I have been told some months ago that the paper and cardboard recycling cycle needed clean raw material. Mostly, paper stained with oil were inappropriate to input in the recycling, and should rather be thrown away.

Where I live we can select/filter/sieve wastes between:

1. glass
2. paper, cardboard, recyclable platic containers, metal cans
3. garbage everything else

When I happen to throw pizza cardboards, they often have oil (pepper oil) that has leaked/stained the inside of the cardboard.

As I am not aware of the chemistry that is at stake for paper/cardboard recycling... I don't know if I should throw the pizza cardboard with stains of oil to recycling or not. If it is a good idead or not.

I don't know the limit where a dirty cardboard/paper should no longer be candidate to recycling. (Namely with oil).

I was told some months ago that paper and cardboard recycling processes need clean raw material. In particular, paper stained with oil may be inappropriate to recycle, and should rather be thrown away.

Where I live we separate our waste between:

1. glass
2. paper, cardboard, recyclable plastic containers, metal cans
3. garbage, that is, everything else

When I happen to have a used pizza box, it is often stained with oil.

As I am not aware of the chemistry that is at stake for paper/cardboard recycling, I don't know if I should throw the oily pizza cardboard in the recycling or the trash. More finely, how oily can the cardboard be and still be a good candidate for recycling?