30 CFR Part 62 MSHA Standards for Occupational

30 CFR Part 62: MSHA Standards for Occupational Noise Exposure

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)

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

What is Noise? l Unwanted or undesired sound

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

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

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

Decibel (d. B) • 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!!

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

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

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

Permissible Noise Exposures Duration per day Sound level (hours of exposure) (d. BA, 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

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

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

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

Anatomy of the Human Ear

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

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

Cross-section Normal Cochlea with Hair Cells

Cross-section Damaged Cochlea & Loss of Hair Cells

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

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

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

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

30 CFR Part 62: Compliance Levels • Action level = TWA 8 of 85 d. BA or 50% dose (80 - 130 d. BA) • Permissible Exposure Level (PEL) = TWA 8 of 90 d. BA or 100% dose (90 - 140 d. BA) • Dual Hearing Protection Level = TWA 8 of 105 d. BA or 800% dose (90 - 140 d. BA) • 115 d. BA maximum sound level

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

Controlling Noise Exposure l l If MSHA (or operator) determines exposure exceeds PEL (TWA 8 of 90 d. BA or 100% noise dose), feasible engineering and administrative controls required (if capable of achieving significant reduction). 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.

Feasible Control & Significant Reduction l l Feasible Control 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). Significant Reduction means a reduction of 3 d. B or greater.

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)

Summary: Actions Required By Operator Section Condition Action Required 62. 120 TWA 8 < 85 d. BA No action required 62. 120 TWA 8 ³ 85 d. BA, but £ 90 d. BA Enroll miner in HCP per 62. 150, HP use optional 62. 130 TWA 8 > 90 d. BA Use all feasible engrng and/or admin controls; enroll miner in HCP; ensure use of HP; post & provide any admin controls 62. 140 TWA 8 > 105 d. BA Ensure use of Dual HP; all 62. 120 and 62. 130 actions

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 TWA 8 of 85 d. BA or 50% dose or higher is measured

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 d. BA or 100% dose.

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)

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

What Other Data ? • 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)

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

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!!!

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

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

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!

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

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

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

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

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 within 10 working days • Followup if indicated

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

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

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

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

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

What if the initial audiogram indicates occupational hearing loss? • On an initial (baseline) audiogram, this is not reportable, unless there is an award of compensation under the local workers’ compensation criteria • File a 7000 -1 if compensation is awarded

What type of training? Within 30 days of enrollment in HCP, and every 12 months thereafter, miner must be trained in: B B B B effects of noise on hearing purpose and value of wearing HPDs advantages/disadvantages of HPDs care, fitting and use of HPDs general requirements of Part 62 operator/miner responsibilities regarding controls purpose and value of audiometric testing

Recordkeeping • Mine Operator maintains a complete record for length of miner’s employment plus 6 months • Copies available to MSHA (DOL) & NIOSH (HHS) representatives within 1 business day • Copies of records available to miner, miner’s written designee, former miners, & miner’s representatives within 15 days

What happens when a new operator acquires the mine? • The baseline audiograms convey for the purposes of determining an STS or reportable hearing loss • Doesn’t apply to a successor operator hiring a miner who has never worked at that location

What if the miner moves to a different mine? • A miner transferring from one property to another may still have the same employer • And may still meet the local criteria for workers’ compensation • The current mine operator is responsible for submitting the 7000 -1

Can the operator hold the miner responsible for the cost of replacement hearing protection? • No - the cost for initial and replacement PPE is borne by the operator for each miner in the HCP • Don’t have to buy the most expensive if the loss rate is too high

What about fitting & maintenance of PPE? • Any required PPE must be fitted & maintained per manufacturers’ specifications • Proper fitting is an indicator of good training

Thank You