About 5 years ago I bought a can of Pepsi Max. It sat at the back of a cupboard since. Whilst tidying out the cupboard, I found the can. It was however half empty. The wierd part is that the can was never opened. About 150ml of Pepsi had to have leaked out, but visible on the shelf was a light brown stain. There are a couple of questions here: 1) How did the Pepsi get out? I'm assuming slow diffusion. Corrosion is troubling to consider. 2) Apart from it probably being flat, would it be unhealthy to drink the remaining Pepsi? Would you expect a high concentration of corroded aluminium ions in the drink? 3) What would drinking aluminium ions do to you? 4) Would you expect this to be unique to the can (a material defect), the product range (Pepsi Max) or acidic/low pH carbonated drinks in general?