Pint size Mylar bags (10cm x16cm or 4”x6”) are ideal and provide ideal oxygen and moisture protection for the sample. The sealed Mylar bag is itself then vacuum packed inside a standard polyethylene food serve bag (Quart size,~20cm x 30cm or 8”x 12”), along with moisture (silica gel) and oxygen absorbing sachets. The finished sample is small and can then be conveniently stored in a cool place (< 200
It will be obvious if the seal is broken as the package will become pliable, at which point the outer vacuum package can be replaced.
Note: Extracting all the air from Mylar bags before heat-sealing can sometimes prove difficult because of the smooth finish of the bag. A solution to this is shown on YouTube:
Note: It has been suggested that metoclopramide anti-emetic tablets can be vacuum-sealed along with the sachets of Nembutal powder. However, it is not clear if the shelf life of the anti-emetic would be increased with this storage method.