Tag: OSHA

Safety Is Everyone’s Responsibility

Published on by Russ BowmanLeave a comment

That’s a direct quote that everyone at EXAIR hears at our regularly scheduled safety training meetings. While our machine tool operators & assembly technicians spend a lot more time “up close and personal” with devices that can hurt you if not used properly, we all work in the same building with them. That’s why EVERYONE is required to attend those meetings. I like the people I work with, so I REALLY like the level of confidence we all have that the company is looking out for us like that.

The confidence in safety that we have in working at EXAIR is built into our engineered Compressed Air Products as well. Compressed air is downright dangerous, so it’s imperative that you use it safely.

I spent 6 years & 23 days in the United States Navy, so I know full well that you can’t make anything “sailor proof” (no offense to you veterans of other branches, but I once got a letter of commendation from my Commanding Officer for fixing something that I’d broken myself) but I cannot figure out, for the life of me, how to violate OSHA’s Standard on using compressed air for cleaning, with an EXAIR Super Air Nozzle:

OSHA Standard 1910.242(b) says that if you use a compressed air device for cleaning, the static air pressure at the nozzle or opening must not exceed 30 PSI when dead-ended (blocked). Since the air from a Super Air Nozzle comes out of those holes recessed between those fins, there’s a (dare I say it?) sailor proof relief path to make sure that can’t happen.

In fact, all of our blowoff products comply with that standard:

The same design feature (the cap overhanging the body) makes our Flat Super Air Nozzle (left) and our Super Air Knife (right) OSHA Compliant.

Another danger associated with the use of compressed air is the noise level associated with introducing a high pressure gas to atmospheric pressure. If you use airguns or other blow offs without engineered nozzles, you likely know this already. EXAIR engineered Compressed Air Products solve this safety issue as well. Each of the products in the photos above has a very specific feature that causes the primary flow of compressed airflow to entrain a secondary airflow, which results in a much higher total developed airflow. That makes them EXTREMELY efficient — but it also forms a low velocity boundary layer around the hard-hitting air stream in the center, which attenuates the sound level.

In each of these EXAIR engineered compressed air products, the primary air stream following the curved surface causes entrainment. And efficiency. And sound attenuation.

The effectiveness of that low velocity boundary layer is so good that all of our Super Air Nozzles except the very largest ones are compliant with OSHA Standard 1910.95(a) for maximum allowable noise exposure (that limit is 90dBA, so you know.)

In closing, let me reiterate: compressed air is dangerous, so use it safely, and that starts with using safe compressed air products. Like EXAIR’s…we’re all about safety. If you’d like to find out more, I can talk about it all day, and sometimes I do…give me a call.

Russ Bowman, CCASS

Application Engineer
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Measuring and Adding Sounds

Published on by John BallLeave a comment

My colleague, Russ Bowman, wrote a blog about “Sound Power vs Sound Pressure vs Sound Pressure Level”.  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 you 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 at 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 = 20 * Log10 (P / Pref)

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 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 on an A-weighted scale.  OSHA created a chart in the standard 29CFR-1910.95(a).  It 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.

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.

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

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 above, 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 1100SS.  The noise level for each nozzle is 74 dBA at 80 PSIG (5.5 bar).  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 for 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 in that area.  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, EXAIR offers a large line of blow-off products that can meet the safety requirements.  You can contact an Application Engineer for more information. 

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

Photo: Ear by PublicDomainPictures  Pixabay License

Noise In The Workplace

Published on by Russ BowmanLeave a comment

The Center for Disease Control (CDC) estimates that 22 million workers are exposed to potentially dangerous levels of noise at work every year. That’s “only” about 15% of the total number of people who are employed in the United States, but if you’re one of them, you should absolutely know the risks, and how to protect yourself. Obviously, high noise levels can cause hearing loss, but do you know what else it causes?

  • Cardiovascular disease. Constant noise exposure causes stress, and stress triggers the release of hormones that increase your blood pressure, which can lead to ischemic heart disease, strokes, and arrhythmia.
  • Sleep disruption. Studies show chronic noise exposure during the day can cause difficulty falling asleep, shortened sleep cycles, and frequent wake-ups during the night. All this leads to chronic fatigue and a host of long-term health issues.
  • Immune system suppression. While the exact nature of the relationship is unclear, recent studies have indicated that noise can cause changes in our immune systems.
  • Cognitive impairment: Continued noise exposure causes memory impairment, attention deficits, and reduced concentration.
  • Mental health issues. Not only does continued noise exposure release hormones like cortisol & adrenaline (causing the chronic stress that’ll literally break your heart; see above), it directly influences anxiety, depression, and irritability.
Don’t let this happen to you.

So, how do we protect ourselves? If you said “ear plugs,” you’re not wrong…but did you know that hearing protection in the form of personnel protective equipment (PPE) is considered the LEAST effective method of mitigating noise exposure? The National Institute for Occupational Safety and Health (NIOSH, a sister agency of the Occupational Safety and Health Administration, or OSHA) developed a hierarchy of controls…a “good, better, best” framework, if you will, of methods to address workplace hazards:

Even though hearing protection (the PPE in this case) is least effective, the intent of the hierarchy graphic is not to dismiss it, but to categorize it as a last resort. If all else fails (or, more often, comes up short,) ear plugs are your – and your hearing’s – best friend.

If the source of the noise cannot be eliminated (and let’s face it, an awful lot of industrial processes are necessarily loud), the next best thing to do is to substitute a quieter method or device. That’s where EXAIR comes in: the design of our engineered Air Knives, Air Nozzles, and Air Amplifiers exploits certain principles of fluidics to mitigate the noise levels associated with the rapid depressurization of compressed air when it’s blown for cleaning, drying, cooling, etc. The key to this is entrainment:

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier are engineered to entrain enormous amounts of air from the surrounding environment.

While this entrainment makes EXAIR products EXTREMELY efficient (the compressed air consumption ends up being a fraction of the total developed flow), it also creates a low velocity boundary layer around the primary high velocity & forceful airflow. This layer attenuates the sound level of that high velocity flow.

Compressed air use can be loud, wasteful, and dangerous, but it doesn’t have to be. If you’re looking for a quiet, safe, and efficient solution for your use of compressed air, give me a call.

Russ Bowman, CCASS

Application Engineer
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How One Customer Improved Safety and Reduced Noise with a Simple Retrofit

Published on by Brian FarnoLeave a comment

I recently had the opportunity to help a customer facing some serious concerns about their compressed air usage. They had just completed a safety audit conducted by a third-party firm, and one of the main issues identified was the use of handheld blow guns throughout their production floor.

“Thumb guns” are especially popular for blowoff because of their compact size, ergonomic design. and low price.

Even though the tools in question were commercially available and marketed as having “safety tips,” the auditors recorded noise levels exceeding 90 dBA—well above the acceptable threshold. The audit team explained that to maintain a safe work environment, noise levels needed to stay below 84 dBA, and the simplest way to get there was to address the blow guns being used.

That’s when the customer turned to us for help.

We discussed the application in detail, and it quickly became clear that EXAIR’s Model 1100 Super Air Nozzle would be a great fit. Not only does it significantly reduce noise levels—down to 74 dBA—but it also meets OSHA’s 30 PSI dead-end pressure requirement, ensuring operator safety in the event of a blocked nozzle.

This customer wasn’t focused on maximizing air output or performance—they simply wanted to make their environment safer for their team. What made this installation even better was the unexpected benefit: while addressing the safety concerns, it also reduced compressed air consumption. A win-win.

It’s always rewarding when we can help customers meet compliance goals and improve safety, but it’s even better when we can go beyond their expectations and help them uncover savings they weren’t even looking for.

Free testing. Verifiable data. EXAIR Efficiency Lab.

If you’re dealing with high noise levels or safety compliance issues around your compressed air applications, don’t hesitate to reach out. Our team is ready to help you find a solution that protects our people, meets regulations, and improves overall efficiency through the EXAIR Efficiency Lab.

Brian Farno, MBA – CCASS
National Business Development Manager

BrianFarno@EXAIR.com
@EXAIR_BF