Since the basic method to deploy the chemical in these strips is via volitilisation, refrigeration and better yet freezing the unused strips will surely decrease the loss of active ingreadient, thereby prolonging storage. Care should definately be exercised to insure the strips are in a sealed nonporus conainer especilly if they will be in a freezer that has food. It would be far better to store them in a freezer that does not contain food, but this may not be feasable for hobyists. I use a glass jar with a ground glass seal that I got from a laboratory supply house. I have used frozen strips after a year and they apaently work as well as new. Your milage may vary. The important part is to insure sealed, nonporus (plastics can allow some volitile through) sealed containers. My second choice would be to place the strips in a mason jar. Mike Griggs Entomologist/Apiculturalist/Arborist >Does anyone know if putting Apistan in the fridge/freezer might extend >the life of opened packs? I, too, would be interested. I only have one >hive, and hence have a lot of strips left over. > >Jane B.