Proper Labelling-Cosmetics
Labels are applied immediately, or even before bottling, as it is impossible to differentiate between a hundred blue bottles without removing the lids. The beauty of spray bottles is that once on, the lid never needs to be removed. From the day of bottling to the day the bottle is empty, you can disperse your hydrosol without risking contamination through frequent opening and closing of the container.
Even when bottles are labelled STERILE CONTAINERS, DO NOT OPEN, I watch people walk over, unscrew the lid, and hold the bottle to their nose. I know they just ain't help it, but really.....
If you buy hydrosols to resell, you should include the distillation date, the expiration or best-before-date, or both on your labels. You should also include the plant's country of origin as well as common and Latin names. The labelling requirements for hydrosols should be no less than those for oils.
Reference: Hydrosols, The Next Aromatherapy: Suzanne Catty