Better term than "off label" to describe something used other than as stated

In Australia, raw milk has been sold as "bath milk" (milk that's used for a milk bath), and labelled as not fit for human consumption. However, some people have deliberately consumed such milk, and the producer of the milk has posted on Facebook about how raw milk is better than pasteurised milk.

The only term I can think of for this state of affairs is "off-label", which is discussed in this question, and the consensus is that it's not exactly standard English. Wiktionary doesn't have any synonyms for the term.

Are there any good terms for describing something being used other than as stated? A term about something being used in a way explicitly denied would be ideal, if it exists.

Solution 1:

To me, the adjectives that seem most fitting in this situation are 'non-standard', 'unconventional' and possibly 'unorthodox'.

The descriptor 'off-label' for the case you are describing has the problem that it implies a use for raw milk that is 'labelled' (or 'on-label').

But as there isn't one, such an implication cannot be drawn. To describe the use of raw milk for bathing as 'off-label' would therefore be misleading, or silly, or both.

To answer the second part of your question,

Are there any good terms for describing something being used other than as stated? A term about something being used in a way explicitly denied would be ideal, if it exists,

the terms 'unauthorized', 'unapproved', 'unsanctioned', 'forbidden', 'prohibited', 'illegal', 'non-allowed', 'impermissible' and 'non-permitted' all occur to me as possibilities.

Solution 2:

Contraindicated, another word borrowed from medicine, means

to give indication against the advisability of (a particular or usual remedy or treatment).

I think off-label is a perfectly fine and well understood word (in the US anyway) for using a product in a manner unintended by the manufacturer. The fact that it's used predominantly in medicine doesn't limit its use to medicine.

• This tub is already an off-label use for a bath. We can't imagine anyone repurposing the jet to, say, wash dishes. - The Atlantic
• Like any other tool in the toolbox, Sac City is finding some off-label solutions.

Solution 3:

Perhaps Unintended usage would work in this case.

Children use the equipment as intended at all the play spaces. Intended use is defined as the types of use for which the manufacturer designed the play equipment. Unintended use, or misuse of equipment, also occurred at all play spaces except the water park. Unintended use is defined as the types of use for which manufacturers did not design the play equipment.

From:The Developmental Benefits of Playgrounds by Joe L. Frost