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Certified Pathogen Free - What Does It Mean?

Understandably, there are concerns over the potential health and environmentally consequences of pathogens (disease-causing organisms). The issue receives national attention, especially when unpasteurized apple juice is contaminated with the E.coli bacteria.

The most effective method for destroying pathogens is heat and time. When exposed to heat over time, some pathogens die within a few minutes, while others require several hours. The most persistent pathogen known will die in about 15 hours when exposed to a constant temperature of 124ºF or more.

A1 Organics maintains its compost windrows at temperatures of 131ºF to 150ºF for a minimum period of 30 to 60 days and often 150 days. This time/temperature relationship is 50 to 100 times greater than what is required to safely destroy any pathogen.

E.coli and Raw Manures

In 1996, hundreds of people who drank unpasteurized apple juice got sick and one person died as a result of an E.coli (a pathogen) outbreak. The E.coli contamination was traced back to the orchards that were fertilized with raw manure. Some apples had been picked up off of the ground and processed along those from the trees. As a result, the E.coli organism ended up in the juice. When the juice wasn't pasteurized (time - temperature), the pathogens stayed alive and were passed along to humans.

Each year the news carries stories on E.coli outbreaks that have been traced to fruits and vegetables, especially from organically grown crops. Again, a common link in all of these cases has been the use of raw manure to fertilize a crop.

Pathogens

Pathogens are any organism capable of producing a disease or infection. They make us sick, with flu like symptoms. The most common pathogens are E.coli (Escherichiacoli 0157:H7) and/or Salmonella sp. (commonly found in eggs). Pathogens can be found in sewage, municipal solid waste, yard trimmings, food by-products, and animal manures.

There are four common ways to destroy pathogens. All four methods use a time/temperature formula.

A1's Certified Compost

A1 compost is produced at facilities that are fully permitted, regulated, and inspected by the State of Colorado Department of Public Health and Environment and/or the county in which the facility operates. A1's compost is produced in a manner that meets US EPA 40CFR 503.12 standards for pathogen destruction under a controlled, monitored, and documented process. A1 utilizes scheduled windrow turning (aeration), moisture control, and heat to insure a pathogen free product. As required by the EPA, we test these materials for pathogen destruction at certified laboratories.

Data collection starts from the time a new windrow is built until the product is inventoried for shipment. Data collection includes the number of times the windrow is turned and a complete history of the temperatures. This graph shows temperature history and frequency of turning. In this figure, the windrow was started on July 12th. By August 2, the first temperature recorded of 110ºF. This indicates microbial population has starting working. The highest temperature, recorded on November 2, was 153ºF. There were 60 plus days where the temperature was above 131ºF (the line across the figure). This is the minimum temperature needed for pathogen destruction.

References

• A Plain English Guide to the EPA Part 503 Bio Solids Rule, United States Environmental Protection Agency, Office of Wastewater Management, EPA/832/R-93/003, September 1994.
• Hillary Nelson, The Contamination of Organic Produce by Human Pathogens in Animal Manures, Ecological Agriculture Projects, McGill University, Ste-Anne-de-Bellevue, QC, H9X 3v9 Canada, 1997
• Rubin, A.R., Extension Specialists, Is Time-Temperature Really Import? The 10th Annual WEF Residuals & Biosolids Management Conference, Denver Marriott Techg Center, Denver, Colorado, August 18-21, 1996
• Hay, Jonathan C., Pathogen Destruction and Biosolids Composting, BioCycle 1996, 37, 6: 67-76.
• Millard, Peter S., Gensheimer, Kathleen F., et al., An outbreak of Cryptosporidiosis From Fresh-Pressed Apple Cider, JAMA 1994, 272: 1592-6