REACH defines an intermediate as “a substance that is manufactured for and consumed in or used for chemical processing in order to be transformed into another substance.” The main implication of this definition is that the substance used as an intermediate will be reacted, and will not be present in any (end)product. The (potential) exposure of humans and the environment to this substance is therefore limited, especially when used under strictly controlled conditions.

Please note: where a chemical process does not lead to the manufacture of another substance, but instead produces mixtures or articles or results in a specific function or property, the substances used for this activity do not have the status of an intermediate.

Under REACH, three types of intermediates are defined:

• A non-isolated intermediate is “an intermediate that during synthesis is not intentionally removed (except for sampling) from the equipment in which the synthesis takes place.”
• An on-site isolated intermediate is “an intermediate not meeting the criteria of a non-isolated intermediate and where the manufacture of the intermediate and the synthesis of (an)other substance(s) from that intermediate take place on the same site, operated by one or more legal entities.”
• A transported isolated intermediate is “an intermediate not meeting the criteria of a non-isolated intermediate and transported between or supplied to other sites.”

Read why your substance supplier may ask you to sign a statement of compliance with transported isolated intermediates under strictly controlled conditions.