4. Environmental aspects

Isosorbide is biodegradable, non-toxic and has been classified by the Food and Drug Administration as a GRAS (Generally Recognized As Safe) substance. It is registered in the REACH (Registration, Evaluation, Authorization and Restriction of CHemicals) or TSCA (Toxic Substances Control Act) chemical inventories, and toxicological evaluation has shown isosorbide to be safe, so it is excluded from any classification.

From an environmental point of view, the molecule's synthesis is formally very clean, since the hydrogenation of glucose is a 100% atom-saving reaction, and the sorbitol dehydration steps lead to the formation of water as a reaction by-product. It is also important to note that the syntheses are carried out in aqueous medium for hydrogenation, or solvent-free for the dehydration steps (liquid sorbitol medium), with catalysts that can certainly be improved...