Hand sanitizers can be used beyond their expiry date. Some have expiry dates while others don’t. The expiry date on them is a manufacturer/ reseller assurance that it will be 100% effective for use against killing bacteria. After the expiry date, hand sanitizers can still be effective against bacteria for a long period of time.
HypaClean antibacterial hand sanitizer, for example, contains 70% ethyl alcohol. When used before its expiry, the percentage of ethyl alcohol in the container will not be lower than 70%. After expiry and for a period of time, the sanitizer will continue to comprise of 70% ethyl alcohol.
The HypaClean hand sanitizer does not have an expiry date because it can still be used many months/years after purchase. However, at some point the sanitizer will no longer comprise of 70% ethyl alcohol and the percentage in the bottle will continue to reduce. At the point where the ethyl alcohol in the bottle is below 70%, then the sanitizer has technically expired. It can still be used and be effective against many types of bacteria, but it may no longer be 100% effective against every type of bacteria.
The level of ethyl alcohol will continue to reduce further the longer it continues to be used and it will eventually get to a point where the level of ethyl alcohol in the bottle will be so low that it is no longer effective or advisable to use to kill bacteria.