Volume 4: s-z; Appendices; Index EDITORS AND CONSULTANTS EDITOR IN CHIEF Eric Cohen Helen Nissenbaum Carl Mitcham Ethicsand Public PolicyCenter Associate Professor, Cultureand Com- munication,Computer Science, New Professor, Liberal ArtsandInternational Stephen H. Cutcliffe YorkUniversity Studies, ColoradoSchool ofMines; Professor,History; Professor and Chair, Faculty Affiliate,Center forScienceand Science, Technology, and SocietyPro- Roger A. Pielke, Jr. Technology Policy gram,Lehigh University Professor, Environmental Studies; Research, University ofColorado, Director, Center forScience andTech- Paul T. Durbin Boulder nology Policy Research,University of Professor Emeritus,Philosophy, Univer- Colorado, Boulder sityofDelaware ASSOCIATE EDITORS Michael Ruse Deni Elliott Larry Arnhart LucyleT. Werkmeister Professor of Poynter Jamison ChairinMedia Ethics Professor, Political Science,Northern Philosophy, Florida StateUniversity andPressPolicy, University ofSouth Illinois University Florida Daniel Sarewitz Deborah G. Johnson Professor,ScienceandSociety;Director, Franz Allen Foltz Anne Shirley Carter OlssonProfessor of Consortium for Science, Policy,and Associate Professor, Science, Technol- Applied Ethics andChair, Science, Outcomes, Arizona StateUniversity ogy, andSociety, Rochester Institute of Technology, andSociety, University of A. George Schillinger Technology Virginia Professor Emeritus, Management, Poly- Robert Frodeman Raymond E. Spier technicUniversity, Brooklyn Associate Professor andChair, Philo- Emeritus Professor, Scienceand Engi- Paul B. Thompson sophyandReligionStudies,Universityof neering Ethics, University ofSurrey North Texas W.K.Kellogg Professor ofAgricultural, Foodand CommunityEthics, Michigan SPECIAL EDITORIAL Francis Fukuyama StateUniversity CONSULTANT Bernard L.Schwartz Professor in Inter- Nancy Tuana national Political Economy, Johns Hop- Stephanie J. Bird Professor, Philosophy; Director, Rock kins University Editor, Scienceand Engineering Ethics EthicsInstitute, Pennsylvania State Rachelle Hollander University CONSULTANTS Baltimore, Maryland Vivian Weil Robert H. Blank Sheldon Krimsky Professor, Ethics; Director, Centerfor Professor, Public Policy, Brunel Professor,Urban andEnvironmental the Study ofEthicsin the Professions, University Policyand Planning, Tufts University Illinois Institute ofTechnology George Bugliarello Jose´ Antonio Lo´pez Cerezo Caroline Whitbeck Professor,CivilEngineering;Chancellor, Professor,Philosophy ofScience, Uni- Elmer G.Beamer–HubertH.Schneider Polytechnic University, Brooklyn versityofOviedo, Spain Professor inEthics, Case Western Re- Ruth Chadwick Valerie Mike´ serve University Professor, InstituteofEnvironment, ClinicalProfessor, Public Health, John Ziman Philosophy, andPublic Policy, Lancaster WeillMedicalCollege ofCornell Emeritus Professor, Physics, Bristol University, UK University University (dec.) ii EDITED BY CARL MITCHAM volume 4 s–z appendices index GALE Encyclopediaof Science,Technology,andEthics CarlMitcham,EditorinChief #2005ThomsonGale,apartofTheThomson ALLRIGHTSRESERVED Forpermissiontousematerialfromthispro- Corporation. 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LIBRARYOFCONGRESSCATALOGING-IN-PUBLICATIONDATA Encyclopediaofscience,technology,andethics/editedbyCarlMitcham. p.cm. Includesbibliographicalreferencesandindex. ISBN0-02-865831-0(set,hardcover:alk.paper)—ISBN0-02-865832-9(v.1)— ISBN0-02-865833-7(v.2)—ISBN0-02-865834-5(v.3)—ISBN0-02-865901-5(v.4) 1. Science—Moralandethicalaspects—Encyclopedias. 2. Technology—Moralandethicalaspects–Encyclopedias. I.Mitcham,Carl.Q175.35.E532005 503—dc22 005006968 Whileeveryefforthasbeenmadetoensurethereliabilityoftheinformation presentedinthispublication,ThomsonGaledoesnotguaranteetheaccuracyof thedatacontainedherein.ThomsonGaleacceptsnopaymentforlisting;and inclusioninthepublicationofanyorganization,agency,institution,publication, service,orindividualdoesnotimplyendorsementoftheeditorsorpublisher. Errorsbroughttotheattentionofthepublisherandverifiedtothesatisfactionof thepublisherwillbecorrectedinfutureeditions. Thistitleisalsoavailableasane-book. ISBN0-02-865991-0 ContactyourThomsonGalerepresentativefororderinginformation. PrintedintheUnitedStatesofAmerica 10987654321 S SAFETY ENGINEERING theywereacceptedbyworkersandthepublicasaneces- saryconcomitanttotechnologicalprogress. (cid:1)(cid:1)(cid:1) However,overthecourseofthenineteenthcentury HistoricalEmergence the protection of human safety became an increasingly Practices important priority for engineers, companies, and even- tually federal and state governments. Indeed, the first HISTORICAL EMERGENCE scientificresearchcontractfromthefederalgovernment was issued to the Franklin Institute in Philadelphia in The protection of people from harm increasingly has 1830toinvestigatethecausesofsteamboatboilerexplo- been a focus of many fields of engineering since the sionsandtoproposesolutions(Burke1966). nineteenthcentury.AtthedawnoftheIndustrialRevo- lution (c. 1750–1850) engineers, as the term is used As each new technology matured to the point today, devoted their efforts almost entirely to making where advances in performance were incremental, a devicesthatfunctionedreliablyandprofitably,butwith poor safety record became a barrier to increased public littleattentiontosafety.OnenotableexceptionisJames acceptance and use. Workers began to organize into Watt (1736–1819), the so-called inventor of the steam unions and insist that they be better protected from engine.Despiteintroducingnumerousimprovementson workplacehazards.Engineeringsocieties,whoseoriginal the Newcomen steam engine, Watt intentionally charters tended to stress the promotion and facilitation resisted building a high-pressure engine because of the of the profession(cid:1)s work, by the mid-twentieth century dangers it posed to those working with it. In fact, when began to impose safety as a primary ethical duty of the Richard Trevithick (1771–1833) began experiments engineer. The end of the nineteenth century also wit- with the high-pressure steam engine, which increased nessed the development of safety codes and standards both efficiency and power, Watt (and his partner Mat- governing the use of natural gas and electricity, the thewBoulton)petitionedParliamenttopassanactout- design of building and steam boilers, and the storage lawingtheuseofsuchenginesasapublicdanger. anduseofexplosives. The second generation masters of steam power for Inthetwenty-firstcenturynearlyeveryengineering railroadsandsteamboatsthusbroughtwiththemboiler codeofethicsstressesthesafetyofworkersandthepub- explosions, brakeman maimings, and wrecks causing lic. The American Nuclear Society(cid:1)s Code of Ethics astonishing loss of life. In Life on the Mississippi (1883) (2003)states: and again in Huckleberry Finn (1894) Mark Twain We hold paramount the safety, health, and wel- described in vivid detail the explosion of steam ships fareofthepublicandfellowworkers,worktopro- andthe resultant deathandinjuryofpassengers. Manu- tect the environment, and strive to comply with factories too subjected workers (and often those living the principles of sustainable development in the nearby) to industrial accidents, toxic fumes, and loss of performance of our professional duties. The first hearing. Although those risks were hardly unknown, commitment in the Code of Ethics for the Insti- 1673 SAFETYENGINEERING tute of Electrical and Electronic Engineers man- SEEALSO EngineeringEthics;SafetyFactors. dates that members ... accept responsibility in makingengineering decisionsconsistentwiththe BIBLIOGRAPHY safety, health and welfare of the public, and to Burke, John G. (1966). ‘‘Bursting Boilers and the Federal disclosepromptlyfactorsthatmightendangerthe Power.’’ Technology and Culture 7:1(1–23). A widely rep- public or theenvironment(InstituteofElectrical rinted article. For critical comment, see Richard N. Lan- andElectronicEngineers1990). glois, David J. Denault, and Samson M. Kimenyi, ‘‘Burst- ing Boilers and the Federal Power Redux: The Evolution All licensed professional engineers are bound by of Safety on the Western Waters,’’ University of Connecti- the Code of Ethics for Engineers promulgated by the cut Department of Economics Working Papers Series (May 1994). NationalSocietyofProfessionalEngineers.BothFunda- mental Canon No. 1 and the first Rule of Practice Joyce,MalcolmJ.,andDerekW.Seward.(2002).‘‘Innovative M.Sc. in Safety Engineering—A Model for Industry-Based impose on the engineer a duty to ‘‘hold paramount the Courses in the 21st Century?’’ Engineering Education 2002: safety, health and welfare of the public’’ (National ProfessionalEngineeringScenarios2002/056:(2:28/6). SocietyofProfessionalEngineers2003). INTERNETRESOURCES Apart from these commitments by long-standing communities of engineers there are many engineers American Nuclear Society. Code of Ethics. (2003). Avail- ableatwww.ans.org. whose work is devoted entirely to the protection of the AmericanSocietyofSafetyEngineers.(2004).VisionState- public and workers from the hazards of technology and ment.Availableatwww.asse.org. natural phenomena: Fire protection engineering, auto- Institute of Electrical and Electronic Engineers. Code of mobile safety engineering, and industrial safety engi- Ethics.(1990).Availableatwww.ieee.org. neering are a few examples. Safety engineering is itself National Society of Professional Engineers. Code of Ethics. an engineering discipline; its practitioners attempt to (2003).Availableatwww.nspe.org. understandthewaysinwhichtechnologicalsystemsfail and discover ways to prevent such failures. The Ameri- can Society of Safety Engineers, founded in 1911 and PRACTICES now numbering over 30,000 members, is devoted to Safety is one of the primary goals of engineering. In being ‘‘the premier organization and resource for those most ethical codes for engineers safety is mentioned as engaged in the practice of protecting people, property an essential area of professional competence and and the environment, and to lead the profession glob- responsibility. ally’’(AmericanSocietyofSafetyEngineers2004). In everyday language, the term safety is often used Theintertwiningofengineeringandsafetyprobably todenoteabsolutesafety,thatis,certaintythataccidents willintensifyinthefutureinresponsetoconstantlyris- or other harms will not occur. In engineering practice, ing public expectations. Two prominent engineering safetyisanidealthatcanbeapproached,butneverfully scholars in Lancaster University(cid:1)s Department of Engi- attained. What can be achieved is relative safety, mean- neering have observed the large gap between the safety ing that it is unlikely but not impossible that harm will expectations of today and those in the early days of occur. The safety requirements in regulations and stan- moderntechnologies: dards represent different (and mostly high) levels of Safety is rapidly becoming a means by which the relative safety. Industries with high safety ambitions, public and governments judge the viability of such as airway traffic, are characterized by continuous organisationsinvolvedinsafety-related processes, endeavorstoimprovethelevelofsafety. possiblymoresothanenvironmentalissues.Many large organisations could not afford a single, Theambiguitybetweenabsoluteandrelative safety large-scaleincidentasaresultofaninferiorsafety is a common cause of misunderstandings between culture, despite buoyant economics. This is a sig- experts and the public. Both concepts are useful, but it nificant dynamic departure from past public isessentialtodistinguishbetweenthem. acceptabilityoffatalincidents(JoyceandSeward In decision theory, lack of knowledge is divided 2004). into the two major categories: ‘‘risk’’and ‘‘uncertainty.’’ The dedication of the engineering profession to Indecision-makingunderrisk,theprobabilitiesofpossi- safety as a primary goal and an ethical duty is in accor- ble outcomes are known, whereas in decision-making dancewiththischangeinpublicexpectations. under uncertainty, probabilities are either unknown or WILLIAM M. SHIELDS known with insufficient precision. In engineering prac- 1674 EncyclopediaofScience,Technology,andEthics SAFETYFACTORS tice, both risk and uncertainty have to be taken into tions or pieces of equipment that were originally in account. Even when engineers have a good estimate of excellent shape. Regular inspections by persons with the probability (risk) of failure, some uncertainty sufficient competence and mandate are an efficient remainsaboutthecorrectnessofthisestimate. meanstopreventthisfromhappening. Safety has often been defined as the antonym of Educated and responsible operators. Human mistakes risk, but that is only part of the truth. In order to areanimportantsourceofaccidents.Anefficientcoun- achievesafetyinpracticalapplications,thedangersthat termeasureistoeducateworkers,authorizethemtotem- originate in uncertainty are equally important to elimi- porarily stop processes they consider to be acutely dan- nateorreduceasthosethatcanbeexpressedintermsof gerous, and encourage them to take initiatives to risk. Many safety measures in engineering are taken to improvesafety. diminish the damages that would follow from possible unknown sources of failures. Such measures protect Incidence reporting. Experience from air traffic and againstuncertaintyratherthanrisk. nuclearenergyshowsthatsystemsforreportingandana- lyzing safety incidents are an efficientmeansto prevent Several methods are used by engineers to achieve accidents. Systems for anonymous reporting facilitate safetyinthedesignandoperationofpotentiallydanger- thereportingofhumanmistakes. oustechnology. Inherently safe design. The first step in safety engi- Safety management. Safety can be achieved only in neering should always be to minimize the inherent dan- anorganizationwhosetopmanagementgivespriorityto gersintheprocessasfaraspossible.Dangeroussubstances safetyandaimsatcontinuousimprovement. orreactionscanbereplacedbylessdangerousones.Fire- proofmaterialscanbeusedinsteadofflammableones.In SVEN OVE HANSSON somecases,temperatureorpressurecanbereduced. Safety reserves. Constructions should be strong SEE ALSO Airplanes; Automobiles; Aviation Regulatory enough to resist loads and disturbances exceeding those Agencies; Building Destruction and Collapse; Engineering that are intended. In most cases, the best way to obtain Ethics; Fire; Regulatory Toxicology; Robot Toys; Safety sufficient safety reserves is to employ explicitly chosen Factors. safetyfactors. BIBLIOGRAPHY Negativefeedback.Dangerousoperationsshouldhave negative feedback mechanisms that lead to a self-shut- Marshall, Gilbert. (2000). Safety Engineering, 3rd edition. Des Plaines, IL: American Society of Safety Engineers. downincriticalaccidentsituationsorwhentheoperator General safety principles and their application on indus- losescontrol.Twoclassicalexamplesarethesafetyvalve trialworkplaces. that lets out steam when the pressure becomes too high inasteamboilerandthe‘‘deadman(cid:1)shandle’’thatstops the train when the driver falls asleep. One of the most SAFETY FACTORS important safety measures inthe nuclear energyindustry istoensurethata nuclearreactorclosesdownautomati- (cid:1)(cid:1)(cid:1) callywhenameltdownapproaches. A safety factor (also called an uncertainty factor or Multiple independent safety barriers. In order to avert assessment factor) is a number by which some variable serious dangers, a chain of barriers is needed, each of such as load or dose is multiplied or divided in order to which is independent of its predecessors so that if the increase safety. Safety factors are used in engineering firstfails,thenthesecondisstillintact,andsoon.Typi- design,toxicology,andotherdisciplinestoavoidvarious cally the first barriers are measures to prevent an acci- typesoffailure. dent, after which follow barriers that limit the conse- The sources of failure that safety factors are quencesofanaccident,andfinallyrescueservicesasthe intended to protect against can be divided into two lastresort.OneofthemajorlessonsfromtheTitanicdis- major categories: (a) the variability of conditions that aster(1912)isthatanimprovementoftheearlybarriers influence the risk of failure, such as variations in the is no excuse for reducing the later barriers (such as strength of steel and in the sensitivity of humans to accesstolifeboats). toxic substances, and (b) the uncertainty of human Maintenance and inspections. Many severe accidents knowledge, including the possibility that the models have resulted from insufficient maintenance of installa- usedforriskassessmentmaybeinaccurate. EncyclopediaofScience,Technology,andEthics 1675 SAKHAROV,ANDREI Safety factors are used to obtain a safety reserve, a tionship), then the risk reduction will be proportionate margin between actual conditions andthose that would to the safety factor. If the dose–response relationship is lead to failure. Safety reserves can also be obtained nonlinear,thenthereductioninriskcanbeeithermore withouttheuseofexplicitlychosensafetyfactors. or less than proportionate. Because the dose–response relationship at very low doses is always unknown, the At least since antiquity, builders have obtained exact effect of using a safety factor cannot be known safety reserves by adding extra strength to their con- withcertainty. structions.The earliest knownuse ofexplicit safety fac- tors in engineering dates from the 1860s. In modern Natural organisms often have safety reserves that engineering, safety factors are used to compensate for can be described in terms of safety factors. Structural fivetypesoffailure: safety factors have been calculated for mammalian bones,crabclaws,shellsoflimpets,andtreestems.Nat- (1) higherloadsthanthoseforeseen, uralsafetyreservesmaketheorganismbetterabletosur- (2) worsepropertiesofthematerialthanforeseen, vive unusual conditions. Hence, the extra strength of (3) imperfect theory of the failure mechanism in tree stems makes it possible for them to withstand question, storms even if they have been damaged by insects. But safety reserves also have their costs. Trees with large (4) possiblyunknownfailuremechanisms,and safetyreservesarebetterabletoresiststorms,butinthe (5) humanerrorindesignorcalculations. competition for light reception, they may lose out to Thefirsttwoofthesecaningeneralbeclassifiedasvari- tenderandhightreeswithsmallersafetyreserves. abilities,whereasthelastthreebelongtothecategoryof At least two important lessons can learned from (genuine)uncertainty. nature in this context. First, resistance to unusual loads In order to be an efficient guide for safe design, isessentialforsurvival.Second,abalancewillneverthe- safety factors should be applied to all the integrity- less always have to be struck between the dangers of threatening mechanisms that can occur. For instance, havingtoolittlereservecapacityandthecostsofhaving onesafetyfactormayberequiredforresistancetoplastic an unused reserve capacity. Perfect safety cannot be deformation and anotherfor fatigueresistance. Asafety obtained,butachosenbalancebetweensafetyandcosts factor is mostcommonly expressed as the ratio between can be implemented with the help of safety factors and ameasureofthemaximalloadnotleadingtothespeci- otherregulationinstruments. fied type of failure and a corresponding measure of the applied load. In some cases it may be preferable to SVEN OVE HANSSON express the safety factor as the ratio between the esti- mateddesignlifeandtheactualservicelife. SEE ALSO BioengineeringEthics;EngineeringEthics;Safety The use of explicit safety factors in regulatory toxi- Engineering. cology dates from the middle of the twentieth century. In 1954 Arnold J. Lehman and O. Garth Fitzhugh, two BIBLIOGRAPHY U.S. Food and Drug Administration (FDA) toxicolo- Dourson,MichaelL.,andJerryF.Stara.(1983).‘‘Regulatory gists, proposed that ADIs (acceptable daily intakes) for HistoryandExperimentalSupportofUncertainty(Safety) food additives be obtained by dividing the lowest dose Factors.’’ Regulatory Toxicology and Pharmacology 3(3): causing no harm in experimental animals (counted per 224–238.Safetyfactorsintoxicology. kilogram body weight) by 100. This value of 100 is still Randall, F. A. (1976). ‘‘The Safety Factor of Structures in widely used. It is now often accounted for as being the History.’’ProfessionalSafety,January:12–28.Safetyfactors inengineeringdesign. product of two subfactors: one factor of 10 for interspe- cies (animal to human) variability in response to the toxicity and another factor of 10 for intraspecies (human) variability in the same respect. Higher safety factorssuchas1,000,2,000,andeven5,000canbeused SAKHAROV, ANDREI intheregulationofsubstancesbelievedtoinducesevere toxiceffectsinhumans. (cid:1)(cid:1)(cid:1) The effect of a safety factor on the actual risk Theoretical physicist and the ‘‘father of the Soviet H- dependsonthe dose–responserelationship. Ifthe riskis bomb,’’AndreiSakharov(1921–1989),whowasbornin proportionate to the dose (linear dose–response rela- Moscow on May 21, became a prominent human rights 1676 EncyclopediaofScience,Technology,andEthics