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

 

Promo’s: Everybody Loves Free Stuff

I have been wanting to purchase a pair of good quality headphones for a while now and with vacation coming next week, I figured now was a good time to make my purchase. I was pretty set on the manufacturer but the tough choice for me was going to be if I wanted a set of earbuds (that fit directly in the ear) or a more traditional pair of “over the ear” headphones. smiley_face_headphones_tshirt-d23545082320430684226v7p_325I tried about 4 different pairs of over the ear units to see what the quality of sound was versus the feel/comfort and was pleasantly surprised but was still leaning towards earbuds. Unfortunately, due to health/cleanliness issues, you aren’t allowed to try on earbuds – which makes sense. So if I was going to go the earbud route I wanted to make sure I had all my questions answered so I decided to get a salesperson to assist me.

We went over features/benefits but this only made me question myself more. Seeing that I was struggling with a decision, the salesperson decided to make my choice a little easier – he mentioned that his store, along with the manufacturer, were offering a free promo but only if I purchased a set of earbuds (at a certain price of course). Due to the sound quality and trusted manufacturer, I was leaning towards a set of earbuds anyway, but hey – who doesn’t love FREE stuff? What they were offering was a free carrying case (not really free since it was already in the box), a free 2 year service agreement ($37 value) and a $25 gift card to their store.

Of course, I took advantage of their offer and made the purchase. After listening to the earbuds while I finished my packing, I couldn’t be happier with my selection.

At EXAIR, we occasionally run promotional offers too. From now through September 30th, 2014, if you purchase one of our Precision Safety Air Guns, Soft Grip Safety Air Guns or our Heavy Duty Safety Air Guns (with or without an Aluminum extension), you will receive a FREE Chip Shield.

Free Chip Shield Promo
The polycarbonate Chip Shield, meeting OSHA 1910-242(b) for compressed air use, offers the operator safe and smart protection from flying debris as well as any splashing. Not to mention that all of our Safety Air Guns incorporate one of our Engineered Super Air Nozzles that meet or exceed the same OSHA standard and reduce air consumption and sound level.

This offer is good for all three models of our Safety Air Guns:

  • Durable, Lightweight, Precision Airflow – The Precision Safety Air Gun is a small ergonomic gun good for light duty cleaning or blowoff and fits well in smaller hands. It also has a strong focused blast of air capable of reaching into tight spaces.
  • Versatile, Industrial Duty, Most Popular – The Soft Grip Safety Air Gun is our most popular gun cast from aluminum with a comfortable four finger trigger to reduce fatigue over long periods. A large variety of air nozzle options provides a solution for light to heavy duty blowoff applications.
  • Powerful, Rugged, Robust – The Heavy Duty Safety Air Gun is the powerhouse you need for the harshest environments and stubborn blowoff applications. It is outfitted with many of our most powerful nozzles to provide the highest force upon your application.

To learn more about this offer, please visit our website www.EXAIR.com or if you have a specific application you would like to discuss, give us a call at 1-800-903-9247.

Justin Nicholl
Application Engineer
JustinNicholl@EXAIR.com
@EXAIR_JN