Create a special type of item "consumable". This type of item would have the ability to be "stock' and "pull' specific quantities from the items. It would be different from checking out.
This would be things like earplugs, screws, gels, etc. The quantity going out is not necessarily intended to be returned. It will, however, be restocked with new. There should be a cost value recorded when it is stocked, and the option to count the cost going out.
Please let us know if this is a feature you would use; and how specifically you would want it to function.
Todd Kulik commented
It is interesting, but it is pretty low on my priorities I don't really "stock" consumable props