Safe enough

The core function of QRA is to provide information for decision making. QRA results in and of themselves cannot prove anything. However, decision makers can compare QRA risk estimates to their own risk tolerance criteria to decide whether a plant or operation is safe enough. The same QRA results can support both the plant manager s contention that the plant is safe, as well as the community activist s claim that the plant is unsafe. The difference lies in the individual s risk tolerance, not the QRA. 

Relative risk results show only the difference between the levels of safety of one or more cases of interest and a reference, or baseline, case. Relative risk estimates can be used (as can absolute estimates) to determine the most efficient way to improve safety at a facility. But, the use of relative risk estimates alone does little to help ensure that the most efficient way is safe enough unless one of the cases meets qualitative safety criteria (e.g., compliance with relevant codes, standards, and/or regulations consistency with current industry practice). 

The literature on this subject is so large that it cannot be encompassed in a brief review. N UR CG/CR-1030(1981) is a bibliographical survey of 123 references Covello, 1981 lists 148 rcler-ences. Since no risk should be tolerated if it has no benefits, most of the papers address the question "How safe is safe enough," by comparisons with acceptable risks. (In many cases these "acceptable" risks are really "tolerated" risks in that the cost of reduction does not seem to be warranted.)... 

After reading that, you might expect that such a dangerous chemical had no business being around people, especially children. Yet in actuality, its a chemical we can t live without salt. And it s safe enough to put in shampoo. 

It was not so likely. Warwick s archers shot at the lords about the King, not the commons, and they know their business. We were safe enough. ... 

Mark holds out a hand to me, palm down, the way you do when you want to touch someone just a little, at a safe distance. Yes, I stayed. . . Our eyes meet, but not with the heat of our shared past and present as they did at the castle. He looks tired and a little sad. Maybe he feels I m a safe distance away from him, safe enough to say these things, to ask for just a little help. His hand cups the back of mine for a moment. 

If the placebo effect in depression is so powerful, perhaps we should just prescribe inert placebos to depressed patients. They have been tested in thousands of clinical trials, they are the standard against which all other medications are evaluated, and they are safe enough to be taken by pregnant women, small children,... 

Nitro Compounds, Feuer H. Nielsen A. T. (Eds), New York, VCH, 1990, 315 The crude product is too explosive to be worked up. Analogy with other olefins indicates that the final product will be ethylene glycol dinitrate, a known explosive though safe enough to have largely replaced nitroglycerine. That will be preceded by 1,2-dinitroethane and nitratonitroethane, more sensitive if less powerful. 

Fischhoff, B., Slovic, P., Lichtenstein, S., Read, S., and Combs, B. 1978. How safe is safe enough A psychometric study of attitudes towards technological risks and benefits. Policy Sci. 9, 127-152. 

The main drawback of the use of color reactions for the analysis of explosives lies in their often low specificity. Although their specificity varies according to the type of reactions - and some reactions are quite specific - it is generally not safe enough to establish an identification of an explosive in a forensic laboratory on color reactions alone. When the color is obtained, the key question is whether other compounds, which are not explosives, can produce the same color under identical experimental conditions. Unfortunately, the answer is usually, yes. Thus, in forensic analysis, where an erroneous identification may lead to a gross injustice, it is generally accepted that the identification of an explosive should not depend on color reactions alone. 

Slovic, P, Fischhoff, B. and Lichtenstein, S. (1980) Facts and fears Understanding perceived risk , in R. C. Schwing and W. A. Albers Jr (eds) Societal Risk Assessment How Safe is Safe Enough , General Motors Research Laboratories, Plenum Press, New York Thompson, M. (1980) The aesthetics of risk , in J. Perrin (ed) Mirrors in the Cliffs, Diadem Books, London... 

Vessey MP, Doll R. Evaluation of existing techniques is the pill safe enough to continue using Proc R Soc Lond B Biol Sci 1976 195(1118) 69-80. 

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