INERT INGREDIENTS IN PESTICIDES AND THE USDA PROPOSED NATIONAL ORGANIC RULE
by Eric Sideman, Ph.D., MOFGA’s Director of Technical Services
published in The MOF&G, September, 1999
Organic agriculture is based on systems that have evolved through natural processes. Of course, growing crops organically is not a natural process itself because agriculture, by nature, is not natural. Here in Maine natural vegetation on most of the land base would be forest. The basic premise is that the farming practices and inputs in organic production should be those that are most compatible with the natural communities. For the most part the materials that are used in organic systems are in their native state-perhaps physically modified by grinding, for instance, or produced by biological processes. Synthetic materials are almost entirely prohibited. However, organic standards selected a few synthetic materials that they allowed—requiring that they meet stringent criteria concerning their safety to humans and the environment, their place in the agroecosystem from origin to breakdown, and their compatibility with a system of organic production. Soap is an example of a permitted synthetic chemical.
One exception to this basic guideline is the group of chemicals known as ”inerts.” Every time I run spell check my computer tries to correct ”inerts” to “inert.” I guess the word is not a noun in the English language, but it has become one of the most commonly used nouns recently at the National Organic Standards Board (NOSB) meetings. Inerts refer to ingredients in pesticide formulations that are not active in relation to the particular purpose of that pesticide. In other words, any chemical in the pesticide formulation that is not actively killing the target pest is an inert.
The word ‘inert’ is actually a misnomer in most cases, because inerts are almost always chemically functional and actually are added intentionally to enhance the performance of the active ingredient. They are generally solvents, emulsifiers or synergists or compounds that in some way make the active ingredient work better.
What is so upsetting about inerts is that they are secret ingredients. According to EPA rule, pesticide manufacturers must reveal their active ingredient on the pesticide label. But inerts, no matter how many or whatever they are, can simply be lumped together and called “inert ingredients.”
While their name suggests otherwise, inert pesticide ingredients vary widely in their acute and chronic toxicity and environmental effects. Some, such as water, honey, wheat, carrots and sawdust, are relatively nontoxic. Others, such as methylene chloride, methyl bromide and naphthalene, are active ingredients in other pesticides and are clearly acutely toxic to living things. Many inerts are organic solvents, such as glycol ethers or xylenes, that have numerous toxicological problems and often are found in ground water.
The Inert Issue
Organic crop protection generally relies on methods other than directly killing target pests. Methods used include crop rotation, crop barriers, maintaining beneficial habitat and other cultural and biological means. As a last resort, however, pesticides are permitted. The permitted pesticides are natural in origin, including those derived from plant material (such as rotenone) or microbes (such as ***Bacillus thuringiensis***).
Most organic farm certifiers, such as MOFGA, want to do the best they can when determining whether a particular pesticide formulation meets organic standards or not. We ask for a list of all the ingredients in the formulation and all the processes that the manufacture uses in production. We premit very few synthetic materials; those that we do permit are justified by meeting a set of criteria assuring health and environmental safety. However, inerts are a different issue. Since they are secret and are not required to be revealed by law, most manufactures consider them trade secrets. Many pesticides that have been used by organic farmers since the beginning, such as rotenone, pyrethrum, Bt, etc., contain synthetic inerts. These continue to be permitted by MOFGA, even though we may not know the inert ingredients, simply because organic growers used them before MOFGA existed.
I thought that the greatest benefit to MOFGA and our farmers of the Organic Food Production Act and the developing National Organic Program would be that someone with clout (the USDA) would be able to handle this issue. I thought that the USDA would develop and keep an up-to-date list of brand name products that are permitted according to organic standards. The USDA is not.
A private, nonprofit organization called the Organic Materials Review Institute (OMRI) has been set up and is run by a board of directors of many of the old time players in the organic industry. I am on the advisory council of the Institute. The main purpose of OMRI is to review brand name products and determine if they meet organic standards. The Institute requires full disclosure of all ingredients, including inerts, for a review. It has reviewed many of the materials commonly used, but most are still on the market with no review and with secret inerts.
The NOSB is now working on a project to get a list of all of the inerts found in pesticides that are commonly used in organic production. The goal is to take that list and determine which of the inerts meet the criteria for permitted synthetic chemicals. Then it will be up to OMRI to use that list of permitted inerts and decide which products truly meet organic standards. We hope for no surprises, but I think there will be. I think we will lose some products that are now widely used. I guess that you all agree that we still want to know.
You can help by writing to the manufactures of the materials you use and asking them to get a full OMRI review of their products. The Organic Materials Review Institute can be reached at P.O. Box 11558, Eugene, Oregon 97440.
***About the author: Eric is MOFGA’s Technical Director, essentially an organic “extension agent” and is available to answer questions at the MOFGA office and at the Common Ground Country Fair.