As long as you are not handling the foil constantly. If the foil is in contact with your body heat if will cause the blotters inside the foil to heat up hotter than body heat temperature, degrading the LSD. But even room temperature is not great for storage in foil, and it will be hotter inside the foil than the room is. Foil is fine for long term cold storage.
All I know is that foil, like a lot of metals, is very reactive with a lot of things under certain circumstances. Eons ago when I was a distibuter of liquid, our supplier told us not to drop it on sugar unless it was going to be consumed within a couple of days, and then for sure don't wrap it in foil. Never got a complete answer as to the reasons, but it came from someone who had been working with LSD at all levels for over 15 years. What baffles me is the almost religious stigma associated to storing acid in foil. What the fuck? Main concerns to store LSD are; light, heat, oxygen, foil only can protect from light so whats with all the bs about wrapping doses in foil? Do whatever to protect from those three and your good. Sandoz liquid was distibuted in ampules 100ugs in I think 10cc of de-ionized water and nitrogen gas and if kept from light and heat had a shelf life of decades. The other form they produced were 25ug white tablets that reportedly had a much shorter shelf life. All this information really isn't to hard to come by, make use of it. http://images.google.com/imgres?img...LSD&hl=en&sa=N&um=1&ei=3v8CS8bzMpjYswO3punKDg