hello, I got this from a little book called 'the chemical maze - shopping companion'. I hasten to add that I am not an expert!
My dd also has allergies and excema. Sory I didn't see your thread in the allergies bit.
Anyway...E905 is called microcrystalline wax, and is derived from crude oil. it is used in food as a glazing agent and in patricular in cake decorations. it is also used in tablet coatings, laminating paper and foils. It doesn't have any particular nasty effects to people generally (unless you're allergic of course) and the book gives it two smiley faces which means it's not at all damaging to the environment or people generally.
HTH - you could always google 'microcrystalline wax' to find more detailed info.
BTW I'd recommend this book 'the chemical maze' as it gives useful info about the enviornmental/people hazards in food and cosmetic ingredients. It's by Bill Statham and I use mine all the time.