Years ago, Martha Stewart said she prefers to use parchment next to the foods and foil on top of that to avoid direct contact of foil with foods.

I buy 18 inch x 500 foot rolls of aluminum foil at Sams Club. I also buy 18 inch wide plastic wrap in the big box at Sams. I bought a 1000 count case of full sheet pan size parchment paper at the restaurant supply store several years ago, since the half-sheet size ones are too small for my 3/4 size sheet pans. I've used less than half the box, so it'll last me quite a few more years.

Len is right, aluminum is reactive so acid or high enough heat may cause changes in the foil.

I have 18 & 12 inch wide aluminum. I use the 18 inch to cover pans to make clean up easier. I will still put parchment on the foil on the pans to make things stick less.

Aluminum used to be thought to contribute to Alzheimer's but that research was faulty and has been discredited. It still seems to be floating around the internet. Not sure if there is any other health hazard that has been pointed out but I'll do some research.