In a previous post, we recommended adding paper or cardboard to a compost heap that’s too moist. Paper will absorb water as well as provide short-term air space to aide in circulation if it’s crumpled. That suggestion, as pointed out by one of our more careful readers, brought up an entirely different subject: is composting paper safe? The answer is yes. And no.
Paper — made from wood pulp — seems a likely addition to compost because of its source: nature. Newspapers have long been held as a good source of “brown” component in the brown-green, carbon-nitrogen balance that compost piles need (so much so that adding too much paper will tip the balance). But paper might also contain some harmful ingredients in the form of inks, dyes and other treatments. These days, most newspaper inks are soy-based, a good thing for the environment (though the soy used in inks is likely from GMO sources). But some inks may still contain petro-chemicals or pigments if they include color as most papers do. Also newsprint may hold some chlorine from the bleaching process. Newspaper is bleached less than most commercial office papers but may still contain some chlorine. (more…)