30 CFR Part 62: MSHA Standards for Occupational Noise Exposure

1. 30 CFR Part 62:MSHA Standards for Occupational Noise Exposure

2. Noise Induced Hearing Loss • Among the top ten work-related illnesses according to National Institute of Occupational Safety & Health (NIOSH) • 24,000 M/NM miners at risk under old rule (30 CFR 56/57.5050)

3. Mining - “High Risk” Occupations Task Area: Jobs: Drilling/Cutting Wagon/Rotary Drill, Jachammer, & Stone Saw Operators Haulage Truck, Bulldozer, Front-End-Loader, Shovel, Dragline, & Dredge Operators Plant/Mill Plant Workers: Crushing, Sizing, Washing, Grinding, & Bagging Maintenance Laborer, Cleanup, Mechanic, & Welder

4. What is Noise? Unwanted or undesired sound

5. Sound is Vibrational Energy Travels in Waves from a Source FREQUENCY INTENSITY Cycles per Second Hertz (Hz) Decibels (dB)

6. Characteristics that Determine the Degree of the Noise Hazard:1. Intensity (volume, loudness)2. Frequency (pitch)3. Duration of exposure

7. Common Frequencies Hertz (CPS) 63 125 250 500 1000 2000 4000 8000 -trombone-- ----------piccolo---------------- ----truck---- -------compressed air noise---------------- -------------speech---------------

8. Decibel (dB) • A unit of measure of sound pressure levels • 20 times the common log of the ratio of the measured sound pressure level to the threshold of hearing @ 1000 Hz • NOT SIMPLE MATH!!

9. Relationship between intensity and decibels for measuring hearing dB Intensity 0 1 10 10 20 100 30 1,000 (1 thousand times) 40 10,000 50 100,000 60 1,000,000 (1 million times) 70 10,000,000 80 100,000,000 90 1,000,000,000 (1 billion times) 100 10,000,000,000 110 100,000,000,000 120 1,000,000,000,000 (1 trillion times) 130 10,000,000,000,000 140 100,000,000,000,000

10. Common Sound Levels Pain Threshold 140 dB Channel Burner 125 dB Chain Saw 120 dB Air-Track Drills 115 dB Large Haul Trucks 109 dB Bulldozers 107 dB Scrapers 104 dB Front-end Loaders 101 dB Rock crusher 94 dB Street Traffic 83 dB Normal conversation 60 dB Inside house 45 dB Soft Whisper 10 dB Threshold of hearing 0 dB

11. What Difference Does 5 Decibels Make? • MSHA uses a 5-dB doubling factor as the basis of its regulations • With every increase in exposure of 5 dB, the worker’s allowable time in an area is cut in half. • 3 dB is the mathematically correct value & is used for noise control engineering

12. Permissible Noise Exposures Duration per day Sound level (hours of exposure) (dBA, slow response) 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 1-1/2 . . . . . . . . . . . . . . . . . . . . . . . . . 102 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 1/2 . . . . . . . . . . . . . . . . . . . . . . . . . . 110 1/4 or less . . . . . . . . . . . . . . . . . . . . 115

13. Noise Measurement • Expressed as a “dose,” or percentage of allowable limit, where 90 dB is the criterion & 5 dB is the exchange rate • TWA of 90 dB for 8 hours = 100% • Measured on “A” scale & slow response • Either by dosimeter or sound level meter • Personal sampling

14. “A” Weighting (dBA) 50 HZ at 95 dB 5000 HZ at 76 dB PERCEIVED AS EQUALLY LOUD BY THE HUMAN EAR Adjust the dB Scale to Account for the Ear’s Sensitivity to Different Frequencies

15. The Human Ear • The ear of an average, healthy, young adult can respond to frequencies in the range of 20 Hz to 20,000 Hz • The human ear is most sensitive to sounds of 1000 Hz to 4000 Hz

16. Anatomy of the Human Ear

17. Transmission of Vibrations through Inner Ear Long Waves (Low Frequency and Low Pitch) act at top of the Cochlea Oval Window Ossicles Short Waves (High Pitch and High Frequency) act at the base of the Cochlea Round Window

18. Early Signs of Hearing Loss • Ringing in the ears after a noisy activity • Difficulty understanding what people say • Turning up the volume of the TV or radio when others hear fine • Not hearing background noises such as the telephone or doorbell

19. Cross-section Normal Cochlea with Hair Cells

20. Cross-section Damaged Cochlea& Loss of Hair Cells

21. Temporary Threshold Shift • Hearing loss may initially be temporary • Ear becomes fatigued by noise • Recovers after a period of rest • Pattern repeated for months & years

22. Leads to: • Permanent threshold shift • Standard threshold shift (STS) • Change in hearing threshold relative to the baseline - An average of 10 dB or more at 2K, 3K and 4K Hz in either ear.

23. May Lead to: • MSHA Reportable Hearing Loss • Change in hearing threshold relative to the baseline - An average of 25 dB or more at 2K, 3K and 4K Hz in either ear. • Or, an award of compensation.

24. Problems: • Can’t give and receive instructions • Can’t hear warning signals • Hard to communicate • Can’t hear sounds from machinery • Reduced communication leads directly to accidents

25. 30 CFR Part 62: Compliance Levels • Action level =TWA8 of 85 dBA or 50% dose (80 - 130 dBA) • Permissible Exposure Level (PEL) = TWA8 of 90 dBA or 100% dose (90 - 140 dBA) • Dual Hearing Protection Level =TWA8 of 105 dBA or 800% dose(90 - 140 dBA) • 115 dBA maximum sound level

26. What triggers an MSHA citation? • Any miner’s full-shift exposure > 2 dB* above an allowable exposure level (i.e., 85, 90, 105) • measured via personal dosimeter using “A” scale & slow response • Any exposure > 2 dB* above 115 dBA maximum sound level via SLM using “A” scale & slow response • 95% confidence limit

27. Controlling Noise Exposure • If MSHA (or operator) determines exposure exceeds PEL (TWA8 of 90 dBA or 100% noise dose), feasible engineering and administrative controls required (if capable of achieving significantreduction). • This requirement applies even if the final noise level continues to exceed the PEL. • In addition to engineering and administrative controls, adequate hearing protectors also required.

28. Feasible Control &Significant Reduction • FeasibleControl means: • The control reduces exposure. • The control is economically achievable (costs proportionate to “expected benefits”). • The control is technologically achievable (need not be “off-the-shelf,” but must have realistic basis in present technology). • SignificantReduction means a reduction of3 dB or greater.

29. Noise Reduction Methods • At the Source:- Select quiet equipment- Reduce speed, impact or impulsive force in machines • In the Transmission Path:- Separate noise and receiver (booths/cabs)- Use sound absorbing materials • At the Receiver:- Reduce exposure time- Alter work schedules- Hearing protective devices (last resort)

30. Summary: Actions Required By Operator Section Condition Action Required 62.120 TWA8 < 85 dBA No action required 62.120 TWA8³ 85 dBA, Enroll miner in HCP per but £ 90 dBA 62.150, HP use optional 62.130 TWA8 > 90 dBA Use all feasible engrng and/or admin controls; enroll miner in HCP; ensure use of HP; post & provide any admin controls 62.140 TWA8 > 105 dBA Ensure use of Dual HP; all 62.120 and 62.130 actions

31. System of monitoring • Operator must establish a system of monitoring that evaluates each miner’s exposure to determine continuing compliance • Evaluation must reflect a full work shift • Operator must notify the miner of results and any proposed actions within 15 days if TWA8 of 85 dBA or 50% dose or higher is measured

32. What is a system of monitoring? • A way of relating the miner’s daily noise dose* to a measurable parameter, such as:- Hours worked- Tonnage produced or consumed- Other data • Expressed as % dose where 8 hours @ 90 dBA or 100% dose.

33. Who is covered by the system of monitoring? • The system of monitoring must provide an initial exposure assessment for all miners on site • It must ensure continuing compliance of all miners’ exposures with the standard (Both Action Level and PEL)

34. Does the operator have to do noise monitoring? • No - the operator can base the system of monitoring on exposure predictions (i.e., other data) • The operator can protectively place all miners in the HCP

35. What OtherData ? • MSHA’s or other historical monitoring (available from MSHA Web Page) • Representative personal monitoring • Manufacturers’ information (e.g., cab noise levels in a Front-End-Loader)

36. When does this have to be done? • The standard was effective 9/13/00 - a year after publication. • Exposure assessments for existing operations were to be completed by then. • Complete audiometric testing by 3/13/01 or 9/13/01* • If using mobile van option

37. What are the operator’s responsibilities if the miners are protectively placed into the HCP? • All provisions of the HCP apply • This includes notification, provision of PPE, audiograms, initial training, & recordkeeping • Within the established deadlines • Evaluate exposures for compliance with PEL!!!

38. Who should be included if the operator elects to sample ? • A least one miner as a representative of each exposure group (e.g., allEuclid R-50 haul truck drivers) • Representative monitoring assumes that all miners doing the same operation with the same equipment have the same exposure

39. Do I have to sample for the whole shift? • No - But, all exposure models have to reflect the miner’s full-shift exposure • As long as the exposure interval is representative of the whole day’s exposure you can simply adjust for the rest

40. How? • The mine operator can assume* that the percent noise dose is accumulated in a predictable fashion • For example: • 40% in 5 hours = 8% dose per hour • Therefore, a 12-hour shift @ 8% dose per hour = 96% dose per shift • MSHA inspectors can’t assume - they must measure miner’s actual full-shift dose!

41. Hearing Conservation Program: • If AL (or higher) is exceeded* a Hearing Conservation Program that includes the following must be in place (or instituted):- A system of monitoring- Provision & use of PPE- Audiometric Testing- Training- Recordkeeping (i.e., monitoring results, notifications, audiograms, training certification, etc.) • Or if miners are protectively placed into HCP

42. Hearing Protectors • Provided by mine operator at no expense to miner (in HCP) including replacements • Choice of 2 muff & 2 plug types • Maintained & fitted per manufacturers’ instructions • Voluntary use < PEL*, Mandatory at or above • Required until baseline audiogram or if an STS has been detected

43. Hearing Protection • IF WORN CORRECTLY & FITTED PROPERLY:- Effective within limits of bone conduction & transmission through absorbing material- Comfortable fit more important than high NRR

44. Audiometric Testing • Under supervision of physician, audiologist, or qualified technician • Initial within 6 months of entry into HCP (or 12 months if a mobile van is used) • Annually (thereafter, as long as in HCP) • Voluntary on the miner’s part • Initial, annuals, and followups* at no cost to miner • unless not occupationally related

45. Test Procedures • Must use scientifically valid procedures (OSHA’s specified procedure is OK) • Pure tone, air conduction, hearing threshold, @ 500, 1000, 2000, 3000, 4000, & 6000 Hz in either ear • Operator provides results within10 working days • Followup if indicated

46. Understanding Audiograms 125 250 500 1K 2K 3K 4K 6K 8K -10 0 10 20 30 40 50 BASELINE ANNUAL

47. Determine if Any Hearing Loss 125 250 500 1K 2K 3K 4K 6K 8K -10 0 10 20 30 40 50 BASELINE 16 9 8 ANNUAL

48. Determine if STS or Reportable 125 250 500 1K 2K 3K 4K 6K 8K -10 0 10 20 30 40 50 BASELINE 16 9 16 + 9 + 8 = 33 33 / 3 = 11 Reportable ? NO 8 ANNUAL

49. Determine if STS or Reportable 125 250 500 1K 2K 3K 4K 6K 8K -10 0 10 20 30 40 50 BASELINE 16 9 16 + 9 + 8 = 33 33 / 3 = 11 Reportable ? NO STS? YES 8 ANNUAL

50. 25 Years Later . . . Is there a Reportable Hearing Loss? Loss at 2K, 3K, and 4K (from Baseline to Annual) 27 + 37 + 35 = 99 99 / 3 = 33 Reportable? YES