing his hearing, and was getting his new hearing aids “tuned in” at his doctor’s office, which was located in the Carew Tower. He never let the dark cloud of going deaf get in the way of providing a few hours of excitement and adventure for his sons.

His hearing worsened to a point past the usefulness of hearing aids, and it became a genuine quality-of-life issue in his last few years. I’m serious about preserving my hearing, and being a self-appointed advocate for hearing protection, because of this. OSHA has published a table of Permissible Noise Exposures, which anyone who is regularly exposed to above-conversation-levels of noise should be familiar with. If you wear hearing protection religiously in these environments, good for you. If you don’t, it’s never too late to start.

Compressed air is a notorious source of noise in commercial and industrial environments. Joe Panfalone wrote about the harmful effects of noise pollution in a recent post, and he detailed typical noise levels associated with sources that most of us are familiar with. Contrasting these with OSHA’s limits can put a lot into perspective.

If you know the noise levels you’re subjected to, that’s great. Use that to determine when/where you need to use hearing protection. If you don’t know your environmental sound levels, EXAIR can help. Our Digital Sound Level Meter is easy to use, and allows you to measure and monitor the sound level in your environment. If you can’t measure it, you can’t manage it.

Additionally, the sound levels of many of our products are published in our catalog. Products like our Air Knives and Super Air Nozzles are specifically designed with sound level reduction in mind. They’re also engineered to maximize efficiency, so, in a lot of cases, you can turn down the supply pressure, decreasing the sound level further.

Our sense of hearing is a good thing. Too good to ignore the simple steps it takes to preserve it. If you want to discuss how EXAIR products can help reduce your noise levels, you’ve got my undivided attention. Call me.

Russ Bowman
Application Engineer
EXAIR Corporation
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax
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Blog: http://blog.exair.com
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