Procedure for classifying substances

Where you haven’t got a published classification for your substance and you have to classify from scratch, there are two different procedures, one for physical hazards and another for the health and environmental hazards.

Procedure for classifying physical hazards of substances

1. Based on the chemistry of the substance, screen out non-relevant physical hazards (this should be carried out by a trained chemist, seek help if you do not have the right skills)
2. If you have test data available for the relevant physical hazards, classify from first principles (or use modelling, where this is permitted)
3. If you suspect one or more physical hazards may be present, but do not have test data, then testing will be required.

We have a screening form to help you decide which physical hazards may be applicable to your substance: Screening questions for substance physical hazards v1.2.

If you are uncertain about the chemistry of the substance, or not a trained chemist, it is advisable to get help from a chemist with screening out physical hazards.

Testing for physical hazards is not subject to any controls (apart from cost!).

Procedure for classifying health and environmental hazards of substances

1. If you have test data available for the substance, you can classify it from first principles (or use the test data in modelling, as appropriate)
2. If you don’t have test data, but similar substances have been classified, or have had their hazards assessed, use modelling (QSAR) or read-across.  (This type of work is usually carried out by a specialist regulatory affairs chemist, or a toxicologist, seek help if you do not have the right skills).
3. If you can’t use modelling or read-across, tests may be required. Where possible, in-vitro tests should be used, and testing on live animals avoided.  CLP states “Tests on animals within the meaning of Directive 86/609/EEC shall be undertaken only where no other alternatives, which provide adequate reliability and quality of data, are possible“.  (Note that fish are vertebrate animals, so this applies to environmental testing as well as health testing).
4. When testing for health purposes, you do not test for every hazard, but there are screening tests which show whether further testing is required, or whether a substance does not have a hazard.

In the UK, you need permission before conducting animal tests, and you may also require permission from ECHA for REACH tests, see https://ttenvironmenta.wpengine.com/clp-knowledgebase/clp-health-hazard-tests/ for details.