The ANSI guideline on machine risk assessment, B11-TR3, describes risk assessment as an iterative process. This implies that protective measures of varied levels of technology can be successively evaluated until a risk that is acceptable is attained. The theories of risk acceptance are many. Reducing risk to a level that is agreed to be 'as low as reasonably practicable' (ALARP) is said to give focus to making a decision about when risk has been adequately reduced. Main (2004) says that "Although the concept of acceptable risk is becoming more commonly adopted throughout the world, a single level of acceptability cannot be universally applied. Acceptable risk is a function of many factors, and is specific to a company, culture, and time-era." Fischhoff et al. (1981) have argued that "the risk associated with the most acceptable option is not acceptable in any absolute sense. One accepts options, not risks, which are only one feature of options." This paper describes risk assessment groups in five manufacturing workplaces and discusses training that led to acceptable risk decisions for a hazardous machine system in each workplace. The composition of the five teams in this study ranged from a team with just a single engineer to teams involving several workplace personnel. The applied preventive measures ranged from measures that were tailored to meet corporate safety goals to measures that evolved from the local risk assessment team's ingenuity. The paper concludes with suggestions on how to make the risk acceptance concept meaningful in the training of future machine risk assessment teams.

ANSI B11-TR3 [2000] Risk Assessment and Risk Reduction-A Guide to Estimate, Evaluate and Reduce Risks Associated with Machine Tools. The Association for Manufacturing Technology, McLean, VA.
Archambault R [1974] John Dewey on Education: Selected Writings, Chicago, University of Chicago Press.
Clancey W [1995] A Tutorial on Situated Learning, In Proceedings of the International Conference on Computers and Education (Taiwan), J. Self, Ed. Charlottesville, VA: AACE. 49-70.
Cotter D [1986] Work-related Deaths in 1984: BLS survey findings. Research summaries. Monthly Labor Review (May):42-44.
Dewey J [1959] Dewey on Education: Selections, New York, Teachers College Press.
Etherton J, Main B, Cloutier D and Christensen W in press Reducing Risk on Machinery: A Field Evaluation Pilot Study of Risk Assessment, Risk Analysis Journal.
Guidelines for a NIOSH Policy on Occupational Carcinogenesis
Ann. N. Y. Acad. Sci.
Acceptable Risk: A Conceptual Proposal
Risk: Health, Safety & Environment
Fischhoff B, Lichtenstein S, Slovic P, Derby S and Keeney R [1981] Acceptable Risk, Cambridge University Press, Cambridge.
Health and Safety Executive [2001] Reducing Risks, Protecting People: HSE’s Decision Making Process, Health and Safety Executive. Available at:
ISO 12100-1 [2003] Safety of Machinery. Basic Terminology, Methodology. ISO, Geneva. Available at:
ISO 14121 [2006] Safety of Machinery–Risk Assessment – Part 1: Principles, ISO, Geneva. Available at:
Jensen P [2001] Risk assessment: A Regulatory Strategy for Stimulating Working Environment Activities? Human Factors and Ergonomics in Manufacturing, 11(2), 101–116.
Lowrance W [1976] Of Acceptable Risk: Science and the Determination of Safety, William Kaufman, Inc., Los Altos, CA.
Main B [2004] Risk Assessment: Basics and Benchmarks, Design Safety Engineering, Ann Arbor, MI.
National Academy of Science [2000] Safe Work in the 21st Century: Education and Training Needs for the Next Decade’s Occupational Safety and Health Personnel, Washington DC.
National Academy of Science 2004 Appendix B: Review of Acceptable Cancer Risk Levels, in Review of the Army’s Technical Guides on Assessing and Managing Chemical Hazards to Deployed Personnel, Washington DC.
National Institute for Occupational Safety and Health 2002 NIOSH Pocket Guide to Chemical Hazards, Appendix A. NIOSH Potential Occupational Carcinogens. NIOSH, U.S. Dept. of Health and Human Services, Cincinnati, OH
Rodricks J, Brett S, and Wrenn G 1987 Significant Risk Decisions in Federal Regulatory Agencies. Regul. Toxicol. Pharmacol. 7(3):307–320.
Rogers C and Freiberg H 1994 Freedom to Learn (3rd Ed). Columbus, OH: Merrill/Macmillan.
Slovic P 1993 Perceived Risk, Trust, and Democracy, Risk Analysis 13(6), 675-82.
SOII 2006 Survey of occupational injuries and illnesses. Washington, DC: U.S. Department of Labor, Bureau of Labor Statistics. Database.
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