Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Hazard, risk & precaution in an imperfect world
1. Hazard, Risk & Precaution in
an imperfect world.
Dr David Taylor
Royal Society of Chemistry
Environment, Health &
Safety Committee
Hazardous Substances Advisory Committee
20th December 2012
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 Committee
20th December 2012
3. Choose the least hazardous
solvent
Toxicity Ecotoxicity Volatility
Decreasing 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 Committee
20th December 2012
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 Committee
20th December 2012
6. High Hazard + Low Risk is
commonplace in society
Low Hazard But
High Risk
There were 19 fatal domestic
electrocutions in the UK in 2007
Hazardous Substances Advisory Committee
20th December 2012
7. “The Dose Makes the
Poison !”
Paracelsus (1541)
>4 million patients currently take a daily dose of
rat poison to prevent fatal thrombosis
Hazardous Substances Advisory Committee
20th December 2012
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 out
Hazardous Substances Advisory Committee
20th December 2012
9. The ‘Public’
The ‘Public’ tends to be pragmatic
Hazardous Substances Advisory Committee
20th December 2012
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 benefit
Hazardous Substances Advisory Committee
20th December 2012
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 don't know we don't know
US Department of Defence news briefing Feb 12, 2002
Hazardous Substances Advisory Committee
20th December 2012
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, 2000
Hazardous Substances Advisory Committee
20th December 2012
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 Committee
20th December 2012
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 Committee
20th December 2012
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 SVHCs
Hazardous Substances Advisory Committee
20th December 2012
16. Hazard, Risk & Diversity
A simple example
Control without taking
risk into account
requires extermination
Hazardous Substances Advisory Committee
20th December 2012
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 Warfarin
Hazardous Substances Advisory Committee
20th December 2012
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 management
Hazardous Substances Advisory Committee
20th December 2012
19. Always bear in mind that precautionary action
based solely on hazard rather than risk can
have very significant adverse consequences
Hazardous Substances Advisory Committee
20th December 2012
