Package prepared for Jim Maddux, OSHA Office of Safety Standards
By Alice H. Suter, Ph.D.
February 7, 2001
Summary of the noise management process, including the client’s specifications, the tenderer’s proposal (who appears to be the consultant), planning of site activities, and monitoring the program during the construction phase.
Summary of retrofit of a Caterpillar 930 front end loader, achieving a 9 dBA reduction.
Case study illustrating the control of generator noise by purchasing new equipment and controlling noise in the transmission path by building an enclosure for an existing generator.
Legris-Dynamic Safety Blowgun, Series 0645
Retrofit of a high-velocity air nozzle to reduce noise by 8-12 dBA.
Quiet Torque Wrench
Use of a new quieter torque wrench reduced noise by more than 20 dBA.
Reduction of Vibration Noise on Bench Grinders
Retrofit by rubber mounting reduced noise up to 10-12 dBA.
Substitution of a new, lightweight gas-driven breaker with the same work capacity as heavier pneumatic and hydraulic breakers, resulted in decreased noise and vibration.
Noise Control - Brick Cutting Saws
Summary of a report comparing noise levels generated by cutting clay bricks using two different saw blades, with benefits of 10 dBA.
Buying Quiet #1
Summary of various steps and questions regarding the buy-quiet process.
Buying Quiet #2 - Selecting a Sawblade
Detailed discussion of the noise from sawblades and how to control it by selecting a quieter version.
Working Quiet #1 - Making the Job Quieter
Practical discussion of the use of quieter methods, such as pressure rather than impact, choosing quieter tools or machines, reducing the amount of time spent on noisy work, reducing impact velocity, cushioning impacts, damping noise radiation, etc.
Working Quiet #2 - Maintaining Your Machines
Practical discussion of how wear and tear affects noise output, why machines get noisier with use, and how to tell when a machine needs servicing.
West Australian companies in metal manufacturing and construction industries have agreed to share their experiences in noise control to enable more workplaces to achieve the 85 dBA noise exposure standard.
Baulderstone Clough Joint Venture - Noise Control Case Studies
Significant noise reduction has been achieved in the following equipment:
McMahon Contractors (WA) Pty Ltd - Noise Control Case Studies
This report summarizes the company’s efforts at noise control by describing their “buy-quiet” policy, substitution of quieter work processes, replacement of noisy machines with quieter ones, and retrofit.
Worker Killed by Reversing Grader
Brief discussion of a fatality when a road worker was run over by a reversing grader. Road traffic and wind noise, as well as noise from other earth moving equipment, rendered the reverse alarm difficult to hear or even inaudible. Recommendations include training, supervision, and more effective systems of communication.
Reducing Cuts and Amputations from Masonry Power Tools
Summary includes the benefits of noise reduction as well as safety in replacing the rotating-blade cutting mechanism with a vibrating blade action.
Personalised Hearing Protectors
Brief discussion of the economic benefits of custom molded hearing protectors. Foam plugs at .20 per pair, using 3 pairs per day cost approximately $135 per year (Australian currency). Estimated cost of custom-molded protectors $40 per year.
“Noise Management for the Building Industry: Current Practices and Strategies for Improvement.” The condensed version is an 18-page report by Marion Burgess and Joseph Lai of the Acoustics and Vibration Unit, University of New South Wales, Australia. It was prepared under a grant from WorkCover NSW. The full report may be obtained via www.adfa.edu.au/amec/avu/ or from the Acoustics and Vibration Unit, e-mail: firstname.lastname@example.org . The condensed report covers current (minimal) noise management practices in the building industry, typical noise exposure levels, the extent (minimal) to which the current NSW Code of Practice for noise is being implemented, strategies for improving its implementation, and recommended actions. A comprehensive bibliography is included, along with a list of documents and brochures available from WorkCover NSW and WorkSafe Australia and Western Australia.
The Blue Angel program is run by the government of Germany to encourage manufacturers to produce equipment and other products that are safe and healthy for workers and for the environment. There is a special program for low-noise construction machinery. A program for low-noise chain saws is listed separately. The Blue Angel program awards a special label to be affixed to products that perform significantly better than the prevailing regulations.
Low-noise Construction Machinery
Performance requirements are given for various types of construction machinery, including: graders, loaders, excavators, other tracked machines, compressors, power generators, welding-current generators, combined generators, road-making vehicles, concrete mixer trucks, tower cranes, and concrete pumps. Criteria are stated in terms of performance categories, measuring method, operating conditions, and required sound intensity level in LWA. (Sound intensity - or power- level usually is from 10 dB to 20 dB higher than sound pressure level.)
For construction noise equipment to merit the Blue Angel Label the sound pressure level at the workplace must not exceed 80 dBA.
Low-noise Construction Machinery - Label Users and Products as of Jan. 2001
Names and addresses of companies are given for all low-noise label users. Countries are not listed, but can usually be inferred, for example, Saint-Dizier is in France, Leistung in Germany, Hannover in Germany, Volvo in Eskilstuna is in Sweden, etc. The only American manufacturer is Caterpillar, but only the offices in Belgium and the U.K. are listed, indicating that no American company is marketing products that qualify for the Blue Angel label in the U.S.
Performance requirements are given for both electric-motor and combustion-engine chain saws. The noise requirements are stated in terms of drive, operating state (no-load or on-load operation), the A-weighted sound intensity level, and in this case the sound pressure level at the user’s ear in dBA. The operating instructions must include a note advising the user to wear ear muffs if the saw is operated for more than 2.5 hours per day. Allowable sound pressure levels range from 82 dBA for combustion engine saws in the no-load condition, to 95 dBA no-load at full speed. Maximum on-load operations for both types of equipment are 92 dBA.
Chain Saw Label Users and Products as of Jan. 2001
Four companies are listed, all of them German.
Sound Alert Technologies is a company located in Leeds in the U.K. Sound Alert markets a product called “The Localizer,” which uses electronic circuitry in speaker devices, producing directional sound that facilitates the identification and localization of important signals, such as warning sounds or sirens.
One of the applications of “The Localizer” is in reverse alarms, or back-up signals. This information sheet states that between 1986 and 1996 nearly 5,000 people (presumably in the U.K.) were killed or injured as a result of being struck by moving vehicles. Twenty-five percent of these accidents occurred while the vehicle was reversing. The company advocates using The Localizer to overcome some of the directional and masking problems inherent in the use of conventional alarms.
This is a summary of the physical and physiological processes involved in sound localization, including the differences in timing and loudness at each ear, and why broadband noise signals are more easily localized than the narrow bands or pure-tone signals.
“Localisable Alarms,” by Deborah J. Withington, is a 5-page extract of a book chapter from “Human Factors in Auditory Warnings” by N.A. Stanton and J. Edworthy, published in 1999. Stanton and Edworthy are well-known researchers in the area of audible warning signals in the U.K. Withington emphasizes the need for a multi-frequency signal for effective localization. For optimal localization she recommends sounds characterized by pulses of rapidly rising frequency sweeps, followed by a burst of broadband noise. Although most of this paper concerns emergency sirens, certain of the findings should also apply to reverse alarms.
This is a list of items published by Sound Alert, including PowerPoint Presentations and research papers.
An article from the Canadian Edition of Time (12-4-00) contained a short write-up of a concrete cutter being developed by the Brookhaven National Laboratory called “Raptor.” It is a gasoline-powered gun that fires projectiles into concrete as a cutting mechanism. The developers anticipate a sound level of approximately 82 dB.
“Sound solutions: Techniques to reduce noise at work,” was published by the British Health and Safety Executive in 1995. The book consists of 60 case studies of noise control solutions, most of which pertain to general industry, but several could apply to the construction industry. These include: reducing noise in dump trucks (also when loading dump trucks), drag-line cabs, crew-carrying road vehicles, pneumatic screwdrivers, vertical grinders, and saw blades used for stone cutting. Each case describes the problem, the solution, the cost of quieting, and the resulting reduction in dBA. Some of the solutions are costly, and in others the cost is negligible. The book also includes a comprehensive checklist for managers, written in practical language.
Noise in Construction: Further guidance on the Noise at Work Regulations, 1989. This booklet describes the duties of employers and employees in complying with the U.K.’s noise at Work Regulations. It includes a chart of construction activities and their associated noise exposure levels.
Keep the Noise Down. Advice to employers about the reasons for buying quieter machinery, their legal duties, and information that they should receive from equipment suppliers.
Buying New Machinery. A short guide to health and safety laws that purchasers need to know about when buying new machinery. Contains information about the European Community’s Machinery Directive and the CE marking. (Noise is included as a factor.) Supplying New Machinery. A short guide to health and safety laws that manufacturers and suppliers need to know about, including the EC’s Machinery Directive and the CE marking. (Noise is included.)
Report from the Workers’ Compensation Board of B.C.
Construction Noise is a report developed by Stuart Eaton of the Engineering Section, Workers’ Compensation Board of British Columbia, dated February 2000. In addition to a discussion of noise exposure levels by trade, activity, equipment, and construction stage, the report discusses various approaches to noise control. The section on engineering noise control covers various types of equipment, such as mobile equipment, pile drivers, portable air compressors, hand tools, pneumatic tools, etc. Another section discusses practical on-site noise control methods, such as the erection of barriers and equipment maintenance, as well as a brief discussion of hearing protection devices. A section on “inspection hints” provides a checklist for managers.
Articles from Noise Control Engineering Journal
“A global vision for the noise control marketplace,” by B.M Brooks, T.J. DuBois, R.M. Hoover, G.C. Mailing, and L.C. Sutherland. NCEJ, 44 (3), 1996. This article discusses progress that has been made over the past 25 years in the U.S. to define the dangers of noise exposure, issue regulations, and develop the means to control it. The authors state that today’s manufacturers are challenged by increased motivation for noise control, especially those companies which seek to sell their products in Europe or Japan, where they must meet stricter standards for noise than now exist in the U.S. In addition, they note that foreign companies that live with stricter standards are producing quiet products that compete favorably with U.S. products (mainly consumer products.) Their recommendations include an information clearing house that will provide manufacturers, consumers, and other interested parties with documentation on noise assessment, measurement, mitigation, and management, as well as a database on the feasibility and costs of engineering noise controls.
“Construction noise control program and mitigation strategy at the Central Artery/Tunnel Project,” by E. Thalheimer, NCEJ, 48 (5), 2000. This article deals mainly with the hardship that construction noise poses for neighboring communities. The author states that the solution is a willingness to use any and all reasonable and feasible noise control to mitigate construction noise. Suggestions for source controls include restrictions on the type of equipment used, specifications for stringent noise emission limits, use of quieter methods or equipment when possible, the use of quality exhaust mufflers, and lubrication and maintenance. He states that the greatest single source of noise complaints from communities results from the use of loud back-up alarms on vehicles working at night. The project has even prohibited the use of back-up alarms at night, requiring the contractor to use dedicated observers to comply with OSHA requirements.
Papers from Noise-Con 2000 - Newport Beach, CA
“Noise control and the machinery safety standardization programme of CEN (European Standardization Committee)” by J. Jacques, R. Higginson, and P.Kurtz. This paper discusses current information on the complex relationships between different European standards bodies and types of standards, with particular emphasis on machinery nosie.
“Recent development in European noise legislation concerning construction equipment” by V.K.P. Irmer. The paper gives background on the establishment of noise standards by the European Community. Prior to 1997 the focus was mainly economic, but with the Amsterdam Treaty, the Commission has become concerned with a “high level of protection,” paying particular attention to any new scientific developments. The Commission published a directive in July of 2000 that identifies 22 types of equipment used out of doors. Noise limits are set forward in two steps, the first starting on 1-3-02 and the second on 1-3-06, with a reduction in allowable limits of 2 to 3 dB between these two stages. The directive gives guidance for measuring noise and labeling equipment, and makes requirements for permissible sound power levels. All equipment must be labeled with the CE mark and an indication of its guaranteed sound power level. Noisy products have been selected so that in the first phase, only some very noisy products are eliminated from the market, but in the second phase, about 50 % of the products now on the market may not be sold. The directive also orders periodic checks to verify compliance. A repository of noise data will be collected by the Commission, which may serve to guide customers to low-noise equipment, and it could also be viewed as an incentive for companies to develop low-noise equipment. Member states of the EU are now obliged to adopt and publish their own national legislation to comply with the directive no later than 7-3-01. The author recognizes that the European market, with its 375 million citizens, “is a very big and interesting one, and is not only served by European industry.” Although manufacturers in non-European nations have not been very interested in these kinds of rules in the past, they are now being challenged by these more stringent requirements.
“Legislation concerning construction noise in Germany” by E. F.-S. Ali and V.K.P. Irmer. This paper reviews the history and current status of the Blue Angel program in Germany. The authors state that the differences between current noise limits and the Blue Angel criteria range from 5 dBA to 14 dBA, depending upon the type of construction machine. There are more than 40 companies that have applied for the Blue Angel label and around 200 products to which the label has been awarded. The power range of low-noise construction equipment has been broadened to about 200 kW, such that “nearly all construction machines used in urban areas may be bought in a low noise version.”
EPA regulation of portable air compressors for noise
Title 40, Chapter I, Part 204 from the Code of Federal Regulations has been reproduced, which covers noise emission standards for portable air compressors. This is the only regulation from EPA’s Office of Noise Abatement concerning construction noise that has survived the closing of the noise program. It calls for a maximum sound level of 76 dBA when measured and evaluated according to specified test procedures. The regulation requires a permanently attached label in a readily visible position on the compressor enclosure. It also includes testing and anti-tampering requirements, and instructions for maintenance, use and repair. However, since the Office of Noise Abatement was closed in 1982, the regulation has not been enforced.