1. Chemicals and their properties Day 1.
Adam Peters and Graham Merrington
2017

2. Identification Chemical Properties Environmental Fate
Information Sources
Missing Information
Example Chemicals
Summary
2017

3. Identification Chemicals or Substances?
Unique structure or complex mixture?
Ambiguity in chemical identification
Multiple CAS numbers , stereo isomers
Commercial products (mixtures)
CAS or EC numbers (EINECS, ELINCS)
IUPAC name, Trade name, Common name
Identify most suitable CAS/EC number and name for searching
2017

4. Chemical Properties Partition coefficient Water solubility
Log KOW, partitioning, accumulation,
Water solubility
Environmental mobility, bioavailability
Vapour pressure
Environmental mobility, long range transport
Potential for ionisation?
May be predictable from the chemical structure if not available (USEPA EPISuite)
2017

5. Environmental Fate Partitioning Degradation Bioaccumulation
KOC, KD, KP, soil, suspended sediment
Henry’s Law Constant
Degradation
Photolysis
Hydrolysis
Biodegradation, primary or ultimate
Bioaccumulation
KOW, BCF, BAF, BMF
2017

6. Finding Information Is an EQS available? Searching databases
Use the EQS as the basis for effects information, additional information on fate may still be required
Searching databases
ECHA dissemination portal
IUCLID, ESR risk assessments
OECD HPV programme
USEPA ECOTOX
Open literature…
2016

7. Missing Information QSAR estimates Requires structure
USEPA EPI Suite models
Requires structure
Many structures in database
SMILES code
Requires some expert chemical knowledge
Validity of applied models
Comparison against measured data
Peer review of outputs by experienced staff
2017

8. Partitioning and Fate How will a substance behave in the environment?
Volatile, transport and exposure via air, rapid removal and dispersion
Water soluble, transport and exposure via water, available for biodegradation
Highly insoluble, high partition coefficient, binds strongly to soils and sediments, low availability for biodegradation, resistant to degradation, accumulates in organisms
2017

9. Predicting Fate Fugacity modelling – Don Mackay
Affinity of a substance for different phases
Air, soil, water, sediment, biota
Simplistic systems and routes of entry
Level I, single input, equilibrium
Level II, continuous inputs, transformation
Level III, compartment specific inputs
2017

10. Example Chemicals
Example substances which will be used throughout the course to demonstrate the complete risk assessment process for a diverse range of substances
You will be obtaining, and assessing, information on some substances yourselves
2017

11. Approaches
Risk assessment approach taken may define some of the information requirements
Many models require a selection of specific input parameters
In many cases the selection of the most appropriate value for each input parameter will need to be justified and recorded
2017

12. 2016