Yes you can compost cardboard, although the slick waterproof stuff used for beer cartons and detergent and pet food bags doesn't break down well. Best stuff is the dull tan on both sides with just ink printing. Peel off any packing tape and shipping labels - they don't compost easily.

As for "eating chemicals" ... everything is made of chemicals.Just look at all the chemicals in an all-natural organically grown banana:

One great helper there is time, as most of the chemical concoctions added to OM will break down to harmlessness in the compost if given enough time. Not talking Cleanup Superfund chemicals here, but all the gazillion of those compounds added to inks, glues, paper pulp, and so on. Even the fungicide in feathers and the iron oxides in hair will pass on.

And then consider how little affinity that plants have for chemicals that might get stored in their fruits and leaves. You can't be truly organic; the junk is everywhere. All you can do is try and you'll end up waaaaay up there.

You might be able to tell that I let a lot of composted stuff just sit. Comes from fear of horse diseases. Sit a long time...

ozgoz, there is no such thing as a "stupid" question except the one you do not ask. We learn by asking questions.

You can use cardboard in your compost as a Carbon source, just as many of us use it, as well as newspaper, in our gardens and your compost will still be organic. The cardboard will be digested and become part of the soil, but no matter what you will be eating "chemicals" since your veggies are made of them. You will not, however, be eating synthetic chemicals.

kimmq is kimmsr