AmethystFloris

Thank you so much! This is exactly what I needed to know -- I wanted to make sure that aluminium foil didn't have any kind of special properties, and now that I know any metal box will do, a metal box is exactly what I'll get! Thank you!! I have no intrinsic factor (pernicious anaemia), so in my case it's injections every single day for the foreseeable future; and the form I take, methylcobalamin, comes in just one large vial, which you unscrew and draw from what you need each time, so they're not in separate ampoules that stay in their box till I'm ready to use them -- it's essentially just one bottle that has no box, which is why it needs something to shield it from light. Thank you all very much.

Well, the reasons why I want to know don't really matter; I've edited my original post, to reflect the fact that the motivation for my question has no bearing on the answer. Essentially, "what is as or more light-resistant than aluminium foil" isn't actually a medical question, and I'm not looking for a medical answer; rather, the question requires the knowledge of someone familiar with the study of light, which I was hoping to find here. Thank you.

I really hope this is the right place for this, and I'm very sorry if it isn't. The study of light has always come under the heading of "physics" when it's been taught to me, but I'm afraid science is my weakest area! I'm told aluminum foil is extremely light-resistant. Can anyone tell me what other materials/substances have light-resistant properties equal to or greater than aluminum foil? I'd be tremendously grateful for any help. Thank you very much for your time. The thing is, I have B12 injections, and the glass vials of B12 I use are extremely vulnerable to light, so the supplier suggests aluminum foil be used to wrap around the vials at all times (except when they're actually being used to draw B12 into the syringe). According to the supplier, aluminum foil is extremely light-resistant. I was just wondering if anyone with a solid science background in the study of light could tell me if there were any other materials that were as light-resistant as aluminum foil? The problem is, the aluminum foil gets cracks in it from being unwrapped and re-wrapped every day, and constantly needs replacing. Can anyone recommend anything more permanent that I could use, like some sort of "light-proof box" (I'm sure that's the technical term for such a box ;D).