OSHA 29 CFR 1910.95 (a) – It’s a Noise Exposure Standard, Not Just a Confusing Number

Strings of numbers and characters can often appear daunting.  For instance, if I wrote in binary code it would be a string of ones and zeros.  (01000101 01101110 01100111 01101001 01101110 01100101 01100101 01110010 01101001 01101110 01100111 00100000 01101001 01110011 00100000 01000001 01010111 01000101 01010011 01001111 01001101 01000101.) That can look like gibberish and cause concern if unknown or it can make sense to programmers and people familiar with binary code.

Other alphanumeric strings may cause some concern for industry professionals.  Take, for instance, OSHA standards. The OSHA standard 29 CFR 1910.95 (a) may be unfamiliar to some, and thus concerning. Many Environmental Health and Safety Engineers will recognize this code.  It is an OSHA standard that revolves around the amount of time an employee is permitted to be exposed to specific sound levels. These sound levels are all based on the weighted sound level of the noise the operators are exposed to. To better understand how the octave and frequency of the sound play into this, there is a chart provided below.

Equivalent A-Weighted Sound Level Chart – (1)

The weighted sound level is the level at which a Digital Sound Level Meter will read the current level of noise within an environment. This scale is then used to move further into the OSHA directive that we focus on helping companies meet to best provide safe environments for their employees to work in.

If you notice, the lowest weighted sound level is 90 dBA, this is also the lowest-rated noise level that OSHA speaks of in 1910.95(b)(2). It has been shown that noise levels over this level for extended periods will result in permanent hearing loss. The standard then goes on to discuss the duration an employee can be exposed to noise levels even with the use of personal protective equipment as well as even impulsive or impact noise.  The table of permissible time limits is shown below.

Permissible Noise Exposures (2)

As you can see from the table above provided by OSHA, any noise level that an operator is exposed to for eight hours cannot exceed 90 dBA. Noises within an industrial environment can also be variable throughout the day. For instance, the operator stands outside of a sheet metal press and the concussive strike on the press gives off a 90 dBA strike for every stroke of the press. This would not be a continuous noise level. Maybe the operator is operating a CNC machine that is cutting a nest of parts and uses a handheld blowgun to remove debris and coolant from the parts before taking them from their fixture. This blowgun is not used continuously and therefore would not be rated as such for the exposure time. A time study would be conducted on the average length of time the operator is utilizing this gun along with the level of noise it produces during use. OSHA then gives a calculation to use to appropriately combine the sound level while the gun is being used and when it is not in use. That equation is written out below.

Mixed Environment Exposure Fraction
C1/T1+C2/T2+… = ____
Total Exposure Fraction
Cn/Tn = ____

Where:
C1 = Duration of time for a specified noise level
T1 = Total time of exposure permitted at that level
Cn = Total time of exposure at a specified noise level
Tn = Total exposure time permitted at that level

Should the summation of the fractions for different exposures be greater than the Total Exposure fraction, the summation value should be used. As mentioned above, a time study on exposure to noise levels will be needed to obtain the information needed for this type of study. Once the study is done the process can proceed to the next level within the OSHA standard which is a hearing conservation program.

I would like to interject a small side-step at this point. Rather than rolling straight into the implementation of PPE which is proven to be the lowest reliable factor of protection by the CDC and NIOSH. If any of these noise levels being generated are due to the use of compressed air points of use, EXAIR can potentially lower the noise of these point of use applications. In the events, open blowoffs or “band-aid” fixes are in place to keep processes running, and Engineered Solutions can easily be implemented that will reduce the noise level produced by this operation. Whether it is on the handheld Safety Air Gun in the hands of a CNC operator, or if it is a part/scrap ejector that is blowing the sheet metal press out after every strike, we have products that have proven time over time using an Engineered Solution will save air, reduce noise levels, and still get the job done.

If you would like to discuss OSHA directives revolving around compressed air, share with us a recent citation you received from an inspector for this standard, or just discuss compressed air usage in general, contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

1 – Equivalent A-Weighted Sound Level Chart – Retrieved from OSHA.Gov – https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9735&p_table=standards

2 – Permissible Noise Exposures – Retrieved from OSHA.Gov – https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9735&p_table=standards

 

EXAIR and the Hierarchy of Controls

The CDC (Center for Disease Control) published a useful guide called “Hierarchy of Controls” that details (5) different types of control methods for exposure to occupational hazards while showing the relative effectiveness of each method.

NIOSH_Hierarchy_of_Controls
Hierarchy of Controls

 

The least effective methods are Administrative Controls and Personal Protective Equipment (PPE). Administrative Controls involve making changes to the way people perform the work and promoting safe practices through training. The training could be related to correct operating procedures, keeping the workplace clean, emergency response to incidents, and personal hygiene practices, such as proper hand washing after handling hazardous materials. PPE is the least effective method because the equipment (ear plugs, gloves, respirators, etc.) can become damaged, may be uncomfortable and not used, or used incorrectly.

In the middle range of effectiveness is Engineering Controls. These controls are implemented by design changes to the equipment or process to reduce or eliminate the hazard. Good engineering controls can be very effective in protecting people regardless of the the actions and behaviors of the workers. While higher in initial cost than Administrative controls or PPE, typically operating costs are lower, and a cost saving may be realized in the long run.

The final two, Elimination and Substitution are the most effective but can be the most difficult to integrate into an existing process. If the process is still in the design phase, it may be easier and less expensive to eliminate or substitute the hazard. Elimination of the hazard would be the ultimate and most effective method, either by removing the hazard altogether, or changing the work process so the hazard is no longer part of the process.

EXAIR can help your company follow the Hierarchy of Controls, and eliminate, or substitute the hazards of compressed air use with relative ease. 

Home of Intelligent Compressed Air Products

Engineers can eliminate loud and unsafe pressure nozzles with designs that utilize quiet and intelligent compressed air products such as Air NozzlesAir Knives and Air Amplifiers. Also, unsafe existing products such as air guns, can be substituted with EXAIR engineered solutions that meet the OSHA standards 29 CFR 1910.242(b) and 29 CFR 1910.95(a).

In summary, Elimination and Substitution are the most effective methods and should be used whenever possible to reduce or eliminate the hazard and keep people safe in the workplace. EXAIR products can be easily substituted for existing, unsafe compressed air products in many cases. And to avoid the hazard altogether, remember EXAIR when designing products  or processes which require compressed air use for cooling, cleaning, ejection, and more. 

If you have questions about the Hierarchy of Controls and safe compressed air usage from any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer

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Hierarchy of Controls Image:  used from  Public Domain

Chip Shields, OSHA, And You

Safety is a key part of our culture at EXAIR Corporation.  We have regularly scheduled, all-hands required, safety training on a number of topics.  Our Order Entry team can likely tell you as much about our lockout/tagout procedures as our Machinists can.  Nobody even thinks about entering The Shop without safety glasses, and it’s not just because of the signs.

We pay attention to these…

…so we don’t ever have to use this.

OSHA 1910.242(b) states that “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. (emphasis mine)  All EXAIR Intelligent Compressed Air Products are engineered to meet the requirements of the first part (30psi outlet pressure to prevent dead ending…we’ve written about that numerous times, including here, here, and here) and we can also provide pre-installed devices to satisfy the second part:  the EXAIR Chip Shield.

Any EXAIR VariBlast or Heavy Duty Safety Air Gun can come fitted with a Chip Shield, and any Soft Grip Safety Air Gun, except for those with Stay Set Hoses, can as well.  Safety Air Guns with Back Blow Nozzles automatically come with a Chip Shield. The principle is simple: a clear polycarbonate (so you can still see what you’re doing) round disc slips over a short (or long if you want) pipe extension between the gun & the nozzle.  It’s fitted with a rubber grommet so you can position it to where it’s most effective – sometimes that might be closer to the part being blown off; sometimes it may be back a little closer to the operator.

EXAIR Safety Air Guns are available, from stock, with Chip Shields.

If you already have an air gun that’s doing the job, you can easily add an EXAIR Chip Shield to it.  They’re made to fit a wide range of extension diameters, and can even come with the extension if you need it.  We also stock a number of adapter fittings; if you know what threads your air gun has (or if you can send us some photos) we can quickly & easily spec those out for you.

Convenient and inexpensive “thumb guns” with cross drilled nozzles (left) are compliant with the first part of OSHA 1910.242(b). Fitting one with an EXAIR Chip Shield (center) makes it compliant with the second part. A Model 1102 Mini Super Air Nozzle (right) makes it quiet & efficient.

We can provide a Chip Shield for most any device with a threaded fitting. I couldn’t find a way to re-use the non-OSHA-compliant nozzle that came with this gun (thank goodness.)

Another example of a larger air gun fitted with a more powerful cross drill nozzle (left) that can be made totally OSHA compliant with an EXAIR Chip Shield (center.) An EXAIR High Force Super Air Nozzle (right) keeps the power, while reducing noise level and compressed air consumption (right.)

Since 1983, EXAIR Corporation has been manufacturing quiet, safe, and efficient compressed air products for industry (emphasis mine.)  If you have concerns or questions about safety in regard to your compressed air use, call me.

Russ Bowman
Application Engineer
EXAIR Corporation
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Minimize Exposure to Hazards Using the Hierarchy of Controls

The CDC (Center for Disease Control) published a useful guide called “Hierarchy of Controls” that details (5) different types of control methods for exposure to occupational hazards while showing the relative effectiveness of each method.

HierarchyControls
CDC Hierarchy of Controls

The least effective methods are Administrative Controls and PPE. Administrative Controls involve making changes to the way people perform the work and promoting safe practices through training. The training could be related to correct operating procedures, keeping the workplace clean, emergency response to incidents, and personal hygiene practices, such as proper hand washing after handling hazardous materials. PPE (Personal Protective Equipment) is the least effective method because the equipment (ear plugs, gloves, respirators, etc.) can become damaged, may be uncomfortable and not used, or used incorrectly.

In the middle range of effectiveness is Engineering Controls. These controls are implemented by design changes to the equipment or process to reduce or eliminate the hazard. Good engineering controls can be very effective in protecting people regardless of the the actions and behaviors of the workers. While higher in initial cost than Administrative controls or PPE, typically operating costs are lower, and a cost saving may be realized in the long run.

The final two, Elimination and Substitution are the most effective but can be the most difficult to integrate into an existing process. If the process is still in the design phase, it may be easier and less expensive to eliminate or substitute the hazard. Elimination of the hazard would be the ultimate and most effective method, either by removing the hazard altogether, or changing the work process to the hazardous task is no longer performed.

EXAIR can help your company follow the Hierarchy of Controls, and eliminate, or reduce the hazards of compressed air usage.

Engineers can eliminate loud and unsafe pressure nozzles with designs that utilize quiet and pressure safe engineered air products such as Air Nozzles, Air Knives and Air Amplifiers. Also, unsafe existing products such as air guns, can be substituted with EXAIR engineered solutions that meet the OSHA standards 29 CFR 1910.242(b) and 29 CFR 1910.95(a).

Nozzles

In summary, Elimination and Substitution are the most effective methods and should be used whenever possible to reduce or eliminate the hazard and keep people safe in the workplace.

If you have questions about the Hierarchy of Controls and safe compressed air usage from any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
Send me an email
Find us on the Web 
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Twitter: @EXAIR_BB