The Inspector’s Notebook #2
Protecting the integrity of organic grains during harvest
Develop strict cleaning protocol for harvesting and handling equipment to keep grain clean, pure and uncontaminated.

By Jim Riddle

Editor’s NOTE:

Certified organic farmers do an odd thing – they pay people to visit their farms with a critical eye to assure they are adhering to every aspect of the USDA’s national organic standard.

The farmers should already be trying to produce, harvest and market their organic crops, livestock and related products by these rules. The on-farm review of fields, facilities and records by an approved inspector sent by the farmer’s accredited organic certifier is the critical point in confirming that the farmer and the farm meet the organic standards – and can prove it to anyone who needs to know.

The visits are pivotal for applying farmers to become certified, and for certified farmers to keep that certification. For the good of organics, we want to help build the foundation for effective inspection visits. We’ve asked Jim Riddle to provide an inspector’s inside view to help farmers understand an inspector’s role, responsibilities and limitations.

In the months ahead, Riddle will elaborate on many items to help farmers understand regulations that apply to them, and how to document their compliance.
Jim Riddle has been on hundreds of farms in the inspector role, and he’s been inspected himself during his time as a farmer. His leadership in bringing professional training to inspectors helped to earn greater acceptance of organic farming in the U.S. He serves as vice-chair of the National Organic Standards Board, which advises the USDA on organic agriculture policies and regulations. He has been an organic farmer, gardener, inspector, educator, policy analyst, author, and consumer.

He was founding chair of the Independent Organic Inspectors Association, (IOIA), and co-author of the IFOAM/IOIA International Organic Inspection Manual. Riddle has helped train hundreds of organic inspectors throughout the world. In 2003, Jim was appointed Endowed Chair of Agricultural Systems at the University of Minnesota.

He serves as an organic policy specialist for

Posted August 17, 2004: Organic farmers do a great job of growing organic crops while improving soil health, balancing a variety of weed and pest management strategies, and using approved inputs.

During the inspection, however, I often find that they have not thought about what happens to their organic crops during and after harvest. You may have your grain harvested by a custom operator, or share a combine with your neighbor. You may borrow gravity wagons and trucks from a neighbor or relative to transport your grain to storage units. Any of these practices may compromise the integrity of your organic crop.

Commingling can occur when equipment used for harvesting conventional crops is used to harvest organic crops. Equipment, such as swathers, combines, and balers; transport units such as augers, conveyor belts, elevators, wagons, trucks; and storage units including bins, tote bags, and shipping containers, all have the potential to commingle your organic crops with conventional crops left in the equipment.

A study done by 2 engineering specialists at Iowa State University evaluated contamination of a grain crop by another crop left in the combine with a 45-minute “farmyard intensive cleaning” and less intensive “field cleaning.” They concluded that “it’s not unrealistic to remove about 60 pounds or more of grain, vegetative matter, and dirt from the combine after the grain tank had been apparently emptied.”

The National Organic Program (NOP) rule §205.201 requires that organic farmers and handlers must describe, in their Organic System Plans, the management practices and physical barriers they have established to prevent commingling of organic and nonorganic products. Section 205.272 requires that certified operations “must implement measures necessary to prevent the commingling of organic and nonorganic products and protect organic products from contact with prohibited substances.” This includes contamination of packaging materials, storage containers, and bins by synthetic fungicides, preservatives, or fumigants.

Commingling is defined as “physical contact between unpackaged organically produced and nonorganically produced agricultural products during production, processing, transportation, storage or handling…”

In your Organic Plan, you should provide information on how your crops are harvested, the type of equipment and storage units used, if equipment and storage units used for organic crops only, and if crops are custom harvested. You should describe your post harvest handling procedures and equipment used. These questions are designed to help you identify potential problems and develop strategies to comply with the NOP.

What You Can Do

The first thing to do is to identify all areas where commingling with nonorganic crops or contamination by prohibited substances may occur. List all pieces of equipment. If they are only used for organic crops, commingling is prevented. For equipment that is also used for nonorganic crops, determine what type of “thorough cleaning” is needed prevent commingling. Develop a written protocol or list of actions that you need to take to clean a particular piece of equipment. This will help you or your employees remember each step. This may be submitted as part of your Organic Plan, or you may simply show it to your inspector.

Some pieces of equipment will only need hand cleaning. Others may need pressure washed or blown out with pressurized air before organic use. Gravity boxes, truck beds, and other transportation units, and storage bins and hoppers may need to be swept, vacuumed, or blown out with compressed air.

For combines, open all trap doors and run the combine empty for about 15 minutes. Sweep the hopper and use an air compressor or vacuum cleaner to remove leftover grains, vegetative matter, and dirt from “hard to clean” areas. Manipulate the sieves to shake out residues. Purge any leftover grains by running three to five bushels of organic grains through the combine before beginning the actual harvest of your organic crop. (The purged grain cannot be sold as organic or used for organic feed.)

In addition to old grain, all harvesting and handling equipment and transport and storage units should be cleaned to remove bird droppings, rodent feces, insects, dust, and dirt. Ideally, equipment and transport and storage units should be cleaned soon after being used or emptied. This prevents future pest, moisture, rust, and mold problems, and makes cleaning before use much easier.


Records are an integral requirement for organic certification. Keep an equipment-cleaning log on a clipboard or notebook in the machine shed or other convenient location to record the date, piece of equipment cleaned, and methods used. Keep a record of equipment purges.

Date cleaned Type of equipment Methods used to clean Quantity of crop purged (if applicable) How was purged crop used?

Good luck, and have a safe and bountiful harvest!