Over the past decade, the concept of organic food has taken off in a big way. Today, just about every grocery store offers some selection of organic produce,  and it is generally accepted that organic growing practices yield produce that is tastier, healthier and more environmentally-friendly than traditionally grown fruits and vegetables. While recent studies have found no significant difference in nutritional value between organic and non-organic produce, health-conscious consumers are still likely choose organic in exchange for the assurance that their food has not been exposed to dangerous chemicals.

But the truth behind the Certified Organic label is a little more complicated than we might like to believe. While it's certainly true that organic crops has been exposed to substantially fewer chemicals than their non-organic counterparts, consumers may be surprised to learn that synthetic chemicals continue to play a significant role in the cultivation of organic produce.

What Makes Produce 'Organic', Anyway?

In order for produce to be labeled USDA Certified Organic, the farm must undergo rigorous inspection and growers must provide documentation that their growing and handling methods fall within the guidelines of the National Organic Standards Board (NOSB). Prohibited substances must be absent from the farm site for a minimum of three years before its produce can officially be labeled Organic.

Broadly speaking, prohibited substances are those that have been found to adversely affect the environment and/or human health. Many chemicals used in commercial pesticides and fertilizers pose a variety of health risks, with problems ranging from acute poisoning symptoms to long term physical and behavioral changes. Several of these chemicals have been labeled suspected or confirmed carcinogens (cancer-causing agents) and/or groundwater contaminants. Additionally, these chemicals often create hostile conditions for beneficial organisms such as earthworms and microbes. Prolonged use of chemical fertilizers can leach the soil of its natural nutrients, over time rendering the land unusable.

Organic growers, on the other hand, rely primarily on natural rather than synthetic resources. Compost and manure take the place of chemical fertilizers, predatory insects, such as ladybugs, are used to control pest populations and yearly crop rotations help prevent the spread of disease. The main goal of organic agriculture is to farm in a way that promotes biodiversity and works with the land, rather than against it.

These natural methods can go a long way in the cultivation of healthy crops, but the fact remains that commercial growing, even on a small scale, would be nearly impossible without the use of some chemicals. Agriculture is, after all, a business, and any number of unpredictable factors can wreak havoc on a growing season. For decades synthetic methods have given growers the tools to protect their crops and their livelihood from pests and disease that would otherwise devastate them. While the USDA places fairly rigid restrictions on which substances organic farmers can and cannot use, but the use of chemicals in organic agriculture remains widespread.

What's Allowed In My Organic Food?

Growers participating in the USDA's National Organic Program (NOP) are restricted to the use of chemicals found on the NOP's National List of Allowed and Prohibited Substances. This list contains only chemicals that have been classified by the Environmental Protection Agency (EPA) as either List 4A or List 4B ingredients. Substances found on these lists are believed to pose minimal risks to human health and the environment when used in pesticides.

This approach is probably the most practical option for growers looking to minimize their impact on the environment, but it is not without its drawbacks. For one, because organic compounds are often less effective than synthetic chemicals, they are frequently applied at far greater quantities, leading to questions about their safety. Moreover, the NOSB is constantly revising the National List as new evidence finds approved substances to be more harmful than previously believed.

 In 1996 the EPA began a reassessment of the ingredients on lists 4A and 4B and after a decade of research decided to remove eight substances from List 4A after determining that these substances did not, in fact, meet the EPA's safety guidelines. This means that several substances once thought to be harmless and permitted for use in organic farming were subsequently banned. Although the EPA completed its assessment in 2006, changes to the National List did not take effect until 2010.

A more recent example involves the use of oxytetracycline (sometimes referred to as tetracycline), an antibiotic used to prevent fungal outbreaks in fruits such as apples and pears. Concerns that the widespread use of oxytetracycline on crops could cause human pathogens to become resistant to the antibiotic -- which is used frequently in human medicine -- prompted the NOSB to implement plans to phase oxytetracycline out of organic growing by October of 2012. Since then, growers have successfully petitioned for an extension of that expiration date, claiming  the date does not provide sufficient time to find a viable alternative. Oxytretracycline is now scheduled to expire from the National List in 2016, with some organizations, such as the Midwest Organic Services Association, pushing for further extensions.

All this goes to show that the regulations behind organic growing methods are not as cut and dry as we might like to believe. Chemicals allowed in organic food today may be banned from organic farming a year from now, raising questions about just how much weight the organic label carries.

Is Organic Really The Best Option?

When it comes to buying food, choosing items labeled "USDA Organic" is probably the simplest option for those looking to reduce their exposure to chemicals, but as we've seen, it certainly isn't foolproof. For some, revisions to the National List may cast doubt on the legitimacy of this label, but these revisions can also be interpreted as evidence that federal regulating bodies remain vigilant about consumer health; the EPA, USDA and FDA continue to reevaluate substances used in agriculture and will remove them from the National List if they fail to meet NOSB guidelines.

That said, our understanding of the effects of chemicals is still evolving, and lists like those used by the NOSB often reflect the limits of our knowledge. Moreover, the lobbying powers of growers who want to continue using certain substances without compromising their organic status don't always have the consumers' best interest in mind.

Rather than simply relying on government-issued labels, consumers who are really concerned with what's used in their produce need to go to the source, the farmer. Farmers' markets provide an excellent opportunity to speak directly with growers; they also promote local farms which further reduce the environmental impact by cutting down on fuel consumption used in transport. In fact, many small-scale farmers use organic methods but decline to undergo USDA certification procedures due to the cost and the hassle of gathering the necessary records. In many cases, buying locally may be the better option, even if the produce is not Certified Organic.

The bottom line: Consumers looking for produce grown 100 percent chemical-free will need to look a little further than the "USDA Organic" sticker.

Works Referenced:

Midwest Organic Services Association. March, 2013. MOSA Comments on NOSB Work.

National Agriculture Library. 2007. Organic production and organic food: information access tools.

Pesticide Action Network. 2010. PAN pesticide database.

U.S. Department of Agriculture. February, 2013. National Organic Standards Board Crops Subcommittee Petitioned Material Proposal Oxytetracycline.

U.S. Department of Agriculture. January, 2010. National Organic Program; proposed amendments to the National List of Allowed and Prohibited Substances (crops). Federal Registrar, Vol. 75, No. 7.

U.S. Department of Agriculture. September, 2010. Guidance: reassessed inert ingredients.

U.S. Department of Agriculture, National Organic Program. 2008. Certification.