Hearing Conservation

1. Hearing Conservation • Prevention of Occupationally Induced Hearing Loss NSTC-09

2. Introduction

3. Introductions • Name • Company and/or Position • Experience related to working areas with high noise levels

4. Administration and Safety • Emergency Procedures • Restrooms/Breaks/Smoking • Safety Minute

5. Goal • To introduce employees to the potential hazards and the control measures for working safely in areas where noise levels can contribute to hearing loss.

6. Objectives • Explain the health effects of excessive noise in the workplace • Explain the control measures that can be taken to reduce workplace noise and prevent noise-induced hearing loss • Demonstrate the proper selection, fitting, use, and care of hearing protection devices

7. Objectives • Identify and describe the components of a Hearing Conservation Program • State the purpose of baseline audiometric evaluations • Discuss personal compliance in hearing conservation and noise control practices

8. Why Noise is a Hazard

9. Those Affected by Noise • The National Institute on Deafness and Other Communication Disorders (NIDCD) estimates 26 million Americans between the ages of 20-69 have high frequency hearing loss from excessive noise at work or in leisure activities. • Noise is a common health hazard at industrial sites on the North Slope of Alaska (BP ASH, p. 22).

10. What is NOISE? • Noise is a physical energy that moves through air as sound waves. • Its frequency (pitch) is measured in cycles/second or hertz (Hz). • Its intensity (loudness or sound pressure) is measured in decibels (dBA). • Its duration or the length of exposure is classified as continuous, intermittent, or impact noise. Pressure Hazard, BP ASH, page 127

11. Noise TWA • Noise is measured as a time weighted average (TWA). • It is a daily “dose” of noise during the period of time that an employee is working in an area. • The TWA is determined by: • how loud the equipment is (intensity). • how close the employee is to the noise. • how long the employee is exposed to the noise (duration). ASH, page 16; BP ASH, pages 22, 41

12. OSHA Noise Standard • Action Level: An 8 hr. TWA of 85 dBA requires employers to implement a Hearing Conservation Program. • Ceiling or PEL: An 8 hr. TWA of 90 dBA requires employers to implement engineering controls, administrative controls, and personal protective equipment to lower the noise exposure levels. 29 CFR 1910.95 (a) – (c )

13. North Slope Noise Standard • Action Level: A 12 hr. TWA of 82 dBA requires North Slope employers to implement a Hearing Conservation Program including the use of hearing protection. • Noise levels of 100 dBA or more require the use of double hearing protection (earplugs and earmuffs) and limited exposure. • Signs are posted in production facilities to warn against noise hazards and to indicate the level of hearing protection required. ASH,page 16; BP ASH, page 22

14. Recreational Noise Levels

15. Workplace Noise Levels

16. Noise-Induced Hearing Loss (NIHL)

17. Anatomy of the Ear • The ear has three (3) basic regions • The Outer Ear • The Middle Ear • The Inner Ear

18. How We Hear • Sound waves create pressure variations that cause the eardrum to vibrate. • Bones in the middle ear transmit vibrations to the cochlea. • Receptors (hair cells) in the cochlea convert vibrations to electrical energy.

19. How We Hear • The brain interprets electrical impulses as sound. • Nerve cells in cochlea are tuned to specific frequencies. • Base of cochlea: sensitive to high frequencies • Tip of cochlea: sensitive to low frequencies

20. How NIHL Occurs • NIHL is unnoticeable in its earliest stages. • NIHL accumulates with each over-exposure because excessive noise damages the receptors (auditory hair cells). • NIHL increases with the reduction in the number of functioning receptors. • NIHL is permanent, but 100% preventable.

21. Normal Cochlea Auditory receptors line the inside of the cochlea

22. Damaged Cochlea Damaged auditory receptors Normal auditory receptors

23. Types of Hearing Loss • Tinnitus: a permanent ringing in the ears • Temporary Threshold Shifts (TTS): Hearing returns to normal after noise exposure • Permanent Threshold Shifts (PTS): Repeated noise exposure without a return to normal • Standard Threshold Shifts (STS): A change in hearing threshold of more than 10 dBA average loss in 2000, 3000, or 4000 Hz in either ear • Presbycusis: hearing loss due to aging and repeated long-term environmental noise

24. Other Harmful Effects from Noise Exposure • Increased fatigue • Headaches • Muscular tension • Increased heart rate and blood pressure • Impaired balance • Decrease in work productivity

25. Noise Control Measures

26. Noise Control Measures NIHL is preventable if the proper control measures are implemented. • Engineering Controls: Remove, reduce, mitigate or isolate the hazard • Administrative Controls: Reduce the hazard while the worker is exposed • Personal Protective Equipment: Wear hearing protection devices

27. Engineering Controls • Erect acoustical enclosures and barriers around noisy equipment. • Move noise sources away from reflective surfaces (concrete or brick walls, corners). • Retrofit (install mufflers, silencers) and maintain (replace worn parts, lubricate, balance) older equipment which gets noisier over time. • Install sound dampening material and/or devices on equipment and tools.

28. Administrative Controls • Put distance between the noise source and workers. • Limit the amount of time workers are exposed to the noise (job rotation, frequent breaks, scheduling equipment operating times). • Limit the number of workers allowed in an area with excessive noise. • Provide worker training in hazard recognition and methods of protection. • Provide warning signs. BP ASH, page 141; ASH, page 16

29. Hearing Protection Devices Earmuffs Foam (Disposable) Earplugs Molded (Reusable) Earplugs

30. Hearing Conservation Program

31. Action Levels • OSHA requires employers to administer a hearing conservation program whenever employee noise exposure levels equal or exceed the action level of an 8-hour TWA of 85 dBA). • The action level on the North Slope, as stated in the Alaska Safety Handbooks, is when noise exposures exceed a 12-hour TWA of 82 dBA . 29 CFR 1910.95 (c ); ASH, page 16; BP ASH, page 22

32. Components of a Hearing Conservation Program • Noise Monitoring at Worksite (Hazard Assessment) • Controlling Excessive Noise • Employee Notification and Training • Audiometric Testing • Hearing Protection Device Distribution • Program Record Keeping 29 CFR 1910.95 (c ) – (o)

33. Audiometric Testing Program • An evaluation to measure an individual’s ability to hear • Performed by a licensed or certified audiologist or other physician • Establishes a baseline for the annual hearing profile that will indicate if there is a threshold shift in subsequent years 29 CRF 1910.95 (g)

34. Training Requirements • Effects of noise on hearing • Purpose of hearing protection, types of devices and the advantages and disadvantages of each • Proper selection, fitting, and use of hearing protection devices • Purpose of audiometric testing and an explanation of test procedures • Refresher training required annually 29 CRF 1910.95 (k)

35. Employer Responsibility • Must protect workers exposed to hazardous noise levels that exceed the Permissible Exposure Limit (PEL) • Must ensure that engineering and administrative controls are followed and hearing protection is provided and used with training • Must have a Hearing Conservation Program whenever noise levels equal or exceed the action level of 85 dBA for an 8 hr. TWA 29 CFR 1910.95 (c ) – (o)

36. Employee Responsibility • Must follow administrative controls established to reduce or eliminate noise exposure • Reduced work shifts or job rotations • Avoidance of high noise areas • Must wear hearing protection when exposed to high noise levels on the North Slope • < 82dBA– no protection necessary * • 82-99dBA– protection necessary * • >100dBA– double protection necessary * * Time Weighted Average over a 12 hr. shift ASH, page 16; BP ASH, pages 22, 41

37. Proper Fitting of Hearing Protection

38. Fitting Guidelines • Earplugs come in a variety of sizes because no one earplug fits all ear canals. • Correct fit is essential, so find the right size. • Employers may provide fit testing. • Maximum protection occurs when the earplug provides an airtight seal in the ear canal or against the side of the head. • User needs to check and adjust earplugs throughout the day.

39. Fitting Foam Earplugs (Disposable) • Be sure your hands are clean. • Roll the earplug into a crease-free cylinder. • Pull back the ear by reaching over the head with your free hand and gently pull the top of the ear up and out. • Insert earplug well into ear canal and hold until it fully expands. • If properly fitted, the end of the earplug should not extend beyond the flap (tragus) of the ear canal.

40. Proper Fitting of Earplugs • Reach over your head with the opposite hand and pull the top of the ear outward to open the ear canal.

41. Proper Fitting of Earplugs • While holding the ear open, insert the earplug into the ear canal.

42. Visual Check for Properly Fitted Earplugs • The earplug should fit inside the ear without protruding past the ear flap (tragus).

43. Fitting Molded Earplugs (Reusable) • Be sure your hands are clean before inserting the earplug. • Reach over head with free hand, pull top of ear up and back. • Insert earplug so all flanges are well inside the ear canal. • If properly fitted, only the stem of the earplug should be visible to someone looking at you from the front.

44. Fitting Earmuffs • Place ear cups over each ear and adjust the headband by sliding it up or down at the attachment buttons. • The ear cushions should seal firmly against the head. • For best results, remove all hair from underneath the ear cup. • Make sure the ear cup creates a seal and completely covers the ear. • Temple bars on safety glasses will break the protective seal.

45. Care and Maintenance

46. Care and Maintenance of Earplugs • Dispose of single use earplugs daily. • Inspect reusable earplugs for dirt, cracks or hardness and replace if damaged. • Clean reusable earplugs with mild soap and water, as appropriate, and dry thoroughly.

47. Care and Maintenance of Earmuffs • Clean ear cushions and headband regularly with mild soap and water. • Replace ear cushions and foam inserts every 6 months with normal wear and more often with heavy use or under humid/extreme conditions.

48. Summary • Noise is a common health hazard on the North Slope. • The action level on the North Slope is 82 dBA for a TWA of 12 hours which requires participating in the Hearing Conservation Program and the wearing of hearing protection. • Proper selection and fitting of hearing protection devices is the key to preventing NIHL. • Hearing loss is preventable. ASH, page 16; BP ASH, pages 22, 41