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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Explanation of OSHA Standard 1910.242(b)

Open air lines and homemade blow offs violate OSHA standard 1910.242(b) because of harmful dead end pressures. In 1972, OSHA established Standard 29 CFR 1910.242(b) requiring that the outlet pressure of an open pipe, nozzle, air gun, etc., when used for cleaning purposes, must remain below 30 PSI with the intent to protect workers from serious injury. They determined that when dead-ended against the skin, if the outlet pressure reached 30 PSI 0r higher,  it posed a risk of entering the bloodstream through the skin. This is commonly referred to as an air embolism – a serious condition which can be life threatening. Once air has entered the bloodstream, it can restrict the free movement of blood throughout the body, disrupting normal heart function, leading to abnormal heart rhythm, possible lung or brain damage, cardiac arrest, stroke or possible death.

OSHA explains that you can use compressed air for cleaning purposes, as long as the outlet or source is fitted with some type of relief device that drops the outlet pressure to below 30 PSI if dead ended. There are basically two ways to go about gaining compliance. The first is to regulate the operating supply pressure to less than 30 PSI, assuring that the outlet pressure doesn’t exceed the threshold. While this does comply with the Standard, it can negatively affect the performance by reducing the strength of the outlet flow, limiting the usefulness of the blowoff device.

The other method is to use some type of nozzle which includes a pressure reducer or a relief device which will reduce the air pressure to less than 30 PSI if the nozzle is dead ended.

For example, EXAIR engineered air nozzles are designed so the outlet holes cannot be blocked directly. Any potential obstruction of the outlet air holes results in the air having an alternative exit path to avoid injury to operators and personnel.

sag-osha-compliant
With our Super Air Nozzles, the air exits through a series of jets, recessed behind an array fins so the exhausting airflow can never be blocked.

With the design of our Super Air Knife, the cap overlaps the body, leaving a gap on both sides of the knife, allowing the exhausting air to safely vent.

osha-sak
Picture of the Super Air Knife, showing how the cap overlaps the body and cannot be blocked, providing a safe exit path.

ALL of EXAIR‘s engineered products incorporate these principles, providing some type of relief, allowing for the air to safely vent well below the 30 PSI requirement, meeting and in many cases, exceeding the OSHA Standard.

To discuss how EXAIR can help you gain OSHA compliance to improve operator safety, avoid costly fines and improve overall efficiency, contact an application engineer for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

One Air Nozzle Saves $960 per Year – How Many Nozzles Could You Use?

A cardboard manufacturing facility was using a 3/8” outside diameter (OD) open tube to blow scrap cardboard off a conveyor. This scrap cardboard would occasionally be blown inside the roller area at the end of a conveyor creating a maintenance nightmare that required hours to disassemble and remove. To prevent this from occurring they installed another 3/8″ OD open compressed air tube to divert any cardboard headed toward the conveyor roller. The 3/8″ open tubing eliminated the scrap problem, but introduced a few new ones. The open hose is extremely noisy over (100 dBA). It does not comply with OSHA standard CFR 1910.242(b), which requires that a compressed air blow off device may not be dead ended at more than 30 PSIG. The most costly problem though is a 3/8″ open tubing uses a tremendous amount of compressed air.

They were using so much air in the facility that they were draining the system pressure in their facility. Obviously, they were going to replace the open tube with EXAIR 2” Flat Super Air Nozzle. Replacing this open blow off with an intelligent compressed air product, like the HP1125 High Powered Flat Super Air Nozzle or the 1104 Super Air Nozzle, would lower the noise level below 83 dBA. Also, those nozzles use significantly less air. They decided to use the model HP1125 for its thin profile to fit into the tight location. The only question was how much air and energy cost would they save. They could have easily installed a Digital Flow Meter on the supply pipe of the open tube to measure the change in flow once the EXAIR nozzle had been installed, but they wanted to try and estimate the air usage.

Using EXAIR’s test data, we know a 3/8″ OD open tube that is 18″ long will flow 68.5 SCFM at 80 PSIG. An HP1125 2″ Flat Super Air Nozzle utilizes 37 SCFM when fed with 80 PSIG inlet pressure. By removing one 3/8″ OD tube the cardboard manufacturer saved 31.5 SCFM of compressed air. With an electrical cost of $0.08 per kWh, compressed air costs $0.25 per 1000 SCF. Saving 31.5 SCFM reduces the manufacturers electrical bill by $0.48 every hour, $3.48 for every 8 hour shift, and $960 per year (250 working days, eight hours a day). If the manufacturer runs two shifts, the savings will double. The simple return on investment for this nozzle is 130 hours! How many projects can you measure a return on investment in hours?

2 Inch Flat
EXAIR’s 2 Inch High Power Flat Super Air Nozzle, HP1125

Take advantage of our free service – the EXAIR Efficiency Lab. Our Application Engineers will test any nozzle or device you choose to send in to the Lab using our calibrated testing equipment. We’ll compare the performance of your existing product (air consumption, noise, force, etc.) with an EXAIR Intelligent Compressed Air product. The results will be published in a comprehensive report, including a cost savings analysis with simple ROI. For most applications, EXAIR products can help you improve compressed air efficiency AND pay for themselves in a matter of weeks!

EXAIR intelligent compressed air products are easy to install, safe, and efficient. By installing these products instead of using unsafe open blow offs, your company can save thousands of dollar every year with minimal investment. While saving electrical expenses, we decrease the noise level which makes your production force a nicer place to work. We also comply with OSHA’s standards. Finally, we may be able to design the blow off better to consistently produce the quality product you expect. Call EXAIR today to discuss your application.

Dave Woerner
Design Engineer at EXAIR Corporation
DaveWoerner@EXAIR.com

Dead End Pressure

With all the warm weather and outdoor activities around the house the past few weeks I had somewhat forgotten about a nice wasp nest that had been constructed in between the front door to our house and my bedroom window.  This also happens to be right in the corner of two walls and in the deepest portion of the landscaping.   Like I said though, I had forgotten about it for a few weeks which gave the inhabitants enough time to double the size of the nest.

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With that being said, I didn’t want to use wasp or bee spray because it means I would have to get close to the nest and I have a strong belief that all of those products just make them really angry and don’t bring death right away.  I wanted the nest to have a quick death because then I don’t have to run around my yard, screaming, because I have a wasp chasing me after destroying their home.

I cam up with several methods to get rid of the nest.

1.) Brake Cleaner – Very effective, however the nest was also right above our air conditioning condenser so that was out.

2.) Small controlled burn – In my experience it is never small nor controlled.   Plus it was way to close to the dry roofline.

3.) 3,000 psi of water in a jet stream from the pressure washer.  WINNER!!!!

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So I set out to the front of the house with the pressure washer and hose in tow.  Get everything setup and notice that there is one sentry wasp sitting right at the entrance.  So I simply got the nozzle of the gun with pin point spray as close as I could and as soon as the wasp started to move I shot the entire nest off the house.   Then I proceeded to shoot it back and forth in the landscaping until I saw no survivors.

That was 3,000 psi of water that tore through a nest and rid my house of a pest.  This made me think of just how little pressure the human skin can take.  OSHA standard CFR 1910.242(b) guards against a mere 30 PSIG. Higher pressure air, when blocked up against our skin, has the potential to push air into our bloodstream and cause air embolism – a serious threat to our health. Too many commercial air nozzles and guns, open pipes and homemade blow off violate this OSHA standard and pose a threat to personnel.

EXAIR engineered air nozzles and products have been designed to eliminate the possibility of being dead-ended (blocked). This is why all of EXAIR’s products meet or exceed the OSHA standard 1910.242(b) for 30 psi dead-end pressure.  None of our products can be dead ended and cause bodily harm when used properly.  These engineered features also reduce noise levels and minimize air consumption. So if you are concerned with any of your compressed air applications, and just how safe they are, contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF