Expired reagents

Once a reagent expires, it should be quarantined immediately. It should be disposed of as soon as possible, to prevent it being used and causing a failed stock or process.
To simply make a mental not that it should no longer be used, without making it obvious to other operators, is less than acceptable.
Though one person knows not to use it, the next person to pick up the bottle may well be a different operator.
A physical barrier will prevent it from being used.