problematic & toxic
Some things should never meet your compost, and knowing why makes the rule stick. Pressure-treated lumber carries copper and arsenic compounds; glossy and laminated papers shed plastic coatings; cigarette butts are plastic filters soaked in toxins; coal and briquette ash concentrate heavy metals. This category also covers the plants that fight back — poison ivy's urushiol survives composting, and some invasives resprout from fragments. Most items here get a clear no plus a real disposal answer, because 'don't compost it' is only half the question. If you searched for something in this category, the page will tell you what the hazard actually is and where the item should go instead.
compost it, with care (4)
Read the catch first.
keep it out (31)
Every page says what to do instead.
plastic no styrofoam no treated wood no aluminum foil no charcoal ash no cigarette butts no drywall no plastic bags no plywood no poison ivy no tape no carpet no coal ash no crystal cat litter no diseased wood no glass no mdf no metal no motor oil rags no paint chips no painted wood no particle board no poison oak no polyester no rubber no shoes no stained wood no tin cans no tires no treated pallets no twist ties no