Manure Composting Safety

Why does manure need special handling?

Raw manure can contain bacteria, parasites and other organisms that cause illness in people. Fresh manure can also contain weed seeds, and it may carry residues of medications or herbicides from the feed. Virginia Cooperative Extension and others describe manure as a valuable amendment that must be handled with food safety in mind.

If you grow food for your household, for sale or for children, handle manure as a potential health hazard and ask your extension office for guidance specific to your crops.

Think about what the pile will be used for. A pile for ornamental beds has fewer rules than one for food crops, but the same habits protect your family and neighbors.

What does composting do to the risks?

Properly managed composting creates conditions in which heat and microbial activity reduce many harmful organisms. The key words are properly managed. A pile that never heats, is not turned or is built of the wrong mix may not provide the benefit.

Extension guidance describes time and temperature goals for compost used on food crops. This guide does not list numbers because they vary by source and situation; ask your extension office for the current recommendation and how to record it.

The word compost on a bag or from a seller does not guarantee a managed process. Ask how it was made, how long it was held and whether temperatures were recorded.

How do I build and manage a manure compost pile?

Mix manure and bedding with carbon-rich material such as straw, sawdust or leaves to reach a workable balance. Keep the pile moist but not soggy, and build it large enough to hold heat. Turn it according to extension guidance so that all material spends time in the hot zone.

Place the pile away from wells, streams, ponds and drainage paths so runoff does not carry contaminants. Rules on distance and storage vary by state and county, so ask your local conservation district and extension office.

Cover the pile to prevent rain from leaching nutrients and soaking the material. Use a firm base such as packed soil or a pad, so runoff and liquid are easier to control.

• Mix manure with carbon-rich material
• Keep moisture like a wrung-out sponge
• Build a pile large enough to hold heat
• Turn as extension guidance recommends
• Keep away from water sources

Why monitor temperature and keep records?

A compost thermometer lets you see whether the pile is reaching the heat that extension guidance describes. Record the dates you build and turn the pile, the temperatures and any problems. These notes show whether the process worked and help if you ever need to explain your practices to a buyer or inspector.

If you cannot confirm that the pile reached the right conditions, treat the material as not fully safe for food crops and use it elsewhere, such as on ornamental areas or fields not used for food, according to local guidance.

Label each batch with the date it was started and the date of each turn. If a batch fails to meet the goals, restart the clock with another full cycle rather than guessing.

What personal safety steps apply?

Wear gloves and wash hands thoroughly after handling manure or compost, and keep children away from piles. Do not eat, drink or smoke while working. Keep tools and boots clean and out of the kitchen. If you have a weakened immune system or are pregnant, ask your doctor before handling manure.

Keep pets and livestock out of the compost area, since they can spread contamination and may eat harmful material.

What about herbicide and medication residues?

Some herbicides in hay, straw or manure persist through the animal and through composting and can damage sensitive garden plants. Ask where feed, hay and bedding came from and whether persistent herbicides were used. Medication residues are a separate concern, and your veterinarian or extension office can advise.

If you buy manure, ask the seller for the source, the animal type, the age of the material and what it was treated with.

If you buy hay or straw, ask the seller about herbicide use on the field, and keep the answer with your records.

Who should I ask before I use it?

Your county extension office can explain food-safety waiting periods and composting standards for your crops. Your state department of agriculture or health office may have rules if you sell produce. Rules vary by state, so ask what applies to you.

If you are unsure whether a batch is safe, keep it away from food crops until you have an answer.

Last reviewed: November 12, 2026. Written by the Homestead & Small Farm Editorial Team. See our editorial policy.