We constantly get asked: is composting human and animal feces safe?

YES! If done right.

A properly insulated and aerated compost pile with the appropriate ratio of carbon and nitrogen (20:1 - 40:1) will reach sterilizing temperatures 125-180˚F (50-80˚C) owing to the action of thermophillic bacteria, killing human pathogens and parasites. The inside of a proper compost pile reaches and maintains temperatures higher than a well-done steak for days!

Here are the U.S. federal regulations.

To quote from "Processes to Further Reduce Pathogens (PFRPs) Listed in Appendix B of 40 CFR Part 5031," Page 33:

"Using either the within-vessel composting method or the static aerated pile composting method, the temperature of sewage sludge is maintained at 55°C (131°F) or higher for 3 consecutive days.
Using the windrow composting method, the temperature of the sewage sludge is maintained at 55°C (131°F) or higher for 15 consecutive days or longer. During the period when the compost is maintained at 55°C (131°F) or higher, there shall be a minimum of five turnings of the windrow."

Salmonella and Fecal Coliform bacteria tests are also required to verify the production Class A processed waste, i.e. you can use it legally on a garden. Processed waste produced using the same process as certified processed waste is considered safe based on the most recent test data available, and quarterly testing is recommended for each process.

To see summaries of regulations in the US & to download the inactivation of ascaris handout check Biosolids hand outs from PNCA's Sanitation, Hygiene and Integrated Design Course.