Noise in Road Construction

1. Noise in Road Construction Developed by the Division of Occupational Safety and Health (DOSH) August, 2009

2. Hearing loss rates and claims facts Noise levels of construction equipment Control methods to reduce harmful noise exposures Resources What this presentation covers

3. In Washington State, Hearing loss is expensive! • Hearing loss is 1/3 of all costs of permanent impairments. • Hearing loss is the most expensive occupational disease for road construction workers. • Incidence rate is 10 times higher for “Road Construction” risk class than for all other risk classes. • Hearing loss claims rate is highest of all construction risk classes. The result is higher industrial insurance premiums paid by road construction contractors.

4. Noise and hearing loss • Noise is measured in units called decibels (dBA). Threshold of pain Construction noise levels are often above 85 dBA Jet take-off (200’) (“A-weighting” is a standard of sound measurement used to evaluate continuous noise levels; designated as “dBA”) Chipping hammer Jackhammer Bulldozer Freeway noise City traffic • Scientific studies have shown that hearing loss can occur when 8-hour average noise exposure exceeds 85 decibels. Normal conversation (3’) Urban residence Soft whisper (5’) For more information on noise and hearing, see DOSH webpage: Noise Exposure – Hearing Loss Threshold of hearing Noise level (dBA)

5. 60 70 80 85 90 100 110 120 110-113 Pneumatic chipping hammer 102-111 Jackhammer 99-102 Concrete joint cutter 88-102 Skilsaw 93-96 Bulldozer 90-96 Earth Tamper 90-96 Crane Hammer 87-95 87-94 Gradeall 86-94 Front end loader Backhoe 84-93 Source: Center to Protect Worker’s Rights Decibels (dBA) Some Common Noise Levels in Construction

6. Concrete Saw Operator 95 dBA (7-hour sample) Road Equipment Noise Level Measurements Source: OSHA case files

7. Jackhammering 102 dBA (7.5-hour sample) Road Equipment Noise Level Measurements Source: OSHA case files

8. Breaking pavement 112 dBA (7-hour sample) Road Equipment Noise Level Measurements Source: OSHA case files

9. Road Equipment Noise Level Measurements Lateral drilling (2 examples) 97 dBA (6.5-hour sample) 104 dBA (7-hour sample) Source: OSHA case files

10. Bridge Sandblasting 125 dBA (4-hour sample) 109 dBA (inside hood) Sample Noise Level Measurements Source: OSHA case files

11. Dumping concrete 96 dBA (4-hour sample) Sample Noise Level Measurements Source: OSHA case files

12. Several factors influence the noise levels to which workers are exposed: Noise Sources in Road Work • Type and condition of equipment being operated • Other equipment running at the same time • Enclosed or partially enclosed spaces (e.g., underpass) • Traffic around work site Underpass Underpass work

13. At noise exposures of 85 dBA TWA8* and higher, you must use a hearing protection device. • Wherever the noise exposure is 90 dBA TWA8 and higher, feasible controls must be used to reduce your exposure. When is hearing protection required? *Time-weighted average during an 8-hour period High Noise Exposures “Rules of Thumb” You need protection: • If you have to shout at someone 3 feet away to be heard • When using electric, gasoline, or air powered tools • When sitting in an open cab of dozers, rollers, some cranes, earth moving or road building equipment

14. Substitute quieter process or equipment • Eliminate or minimize at the source • Isolate/enclose the process or operator • Increase distance from the source • Change work practices • Implement a hearing conservation program What are some methods to controlnoise exposures? The most desirable methods of controlling a noise problem are to use quieter process/equipment, eliminate the noise at the source, or to block the noise from reaching you. Using hearing protection devices (ear plugs, muffs) isn't considered a control of the noise hazard. There are many drawbacks and using them will not always be effective.

15. Substitute quieter process or equipment: Noise control methods New quieter generators have sound-proofing and produce only 75 dBA at 1 meter and 65 dBA at 7 meters under load. Replacing a large jackhammer with a middle range one reduced the noise level by 10 dBA.

16. Eliminate or minimize noise at the source: Noise control methods • Install silencers/mufflers • Retrofit old equipment • Operate equipment as designedper manufacturer’s instructions • Damp noisy equipment and parts • install sound-absorbing material or vibration isolation systems • Maintain equipment properly • replace worn, loose, or unbalanced machine parts that cause vibration • keep machine parts well lubricated to reduce friction • adjust belts and valves, tighten bolts Acoustically treated operator cabins on earth-moving equipment have noise levels of 75 dBA or below.

17. Isolate/enclose the process or operator: Noise control measures • Noise enclosures • Noise barriers • must be higher and wider than noise source to work effectively • may be simple walls or curtains of acoustic materials • ½-inch plywood can provide a 10dB noise reduction • place close to noise source • Include acoustic panels or baffles to walls/ceilings • Minimize leaks and openings • e.g., cover joints with 1/8-inch thick neoprene strip or duct tape A portable screen set up around a power pack reduced the noise level from 98 to 90 dBA at 1 meter.

18. Reflected Noise TransmittedNoise Noise from source BARRIER Isolating or enclosing noisy equipment with operator- a caveat: Noise control measures This method will reduce noise levels outside the barrier, but may increase noise levels inside the barrier. if the source of noise is equipment operated by a worker, his or her noise exposure may be increased because of reflected noise. Lining the barrier with sound absorbing material will reduce the reflected noise to operator.

19. Increase the distance between the noise source and you: Noise Control measures • Every doubling of the distance between you and the noise source results in as much as a 6 dB decrease in noise level – that’s a four-fold reduction! • Keep noisy equipment away from walls or other surfaces that will reflect noise toward you. • Combine distancing and barriers to further reduce noise exposure. Using both methods results in greater noise reduction than would be achieved from either method alone. -This is true if there is no reflected noise. The reduction will be less if there are walls or partitions between you and the noise source.

20. Change employee work practices: Other Noise Control Measures • limit time exposed: job rotation, rescheduling work • limit use of noisy equipment • provide breaks away from the noisy area • turn off equipment not in use

21. Hearing Conservation Program When noise levels can’t be controlled through other means, you must implement a hearing conservation program which consist of the following: • Provide baseline and annual audiometric testing • Measure noise exposure levels • Provide hearing protection • Do employee training and education • Maintain employee exposure and hearing loss records Details of requirements: Chapter 296-817 WAC

22. Hearing loss is expensive! Summary Many construction noise levels are high and require controls to reduce workers’ exposures. Control methods: • Substitute quieter process or equipment • Eliminate or minimize at the source • Isolate/enclose the process or operator • Increase distance from the source • Change work practices • Implement hearing conservation program

23. DOSH Consultation Services Safety & Health program review and worksite evaluation • By employer invitation only • Free • Confidential • No citations or penalties • Letter explains findings • Follow-up all serious hazards For additional assistance, you can call one of our consultants. Click below for local L & I office locations: http://www.lni.wa.gov/wisha/consultation/regional_consultants.htm

24. More Information • DOSH: Noise Exposure – Hearing Loss • NIOSH: Noise and Hearing Loss Prevention • OSHA: Noise and Hearing Conservation • National Hearing Conservation Association • MSHA Noise Control Manual: Surface Mining Equipment • Institute of Noise Control Engineering of the USA