Know What to Look For – Are Your Compressed Air Guns OSHA Safe?

One of the easiest ways to find out if your compressed air guns are safe for operation is by looking at the nozzle.  First, take your current compressed air gun and disconnect it from the compressed air line.  Second, look directly into the end of the nozzle where the air comes out.  If you can see the inside of the nozzle, then your air gun or blow-off device is unsafe.  Nine out of ten compressed air guns are considered to be dangerous.  In this blog, I will go through the dangers and violations of compressed air guns and nozzles that are very common in the market place.

Occupational Safety and Health Administration, OSHA, is an organization that enforces standards for safe and healthy working environments.  They have training, outreach programs, and educational assistance for manufacturing plant.  But, they will also enforce these standards with heavy fines for violations.  The two most common violations with compressed air guns and nozzles are 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.65(a) for maximum allowable noise exposure.  If you are unfortunate in receiving an audit, the OSHA agent will target your compressed air guns and blow-off devices.

Unsafe Nozzle

Here is the first example of a nozzle that I would like to discuss.  As you can see, there is only one opening where the air can come out from the nozzle.  Other types of nozzles that would fall into this category will include copper pipes, extensions, or worn nozzles.  They are dangerous as the compressed air cannot escape if it is blocked by your skin.  An air embolism could occur within the body which can cause bodily harm or death.  If operated above 30 PSIG (2 bar), these nozzles would violate the OSHA 29CFR 1910.242(b) for dead-end pressure.  This is a hazard which can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed to utilize fins to allow air to escape and not penetrate your skin.  With EXAIR products, you will not violate this standard even if you go above the 30 PSIG (2 bar).

Safety Air Gun

To counteract the dead-end pressure violation, some nozzle manufacturers created a hole through the side of the nozzle (Reference photo below).  This will allow for the compressed air to escape, but, now the issue is noise level.  With an “open” section in the nozzle, the compressed air is very turbulent and very loud.  They state that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air.  For this, OSHA 29CFR 1910.65(a) was created to show the maximum allowable noise exposure.  This chart shows the time and noise limits before requiring hearing protection.  The EXAIR Super Air Nozzles are designed to have laminar flow which is very quiet.  With our typical Safety Air Gun, model 1210, the sound level is only 74 dBA; well under the noise exposure limit for 8 hours.

Unsafe Air Gun
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.

Why do I bring these points up?  Because safety is everyone’s responsibility.  The National Institute for Occupational Safety and Health, NIOSH, has an overview of how to handle hazards in the workplace.  They call it the Hierarchy of Controls (click).  This is a means 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 your unsafe compressed air nozzles and guns, EXAIR can help by substituting the hazardous air gun and nozzle with an engineered solution designed with safety in mind.

In my opening statement, I explained a quick and easy method to determine if your compressed air guns are dangerous.  To keep your company compliant and safe, EXAIR offers a variety of different types of nozzles and Safety Air Guns to best fit your requirement.  If you find that you are using hazardous blowing equipment, you can contact an Application Engineer to find a safe and effective alternative.

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

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

OSHA At 35,000 Feet

Early one morning I was on a flight to the West coast to start up a system that I had designed and built for a large food producer.  After the flight attendants had passed out our first beverage and snack I struck up a conversation with the passenger next to me.  We engaged in the typical banter about how hilarious it is to watch some passengers try to stuff an oversized bag into the overhead compartment and ultimately have to check it.

I then asked the reason for her trip and she explained that she worked for OSHA and had conducted a study on flight crew safety and was in route to give her report on the findings.  I was naturally intrigued and asked her what the risks were for a flight crew other than the obvious perils of being 35,000 Ft. above the ground for long periods of time.

Her reply was radiation exposure from the sun!  I had never considered that flight crews spend long periods of time above the thickest layer of our atmosphere.  Flight crews are exposed to significantly greater amounts of radiation compared to us folks who are on the ground more and consequently develop certain health conditions at a higher rate than the general population.

While EXAIR can’t help you with radiation exposure, we can bring you into OSHA compliance with noise, OSHA Standard 29 CFR – 1910.95 (a).

This standard is concerned with the level of noise that personnel are exposed to over a given period of time.  Often times in plants compressed air noise exceeds the OSHA noise level requirements which unfortunately results in hearing loss.  Noisy air blow-offs can produce noise in excess of 100 dBA.  Studies have proven that noise levels that are sustained for varying periods of time can ultimately result in permanent hearing loss.  Similar to the way flight crews are exposed to the radiation, some employess may not realize they are being exposed to a harmful level of noise from compressed air usage.  This is why OSHA generated the standard that has allowable limits for sustained noise levels in order to mitigate the risks for personnel in the area.  Utilizing EXAIR Super Air Nozzles the noise can be reduced to only 74 dBA.  EXAIR Engineered Air Nozzles reduce the noise without losing the hard hitting force.

dBA Chart

EXAIR also meets OSHA Standard 29 CFR 1910.242(b) for “Dead End Pressure”. This standard addresses how dangerous compressed air can be when the outlet pressure of a hole, hose or open pipe is higher than 30 PSIG (2 Bar).  If the opening is blocked (dead-ended) into any part of the body, air could enter the bloodstream through the skin.  This may result in serious injury.  All EXAIR Nozzles and Jets are designed for safety and can’t be dead-ended into the skin therefore can be safely operated above the 30 PSIG (2 Bar) limit.

sag-osha-compliant

If you would like to discuss noise levels, dead end pressure or any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook

Protect Personnel from Noise with Engineered Products

Sound can be defined as vibrations that typically travel as an audible wave through mediums that can be a gas, liquid or solid. For this blog we will concern ourselves with sound travelling through a gas (atmosphere) in an industrial setting.

Sound is energy that travels in waves and is measured by its frequency (cycles per second) and amplitude (intensity). A common unit of measurement for sound energy is the decibel. The decibel (abbreviated with dBA) is a unit-less number that is based on the logarithm of a known measured quantity to a reference quantity. Without reciting the equation for every increase of 3 dBA is a doubling of sound energy or twice as loud.

Since our focus is on industrial sound one might question why be concerned at all, after all sound emanates from most machines and devices. The reason for concern is that there are OSHA regulations regarding the amount of time workers can be exposed to different levels of sound in their workday as illustrated below. These limits are in place to protect personnel from Noise Induced Hearing Loss or NIHL. When the damage to anyones hearing is caused by their profession, it is also referred to as Occupational Hearing Loss or OHL.

After monitoring for noise, NIOSH and the CDC next recommend administrative controls to minimize or eliminate the noise hazard (click for their helpful PDF). This would include the use of noise reducing EXAIR products like Super Air Nozzles, Air Knives and Air Amplifiers.

dBA Chart.JPG
OSHA Maximum Allowable Noise Exposure

When considering the many items in an industrial setting that produce loud sounds the list would be exhaustive. Many of them simply produce loud sounds that can’t be eliminated or reduced while on the other hand there are some that can. Some of the noisiest offenders that plants have control over are air powered tools and open tube blow-offs.  Eliminating inefficient methods of part blow off & part cleaning with an engineered solution allows a company to significantly reduce the level of sound in their plant, improve worker safety and save money on compressed air consumption.

Employers are required to provide hearing protection to employees whom are exposed to sounds above 90 dBA on a Time Weighted Average (TWA). Without digressing into the formulas TWA calculates a workers daily exposure to occupational sounds by taking into account the average levels (in dBA) and the time exposed to different levels.  This is the how OSHA assesses workers exposure and what steps should be taken to protect the workers.

To conclude, plants need to be mindful of the OSHA regulations for sound levels, time of exposure and that hearing protectors wear out. Earmuff seals can lose their elasticity and reduce their effectiveness and the soft pre-molded earplugs can wear out in a day and need replaced.  Keep a good supply on hand and OSHA suggests letting workers with noisy hobbies take them home for protection off the clock!

If you would like to discuss reducing noise or any EXAIR product, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer

Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook

Measuring and Adding Sounds

Sound

My colleague, Russ Bowman, wrote a blog about “Sound Power Level and Sound Pressure”.  He discussed the logarithmic equations around sound.  I will be discussing what happens when you have more than one sound source, as often heard within manufacturing plants.  Sounds can be added together to determine the overall sound level that your hear.  This is very important when it comes to minimizing hearing loss.

In looking at a single source of sound, sound pressure is created by the loudness of a noise.  The units are measured in Pascals.  The lowest pressure perceived by human hearing is 0.00002 Pa, and we can use this value as a reference point.  From sound pressures, we can arrive to a sound pressure level which is measured in decibel, dB.  This correlation between sound pressures and sound pressure levels are calculated by Equation 1:

 

 

L – Sound Pressure Level, dB

P – Sound pressure, Pa

Pref – reference sound pressure, 0.00002 Pa

As an example, the sound pressure from a passenger car as heard from the roadside is 0.1 Pa.  With Equation 1, we can get the following decibel level:

L = 20 * Log10 (0.1Pa/0.00002Pa) = 74 dB

Because human ears are sensitive to different frequencies, the sound pressure levels can be modified, or weighted, to indicate an effective loudness level for humans.  This adjustment is done in two different ways; A-weighting and C-weighting.  The C-weighting is for very loud noises with high peaks or sharp impacts like gunfire. The A-weighting is the most commonly used value as the sound pressure levels are adjusted by the frequency level.  For higher and lower frequencies, the change in the sound value is much greater than the mid-level frequencies that are within our hearing range.  Sound measurements for safety are measured in the A-weighted scale.  OSHA created a chart in the 29CFR-1910.95(a) standard that shows the noise levels over exposure times for an operator.  To use the OSHA chart accurately, the total noise level in dBA should be calculated.

OSHA Chart

To determine the total sound level, we can add all the sound pressure levels together by Equation 2:

 

 

Where L1, L2… represents the sound pressure level in dBA for each sound source.

As an example, a manufacturing plant had an operator using a machine that had four copper tubes to blow off a cutting operation (reference photo below).

Blow off station

The decibel level for a copper tube was measured at 98 dBA.  The total amount of sound that the operator was exposed to was determined by Equation 2 with four values.

L = 10 * log10 (109.8 + 109.8 + 109.8 + 109.8)

L = 104 dBA

In looking at the OSHA chart, the operator would only be allowed to operate the machine only a little over one hour without hearing protection.  In this same example, we replaced the copper tubes with an EXAIR Super Air Nozzle, model 1110SS.  The noise level for each nozzle is 74 dBA.  By replacing all four copper tubes with Super Air Nozzles, Equation 2 becomes:

L = 10 * log10 (107.4 + 107.4+ 107.4 + 107.4)

L = 80 dBA

The total sound level is now in accordance with OSHA regulations for the operator to work all 8 hours at the machine without hearing protection.

A commonly used acronym in hearing safety is NIHL, or Noise Induced Hearing Loss.  To keep your operators safe and reduce NIHL, it is important to measure the total sound level.  As a protocol in safety, it is a requirement to use engineering standards before purchasing personal protective equipment or PPE.  For the customer above, they followed that protocol with our Super Air Nozzles.  If you need to reduce noise levels in your facility by engineering standards, EXAIR offers a large line of blow-off products that can meet the safety requirements.

 

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

 

Photo of Ear auricle Listen by geraitCC0 Create Commons.

 

Compressed Air and Safety

Warning

Compressed air is generally considered the fourth utility in industrial, commercial and back-yard settings.  It is used to power pneumatic equipment, cleaning surfaces, conveying materials, etc.  The compressor reduces the volume inside a chamber to increase the pressure.  The compressed air typically is contained in a reservoir tank for distribution to pneumatic equipment and devices.  Since air is a compressible fluid it has stored energy; and, if not used properly, it can be hazardous.  Most people perceive compressed air as harmless, but this is untrue.  It can be very dangerous.  Here are some potential risks when using compressed air:

  1. If the air pressure against the skin becomes greater than 30 PSI, air can penetrate through the membrane and cause an embolism which could be fatal.  The term used is Dead-End pressure, any end-use nozzle or blowoff product cannot exceed 30 PSI dead-end pressure.
  2. Hearing damage can occur from exposure to loud noises from compressed air exhausting from pneumatic equipment or devices.
  3. Proper use of Safety Air Guns and Safety Air Nozzles is a must. They should not be modified or tampered with.  For example, tying the trigger on an air gun for continuous blowing or modifying the nozzle to get a different blowing pattern.
  4. Compressed air can generate high velocities which can shoot chards of debris. The accelerated fragment can injure any part of the body even from bounce-back.
  5. If the air pressure is higher than the recommended rating for the equipment, uncontrolled eruptions can occur which can send broken pieces everywhere.
  6. When air hoses or lines are laying on the floor, near pinch points, or degrades from the environment, a break can occur causing unrestrained hose “whipping”.

Some safety precautions can be followed in your area when using compressed air products.  They may seem basic, but they are commonly overlooked.

  1. Verify that all compressed air components are rated to be used for the maximum line pressure.
  2. Use shut-off valves nearby to isolate the system from the main compressed air line.
  3. Have general inspection on your compressed air system to check for pipe degradation, leaks, faulty pneumatics, etc.
  4. When you go to repair items attached to the compressed air line, make sure to use proper lockout procedures to isolate and remove the hazardous energy.
  5. Remember that compressed air is not a toy and use proper PPE when required.
  6. If any pneumatically operated product is damaged, remove it from service and either repair it or replace it.
EXAIR Products

In 1970, Occupational Safety and Health Administration, OSHA, was enacted by the Department of Labor.  This organization was created “to ensure safe and healthful working conditions for working men and women”.  They created a set of laws and standards that they enforce with heavy fines and reoccurring visits if not followed.  The Department of Labor lists these laws under title 29 in the Code of Federal Regulations (CFR).  For general industry, these safety regulations are under part 1910 of 29 CFR.  To give a few examples, 29 CFR 1910.242b gives the explanation about dead-end pressure.  Under 29 CFR 1910.95a shows the maximum allowable noise exposure.  The reason that I noted these two OSHA standards as they are commonly overlooked with Safety Air Guns, and commonly fined by OSHA for improper nozzles.

Safety is everyone’s responsibility, and EXAIR products can be a key.  If you would like to discuss how to improve your workplace, you can contact an Application Engineer at EXAIR.     Because hazards and fines can be detrimental to your company when it comes to compressed air safety.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

 

Photo: Attention Warning Sign by Peter-LomasCreative Commons: CCO

 

 

Increase Safety and Gain OSHA Compliance By Using An Engineered Solution

In 1972, the US Department of Labor’s Occupation Safety & Health Administration (OSHA) established Standard 29 CFR 1910.242(b) to reduce the outlet pressure to less than 30 psi, of an open pipe, nozzle, air gun, etc. when being used for cleaning. The intent of this directive was to prevent injury to operators. They determined that 30 psi was the pressure in which the skin could be broken if the device were dead-ended against the operator’s body, causing an injury known as an air embolism…the dead-ended force of the air, under pressure, breaks the skin and introduces air flow inside the body. This is a VERY dangerous condition which can quickly lead to serious injury, possible stroke or ultimately death.

While OSHA doesn’t recommend any type or manufacturer of device, they do provide two methods you can follow to gain compliance.

The first would be to reduce the operating pressure below 30 PSI, as shown in the below line drawing.  This, of course, limits the strength and usefulness of the exhausting air flow before it reaches the nozzle and before it is used upon the application.

 

The other method indicates using a 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. All of EXAIR‘s products are engineered to meet or exceed this Standard. In the case of our Super Air Nozzles, the air exits through a series of jets, recessed behind an array of fins, so the outlet holes cannot be blocked directly, any potential obstruction of the outlet air holes results in the air having an alternative route to avoid injury to operators and personnel. This allows the full pressure (the highest energy) to reach the nozzle and the application

Open air lines and homemade blow offs violate OSHA standard 1910.242(b) because of harmful dead end pressures. If you would like to discuss how EXAIR products can help you gain OSHA compliance to increase personnel safety and avoid costly fines, please give me a call, I’d be happy to help.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Line drawings used from OSHA’s website