We’ve blogged about sound and what exactly it is before, see the link. Understanding that sound is vibration traveling through the air which it is utilizing as an elastic medium. Well, rather than me continue to write this out, I found a great video to share that is written in song to better recap how sound is created.
Now that we have that recap and understand better what sound is let’s dig a little deeper to better understand why some sounds may appear louder to a person when they may not appear different on a sound scale that is shown by something like a Digital Sound Level Meter.
Loudness is how a person perceives sound and this is correlated to the sound pressure of the frequency of the sound in question. The loudness is broken into three different weighing scales that are internationally standardized. Each of these scales, A, C, and Z apply a weight to different frequency levels.
The most commonly observed scale here in the USA is the A scale. A is the OSHA selected scale for industrial environments and discriminates against low frequencies greatly.
Z is the zero weighting scale to keep all frequencies equal, this scale was introduced in 2003 as the international standard.
C scale does not attenuate these lower frequencies as they are carrying the ability to cause vibrations within structures or buildings and carry their own set of risks.
To further the explanation on the A-weighted scale, the range of frequencies correlates to the common human hearing spectrum which is 20 Hz to 20kHz. This is the range of frequencies that are most harmful to a person’s hearing and thus were adopted by OSHA. The OSHA standard, 29 CFR 191.95(a), that corresponds to noise level exposure permissible can be read about here on our blog as well.
When using a handy tool such as the Digital Sound Level Meter to measure sound levels you will select whether to use the dBA or dBC scale. This is the decibel reading according to the scale selected. Again, for here in the USA you would want to focus your measurements on the dBA scale. It is suggested to use this tool at a 3′ distance or at the known distance an operator’s ears would be from the noise generation point.
Many of EXAIR’s engineered compressed air products have the ability to decrease sound levels in your plant. If you would like to discuss how to best reduce sound levels being produced within your facility, please contact us.
Noise-induced hearing loss, or NIHL, is one of the most common occupational diseases. This doesn’t occur overnight, but the effects are noticed gradually over many years of unprotected exposure to high sound levels. This is 100% preventable! Through proper engineering controls and personal protective equipment (PPE), NIHL can be prevented. It is irreversible, so once the damage is done there’s no going back. OSHA standard 19 CFR 1910.95(a) states that protection against the effects of noise exposure shall be provided when the sound levels and exposure time exceed those shown in the table below.
Intensity of the sound pressure level is expressed in decibels (dB). The scale is logarithmic, a 3 dB reduction cuts the sound level in half. A 10 dB reduction decreases it by a factor of 10, and a 20 dB reduction decreases the sound level by a factor of 100. To calculate the dB level, we use the following formula:
L – Sound Pressure Level, dB
P – Sound Pressure, Pa
Pref – reference sound pressure, 0.00002 Pa
For example, normal conversation has a Sound Pressure of .01Pa. To calculate the dB level:
dB = 20 log10 (.01Pa/.00002Pa)
= 54 dB
When designing a new blowoff process, it’s important to consider the sound levels produced before implementation. EXAIR publishes the sound level for all of our products for this very reason. If you’re implementing multiple nozzles, you’ll need to add the sound levels together. To do so, we use the following formula:
L1, L2… represent the sound pressure level in dB for each source
A customer was using ¼” open ended copper tubes for a blowoff application removing trim after a stamping operation. They had a total of (4) tubes operating at 80 PSIG. Not only were they VERY inefficient, but the sound level produced at this pressure was 94 dBA. To calculate the sound level of all (4) together we use the above formula:
L = 10 x log10(109.4+ 109.4 + 109.4 + 109.4)
L = 100 dB
At this sound level, permanent hearing loss begins to occur in just two hours of unprotected exposure. We recommended replacing the loud and inefficient copper pipe with our 1” Flat Super Air Nozzle, Model 1126. At 80 PSIG, the 1126 produces a sound level of just 75 dBA.
L = 10 x log10 (107.5 + 107.5 + 107.5 + 107.5)
L = 81 dB
At almost a 20 dB reduction, that’s nearly 100x quieter! Don’t rely on just PPE to keep your operators safe from NIHL. Replacing loud inefficient blowoff methods with EXAIR’s Intelligent Compressed Air Products will take it one step further in ensuring your creating a safe working environment for your employees.
EXAIR prides itself in offering products with high-performance and peak efficiency. All EXAIR products are manufactured to meet the strict requirements of a variety of different standards, ensuring that you receive a reliable, high quality product that WILL perform to the specifications we publish.
Safety is a top priority for most companies, EXAIR’s line of Intelligent Compressed Air Products meet or exceed the strict safety standards set forth by both OSHA and the European Union. EXAIR products comply with OSHA 29 CFR 1910.242(b), the standard implemented to ensure safe operation of compressed air blowoff devices, and the EU General Product Safety Directive (2001/95/EC).
Additionally, they comply with the noise limitation requirements set forth under 29 CFR 1910.95(a) and the EU Machinery Directive (2006/42/EC). From the Optimization product line, EXAIR’s Electronic Flow Control and the Electronic Temperature Control meet the low voltage standards of EU Low Voltage Directive (2006/95/EC). A CE label is placed on all products that comply with applicable directives.
UL, or Underwriters Laboratories, is a third-party safety and consulting organization that certifies products after thorough testing and evaluation. EXAIR’s Cabinet Coolers are UL Listed to US and Canadian safety standards. Static Eliminators are also UL Component Recognized. Within our line of Cabinet Coolers is the Hazardous Location Cabinet Cooler, bearing the Classified UL mark for use in classified areas.
In the assembly of electrical products there can be hazardous materials used during production. The Restriction of Hazardous Substances, also known as RoHS or (2002/95/EC), restricts the use of materials such as: lead (Pb), mercury (Hg), cadmium (Cd), hexavalent chromium (CrVI), polybrominated biphenyls (PBB), polybrominated diphenyl ethers (PBDE), and four different phthalates. The electrical portions of EXAIR’s Static Eliminators, Electronic Flow Control, Electronic Temperature Control, Digital Flowmeter, solenoid valves, and thermostats all comply with the amendment outlined in the European Commission decision L 214/65.
In addition to RoHS, EXAIR is also committed to providing products that are conflict mineral free. In support of Section 1502 of the Dodd-Frank Wall Street Reform and Consumer protection Act, EXAIR complies with the conflict minerals rule to curb illicit trade of tin, tantalum, tungsten and gold in the DRC region. Using the CMRT 4.20 template, we’re able to document our supply chain to ensure our materials are not being sourced from places that could finance conflict in the DRC and surrounding countries.
Finally, per Regulation (EC) No 1907/2006 Title I, Article 3, paragraph 3, the European Union enacted legislation requiring substances and chemicals imported into the EU to be registered to ensure a high level of protection for human health and the environment. Per Title II, Article 7, paragraph 1, articles must be registered when a substance is intended to be released during normal conditions of use that would exceed 1 metric ton per producer per year. Since EXAIR products do not contain substances that are intentionally released, registration is not required.
If you’re looking to maintain compliance in your industry, EXAIR products have you covered. If you have any questions about these standards of compliance feel free to reach out to us. Our team of Application Engineers have years of experience in industry are waiting to take your call.
Depending on the context, those may be three words you DON’T want to hear in the same sentence. Case in point…a caller I spoke with recently, who works at a large steel forging plant. During a recent inspection, management was surprised (and disappointed) to find out that, unbeknownst to them, some of their operators had modified some of their compressed air blow off devices.
These modifications left them in violation of both OSHA Standard 1910.242(b) (limit on outlet, or dead end pressure) and 1910.95(a) (limits noise level exposure.) The OSHA inspector left them with an $8,000.00 fine, and a promise to return with an even higher one if the situation wasn’t corrected.
We discussed the ways their current devices were supplied, the conditions they were operating in, what they were used for…and why the operators had modified them. Sadly, we found the devices were underperforming due to air supply issues – hoses that were too small in diameter and/or too long, with restrictive quick connect fittings. And some of their modifications (drilling out the discharge) just exacerbated those problems.
Most of their applications were pretty typical – blowing flash, chips, oil, coolant, etc. from processed metal parts. Typical enough that a couple of EXAIR Safety Air Guns would allow them to determine what they would need, by taking them around to various stations in the plant and trying them out.
I feel pretty good about the chances of publishing a future blog about the success of this application. If you want to keep up, I encourage to follow the EXAIR blog – there’s a link to the right to provide your email address – for more on this one, other applications, and a wealth of expert writings on how to get the most out of your compressed air system.
As always, if you’d like to discuss a particular compressed air application and/or product selection, give me a call.
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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.
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).
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.
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.
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.
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.
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!
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!
I’m pretty impressed with the number of safety features my car has. Aside from the literal lifesaving functions like seat belts and air bags, it’s got anti-lock brakes…if you’ve ever had to counter-steer out of a skid on an icy road, you will appreciate the value of this for sure. Those are just some of the ones I’m keenly aware of – the Federal Motor Vehicle Safety Standards comprise dozens of regulations in three categories: crash avoidance, crashworthiness, and post-crash survivability. None of these prevent me from operating my vehicle at an unsafe rate of speed…an expensive reality that an Ohio State Highway Patrolman dutifully reminded me of last Sunday afternoon.
Likewise, there are many regulations to ensure safety and prevent hazards of all kinds in industry, administered by a host of agencies that are either subordinates of, or accountable to, the federal government. When you manufacture products that are used with high energy sources (compressed air or high voltage electricity,) a strong commitment to safety is not negotiable. So, at EXAIR, we commit considerable resources towards the best engineering and manufacturing practices to make our products as safe as possible. That includes compliance with a number of standards and certifications:
The Occupational Safety and Health Administration (OSHA) is an agency of the U.S. Department of Labor. Their mission is to “assure safe and healthful working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education and assistance.” They are a regulatory body in the truest sense, in that they don’t offer certification or approval of products, processes, etc.; they publish guidelines and standards for manufacturers and users to comply with. OSHA Standard 1910.242(b), for instance, limits the downstream pressure of a compressed air operated device used for cleaning purposes to 30psi. Now, you can regulate the supply pressure to meet this, but that also limits the effectiveness of the air flow generated. EXAIR Intelligent Compressed Air Products are all designed and manufactured to be in compliance with this standard, at any supply pressure. Take, for example, our Super Air Nozzles:
OSHA also has Standard 1910.95(a), that sets limits for maximum allowable noise exposure. All EXAIR Intelligent Compressed Air Products, with the exception of some our largest and most power Super Air Nozzles (which aren’t normally used in areas that don’t already require hearing protection anyway) meet the 8-hour exposure limits of this standard.
CE marking indicates conformity with health, safety, and environmental protection standards for products sold withing the European Economic Area. Unlike OSHA standards, responsibility for CE marking falls solely with the seller of the product – a CE marked product has been tested and certified to have been made in such a way to meet safety & quality benchmarks specified for that type of product. All EXAIR products that are defined under applicable directives have been tested according to these standards, and carry the CE mark.
The Restriction of Hazardous Substances Directive, or RoHS, is another standard borne from the European Union, and is geared towards public & workplace safety by restricting the use of hazardous materials in the manufacture of electronic & electrical equipment. Since its inception in 2006, similar standards have been vigorously adopted around the globe. Electrical portions of EXAIR’s Static Eliminators, EFC Electronic Flow Controls, ETC Electronic Temperature Controls, Digital Flowmeters, Solenoid Valves, and Thermostats all comply with the RoHS Directive.
Section 1502 of the Dodd-Frank Wall Street Reform and Consumer Protection Act doesn’t address a concern for product users, but rather a particularly troubling human rights issue – Conflict Minerals. For almost two decades, trade in tin, tantalum, tungsten and gold in the Democratic Republic of the Congo (DRC) has been used by some very bad people to finance violent campaigns against their neighbors. EXAIR thoroughly and systematically documents our supply chain compliance with this act. We are proudly committed to our support for this effort to the world a better place for everyone…especially those in desperate circumstances beyond their control.
EXAIR Intelligent Compressed Air Products have been successfully implemented into a variety of uses where application- or industry-specific standards are in force. We’re happy to work with you to determine if our products meet those standards…or can be made to meet them. If you’ve got such an application, give me a call.
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