In R v Cato [1976] 1 All ER 260, the court considered whether heroin could be a noxious thing. Lord Widgery CJ stated:

'What is a noxious thing, and in particular is heroin a noxious thing? The authorities show that an article is not to be described as noxious for present purposes merely because it has a potentiality for harm if taken in an overdose … and it is clear on the authorities when looking at them that one cannot describe an article as noxious merely because it has that aptitude. On the other hand, if an article is liable to injure in common use, not when an overdose in the sense of an accidental excess is used but is liable to cause injury in common use, should it then not be regarded as a noxious thing for present purposes?'

The court decided that heroin was a 'noxious thing' even where it is administered to a person with a high tolerance to whom it is unlikely to do any particular harm. Heroin is 'noxious' because it is 'liable to injure in common use'. Although the proposition is given in the negative, the suggestion is that for a substance to be classified as a noxious thing for the OAPA 1861, s 23 it must be inherently dangerous.