How Does OSHA Talk About Compressed Air Use?

When it comes to OSHA and their safety standards in regard to compressed air, it boils down to two main topics. OSHA standard 1910.242(b) and 29 CFR-1910.95 (a).

OSHA standard 1910.242(b) – Compressed air shall not be used for cleaning purposes except where reduced to less than 30 psi and then only with effective chip guarding and personal protective equipment.

For a logical reader, it might seem that this standard requires the air used for tasks like blowing off equipment or cleaning floors to be limited to a maximum of 30 psig. However, this interpretation isn’t entirely accurate. When the standard mentions reducing air pressure to below 30 psig, it specifically refers to the static pressure measured when the air nozzle is blocked against an object, such as a person’s body. The “dynamic” pressure, which is the speed of the air as it flows from the nozzle, can be much higher, provided that the static pressure “Dead end Pressure” remains under 30 psi when the nozzle is obstructed. This is why it’s crucial for employers to educate their workers about the dangers of compressed air and the significance of not modifying air nozzles.

Our Air Nozzles and Jets video shows a great depiction of how this can be achieved with our engineered design of nozzles. The recessed holes and the fact that there are multiple passages for the air to exit are easy to see on the nozzle. Products like the Super Air Knife may not be so easy to see, but the way the air knife cap overlaps prevents the Super Air Knife from being dead-ended in the event an operator comes into contact with the discharged air.

OSHA standard 29 CFR-1910.95 (a) – Occupational noise exposure.

The Occupational Noise Exposure regulation (OSHA’s 29 CFR 1910.95) mandates that employees who are exposed to an average noise level of 85dBA TWA (time-weighted average) must be included in a Hearing Conservation Program (HCP). Employers are obligated to ensure that these employees receive hearing conservation training throughout their employment. This training should commence with an initial orientation and be reinforced annually. Section 1910.95(a) of the standard lays the groundwork for a hearing conservation program aimed at safeguarding workers from the detrimental effects of noise exposure in the workplace. Let’s take a brief look at the key aspects of implementing a hearing conservation strategy, including the “what,” “who,” “how,” and “when.”

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 are compressed air applications.  A prime example would be inefficient blow offs 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.

Crushed open ended pipes blowing chips away

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 homemade 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.

If you have questions regarding OSHA standard 1910.242(b) and 29 CFR-1910.95 (a), or how to solve any issue with an EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR . One of our Application Engineers would be pleased to help you determine your best solution.

Jordan Shouse
Application Engineer

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The Story Behind Decibels

While ‘sound’ has been around (almost quite literally) forever, our units of quantifying it are relatively new. Most of us are familiar with the word ‘decibel’ and know that it has something to do with how ‘loud’ a sound is. The word ‘decibel’ originated, however, as a unit to quantify the loss of the strength of a signal as it traveled through telephone and telegraph wires. From the invention of the telegraph in the 1840’s, miles and miles (and miles) of cable started crisscrossing the country, and eventually the world. The unit they used to quantify signal loss back then was known as a “mile of standard cable” or “MSC”. And it was just that: the loss of signal energy as it traveled through one mile of standard (approximately 19 gauge wire back then) cable.

In 1924, Bell Telephone Laboratories introduced a new unit: the Transmission Unit (TU) which changed the math from linear to logarithmic. One TU was defined such that the number of TUs was ten times the base-10 logarithm of the ratio of measured power to a reference power. In 1928, the Bell folks proposed using a new word they’d coined: ‘decibels’, instead of TU’s, in honor of the founder of their technology and namesake of their company, Alexander Graham Bell.

While the decibel is still the commonly accepted unit of measure for signal loss in cable, it also became popularized as a unit to quantify sound pressure level, since that’s a logarithmic measurement as well, of the ratio of actual sound pressure being applied (determined by the frequency & amplitude of the sound waves hitting your eardrum) to a base level of sound pressure (the low threshold of hearing for a typical person…what we might informally call “complete silence”.)

There are two ways to determine sound pressure level: you can do the math, or you can use a device that measures it, like the EXAIR Model 9104 Digital Sound Level Meter. These will tell us how ‘loud’ a sound (or the overall sound in a given space) is.

In contrast to the 98dBA sound level from this array of nozzles, the sound pressure level from an EXAIR Super Air Knife is only 69dBA.

This is important because too much of ANYTHING is likely to be detrimental, and sound pressure level is absolutely in that category. Exposure to extraordinarily loud sounds, even momentarily, can irreversibly damage your hearing. And constant exposure to moderately loud sound levels can do it too.

In the United States, the Occupational Safety and Health Administration (OSHA) published Standard 1910.95(a) to identify the maximum allowable noise exposure by hours, and sound level. The proper use of hearing protection is mandated if personnel are exposed to levels in excess of these limits for a given period of time:

Working in areas that exceed these levels will require hearing protection.

When I was little, my Dad had to get hearing aids as a result of occupational noise exposure, so I know first-hand what an impact has on one’s quality of life – and that of the people they spend a lot of time around. It’s one of the big reasons that I always talk about how quiet EXAIR engineered compressed air products are, compared with air blowoffs that aren’t designed to attenuate sound pressure levels.

The ability to hear well is a wonderful gift, and one worth preserving. If you have to work in a loud environment, get some good ear plugs or ear muffs. They make them now with noise-canceling features, so you can still hear people talk while wearing them. If you have questions about whether the environment is “too loud”, it very well might be. Take measurements. If they’re higher than the OSHA limits above, consider the source and whether it can be mitigated, or even eliminated. And if the source is from compressed air blow offs, EXAIR can definitely help – give me a call.

Russ Bowman, CCASS

Application Engineer
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Industrial Safety: Compressed Air

At EXAIR, we have a statement that says, “Safety is everyone’s responsibility.”  EXAIR builds its name around manufacturing safe and protective compressed air products.  In the United States, we have an organization called the Occupational Safety and Health Administration (OSHA) that enforces governmental directives for safe and healthy working environments.  They do training, outreach programs, and educational assistance for manufacturing plants to reduce injuries and fatalities.  They can also enforce these directives with heavy fines for violations.  With compressed air systems, the two most common violations are 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.95(a) for maximum allowable noise exposure.

Unsafe Nozzle

Here is an example of a nozzle that is dangerous.  As you can see, there is only one path where the air can pass through.  Other similar types of blow-off devices that would fall into this same group would include copper tubes, flexible lines, and open pipes.  They are dangerous as compressed air cannot escape if it is blocked by your body or skin.  If operated above 30 PSIG (2 bar), these nozzles could penetrate the skin and create an air embolism within the body, which can cause bodily harm or death.  This is a hazard that can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed with fins, which allow the air to escape and cannot be blocked by your skin.  So, you can use the EXAIR Super Air Nozzles safely above 30 PSIG (2 bar) and remain OSHA compliant.

Unsafe Air Gun

To counteract the dead-end pressure violation, some nozzle manufacturers create a hole through the side of the nozzle (reference photo above).  This will allow the compressed air to escape, but now the issue is noise levels.  With an “open” hole in the nozzle, the compressed air is very turbulent and very loud.  The National Institute for Occupational Safety and Health (NIOSH) states that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air.  OSHA created a chart to show the maximum allowable noise exposure.  This chart shows the exposure time and noise limits before hearing protection is required.  The EXAIR Super Air Nozzles, Super Air Knives, and Super Air Amplifiers are designed to have laminar flow, which makes them very quiet.  As an example, the model 1210 Soft Grip Safety Air Gun has a sound level of only 74 dBA, well under the noise exposure limit for 8 hours.

One of the last things that companies think about when purchasing compressed air products is safety.  Loud noises and dead-end pressure can be missed or forgotten.  To avoid any future fines or having to purchase additional personal protective equipment (PPE), it will be much safer to purchase EXAIR products.  If you would like to improve the safety of your facility and reduce energy costs, an Application Engineer at EXAIR can review your current blow-off devices.  Remember, safety is everyone’s responsibility. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Photo: Industrial Security Signal by DavidRockDesignPixabay license

Industrial Safety: Compressed Air

We have a statement that says, “Safety is everyone’s responsibility.”  EXAIR builds its name around this by manufacturing safe and protective compressed air products.  In the United States, we have an organization called the Occupational Safety and Health Administration (OSHA) that enforces governmental directives for safe and healthy working environments.  They do training, outreach programs, and educational assistance for manufacturing plants to reduce injuries and fatalities.  They can also enforce these directives with heavy fines for violations.  With compressed air systems, the two most common violations are 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.95(a) for maximum allowable noise exposure.

Unsafe Nozzle

Here is an example of a nozzle that is dangerous.  As you can see, there is only one path where the air can pass through and be blocked.  Other similar types of blow-off devices that would fall into this same group would include copper tubes, flexible lines, and open pipes.  They are dangerous as compressed air cannot escape if it is blocked by your body or skin.  If operated above 30 PSIG (2 bar), these nozzles could penetrate the skin and create an air embolism within the body, which can cause bodily harm or death.  This is a hazard that can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed with fins, which allow the air to escape and cannot be blocked by your skin.  So, you can use the EXAIR Super Air Nozzles safely above 30 PSIG (2 bar) and remain OSHA compliant.

Unsafe Air Gun

To counteract the dead-end pressure violation, some nozzle manufacturers create a hole through the side of the nozzle (reference photo above).  This will allow the compressed air to escape, but now the issue is noise level.  With an “open” hole in the nozzle, the compressed air is very turbulent and very loud.  The National Institute for Occupational Safety and Health (NIOSH) states that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air.  OSHA created a chart to show the maximum allowable noise exposure.  This chart shows the exposure time and noise limits before hearing protection is required.  The EXAIR Super Air Nozzles, Super Air Knives, and Super Air Amplifiers are designed to have laminar flow, which makes them very quiet.  As an example, the model 1210 Safety Air Gun has a sound level of only 74 dBA, well under the noise exposure limit for 8 hours.

NIOSH created an overview of how to handle hazards in the workplace.  They call it the Hierarchy of Controls to best protect workers from danger.  The most effective way is by eliminating the hazard or by substituting the hazard.  The least effective way is with Personal Protective Equipment, or PPE.  For unsafe compressed air nozzles and guns, the proper way to reduce this hazard is to substitute it with an engineered solution.

One of the last things that companies think about when purchasing compressed air products is safety.  Loud noises and dead-end pressure can be missed or forgotten.  To avoid any future fines or having to purchase additional personal protective equipment (PPE), it will be less expensive and a preferred safety strategy to purchase EXAIR products.  As in the above Hazard Hierarchy of Controls chart, EXAIR products are that engineered solution.  If you would like to improve the safety of your facility and reduce energy costs, an Application Engineer at EXAIR can review your current blow-off devices.  Remember, safety is everyone’s responsibility. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Picture:  Safety First by Succo.  Pixabay License