Transcript
Chemical Alternatives
Assessments: Combining
Exposure, (Health) Effects
and Life Cycle Assessment
Ann Mason, American Chemistry Council
Erin Mulholland, thinkstep
Hans Plugge, 3E Company
Hazard vs Risk
Hazard Assessment – the inherent hazard of a chemical via specific or all routes of exposure without consideration of exposure
Exposure Assessment – the likely amount of chemical exposure to occur from a specific usage scenario for a chemical/product
Risk Assessment – the probability of an effect resulting from a particular chemical exposure scenario – for a single chemical and scenario, the product of exposure and hazard
Hazard Assessment: Health Effects
List scores
Classification scores
Scientific data scores
Probabilistic data
Exposure Assessment
• Hundreds of scenarios available
• One exposure scenario at a time
• Most exposures involve multiple scenarios
• Need a way to sum exposure
Modeling
Spray Finishing
Activity Chemical
h/day Quantity Temp Room PPE
Product Liters °C Volume Value
Transport A, B, C 0.5 3.8 25 140 1
Mixing A, B 1.5 2 25 140 10
Spraying B 3 1.3 25 800 20
Flashing B 0.5 0.5 25 800 20
Cleaning C 1 1 25 140 10
Drying B 1.5 0.2 25 800 20
Exposure Assessment
Detailed analysis of scenarios •May need multiple algorithms Population average vs high exposure
Need lots of physical chemistry data
Detailed chemical analysis of mixtures
Difficult to automate
Time-weighted average vs peak exposure • Exposures modeled to be exceeding e.g. TWA need to be field verified
Exposure Screening
Single model for each scenario
Auto-selection of algorithms
Easy to obtain effect data
Auto-calculation of exposure and risk
Time-weighted summation of exposures and hence risk
• Inherently simple
• Relative vs absolute risk
• Screening vs Regulatory Limits
• Occupational vs consumer
• Average vs sensitive vs high exposure population
Risk Assessment
Alternatives Assessment
Alternatives Assessment is the growing and rapidly expanding art and
science of evaluating the
relative hazards and risks of existing chemicals (or
products).
Informs the scientific process of
substituting functionally similar
chemicals with reduced overall
health & environmental risks.
Maintaining functionality is of utmost importance – substitution must
provide similar functionality within a mixture (product) or inherently makes for an unacceptable
substitute.
Alternatives Assessment
• List based
• Classification based
• Scientific data based
Hazard Assessment
• Screening
• Detailed
Exposure Assessment
• Screening
• Detailed Risk Assessment
Integrated Life Cycle Assessment
WORSE
PRODUCTCOMPO-SITION
CHEMICALSOF
CONCERN
CHEMICALFUNCTIONALITY
EXISTINGALTERNATIVES
R&D
DE NOVOCHEMICALS
STRUCTURESPHYSICAL
CHEMISTRY
CLASSICALIN VIVO
TOXICOLOGYIN VITRO
ADVERSEOUTCOMEPATHWAYS
ENZYMEDATA
TOXICOGENOMICS
DATAANALY-
TICS
DATAGAPS
READ-ACROSS/ QSAR / MOLECULAR TOXICOLOGY
PRELIMINARY SCREENING HAZARD ASSESSMENT
(REGULATORY) HAZARDASSESSMENT
PHYSICALCHEMISTRY
EXPOSUREASSESSMENT
TOXICOLOGYDATA
ECOTOXICOLOGYDATA
(REGULATORY) RISK ASSESSMENT
REGULATORY ANALYSIS
INTERIM
LIFECYCLE
ASSESSMENTSUSTAINABILITY ECONOMICS
ENGINEERINGPERFORMANCE
REGULATORYANALYSIS
ACCEPT
DOCUMENT
IMPLEMENT
FRAMEWORK FORASSESSMENT OF CHEMICALS
GREEN CHEMISTRY AND ENGINEERING CONFERENCEJUNE 14-16, 2016, PORTLAND, OR, USA
Hans Plugge & Longzhu Shen3E Company & Yale University
Bethesda, MD & New Haven, CThplugge@3ecompany.com & longzhu.shen@yale.edu
After National Academy of Sciences, 2014
COMPUTATIONAL CHEMISTRY
CHEMINFORMATICS
PROBABILISTIC MODEL
WORSE
BETTER/EQUIVOCAL
BETTER/EQUIVOCAL
YES
NO
NO
YES
NO
Data Gaps
Read Across
• Homologues e.g. octanal vs heptanal
• Analogues e.g. octanal vs octanone
QSAR Quantitative Structure Activity
Relationships
• Based on existing (classical) data
Molecular Toxicology
• Based on enzyme/in vitro data
Screening Alternatives Assessment
Best outcome: greener Alternatives
No alternative better
Decreased exposure/risk?
Back to R&D
WORSE
PRODUCTCOMPO-SITION
CHEMICALSOF
CONCERN
CHEMICALFUNCTIONALITY
EXISTINGALTERNATIVES
R&D
DE NOVOCHEMICALS
STRUCTURESPHYSICAL
CHEMISTRY
CLASSICALIN VIVO
TOXICOLOGYIN VITRO
ADVERSEOUTCOMEPATHWAYS
ENZYMEDATA
TOXICOGENOMICS
DATAANALY-
TICS
DATAGAPS
READ-ACROSS/ QSAR / MOLECULAR TOXICOLOGY
PRELIMINARY SCREENING HAZARD ASSESSMENT
(REGULATORY) HAZARDASSESSMENT
PHYSICALCHEMISTRY
EXPOSUREASSESSMENT
TOXICOLOGYDATA
ECOTOXICOLOGYDATA
(REGULATORY) RISK ASSESSMENT
REGULATORY ANALYSIS
INTERIM
LIFECYCLE
ASSESSMENTSUSTAINABILITY ECONOMICS
ENGINEERINGPERFORMANCE
REGULATORYANALYSIS
ACCEPT
DOCUMENT
IMPLEMENT
FRAMEWORK FORASSESSMENT OF CHEMICALS
GREEN CHEMISTRY AND ENGINEERING CONFERENCEJUNE 14-16, 2016, PORTLAND, OR, USA
Hans Plugge & Longzhu Shen3E Company & Yale University
Bethesda, MD & New Haven, CThplugge@3ecompany.com & longzhu.shen@yale.edu
After National Academy of Sciences, 2014
COMPUTATIONAL CHEMISTRY
CHEMINFORMATICS
PROBABILISTIC MODEL
WORSE
BETTER/EQUIVOCAL
BETTER/EQUIVOCAL
YES
NO
NO
YES
NO
Uses of Alternatives Assessment
Greener products More acceptable
across supply chain
Consumer vs industrial
Ranking of existing products/releases
Prioritize R&D
New products Up front analysis
of greenness
Incorporate sustainability into
supply chain
Future
Alternatives Assessment is a long term interim solution for selecting greener chemicals.
Increasingly de novo green chemistry will be used to influence the selection of
greener chemicals eventually taking over the entire process of selecting greener chemicals
Eventually we will achieve the Holy Grail: integrating risk
assessment and LCA in a semi-automated screening approach
Authors
• Ann Mason American Chemistry Council, Washington, DC
Ann_Mason@americanchemistry.com
• Erin Mulholland thinkstep, Boston, MA
erin.mulholland@thinkstep.com
• Hans Plugge 3E Company, Bethesda, MD
hplugge@3ecompany.com
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