Hazard, risk & precaution in an imperfect world

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Hazard, risk & precaution in an imperfect world

  1. 1. Hazard, Risk & Precaution in an imperfect world. Dr David Taylor Royal Society of Chemistry Environment, Health & Safety CommitteeHazardous Substances Advisory Committee20th December 2012
  2. 2. The RSC Viewpoint• Risk assessment is an essential step in the management of both synthetic and naturally occurring chemical use.• Hazard assessment is necessary but insufficient on its own. – Substances cannot simply be ranked in order of ‘hazard’. • The question “which substance is the most hazardous?” does not have a simple answer. – Just because something is hazardous does not mean it isn’t useful. • Ozone (used for drinking water disinfection) is extremely hazardous. – Hazards can frequently be tightly controlled. • Electricity and natural gas are intrinsically very hazardous.• Decisions on substance use require assessment of all the hazards, their associated risks and their societal benefits.Hazardous Substances Advisory Committee20th December 2012
  3. 3. Choose the least hazardous solvent Toxicity Ecotoxicity VolatilityDecreasing hazard Dichloromethane Monochlorobenzene Dichloromethane Trichloromethane Trichloromethane Acetone Monochlorobenzene Toluene Trichloromethane Toluene Dichloromethane Toluene Acetone Acetone Monochlorobenzene Substances cannot be ranked in order of ‘hazard’ - Each substance has a ’hazard profile’ so ranking depends on the property Risk assessment is needed to identify the optimum solvent for any particular purpose taking into account the receptors being exposed.Hazardous Substances Advisory Committee20th December 2012
  4. 4. Practical Application GlaxoSmithKline Solvent Selection GuideHazardous Substances Advisory Committee20th December 2012
  5. 5. Use of hazardous substances is essential to modern society • Society demands substances that are specifically used to kill organisms. • Cytotoxic drugs • Antibiotics • Antiseptics • Biocides • Rodenticides • Fungicides • Insecticides • Herbicides Our objective should not be to eliminate hazardous substances but to manage them safely.Hazardous Substances Advisory Committee20th December 2012
  6. 6. High Hazard + Low Risk is commonplace in society Low Hazard But High Risk There were 19 fatal domesticelectrocutions in the UK in 2007Hazardous Substances Advisory Committee20th December 2012
  7. 7. “The Dose Makes the Poison !” Paracelsus (1541) >4 million patients currently take a daily dose of rat poison to prevent fatal thrombosisHazardous Substances Advisory Committee20th December 2012
  8. 8. Different lobby groups approach chemicals management from a range of perspectives Panglossian Chemicals don’t need global control Chemicals should be managed globally Pragmatic on the basis of potential risk Chemicals should be managed globally Precautionary on the basis of potential hazard Paranoid All synthetic chemicals should be phased outHazardous Substances Advisory Committee20th December 2012
  9. 9. The ‘Public’ The ‘Public’ tends to be pragmaticHazardous Substances Advisory Committee20th December 2012
  10. 10. ‘Public’ demand for chemicals management Chemicals don’t need global Panglossian control Chemicals should be Pragmatic managed globally on the basis of potential risk Chemicals should be Precautionary managed globally on the basis of potential hazard All synthetic chemicals Socio-Economic Paranoid should be phased out Case The general public offsets ‘unknown’ future risk against current benefitHazardous Substances Advisory Committee20th December 2012
  11. 11. Dealing with uncertainty Donald Rumsfeld & the Precautionary Principle • As we know, there are known knowns; Management – there are things we know we know. • We also know there are known unknowns; Risk Assessment – that is to say we know there are some things we do not know. • But there are also unknown unknowns Precaution – the ones we dont know we dont know US Department of Defence news briefing Feb 12, 2002Hazardous Substances Advisory Committee20th December 2012
  12. 12. The Precautionary Principle Can mean whatever you want it to mean • “Where there are threats of serious or irreversible damage, lack of scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation” UN Conference on Environment & Development, Rio 1992 • “When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically” Wingspread Conference, 1998 • “Do not use a substance until you have proof that it will do no harm to the environment” Greenpeace, 2000Hazardous Substances Advisory Committee20th December 2012
  13. 13. Better Safe than Sorry ? “No, no, sentence first - verdict afterwards” • The implication by the proponents of the precautionary principle is that its application has no negative effects but: – Applying the Precautionary Principle results in a loss of added value today in order to protect the population at an unspecified point in the future from an unknown consequence whose significance cannot currently be established. • EU has no GM Crop Technology Skills unlike USA, China & India – Actions that are over precautionary can have damaging impacts • FDA 6 year ß Blocker moratorium in the 1970s due to concern over potential for liver cancer is estimated to have cost 100,000 lives. – Action without adequate evidence may be the wrong action. • 1980’s advice on baby sleeping position resulted in an estimated 1000 unnecessary cot deaths per year.Hazardous Substances Advisory Committee20th December 2012
  14. 14. RSC & the Precautionary Principle • We fully support the definition of the Precautionary Principle as defined at the UN Conference in Rio in 1992. • We commend the European Commission Guidance Document of 2000 on the mechanism for its application. “Where there are threats of serious or irreversible • We damage, lack of scientific sometimesshallused on its think that hazard data can certainty be not be used as a reason for postponing cost-effective own to inform a precautionary approach to ‘substances of measures to prevent environmental degradation” very high concern’, – This may, through more careful risk monitoring, prevent significant future manifestation of currently unknown risks. – Decisions on appropriate action must also consider the likely degree of exposure & the ability to monitor the risk together with the potential loss of societal benefit if use is restricted.Hazardous Substances Advisory Committee20th December 2012
  15. 15. Minimisation of ‘unknown’ risks • Substances of potential future concern – Substances that are mobile & with long environmental half-lives are more likely to pose future problems than those that degrade rapidly and/or are immobile. – Substances produced in large quantities and that are widely dispersed in their use are more likely to pose future problems than those produced in small quantities for contained uses. – Substances that are biologically active are more likely to pose future problems than those that are biologically inert. – These are qualitative & incomplete generalisations, not rules. They should be used to inform decisions not make them. • We should therefore be more careful how we use a substance that is biologically active with a long half-life than a substance that is not biologically active that degrades rapidly. – However SVHCs should not be ‘banned’ just because they are SVHCsHazardous Substances Advisory Committee20th December 2012
  16. 16. Hazard, Risk & Diversity A simple example Control without taking risk into account requires exterminationHazardous Substances Advisory Committee20th December 2012
  17. 17. Chemical diversity, like biological diversity should not be reduced (unless absolutely necessary) • We cannot know what the future utility of any chemical will be to society. – Dimethyl Fumarate recently restricted in the EU as a mould inhibitor now in late stage clinical trials as a treatment for MS. – Hg is now an essential component in low energy light bulbs. – Chlorodifluoromethane (R22) was an essential component in 2008 for the manufacture of a replacement for WarfarinHazardous Substances Advisory Committee20th December 2012
  18. 18. Conclusions • Hazard data is essential but insufficient to make decisions on the management of chemical substances. • Hazard data in isolation should not be used to ‘ban’ substances: – Hazards can frequently be controlled satisfactorily. – Hazardous substances are required in modern society. – Chemical diversity needs to be maintained for future generations. • Hazard data in isolation can sometimes be used to inform precautionary actions. – Precautionary action should be reviewed as new data appears. • Risk Assessment is essential for substance managementHazardous Substances Advisory Committee20th December 2012
  19. 19. Always bear in mind that precautionary action based solely on hazard rather than risk can have very significant adverse consequencesHazardous Substances Advisory Committee20th December 2012

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