The E numbers are references toward substances that are added to the food inside the European Union. There are curiosities like the E-513, sulphuric acid, because it automatically attacks living tissues causing automatic burns in high concentrations. Examples of how some opinions consider that even sulphuric acid in low concentrations could be a E number, by definition for food.
From E-1100 and up is where you could expect to find new chemicals, so let's see what's here and other opinions about safety.
There are some concerns about E-1201, Polivinilpirrolidona (PVP) for allergic reactions, also E-1202, or E-1208, all of them using vinyl in the formula. The acronym is similar to PVC, polyvinyl chloride, one of the most widely used plastics.
From Wikipedia, about the E-1518, triacetin: "It is recognized that at an even higher feeding level (10 g per kg per day) male rats developed testicular atrophy and female rats, uterine discoloration". Others say that in little quantities, it is not problematic. And then, it looks in this manner as sulphuric acid!
E-1520, Propylene glycol is partially synthesized in the organism as popionaldehyde, a possible toxic substance.