The economic argument matters too
This is saying that cellular oxidative stress, redox imbalance, and lung inflammation (cell damage and inflation) seem to occur with eCigs and tobacco cigarettes, due to heavy metals and free radicals, in similar ways to tobacco, in tests on mice (we have different ethics for studying humans and it takes longer to get that data)
The regulatory body that is responsible for REACH is the European Chemical Agency (ECHA)
Golden-Silk Smoke: A History of Tobacco in China, 15502010
The proposed location of the membranes must be respected, because a change in them, for example, exchanging M1 with M3, it would cause condensation of the tar in the mouth, generating a very unpleasant sensation for the smoker