Let's say I have a document, a specification for a vitamin mix for addition into animal fodder. This document has a table listing the maximum permitted contents of bacteria in the mix.
The first line reads: "Maximum overall bacterial count, in cells/g: 500 000".
The second, third, and fourth to tenth lines read "E.Coli and coliform bacteria", "Proteus", etc. The column value is "not allowed" for each of these, meaning that it's a no-no to have any such bacteria in the mix.
Is "not allowed" a proper combination of words? I came up with "not permitted" as an alternative, but there could be more idiomatic word combinations.
The Russian original is "не допускаются" ('are not admitted', in a blunt translation; meaning the very existence of such bacteria in a sample of the product is a no-no)