An article in the Independent reports that “Drug specialists say the current system for ranking drugs – class A for the most dangerous to class C for the least dangerous, as set out in [Britain’s] Misuse of Drugs Act – is irrational, arbitrary and ‘lacking in transparency’.” The article continues:
Scientific evidence shows that heroin and cocaine are correctly ranked as class A drugs as they do cause the most harm. But LSD and ecstasy come close to bottom of the league in terms of harm caused, yet they are also labelled as class A.
Alcohol is legal and widely used but comes fifth in the “harm” table, ahead of amphetamines and cannabis, which are ranked as class B and class C respectively. Tobacco is also ranked as more harmful than cannabis.