Accurate Millworks Noise Monitoring Report

Transcription

1 Accurate Millworks Noise Monitoring Report Alan R. Raudenbush Problem Report submitted to the College of Engineering and Mineral Resources at West Virginia University in partial fulfillment of the requirements for the degree of: Master of Science in Industrial Hygiene Dr. Warren Myers, Chair Mr. Roger Wright Dr. Kevin Rider Industrial Hygiene Department Morgantown, West Virginia 2009 Keywords: Hearing Conservation, Industrial Hygiene, Alan Raudenbush, Accurate Millworks, Noise

2 Abstract Accurate Millworks Noise Monitoring Report Alan R. Raudenbush Accurate Millworks was interested in setting up a hearing conservation program. Noise monitoring in the form of dosimetry and area sampling was done in order to evaluate the potential noise problem. Employee dosimetry results showed that some areas of the mill have sound levels high enough to require enrollment into the hearing conservation program while other areas do not. It was determined that most machines require hearing protection to be used. There are a few specific tasks that will also require hearing protection.

3 iii Table of Contents Glossary of Terms.. 1 Executive Summary... 2 Purpose... 2 Background Apparatus... 3 Methods.. 4 Results and Discussion... 8 Conclusion.. 13 Recommendations Works Cited 15 Appendix A: Floor Map Appendix B: Factory Calibration Records Appendix C: Machine Sound Quantitative Sound Levels Appendix D: 29 CFR Occupational Noise Exposure Appendix E: Hearing Conservation Written Program Appendix F: Training Slides

4 1 Glossary of Important Terms (NIOSH, 2008): Action Level: [OSHA has defined certain action levels that when met or exceeded necessitate administrative and/or engineering controls intervention to reduce the risk of noise-induced hearing loss. OSHA currently uses an 8-hour time weighted average of 85 dba action level to implement an effective Hearing Loss Prevention Program]. Baseline (audiogram): The first valid and reliable audiometric test on record to which annual or periodic audiograms are compared. db (Decibel): A unit of measurement used to quantify sound pressure level. Dose (Noise Dose): A noise exposure expressed as a percentage of the allowable daily exposure. [The OSHA noise standard states that a 100% noise dose equals an 8-hour exposure to a continuous 90 dba noise. A 50% dose is an 8-hour exposure to an 85 dba noise or a 4-hour exposure to a 90 dba noise.2] Noise dosimeter: An instrument used to measure a test subject s (employee) noise exposure level. Engineering Controls: Engineering controls are physical actions implemented by facility management to reduce worker noise exposure levels. [E.g. installing noise barriers, dampeners, etc] Noise Reduction Rating (NRR): A manufacturer generated number used to quantify, in (db) a hearing protector s attenuation characteristics, generated in optimum clinically based environments, which are not indicative of real world performances/uses. Permissible Exposure Limit (PEL): OSHA mandates a Permissible Exposure Limit (PEL). Noise exposure level durations are limited by mandate. OSHA mandates a PEL of 90 db for an 8 hour period. Sound Level Meter: An instrument used to measure the acoustical characteristics present in any noise source. TWA (Time Weighted Average): A numerical value expressed in db (A) generated by dosimetry representing actual or estimated noise level exposure over an 8-hour period.

5 2 Executive Summary: Accurate Millworks was interested in setting up a hearing conservation program. The mill currently uses some hearing protection but does not have a defined plan of action. Noise monitoring in the form of dosimetry and area sampling was done in order to evaluate the potential noise problem. Employee dosimetry results showed that some areas of the mill have sound levels high enough to require enrollment into the hearing conservation program while other areas do not. These findings are based on the job activities of workers on the specific day exposure assessment measurements were made. During the assessment survey four out of the six workers sampled were found to be close to or above the OSHA 85 dba action level. Each machine was characterized to determine its contribution to the noise levels. It was determined that most machines require hearing protection to be used. There are a few specific tasks that will also require hearing protection. It is important to note that changes in production levels or the manufacturing process may affect a workers exposure. Therefore the survey performed is only a representation of the noise during that production period. Purpose: Accurate Millworks is a small business housing numerous machines and woodworking processes in two buildings. These machines and woodworking processes produce large amounts of noise. The goal of this project was to create a hearing conservation program that meets all the requirements of OSHA s (a) Occupational Noise Exposure standard. This was accomplished through organizing the audiometric testing, extensive worker and workplace monitoring, creation of easy to use training slides and suggesting a sufficient variety of hearing protective devices. Background: Accurate Millworks became owned by a California based mill working business three years ago. Accurate Millworks staff consists of 22 employees including office workers, management and production staff. The size of the company suggests that prevalence of aspects of a good hearing conservation program such as audiometric testing and monitoring will be lacking (Stephenson, 2001). Accurate Millworks has chosen to take a proactive approach to worker hearing loss. The facilities are located in Princeton, WV and consist of two separate buildings. The rough mill is the larger of the two and contains the administrative offices as well as a majority of the equipment. The second building is smaller but houses operations not found in the other building such as priming and knife cutting. The equipment and equipment locations for the rough mill are mapped out on a diagram in Appendix A. The company specializes in creating the components used to create exterior shutters and hardwood moldings with the production capacity to produce over 1 million lineal feet of molding a month. In addition to creating these components, they have a priming operation to prepare the components for painting.

6 3 The woodworking industry is a high risk industry when it comes to noise induced hearing loss and Accurate Millworks is no exception. It is estimated that over 70,000 workers in the carpentry industry are exposed to noise levels high enough to require enrollment in a hearing conservation program (Suter, 2002). Woodworking noise can be especially deceiving and dangerous due to its intermittent nature and the usually close proximity to which work is conducted in relation to the noise source (Vonasek, 2006). However, exposures from workshop to workshop can vary greatly. Noise levels can be increased by anything from harder species of wood to dull cutting tools (HSE, 2007). Accurate Millworks faces higher sound levels due to it utilizing two hardwoods to create their products, poplar and basswood. This complicated intermingling of noises is compounded by large ventilation systems and wood chipping machines that create a constant background noise (Cmar, 2006). Creating a hearing conservation program will help evaluate the noise levels and lead to better controls and safety for the workers. Noise levels are measured in Decibels (db) and when used as criteria for setting up a hearing conservation program they are Aweighted. A-weighting means that the noise levels are weighted at specific frequencies to better simulate the sensitivity of human ears at reasonable sound levels. At 90dBA the Permissible Exposure Limit (PEL) has been reached. OSHA has determined that a 90dBA sound level average or above over 8 hours can be dangerous and damaging to the human ear. 90dBA means that you have received 100% of your allowable dose. OSHA has set an exchange rate of 5dBA. For every 5dBA more you are exposed to, your allowable exposure time is halved and your dose doubled. When the dba average over 8 hours equals or exceeds the 85dBA action limit set by OSHA, employees need to be enrolled in a hearing conservation program. At 85dBA you are 5dBA lower than the PEL and have reached 50% of your allowable dose. The action level simply informs you that noise levels are getting close to unacceptable levels. Apparatus: In order to accumulate sufficient data a combination of equipment including noise dosimeters and a sound level meter were used. The noise dosimeters were used to determine dba time weighted average exposure measurements. The sound level meter was used to produced contour maps and make supplemental spot db readings. The following is a list of the equipment used. The factory calibration records are in Appendix B Three Quest NoisePro noise dosimeters were used each day with serial numbers: o NLE o NLE o NLF Quest Sound Level Meter with serial number: o CC Quest QC-10/QC-20 Acoustic Calibrator with serial number: o QF

7 4 Methods: Accurate Millworks need for a hearing conservation program was determined by a safety inspector who had previously done a general safety inspection on site. After contact was made with the president of the Millworks a trip was planned to the site and an initial walkthrough was done. A rough sketch of the plant layout was made and machine placement was noted with special attention paid to which machines generated the most sound. Using a sound level meter, spot readings were taken at some of the machines while they were operating. When adequate sound level data had been obtained a literature review on average sound levels of woodworking machinery was done. The research was done to determine sound levels of similar woodworking machines so that a sampling plan could be developed that would ensure that the noisiest machines were sampled. Literature suggested that Ripsaws, Molders, Jointers, Resaw, Chop saws and Gang Saws are among the high noise generators (Stewart, 2005; Lankford, 1993). Using this information and the measurements taken on site, a general idea was developed for what machines and areas were the loudest and a sampling plan was developed. Three major aspects of the sampling strategy are: Personal Dosimetry Area sampling to develop contour maps Specific task analysis Sampling began on March 26 th at 6:45AM. All the equipment was pre-calibrated except for one noise dosimeter (S/N: NLF060078) that initially had an error with the battery cover. All of the pre and post calibrations were performed with the Quest QC-10/20 Calibrator with 114dB at 1000Hz. The calibration results are recorded in the following table. March 26th March 27th Equipment Serial Number Before After Before After Noise dosimeter NLE Noise dosimeter NLF Noise dosimeter NLE Sound Level Meter CC Once the calibration was complete the noise dosimeters were attached to each person. Each worker was informed about the noise dosimeters function and was instructed to return to a designated location to have the noise dosimeter removed and paused during breaks and lunch. Sound level measurements were taken periodically with a sound level meter positioned to sample in the workers hearing zone. The noise dosimeters were clipped on the workers belt or pocket and the microphone was attached to the shoulder near the collarbone on the workers identified in the following table.

8 5 Table 1 Worker Worker #1 Worker #2 Worker #3 Worker #4 Worker #5 Worker #6 General Duties Working at the gang saw and using the forklift in the lumber area Working in the finishing department sanding and material handling Running the press, jointer and material handling Working at the top of the wonder saw feeding boards in Working on the low speed molder and material handling Using the high speed molder and material handling Another phase of the sampling process was to identify machines that were being operated and document their sound levels at the workers hearing zone as well as at 2 and 6 away from the worker. These readings were repeated three times over the course of both days. These measurements were taken to get a general idea of how much noise each machine was producing. In addition to characterizing each piece of equipment a general feel for the sound level of the entire floor needed to be obtained. The rough mill was divided into 25 squares and marked in the center of each square on the ground in chalk so that the measurements could be repeated accurately. That equated to 41 readings in the rough mill. The finishing department was smaller so it was divided into 20 squares and this equated to 22 readings in the finishing department. These readings were repeated once each morning and once each afternoon over the two days spent at the mill. Some tasks were so intermittent or brief that general sound level measuring techniques wouldn t be sufficient. The tasks that were individually measured were the use of the steel cutting chop saw and the pallet making. A sound level meter with a fast response time was used to measure the sound produced by the nail gun and circular saw when making pallets. Information was obtained about the length of each task and the amount of nailing required. Similar data was obtained for the steel cutting chop saw. Sampling ended each day around 4:30 PM and then post-calibration of the equipment was done. Equipment Profiles Below are some general comments regarding the noise levels and operations of some of the machines contained in the rough mill and finishing shop. Machines that were not operating or not operational at the time of the survey are not included. A quantitative list of measurements taken at each machine can be found in Appendix C. The noise levels were sufficient enough that hearing protection should be worn when operating the machines below: Whirlwind Saw There are two of these machines located in the rough mill and they were being used frequently. It is used to cut larger boards into smaller pieces and produces a loud sound for a short period at the moment of cutting. C23 High Speed Molder and Feeder

9 6 This machine has two operating stations and continuously feeds and molds boards. One operator helps feed the boards in and the other receives the boards and stacks them. This machine is equipped with a cover that exposes the inside of the machine when opened. When the cover is open the sound is much louder than when it is closed. This is one of the louder machines in the mill and it is located near the center of the building. Finger Jointer This machine takes boards that have been cut into small segments and cuts joints into them. The machine produces high pitched cutting noises when operating. However, even when this machine is not being used it is creating a loud hissing noise near the base. This could be caused by recently installed parts. Unimat Molder This molder is smaller than the other molder in the mill. It was not in full operation for most of the time the survey was being performed. Often the machine was being repaired and had its sound reducing cover lifted open. This caused an increase in sound and higher than usual exposures for the worker. MJ Gang Rip The workstation at the gang rip is probably the loudest in the mill. Being surrounded by the gang rip and planer the worker is exposed to significant noise levels when these machines are being operated. During the survey the machine was only used intermittently throughout the day. Green Sorting Chain This is a large conveying system that transports cut wood and allows workers to sort it. The close proximity to the gang saw puts workers in this area at risk for high noise exposure. Small chunks and pieces of wood are put on an adjacent conveyor and sent to the chipper. Wonder Saw and Conveyor Belts The wonder saw is a large piece of machinery that has two work areas. The upper area where the wood is fed in is moderately loud. The sound of the rollers, saw, and ventilation system combine to increase the sound. The lower section receives the cut pieces of wood to be stacked and sorted and there are no major sound sources. Western Pneumatics Finger Jointer The finger jointer is a large machine that was run infrequently during the sampling period. When the machine was running it produced high noise. At the time the machine was running there were three workers around the machine. B26 Planer This planer is used in conjunction with the gang saw. The wood is fed through and planed in preparation to being run through the gang saw. The conveyor belt leading

10 7 up to the planer is very long and the noise exposure of the worker who puts the wood on the conveyor is mainly due to the close proximity of the gang saw. SCNI Ripsaw There was one worker using this machine but it looks like it could be a two man operation. The worker fed boards in through the front then went around to collect them in the back. When feeding boards there was a lot of sound produced. A lot of sound was being produced at the back of the machine while collecting boards, even when no boards were going through. Press There is a press against the wall and adjacent to a small finger jointer. The press produced relatively low noise levels but the operators close proximity to the noisy finger jointer resulted in a higher noise area. Steel Cutting Chop Saw (Finishing Shop) This chop saw is used infrequently. When it is in use the operator indicated that it would only take about 15 minutes at maximum to do all the cutting that is necessary. This machine is very loud when in the process of cutting a piece of steel, pushing over 100dB in the work zone. The saw is located in the room adjacent to the finishing shop inside of a ventilation hood. Circular Saw There are several circular saws throughout the shops. The saw in the pallet making area was measured. It produced very high noise levels in the work zone and adjacent areas. It appears that there is no one who is continually using a circular saw for their shift. It takes roughly minutes to cut up enough boards for pallets. Nail Gun The nail gun that is used to nail the pallets together creates a very loud impulse noise. It is an air powered nail gun and easily produces noise above 105dB in the work zone. It takes about 100 nails to make a pallet and it might be necessary to make up to 10 pallets at a time. The following machines requirement for hearing protection depends on what operations are being performed concurrently. Hearing protection may not be necessary when these machines are being operated alone, but as the ambient noise increases, hearing protection is advised. Primer Machine This machine puts a coating of primer on wooden slats. There is a worker at the front feeding the wood in and a worker in the back retrieving the wood. The machine is relatively quiet and most of the noise comes from a large ventilation hood and the radio. If the radio is being played at a very loud volume hearing protection may need to be used at this station.

11 8 Critz Sander Two workers operate this machine by passing boards through one end and receiving them at the other. This machine alone does not produce much sound but is in close proximity to the high speed molder which, when operating, increases the sound levels for the sander operators. Large Knife Grinders (Finishing Shop) The large knife grinders in a room off of the finishing shop produced minimal amounts of noise even during the process of grinding a knife. The room containing the equipment is very quiet when nothing is running. If grinding different types of knives produces different sound levels, hearing protection may still be recommended. Time Saver Sander This large sander takes two operators to feed and retrieve boards from either end of it. This machine is relatively quiet. Its location could subject workers at this machine to noise from the molders, ripsaw and gang saw. Finger Joint Knife Grinder (Rough Mill) This machine was used infrequently during the sampling period. It was in use for a short period and the sound it produced was minimal, especially considering the short amount of time it was used. Baker Resaw This saw was used only for a short time during the sampling period. Measurements were taken at the front of the saw and they were relatively low. Depending on what other machines were being operated in the shop, the worker at this machine could be exposed to high noise levels. Results and Discussion: The noise dosimeters each had two channels to record sound data. Each channel had a specific set of rules determining how the time weighted average and dose would be calculated. All noise dosimeters report A-weighted results and were all set to record with a slow response time per OSHA requirements. The noise dosimeters were set up to correspond with OSHA requirements. The settings are shown in the following table. OSHA HCP settings are those used to determine whether workers need to be enrolled in the hearing conservation program. A threshold of 80 is used for calculating exposure for enrollment in the HCP because it will integrate all noise levels 80dBA and higher. This is important because the HCP needs to be implemented when the TWA is above 85dBA in order to prevent overexposing workers. Engineering Controls settings are used to determine if engineering controls need to be put into place in order to reduce the sound to acceptable levels. This will help in reducing noises that are consistently above the exposure limit of 90dBA. The engineering controls setting only monitors for noise that is 90dBA or above which is why the overall average appears lower than the HCP settings.

12 9 OSHA HCP Engineering Controls Criterion Threshold Exchange Rate 5 5 Upper Limit The noise dosimeter with s/n NLF had a hardware malfunction the first day and turned off after only two hours of sampling. This worker had a similar job throughout the day and the remaining exposure was assumed to be the same as the two hours that were sampled. Not all workers were sampled the full 9.5 hours of their work shift. Workers who were not sampled the entire 9.5 hours had the remainder of un-sampled shift calculated to be the average of the time that was sampled. All workers except for Worker #2 were sampled for at least 7 hours to generate an accurate representation of their sound levels. The results from the noise dosimeters are in the table below. The TWA equivalent is the workers exposure calculated as what an equivalent 8 hour exposure would be. This was calculated with the following equation Log10 (Dose/100) + 90 Name OSHA HCP TWA Dose (%) Equivalent Engineering Controls TWA Dose (%) Equivalent Worker # Worker # Worker # Worker # Worker # Worker # The OSHA action level for noise is 85dBA. Four of the six noise dosimeters measurement results, rounded to the nearest dba, is at or above the action level. The results from the engineering controls channel show that none of the workers working in these high noise environments are at a level where engineering controls need to be put into place in order to reduce sound levels according to OSHA. The closest one is Worker #6 who works at the C23 Molder and that piece of machinery already has engineering controls in the form of an enclosure. Worker #3 was working at the Press for the duration of his shift and was exposed to a moderate amount of noise due to the nearby machines. The jointer that is adjacent to the Press generates most of the noise that he was exposed to because it is continuously loud. Worker #3 also wore earphones during his shift and while the volume level was not determined several studies report that listening to earphones in an already loud environment can lead to even higher exposures (Anku 1987). The workload for the two days of sampling was average according to employees. However, different production schedules result in different machines being run for longer or shorter periods of time. The TWA for different workers will fluctuate depending on which machine they are running and for how long.

13 10 The noise levels that were above the action limit were only moderately above them. The hearing protection currently offered was 33 NRR and should be adequate at acceptably reducing levels. Earplugs can go up to a maximum NRR of 33 and earmuffs can go up to 30. To calculate the actual reduction in dba from the NRR you use the following equation that is strongly suggested by OSHA. Estimated Exposure (dba) = TWA (dba) - [(NRR - 7) x 50%] The data collected for the noise contours represents 4 measurements taken over the course of both days. These measurements provide a general idea of how noise levels are spatially located within the mill. The high noise areas seen in the noise contour for the rough mill are a result of the C23 Molder, Wonder Saw, Ripsaw, and the compressor/hogger area. The high noise area in the finishing shop is due to the radio. The radio is consistently played at a high volume in order to exceed and drown out equipment noise and this serves to increase the workers exposure. It would be best if the radio sound levels were identified and played at a level below 85dBA at all times. When this level is identified the volume control should be marked so it is known what level not to exceed. There is a high noise environment in the pallet making area when pallets are being made as well. The areas in tan represent areas that were not sampled such as the offices and areas that were not accessible.

14 Measurements were taken in 20 squares; noise was fairly constant throughout the room. 11

15 12 Noise in this mill fluctuated greatly depending on which high-noise machines were running. When making pallets or using the steel cutting chop saw noise levels were exceptionally high. Both of these activities are not done consistently throughout the day or even for longer than an hour at a time. However, both activities create high levels of noise and hearing protection needs to be worn while doing either. It appears that most employees have a respect for the danger that noise poses and understand the need for hearing protection. However, when implementing strict hearing protection guidelines some employees may show resistance. It is important to emphasize the life changing implications of hearing loss that will affect every facet of their life from

16 13 their work to their hobbies and family. Employees may not want to wear hearing protection because it is uncomfortable to wear and this is why there is a need to provide more than one type of hearing protection. There are many different types of earplugs that fit in different ways, allow the employees to pick the protection that works best for them. When adequate hearing protection has been determined it is also important to inform he employee that hearing protection and hearing loss are not limited just to work. At home activities such as hunting, woodworking, riding motorcycles and many more can contribute to hearing loss and protection should be worn whenever possible. Conclusion: Workers at Accurate Millworks are exposed to noise levels at or above the OSHA action limit of 85 dba. These exposures should be a concern for plant management. It is clear that there are specific machines in the mill that produce more sound than others. Many machines in the rough mill will require their operators to wear hearing protection. The machines in the Finishing Shop do not expose workers to enough noise to necessitate the need to include them in hearing conservation program. However, depending on how loud the radio is played and the proximity to the radio, a worker has the potential to be exposed to noise levels that exceed OSHA standards. Also, in the room off of the finishing shop where the knife grinding operations is done there is a concern when running the steel cutting chop saw. The rough mill contains many machines that, if continually operated, have the potential to overexpose the worker. Many employees were wearing earplugs with a NRR rating of 33 and there were also a number who were not. A hearing conservation program needs to be implemented in many sections of the mill. Areas immediately adjacent to the loud machines listed above need to be considered a hearing conservation area. Considering the variations in which machines are being run and proximity to these machines as a best practice hearing protection should be worn throughout the rough mill and all employees enrolled in the program. Recommendations: Implementation and enrollment of employees working in the rough mill in a Hearing Conservation Program that includes: o Periodic monitoring and employee notification of results. o Annual audiometric testing for all employees in the program. o Issuance of hearing protection and training on its use. o Proper record keeping including the employees name, job classification, date of audiogram, examiner s name, date of last calibration of audiometer and the measurements of the background sound pressure levels in the audiometric testing room. These records will be maintained for the duration of the affected employee s employment and at least two years thereafter. o Monitoring needs to be done if new machinery is introduced or if there is a change in operation Eliminate loud noise below the jointer Recommend earphones not be used and enforce hearing protection instead

17 Keep the radio in the finishing shop at an acceptably low level Wear hearing protection when operating the steel cutting chop saw or when making pallets Wear hearing protection when utilizing the following machines: Press, Baker Resaw, Unimat Molder, Wonder Saw, SCNI Ripsaw, Green Sorting Chain, B26 Planer, Whirlwind Saw, Finger Jointer, Western Pneumatics Finger Jointer and MJ Gang Rip Keep the doors closed on the molders at all times while operating 14

18 15 Works Cited Anku, Linda. Use of Walkman Radio, Tape, or CD Players and Their Effect When Hearing Protection Is In Use Standard Interpretations May 2008 < ETATIONS&p_id=19542>. Caravanos, Jack DrPH, CIH, Quantitative Industrial Hygiene: A Formula Workbook. Hunter College of CUNY Cmar,David. Noise Control in the Woodworking Industry. Phase To, Inc. PhaseTo.com. 1 Oct < y.htm> Common Hearing Loss Prevention Terms National Institute for Occupational Safety and Health. April < HSE Noise at Woodworking Machines. Health and Safety Executive. September 2007 Lankford, James and Denise West. A Study of Noise Exposure and Hearing Sensitivity in a High School Woodworking Class. Language, Speech, and Hearing Services in Schools. Vol Stephenson, Mark and Carol Stephenson. Noise Induced Hearing Loss in the Construction Industry. National Institute for Occupational Safety and Health. March 15, Stewart, Michael et. al., Noise Exposure Levels for Workers in the Michigan Wood Industry. Central Michigan University, M-TEC at Bay College Suter, Alice. Construction Noise: Exposure, Effects, and the Potential for Remediation; a Review and Analysis. AIHA Journal Vol. 63 (2002) Vonasek, Wade "Woodworkers ask: can you hear this now? Audiologist Brad Witt of the Bacou-Dalloz Hearing Safety Group focuses on the prevention of noise-induced hearing loss and educating workers about it before it occurs". Wood & Wood Products.. FindArticles.com. 2 Oct <

19 Appendix A 16

20 Appendix B 17

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25 22 Appendix C Distance Machine Zone 2 6 Comments Time Saver Sander Back (n=1) Primer Measurement taken at the back of the machine Most of the noise is coming from the nearby radio and ventilation hood Time Saver Sander Front (n=1) Measurement taken at the front of the machine Knife Grinder Measurement taken when a knife was being (n=1) grinded Press Press is relatively quiet, most noise comes from adjacent Jointer Baker Resaw Unimat Molder Measurement taken at the front, the cover was Front (n=1) open Wonder Saw and Conveyor Belts Measurement taken at the top where wood enters SCNI Ripsaw Back Measurement taken at the back of the machine while no wood was being fed through Green Sorting Chain Measurement taken in front of conveyor belts B26 Planer Measurement taken where wood is put on the conveyor belt to be sent down to the planer Whirlwind Saw Impulsive noise, measurement taken when board was being cut, this machine is by the wonder saw C23 High Speed Measurement taken where boards come out of Molder Back the machine Whirlwind Saw Impulsive noise, measurement taken when board was being cut, this is the saw against the wall Finger Jointer Measurements taken in front of the machine and influenced by the loud noise from below Western Measurements taken at the beginning of the Pneumatics Finger jointer next to the input screen Jointer (n=1) Unimat Molder Measurement was taken at the back, the cover Back (n=1) was open C23 High Speed Measurements taken where boards are fed into Molder Front the machine SCNI Ripsaw Front MJ Gang Rip Measurement taken at the front of the machine when wood was being processed Measurement taken at the gang rip station in between the planer and the gang rip

26 23 Steel Cutting Chop Measurement taken while a sample piece was Saw (n=1) being cut Air Powered Nail Measurements taken at time of impact Gun Unless otherwise stated, n=3 for all measurements taken

27 24 Appendix D Part Number: 1910 Part Title: Occupational Safety and Health Standards Subpart: G Subpart Title: Occupational Health and Environment Control Standard Number: Title: Occupational noise exposure. Appendix: A, B, C, D, E, F, G, H, I (a) Protection against the effects of noise exposure shall be provided when the sound levels exceed those shown in Table G-16 when measured on the A scale of a standard sound level meter at slow response. When noise levels are determined by octave band analysis, the equivalent A-weighted sound level may be determined as follows: Equivalent sound level contours. Octave band sound pressure levels may be converted to the equivalent A-weighted sound level by plotting them on this graph and noting the A-weighted sound level corresponding to the point of highest penetration into the sound level contours.

28 25 This equivalent A-weighted sound level, which may differ from the actual A-weighted sound level of the noise, is used to determine exposure limits from Table 1.G (b)(1) When employees are subjected to sound exceeding those listed in Table G-16, feasible administrative or engineering controls shall be utilized. If such controls fail to reduce sound levels within the levels of Table G-16, personal protective equipment shall be provided and used to reduce sound levels within the levels of the table (b)(2) If the variations in noise level involve maxima at intervals of 1 second or less, it is to be considered continuous. TABLE G-16 - PERMISSIBLE NOISE EXPOSURES (1) Duration per day, hours Sound level dba slow response / / /4 or less Footnote(1) When the daily noise exposure is composed of two or more periods of noise exposure of different levels, their combined effect should be considered, rather than the individual effect of each. If the sum of the following fractions: C(1)/T(1) + C(2)/T(2) C(n)/T(n) exceeds unity, then, the mixed exposure should be considered to exceed the limit value. Cn indicates the total time of exposure at a specified noise level, and Tn indicates the total time of exposure permitted at that level. Exposure to impulsive or impact noise should not exceed 140 db peak sound pressure level (c) "Hearing conservation program." (c)(1) The employer shall administer a continuing, effective hearing conservation program, as described in paragraphs (c) through (o) of this section, whenever employee noise exposures equal or exceed an 8-hour time-weighted average sound level (TWA) of 85 decibels measured on the A scale (slow response) or, equivalently, a dose of fifty percent. For purposes of the hearing conservation program, employee noise exposures shall be computed in accordance with appendix A and Table G-16a, and without regard to any attenuation provided by the use of personal protective equipment (c)(2) For purposes of paragraphs (c) through (n) of this section, an 8-hour time-weighted average of 85 decibels or a dose of fifty percent shall also be referred to as the action level (d) "Monitoring." (d)(1) When information indicates that any employee's exposure may equal or exceed an 8-hour time-weighted average of 85 decibels, the employer shall develop and implement a monitoring program (d)(1)(i) The sampling strategy shall be designed to identify employees for inclusion in the hearing conservation program and to enable the proper selection of hearing protectors (d)(1)(ii) Where circumstances such as high worker mobility, significant variations in sound level, or a significant component of impulse noise make area monitoring generally inappropriate, the

29 employer shall use representative personal sampling to comply with the monitoring requirements of this paragraph unless the employer can show that area sampling produces equivalent results (d)(2)(i) All continuous, intermittent and impulsive sound levels from 80 decibels to 130 decibels shall be integrated into the noise measurements (d)(2)(ii) Instruments used to measure employee noise exposure shall be calibrated to ensure measurement accuracy (d)(3) Monitoring shall be repeated whenever a change in production, process, equipment or controls increases noise exposures to the extent that: (d)(3)(i) Additional employees may be exposed at or above the action level; or (d)(3)(ii) The attenuation provided by hearing protectors being used by employees may be rendered inadequate to meet the requirements of paragraph (j) of this section (e) "Employee notification." The employer shall notify each employee exposed at or above an 8- hour time-weighted average of 85 decibels of the results of the monitoring (f) "Observation of monitoring." The employer shall provide affected employees or their representatives with an opportunity to observe any noise measurements conducted pursuant to this section (g) "Audiometric testing program." (g)(1) The employer shall establish and maintain an audiometric testing program as provided in this paragraph by making audiometric testing available to all employees whose exposures equal or exceed an 8-hour time-weighted average of 85 decibels (g)(2) The program shall be provided at no cost to employees (g)(3) Audiometric tests shall be performed by a licensed or certified audiologist, otolaryngologist, or other physician, or by a technician who is certified by the Council of Accreditation in Occupational Hearing Conservation, or who has satisfactorily demonstrated competence in administering audiometric examinations, obtaining valid audiograms, and properly using, maintaining and checking calibration and proper functioning of the audiometers being used. A technician who operates microprocessor audiometers does not need to be certified. A technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician (g)(4) All audiograms obtained pursuant to this section shall meet the requirements of Appendix C: "Audiometric Measuring Instruments." (g)(5) "Baseline audiogram." (g)(5)(i) Within 6 months of an employee's first exposure at or above the action level, the employer shall establish a valid baseline audiogram against which subsequent audiograms can be compared (g)(5)(ii) "Mobile test van exception." Where mobile test vans are used to meet the audiometric testing obligation, the employer shall obtain a valid baseline audiogram within 1 year of an employee's first exposure at or above the action level. Where baseline audiograms are obtained more than 6 months after the employee's first exposure at or above the action level, employees shall wear hearing protectors for any period exceeding six months after first exposure until the baseline audiogram is obtained (g)(5)(iii) Testing to establish a baseline audiogram shall be preceded by at least 14 hours without exposure to workplace noise. Hearing protectors may be used as a substitute for the 26

30 requirement that baseline audiograms be preceded by 14 hours without exposure to workplace noise (g)(5)(iv) The employer shall notify employees of the need to avoid high levels of non-occupational noise exposure during the 14-hour period immediately preceding the audiometric examination (g)(6) "Annual audiogram." At least annually after obtaining the baseline audiogram, the employer shall obtain a new audiogram for each employee exposed at or above an 8-hour timeweighted average of 85 decibels (g)(7) "Evaluation of audiogram." (g)(7)(i) Each employee's annual audiogram shall be compared to that employee's baseline audiogram to determine if the audiogram is valid and if a standard threshold shift as defined in paragraph (g)(10) of this section has occurred. This comparison may be done by a technician (g)(7)(ii) If the annual audiogram shows that an employee has suffered a standard threshold shift, the employer may obtain a retest within 30 days and consider the results of the retest as the annual audiogram (g)(7)(iii) The audiologist, otolaryngologist, or physician shall review problem audiograms and shall determine whether there is a need for further evaluation. The employer shall provide to the person performing this evaluation the following information: (g)(7)(iii)(A) A copy of the requirements for hearing conservation as set forth in paragraphs (c) through (n) of this section; (g)(7)(iii)(B) The baseline audiogram and most recent audiogram of the employee to be evaluated; (g)(7)(iii)(C) Measurements of background sound pressure levels in the audiometric test room as required in Appendix D: Audiometric Test Rooms (g)(7)(iii)(D) Records of audiometer calibrations required by paragraph (h)(5) of this section (g)(8) "Follow-up procedures." (g)(8)(i) If a comparison of the annual audiogram to the baseline audiogram indicates a standard threshold shift as defined in paragraph (g)(10) of this section has occurred, the employee shall be informed of this fact in writing, within 21 days of the determination (g)(8)(ii) Unless a physician determines that the standard threshold shift is not work related or aggravated by occupational noise exposure, the employer shall ensure that the following steps are taken when a standard threshold shift occurs: (g)(8)(ii)(A) Employees not using hearing protectors shall be fitted with hearing protectors, trained in their use and care, and required to use them (g)(8)(ii)(B) Employees already using hearing protectors shall be refitted and retrained in the use of hearing protectors and provided with hearing protectors offering greater attenuation if necessary (g)(8)(ii)(C) The employee shall be referred for a clinical audiological evaluation or an otological examination, as appropriate, if additional testing is necessary or if the employer suspects that a medical pathology of the ear is caused or aggravated by the wearing of hearing protectors (g)(8)(ii)(D) The employee is informed of the need for an otological examination if a medical pathology of the ear that is unrelated to the use of hearing protectors is suspected. 27

31 (g)(8)(iii) If subsequent audiometric testing of an employee whose exposure to noise is less than an 8- hour TWA of 90 decibels indicates that a standard threshold shift is not persistent, the employer: (g)(8)(iii)(A) Shall inform the employee of the new audiometric interpretation; and (g)(8)(iii)(B) May discontinue the required use of hearing protectors for that employee (g)(9) "Revised baseline." An annual audiogram may be substituted for the baseline audiogram when, in the judgment of the audiologist, otolaryngologist or physician who is evaluating the audiogram: (g)(9)(i) The standard threshold shift revealed by the audiogram is persistent; or (g)(9)(ii) The hearing threshold shown in the annual audiogram indicates significant improvement over the baseline audiogram (g)(10) "Standard threshold shift." (g)(10)(i) As used in this section, a standard threshold shift is a change in hearing threshold relative to the baseline audiogram of an average of 10 db or more at 2000, 3000, and 4000 Hz in either ear (g)(10)(ii) In determining whether a standard threshold shift has occurred, allowance may be made for the contribution of aging (presbycusis) to the change in hearing level by correcting the annual audiogram according to the procedure described in Appendix F: "Calculation and Application of Age Correction to Audiograms." (h) "Audiometric test requirements." (h)(1) Audiometric tests shall be pure tone, air conduction, hearing threshold examinations, with test frequencies including as a minimum 500, 1000, 2000, 3000, 4000, and 6000 Hz. Tests at each frequency shall be taken separately for each ear (h)(2) Audiometric tests shall be conducted with audiometers (including microprocessor audiometers) that meet the specifications of, and are maintained and used in accordance with, American National Standard Specification for Audiometers, S , which is incorporated by reference as specified in Sec (h)(3) Pulsed-tone and self-recording audiometers, if used, shall meet the requirements specified in Appendix C: "Audiometric Measuring Instruments." (h)(4) Audiometric examinations shall be administered in a room meeting the requirements listed in Appendix D: "Audiometric Test Rooms." (h)(5) "Audiometer calibration." (h)(5)(i) The functional operation of the audiometer shall be checked before each day's use by testing a person with known, stable hearing thresholds, and by listening to the audiometer's output to make sure that the output is free from distorted or unwanted sounds. Deviations of 10 decibels or greater require an acoustic calibration (h)(5)(ii) Audiometer calibration shall be checked acoustically at least annually in accordance with Appendix E: "Acoustic Calibration of Audiometers." Test frequencies below 500 Hz and above 6000 Hz may be omitted from this check. Deviations of 15 decibels or greater require an exhaustive calibration (h)(5)(iii) An exhaustive calibration shall be performed at least every two years in accordance with sections 4.1.2; ; ; 4.2; 4.4.1; 4.4.2; 4.4.3; and 4.5 of the American National 28

32 Standard Specification for Audiometers, S Test frequencies below 500 Hz and above 6000 Hz may be omitted from this calibration (i) "Hearing protectors." (i)(1) Employers shall make hearing protectors available to all employees exposed to an 8-hour time-weighted average of 85 decibels or greater at no cost to the employees. Hearing protectors shall be replaced as necessary (i)(2) Employers shall ensure that hearing protectors are worn: (i)(2)(i) By an employee who is required by paragraph (b)(1) of this section to wear personal protective equipment; and (i)(2)(ii) By any employee who is exposed to an 8-hour time-weighted average of 85 decibels or greater, and who: (i)(2)(ii)(A) Has not yet had a baseline audiogram established pursuant to paragraph (g)(5)(ii); or (i)(2)(ii)(B) Has experienced a standard threshold shift (i)(3) Employees shall be given the opportunity to select their hearing protectors from a variety of suitable hearing protectors provided by the employer (i)(4) The employer shall provide training in the use and care of all hearing protectors provided to employees (i)(5) The employer shall ensure proper initial fitting and supervise the correct use of all hearing protectors (j) "Hearing protector attenuation." (j)(1) The employer shall evaluate hearing protector attenuation for the specific noise environments in which the protector will be used. The employer shall use one of the evaluation methods described in Appendix B: "Methods for Estimating the Adequacy of Hearing Protection Attenuation." (j)(2) Hearing protectors must attenuate employee exposure at least to an 8-hour time-weighted average of 90 decibels as required by paragraph (b) of this section (j)(3) For employees who have experienced a standard threshold shift, hearing protectors must attenuate employee exposure to an 8-hour time-weighted average of 85 decibels or below (j)(4) The adequacy of hearing protector attenuation shall be re-evaluated whenever employee noise exposures increase to the extent that the hearing protectors provided may no longer provide adequate attenuation. The employer shall provide more effective hearing protectors where necessary (k) "Training program." (k)(1) The employer shall train each employee who is exposed to noise at or above an 8-hour time weighted average of 85 decibels in accordance with the requirements of this section. The employer shall institute a training program and ensure employee participation in the program (k)(2) The training program shall be repeated annually for each employee included in the hearing conservation program. Information provided in the training program shall be updated to be consistent with changes in protective equipment and work processes (k)(3) The employer shall ensure that each employee is informed of the following: (k)(3)(i) 29

33 The effects of noise on hearing; (k)(3)(ii) The purpose of hearing protectors, the advantages, disadvantages, and attenuation of various types, and instructions on selection, fitting, use, and care; and (k)(3)(iii) The purpose of audiometric testing, and an explanation of the test procedures (l) "Access to information and training materials." (l)(1) The employer shall make available to affected employees or their representatives copies of this standard and shall also post a copy in the workplace (l)(2) The employer shall provide to affected employees any informational materials pertaining to the standard that are supplied to the employer by the Assistant Secretary (l)(3) The employer shall provide, upon request, all materials related to the employer's training and education program pertaining to this standard to the Assistant Secretary and the Director (m) "Recordkeeping" (m)(1) "Exposure measurements." The employer shall maintain an accurate record of all employee exposure measurements required by paragraph (d) of this section (m)(2) "Audiometric tests." (m)(2)(i) The employer shall retain all employee audiometric test records obtained pursuant to paragraph (g) of this section: (m)(2)(ii) This record shall include: (m)(2)(ii)(A) Name and job classification of the employee; (m)(2)(ii)(B) Date of the audiogram; (m)(2)(ii)(C) The examiner's name; (m)(2)(ii)(D) Date of the last acoustic or exhaustive calibration of the audiometer; and (m)(2)(ii)(E) Employee's most recent noise exposure assessment (m)(2)(ii)(F) The employer shall maintain accurate records of the measurements of the background sound pressure levels in audiometric test rooms (m)(3) "Record retention." The employer shall retain records required in this paragraph (m) for at least the following periods (m)(3)(i) Noise exposure measurement records shall be retained for two years (m)(3)(ii) Audiometric test records shall be retained for the duration of the affected employee's employment (m)(4) "Access to records." All records required by this section shall be provided upon request to employees, former employees, representatives designated by the individual employee, and the Assistant Secretary. The provisions of 29 CFR (a)-(e) and (g) (m)(4)(i) apply to access to records under this section (m)(5) "Transfer of records." If the employer ceases to do business, the employer shall transfer to the successor employer all records required to be maintained by this section, and the successor employer shall retain them for the remainder of the period prescribed in paragraph (m)(3) of this section (n) 30

34 31 "Appendices." (n)(1) Appendices A, B, C, D, and E to this section are incorporated as part of this section and the contents of these appendices are mandatory (n)(2) Appendices F and G to this section are informational and are not intended to create any additional obligations not otherwise imposed or to detract from any existing obligations (o) "Exemptions." Paragraphs (c) through (n) of this section shall not apply to employers engaged in oil and gas well drilling and servicing operations. [39 FR 23502, June 27, 1974, as amended at 46 FR 4161, Jan. 16, 1981; 46 FR 62845, Dec. 29, 1981; 48 FR 9776, Mar. 8, 1983; 48 FR 29687, June 28, 1983; 54 FR 24333, June 7, 1989; 61 FR 5507, Feb. 13, 1996; 61 FR 9227, March 7, 1996; 71 FR 16672, April, 3, 2006; 73 FR 75584, Dec. 12, 2008] Refer to Occupational Noise Exposure standard on OSHA s website ( or use the direct link:

35 Appendix E 32

36 33 Accurate Millworks Hearing Conservation Program May 2009

37 34 I Purpose The purpose of this program is to identify the elements for effective Hearing Conservation in order to prevent permanent noise induced hearing loss related to on the job noise exposure. The program will ensure compliance with 29CFR set forth by the Occupational Safety and Health Administration (OSHA). II. Scope This program and parts thereof, is applicable to all employees, contractors and visitors at Accurate Millworks where there is a potential to exceed OSHA s Action Limit of 85dBA over an 8 hour period. These required areas include those adjacent to the Press, Baker Resaw, Unimat Molder, Wonder Saw, SCNI Ripsaw, Green Sorting Chain, B26 Planer, Whirlwind Saw, Finger Jointer, Western Pneumatics Finger Jointer and MJ Gang Rip. As a best practice, hearing protection should be used when entering the mill at any time. III. Definitions A. Audiogram a chart, graph, or table resulting from an audiometric test showing an individual s hearing threshold levels as a function of frequency. B. Baseline Audiogram the audiogram against which future audiograms are compared C. Decibel or db - a unit of measurement of sound pressure level. D. Dosimeter An instrument used to measure an employee s exposure to noise over the duration of their entire shift. E. Permissible Exposure Limit (PEL): OSHA mandates a Permissible Exposure Limit (PEL). Noise exposure level durations are limited by mandate. OSHA mandates a PEL of 90 db for an 8 hour period. F. Sound Level Meter an instrument for the measurement of sound level. G. Standard Threshold Shift (10 db STS): A change in hearing as compared to baseline or revised baseline (if applicable) of an average of 10 db or more at 2000, 3000, and 4000 Hz in either ear, age adjusted unless otherwise specified or requested. H. TWA (Time Weighted Average): A numerical value expressed in db (A) generated by dosimetry representing actual or estimated noise level exposure over an 8-hour period.

38 35 IV. Responsibilities A. Safety Manager 1. Administer a hearing conservation program to protect employees from hearing loss. 2. Educate and train employees on the hazards of noise and hearing conservation methods. 3. Instruct employees how to properly use and care for hearing protective devices. 4. Ensure noise analysis evaluations are conducted with approved sound measuring equipment to assess noise levels throughout the facility to identify high noise areas. 5. Inform management of high noise areas and follow up to ensure that areas are identified as such. 6. Aid engineers in developing methods through noise reduction feasibility studies to control noise with engineering principles where feasible. 7. Periodic evaluation of overall program B. Medical Service 1. Conduct baseline audiograms on all new employees. 2. Administer annual audiometric exams to detect early signs of hearing impairment. Recommend, to the employee, measures for preventing further hearing loss. 3. Notify the employee, (in writing) and the Safety Manager within 21 days when an audiometric evaluation shows a threshold shift. Conduct a re-test within 30 days. 4. Refer employees to specialists for the evaluation of audiometric changes when the re-test confirms a threshold shift. C. Management 1. Reinforce the importance of hearing protection and the Hearing Conservation Program.

39 36 2. Ensures that hearing protection devices are readily available to employees. 3. Ensure that hearing protection devices are worn properly by employees in the designated areas. 4. Refer any employee to Safety Manager for any hearing problems or complaints associated with noise exposure or hearing protection devices. 5. Notify the Safety Manager of any changes that may alter the noise level of machinery or equipment. 6. Post warning signs in and around areas designated as high noise areas. D. Accurate Millworks and Contractor Employees 1. Wear proper hearing protection while working in designated high noise areas or when working at a high noise machine. 2. Maintain hearing protection devices so they are clean, and use proper hygiene practices while inserting and wearing these devices. 3. Attend all training sessions, medical examinations, and evaluations concerning hearing protection. 4. Report to management any changes in equipment or process where the noise level has increased. 5. Report to management any difficulties with hearing or difficulties with hearing protection devices. V. Program Requirements A. Monitoring will be conducted of personnel and areas to determine potential exposure. 1. Sound level surveys are conducted to measure the sound pressure levels in the plant and identify the noise sources. Sound level surveys are to be conducted every two years. Additional surveys in areas with new installations or modifications of processes will be performed. Documentation of all sound level surveys will be filed in the Safety Manager's office.

40 37 2. Noise exposure monitoring will be completed to determine the occupation s eight-hour time weighted average. Areas with noise levels above 85 dba must be determined by noise dosimetry. Additional monitoring will be conducted whenever a change in production, process, equipment or controls may alter noise exposures. 3. The worker will be informed of the dose that the worker received; highest volume or peak encountered, and amount of time exposed at these sound levels. This is achieved by discussing the report with the employee. Interpretation of the written sampling results and providing recommended actions to minimize exposure will be documented. The documentation of the discussion shall be in the form of the employee signing the written sampling results and storing the document in the employee's personal file in the Safety Manager's office. 4. Data gathered from dosimetry reports will be used to notify management of any changes of any high noise that may have occurred since the last survey. These reports will be posted throughout the facility to allow the review of the monitoring by other employee's in the same job classification and other employee's that work in the area. B. Engineering Controls 1. When 8-hour TWA noise exposures are at or above 90 dba the use of engineering controls must be reviewed and installed, if feasible. These controls can include: Equipment spacing Noise absorbing or dampening treatments Review process technology and substitute with equipment that produces less noise 2. If engineering controls are not feasible, this conclusion must be documented and sent to the Safety Manager. C. Personal Hearing Protection Devices 1. The use of personal hearing protection devices is required during the evaluation phase and installation of engineering controls. Hearing protection is also required when engineering controls are not capable of reducing the noise exposure to less than 85 dba.

41 38 2. Areas where hearing protection is required shall have signs posted that designate hearing protection areas. Hearing protection devices must be worn within these areas. 3. There are two types of hearing protection available: ear plugs and ear muffs. 4. All Hearing Protection devices used on site will provide at least 33 dba NRR (Noise Reduction Rating). Any new hearing protection devices introduced to the facility will have to meet this requirement and be approved by the safety manager. 5. Employees must be trained annually on the proper method of insertion of earplugs to obtain a proper fit. The Safety Manager will provide fit testing and training in the proper care and use of hearing protection devices. 6. To avoid ear infections and discomfort employees must practice strict personal hygiene practices when inserting and removing earplugs. Hands and earplugs should be clean when inserting or removing earplugs. D. Audiometric Testing 1. All new hire employees are required to have a baseline audiogram test prior to beginning their work assignment 2. Employees will have their annual audiometric test after having 14 hours without exposure to workplace noise prior to undergoing audiometric testing. Hearing protection may be used as a substitute for this requirement. Employees are to be notified of this at the time of their scheduling. 3. Accurate Millworks requires all employees to have an annual audiogram. Exam records will be observed by a health care professional to determine if a standard threshold shift has occurred. These documents will become a part of the employee s medical records and are kept in the employee's medical files. VI. Training OSHA requires all employees exposed at or above the action level (85dBA) are required to be trained on all aspects of the Hearing Conservation Program including: A. Effects of excessive noise on hearing.

42 39 B. Protective measures and methods of control to be used to protect hearing C. The selection, use, care and fitting of hearing protection D. The purpose of annual audiometric testing VII. Program Review This procedure will be reviewed and revised when any of the following events occur: A. Company or governmental requirements change. B. The annual evaluation indicates a change is needed. C. It has been greater than three years since the procedure was last reviewed and certified.

43 Appendix F 40

44 41 Noise Exposure and Hearing Conservation Training Hearing Conservation Program Required for all employees who s noise exposure may exceed an 85dBA time weighted average A Hearing Conservation Program (HCP) is an important tool in identifying and controlling occupational noise hazards OSHA s HCP training requirements necessitate that the following items will be covered: The purpose of hearing protectors, the advantages, disadvantages, and attenuation of various types, and instructions on selection, fitting, use, and care The purpose of audiometric testing, and an explanation of the test procedures

45 42 HCP Covered Areas The entire rough mill is a hearing conservation zone and will require hearing protection to be worn at all times When making pallets or using the chop saw The following machines are the top noise producers in the rough mill Press Baker Resaw Unimat Molder Wonder Saw SCNI Ripsaw Green Sorting Chain Whirlwind Saw Finger Jointer Western Pneumatics Finger Jointer MJ Gang Rip Effects of Noise on Hearing Noise can destroy nerve endings in the inner ear causing irreversible damage Noise above 140dB causes pain Exposure to high noise levels can cause tinnitus which is a permanent ringing in the ears

46 43 Effects of Noise on Hearing Hearing loss due to noise exposure is gradual so it is hard to notice Hearing loss will interfere with communication leading to interference with job performance and safety There is no such thing as getting used to noise Factors Affecting Hearing Loss Noise Intensity Pitch Length of exposure Genetic factors Noise sources encountered outside of work

47 44 Hearing Protective Devices Ear plugs and ear muffs are two different types of hearing protection Both of these types of hearing protection are designed to reduce the harmful effects of sound Ear Muffs Advantages Easy to use Good in an intermittent noise environment Disadvantages Uncomfortable, especially in hot environments May interfere with other safety equipment

48 45 Ear Plugs Advantages Small and lightweight Easily adaptable with additional safety equipment More comfortable in hot environments Disadvantages May jiggle loose requiring refitting periodically Can get dirty and must be replaced Difficult to insert correctly Attenuation Earplugs can offer a Noise Reduction Rating (NRR) of up to 33dB Earmuffs offer an NRR of up to 30dB NRR reflects noise reduction under ideal conditions and not the actual in use attenuation so an equation is used to estimate the actual attenuation: EmployeeTWA(dBA) (NRR 7dB)*50%

49 46 Hearing Protection Selection Many things must be considered when selecting hearing protection: Select hearing protection that provides an adequate NRR Must choose something that provides enough comfort to wear continuously throughout the day Employees must be provided with a variety of suitable hearing protective devices and be able to choose the one that provides the best fit and comfort level Hearing Protection Fitting There are three simple steps to correctly inserting foam earplugs: First roll it thin between your fingers Pull your ear up to straighten your ear canal Insert and hold the earplug inside your ear canal until it expands