Tag: dead end pressure

What OSHA 1910.242(b) Means For Compressed Air Product Users

Published on by Russ BowmanLeave a comment

Medically speaking, our skin is an organ…and an amazing one at that. It protects our internals from an incredibly harsh environment as we’re bombarded by radiation (sunlight), subjected to summer’s heat & the cold of winter, attacked by fierce invaders (from viruses & bacteria to insects & spiders), all while we carry on at the bottom of a 60 mile-deep ocean (of air!)

Our skin requires some protection too: Sunscreen mitigates some of the harmful effects of solar radiation, shoes protect our feet from the ground, gloves & coats prevent frostbite, and compliance with OSHA Standard 1910.242(b) protects operators who use compressed air devices for cleaning purposes from air embolisms. That’s when air, under pressure, has enough energy to break the skin (tough as it is) and reach the tissue underneath. It’s painful, and serious enough that the victim should absolutely seek emergency medical treatment. If the air breaks a blood vessel and enters the pulmonary system, it can be deadly, in a hurry.

In 1971, the U.S. Occupational Health and Safety Administration (OSHA) determined that air under pressure higher than 30 pounds per square inch is capable of causing such injuries, if the pressurized source is dead-ended into the skin. Based on this determination, they included the following verbiage in Standard 1910.242, regulating the safe operation of hand and portable powered tools & equipment:

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

In February 1972, OSHA issued Instruction STD 01-13-001 to clarify the meaning of 1910.242(b), with two illustrations of acceptable methods to meet compliance. The first is the use of a pressure reducer (or regulator):

While this method is compliant with the OSHA Standard, it’s kind of impractical, since you’re not going to get a whole lot of cleaning done with such a low energy air flow. If that’s not bad enough, it’s STILL going to be loud, and wasteful as far as the cost of compressed air goes.

The other method illustrated in the Instruction’s enclosures involves the nozzles themselves:

Compressed air product manufacturers use this method to make OSHA compliant Nozzles.

One design that complies with OSHA 1910.242(b) using this method is the cross drilled nozzle:

Unless it’s blocked off, practically all of the air flow goes straight out the end, but if you block off the end, it all goes out the cross drilled hole. As long that hole is properly sized, you won’t build up 30 psi at the main outlet.

If you’re not concerned about high operating cost or deafening noise, you can stop reading now; these are all you need for OSHA compliance with Standard 1910.242(b). If you DO care about spending less money on compressed air or complying with OSHA Standard 1910.95(a) (which you read all about here), let’s spend a minute on engineered compressed air nozzles:

EXAIR Super Air Nozzles discharge compressed air through an annular array of holes, recessed between a series of fins. This causes the primary (compressed air) stream to entrain an enormous amount of air from the surrounding environment.

In addition to making them cost less to operate (since most of the total developed air flow is entrained), they’re also VERY quiet (since the entrained air forms a boundary layer on the outside of the air stream), AND they can’t be dead ended:

Since the fins won’t allow for a complete blockage of the compressed air discharging from the Super Air Nozzle, this design is a prime example of a built-in “relief device” as defined by Instruction STD 01-13-001, above.

All EXAIR Intelligent Compressed Air Products, in fact, incorporate a form of built-in “relief device”:

The overhang of the cap on the Flat Super Air Nozzles and the Super Air Knives prevent them from being dead ended.

If you’d like to discuss safe use of compressed air, it’s one of our primary goals here at EXAIR – give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR LLC
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OSHA and Compressed Air Safety; Things to Review.

Published on by johnball2014Leave a comment
EXAIR Super Air Nozzles are fully OSHA Compliant – our Compliance Certificate is available upon request (left.) Your power strip and Christmas tree lights should have labels showing their current ratings – check these so you don’t overload the circuit (right.)

At EXAIR, we have a statement that says, “Safety is everyone’s responsibility.”  As a corporation, 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 the compressed air system, 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

Above 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 this path could 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 the compressed air cannot escape if it is blocked by your body or skin.  If operated above 30 PSIG (2 bar), the air from 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 which 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 prevent blockage of the airflow.  So, you can use the EXAIR Super Air Nozzles safely above 30 PSIG (2 bar) and remain OSHA safe.

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 for 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 CDC reports that in 2007, “82% of the cases involving occupational hearing loss were reported among workers in the manufacturing sector.” Compressed air and pneumatic equipment are significant contributors to the noise exposure. OSHA created a chart to show the maximum allowable noise exposure.  This chart shows the exposure time and noise limits before requiring hearing protection.  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.

Hearing loss is the best known, but not the only, ill effect of harmful noise exposure. It can also cause physical and psychological stress, impair concentration, and contribute to workplace accidents or injuries.

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 method to purchase an EXAIR product.  As in that above Hazard Hierarchy of Controls chart, EXAIR products are that engineered solution.  If you would like to improve the safety in your facility, move up to an engineered solution, 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

EXAIR Compliance with OSHA 1910.242(b)

Published on by Jordan T ShouseLeave a comment

OSHA Standard 1910.242(b) discusses the use of compressed air for cleaning and blowoff. It states that the use of compressed air for cleaning purposes is prohibited if the dead-ended pressure exceeds 30 psig. This phrase means the downstream pressure of the air nozzle or gun, used for cleaning purposes, will remain at a pressure level below 30 psig for all static conditions. In the event that dead ending occurs, the static pressure at the main orifice shall not exceed 30 psi. If it does exceed this pressure, there is a very high potential for it to create an air embolism. An air embolism, left untreated, can quickly impede the flow of blood throughout the body. This can lead to stroke, heart attack, and sometimes death.

So making sure you are in compliance with 1910.242(b) is truly a life and death situation. Most people believe that lowering the pressure to the blow off device is the only method to keep their operators safe from an air embolism. However this can become a problem when you really need the force of greater than 30 PSIG to complete your operation. We at EXAIR want to give you the flexibility to run at any pressure with out the risk of building that 30 PSI of dead-end pressure! We do this with our line of Intelligent Compressed Air® nozzles! All of EXAIR’s Air Nozzles are designed so that the flow cannot be dead-ended. The fins on the Super Air Nozzles are not only useful in amplifying the force by drawing in ambient air, but they also prevent an operator from completely obstructing the airflow.

Another great example of this is our 2″ Flat super air nozzle. The design not only allows the nozzle to amplify the air flow in the blast of air, the over hang will not let the dead end pressure build as it can escape around the edges and bottom!

2″ Flat Super Air Nozzle

If you’ve got questions about compressed air safety or have an existing blowoff in place that does not adhere to this OSHA directive, give us a call. We’ll be sure to recommend a solution that will keep your operators and wallets safe!

Jordan Shouse
Application Engineer

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Compressed Air Safety

Published on by johnball2014Leave a comment

At EXAIR, we have a statement, “Safety is everyone’s responsibility”.  And as a corporation, EXAIR builds our name around this by manufacturing safe and protective compressed air products.  In the United States, we have an organization called 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.  They can also enforce these directives with heavy fines for violations.  With compressed air, the two most common violations are air guns and blow-off devices are described in 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.95(a) for maximum allowable noise exposure.

Here is an example of a nozzle that is dangerous.  As you can see, there is only one opening where the air can pass through from the nozzle.  Other similar types of blow-off devices that would fall into this same group would include copper tube, extensions, and open pipes.

Unsafe Nozzle

They are dangerous as the compressed air cannot escape if it is blocked with 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 which can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed with fins which allows the air to escape and not be blocked by your skin.  So, you can use the EXAIR Super Air Nozzles safely even above 30 PSIG (2 bar).

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 for 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 time and noise limits before requiring hearing protection.  The EXAIR Super Air Nozzles, Super Air Knives, Super Air Amplifiers are designed to have laminar flow which is 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.

Hearing loss is the best known, but not the only, ill effect of harmful noise exposure. It can also cause physical and psychological stress, impair concentration, and contribute to workplace accidents or injuries.

NIOSH created an overview of how to handle hazards in the workplace.  They call it the Hierarchy of Controls to best protect workers from dangers.  The most effective way is by eliminating the hazard or 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 stop any future fines or purchasing additional personal protective equipment (PPE), it will be less expensive to purchase an EXAIR product.  And with the Hazard Hierarchy of Controls, EXAIR products are that engineered solution.  If you would like to improve the safety in your facility with your current blow-off devices, an Application Engineer at EXAIR can help you.  Remember, safety is everyone’s responsibility. 

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

Picture:  Safety First by Succo.  Pixabay License