Risks of Composting


Compost is a natural, easy-to-produce, nutrient-rich soil conditioner. It is easily produced in backyard bins or worm boxes. Composting does have a few risks that good "heap" management can help control.


Too few "browns" like dead leaves and cardboard to balance nitrogen-rich "greens" make a bad-smelling pile. Rotting plant matter causes rapid heat buildup, releasing methane and other noxious gases.

Size Matters

Cornell University's Waste Management Institute recommends a heap of at least 27 cubic feet in size to efficiently kill plant pathogens naturally. Smaller heaps may need chemical accelerants.

Fungus Among Us

Dampness breeds molds and fungi that aid decomposition. The Aspergillus website recommends the use of special masks and gloves by asthmatics and people with compromised bronchio-pulmonary or autoimmune systems when using compost.

Animal Waste

Raw poultry, meat from plate scrapings, fats and pet waste---even bird droppings--can contain bacteria that produce human pathogens in the heap.


Insects generally aid composting. Some, like houseflies and fruit flies, however, can cause nuisances.


  • Cornell Waste Management Institute: Health and Safety Guidance for Small Scale Composting
  • Living with Bugs: Insects and Composting

Who Can Help

  • Aspergillus Website: Health Risks
  • UK Department for Environment, Food and Rural Affairs: Composting Risk Assessment
Keywords: risks, composting, compost bin

About this Author

Chicago native Laura Reynolds has been writing for 40 years. She attended American University (D.C.), Northern Illinois University and University of Illinois Chicago and has a B.S. in communications (theater). Originally a secondary school communications and history teacher, she's written one book and edited several others. She has 30 years of experience as a local official, including service as a municipal judge.