How to Compost at Home

5. Materials to Avoid

Keep dog, cat, pig, and human waste out of the pile, since it can carry parasites or bacteria that make people sick. Inorganic materials like plastic, metal, glass, ceramic, used cat litter, particleboard, and plywood won't compost at all. Avoid meat, bones, poultry, fish, whole eggs, fats, grease, and oils, which cause foul odors, feed harmful bacteria, and draw animals and insects. Steer clear of sawdust or chips from pressure-treated or chemically preserved wood, too. It often has a greenish tint from copper, and older treated lumber, made before the mid-2000s, can contain arsenic.