Panel 2: Grouping of chemical substances and how to avoid regrettable substitution

1. © Copyright 2019 Chemical Watch (CW Research Ltd)
Grouping of chemical
substances and
regrettable substitution
Chair: Andrew Turley, Science
Editor, Chemical Watch

2. © Copyright 2019 Chemical Watch (CW Research Ltd)
Panelists
Ninja Reineke, Chemtrust
Jack de Bruijn, ECHA
Maggie Saykali, Cefic
Kerry Nugent, IMAP, NICNAS

3. © Copyright 2019 Chemical Watch (CW Research Ltd)
Grouping
● For overcoming the data deficit problem
● Enables extrapolation of hazard properties from a data-rich
substance to a data-poor substance that is ‘similar’ (read-across)
● When an unsafe substance is substituted for...another
unsafe substance
Regrettable substitution

4. A recent example
● Request made by regulatory authority
● Independent expert committee recommends
grouping (to some extent…) for assessment of
organohalogen flame retardants
● 16 groups
● “The alternative – individual assessments of
hundreds of chemicals – is unrealistic"

5. Opening questions
● Is everyone using the same approaches to grouping?
○ Minimise duplication of work globally; provide greater certainty for industry; but
○ Challenging given diversity of legislative constraints and diversity of chemicals
● In each case, should the approach be:
○ General (IE, agnostic with respect to chemical structure, use, exposure route, etc);
○ Tailored to the chemicals under consideration; or
○ Something in between?
● How should risk assessors define groups?