While the Regulations do make provision for occasions which are not specifically listed in the Regulations, they still require the shipper to classify their product accurately.
There is also a basic responsibility placed upon the shipper to ensure that those who are preparing the consignment have the necessary information to do the job properly (e.g. an accurate MSDS, current edition of the Regulations). The safe philosophy is that if you don’t have the necessary information, you are unable to make an accurate judgment. Never guess. There are commercial consultant chemists who would, for a fee, be able to resolve any areas of uncertainty.