Ask Dr Reach: How can one identify chemically modified naturally occurring substances?
QUESTION. How can one identify chemically modified naturally occurring substances? The questioner represents a Chinese REACH centre.
ANSWER: Presently, REACH grants exemptions from registration to naturally occurring substances if they are not classified as dangerous and not chemically modified. The definitions can be found in Article 3 of the legislation:
- substances which occur in nature: a naturally occurring substance as such, unprocessed or processed only by manual, mechanical or gravitational means, by dissolution in water, by flotation, by extraction with water, by steam distillation or by heating solely to remove water, or which is extracted from air by any means;
- not chemically modified substance: means a substance whose chemical structure remains unchanged, even if it has undergone a chemical process or treatment, or a physical mineralogical transformation, for instance to remove impurities;
The actual details of the exemption are specified in Annex V, subject to current review. Issues being considered during the revision include how to identify chemically modified substances and distinguish chemically identical substances that are ‘synthetic’ rather than ‘sourced from nature’. More fundamentally, some actors continue to examine whether an extraction constitutes a change to chemical species within the extract.
In terms of enforcement, the details of the exemption under Annex V are important. For company compliance checks, methods of characterisation turn critical.
Identifying chemical modification proves challenging. For example, after an extraction, an organic solvent may be evaporated. After further processing, such as purification and formulation, it may be difficult to establish whether the original product resulted from any combination of distillation, expression or water-based extraction.
While a chemical extract may produce a substance that is considered chemically modified under REACH, whether the residual material (e.g. lavender oil stems, rose petals) also constitutes a substance subject to REACH could be debated. Under previous legislation, this was never an issue.
Because chemical modification can occur without chemical process or treatment, what constitutes a change in ‘chemical structure’ becomes important, e.g. crystalline forms. Here, RIP 3.10 on substance identification and naming provides many useful examples.
It may only be after preliminary data exchange and the generation of new data that the potential to submit a single substance registration under an EINECS entry for the extracts and derivatives of specific natural products is established. If the hazard profile differs significantly due to source or process, the substances may require separate substance registrations.
As a concluding comment, it is interesting to note that as REACH applies at point of manufacture or import in the EU, some companies argue that sourcing from EU manufacturers reduces the need for detailed chemical analysis. This follows a view that purchasing from outside the EU requires compositional data to achieve similar levels of REACH-compliance security.
Dr Steffen Erler
Legal Disclaimer: The information contained in this communication follows a technical interpretation of REACH to serve as a thought-starter for discussions; it does not constitute legal or any other form of advice. Note that technical aspects are subject to review and references should be checked for updates. The legal text of the REACH Regulation must serve as the basis for REACH compliance and it may be advisable to seek legal and/or other expert advice on any given issue. The author and Chemical Watch accept no liability whatsoever with regard to the use of information contained in this communication.
