Organic and Synthetic Pesticides: What's the Difference?

Introduction

People often compare organic and synthetic pesticides when choosing products for pest management. However, these terms have distinct meanings and are often misunderstood. Organic refers to a production system governed by U.S. Department of Agriculture (USDA) standards, whereas synthetic and nonsynthetic (natural) describe how pesticide ingredients are derived. This factsheet explains how these terms relate to each other, how pesticides are regulated for use in organic production, and key considerations when selecting and using pesticide products.

Know the Difference

The terms synthetic, nonsynthetic (natural), and organic have distinct meanings but are often confused.

Synthetic substances are manufactured or produced through chemical processes. Pesticides containing synthetic active ingredients are often referred to as “conventional pesticides.” Examples of synthetic pesticide active ingredients include 2,4-D, glyphosate, imidacloprid, and permethrin.

Nonsynthetic (natural) substances are derived from naturally occurring sources such as plants, animals, or minerals. Examples of nonsynthetic pesticide active ingredients include diatomaceous earth (fossilized water microbes), neem oil (an extract from neem trees), pyrethrins (an extract from chrysanthemum flowers), and sulfur.

Organic refers to a production system governed by USDA organic standards. Unlike synthetic and nonsynthetic, which describe how pesticide ingredients are derived, organic describes whether a product is permitted for use in certified organic production. A pesticide’s eligibility for use in organic production is determined by USDA standards and not necessarily by whether its ingredients are synthetic or nonsynthetic (natural). It is also important to note that whether a pesticide is synthetic or nonsynthetic does not, by itself, determine whether it is safe and/or effective.

Throughout this publication, we use the term “organic pesticide” to refer to a pesticide product permitted for use in organic production. However, there is no official regulatory classification known as an “organic pesticide.”

Pesticides Allowed in Organic Agriculture

A common misconception is that organic food and feed are grown without pesticides. However, “organically grown” does not mean “pesticide-free.” Organic production allows the use of certain pesticides that meet organic standards established by the USDA National Organic Program.

Another common misconception is that all pesticides used in organic production are natural and all synthetic pesticides are prohibited. In reality, some synthetic pesticide ingredients such as peracetic acid, petroleum-derived horticultural and mineral oils, and insecticidal soaps are allowed in organic agriculture. Conversely, some naturally occurring (nonsynthetic) substances, including arsenic and nicotine sulfate, are prohibited in organic production. The USDA determines which pesticide ingredients may be used through its National List of Allowed and Prohibited Substances.

EPA Regulation

Organic pesticides are real pesticides (fig. 1) and, like synthetic products, are regulated by the Environmental Protection Agency (EPA). The EPA is responsible for evaluating potential risks of pesticides to human health and the environment before they can be distributed and sold in the United States. Pesticide products registered by the EPA, including those permitted for use in organic production, carry labeling that provides directions for use, safety information, and environmental precautions. By law, users of EPA-labeled pesticides (synthetic and organic) must read and follow all label instructions.

Origin Does Not Dictate Toxicity

All pesticides, including those used in organic production, can be toxic in certain doses. The EPA uses signal words (table 1) to indicate how acutely toxic a pesticide is to humans through different exposure routes (oral, dermal [skin], inhalation, and eye). These signal words appear on the labels of registered pesticides.

Many people assume pesticides used in organic production are safer than synthetic pesticides. However, this is not always the case. Some EPA- registered organic pesticides carry a high toxicity signal word, DANGER. For example, lime-sulfur products often bear this designation and should be used with extreme caution. Conversely, not all synthetic pesticides are highly toxic — many are labeled with the signal word CAUTION, the lowest toxicity category. In other words, organic does not mean “safe,” just as synthetic does not mean “dangerous.” Read the label to determine the hazards of each product you use and follow all label directions to protect yourself and the environment.

Pros, Cons, and Considerations When Using Organic and Synthetic Pesticides

Choosing between products marketed for organic use and synthetic pesticides is rarely straightforward. Both types of pesticides have benefits and limitations. You must weigh these pros and cons to determine which type of pesticide best suits your pest management goals.

Persistence

One key consideration is how long a pesticide remains effective after it is applied. This is called “persistence.”

Organic pesticides are often less persistent in the environment than many synthetic alternatives. They tend to break down more quickly, leaving little or no residual activity after a short period. This can help reduce environmental impacts and residue concerns. However, it also means you may need to apply it more often to achieve effective pest control. Over time, the total amount of pesticide applied may be greater compared to a more persistent product.

In contrast, many synthetic pesticides can provide longer-lasting protection, reducing the need for repeated applications. This can result in long-lasting protection with less frequent and lower overall volumes of pesticide applied, saving both time and money. However, their slower breakdown may raise environmental concerns or result in harvest restrictions. Still, when used according to label directions, foods and sites treated with synthetic pesticides are considered safe when used according to the label.

Selectivity

Another important consideration is whether a pesticide targets a specific pest or affects many different organisms. This is called “selectivity.”

Organic pesticides, particularly biological products (e.g., insecticides containing Bacillus thuringiensis [Bt]), are often valued for their selectivity. This means they target specific pests, which can help protect pollinators and other beneficial organisms from harm. However, because they affect only certain pests, these products may not provide complete control when several pest species are present. Additional treatments may be needed to manage pests that are not affected. Conversely, some synthetic pesticides (e.g., pyrethroids), as well as certain organic options (e.g., pyrethrins), are broad spectrum, meaning they can harm a wide range of organisms. These products can harm beneficial species along with pests. As a result, pests that were previously kept in check by natural enemies may increase, requiring additional control measures.

Timing, Knowledge, and Convenience

Because organic pesticides are often less persistent and/or more selective, effective use requires a deeper understanding of the target pest. Accurate identification and knowledge of the pest’s life cycle are critical, as many organic products rely on precise timing for success. For example, neem oil can disrupt feeding in immature insects but may have little effect on adults, making proper timing essential. These considerations are not unique to organic pesticides. Many synthetic products also require proper timing and accurate pest identification for effective control.

Synthetic pesticides often offer practical advantages in cost and availability. They are typically less expensive than organic products, more widely available, and have longer shelf lives. This reduces the logistical challenges of purchasing and applying products within short time frames. By comparison, some organic pesticides require special handling to remain effective. For instance, beneficial nematodes applied as a biopesticide often need refrigeration and must be used within weeks of receipt. This makes proper storage, handling, and application timing especially important.

Selecting an Organic Product

If you are interested in using pesticides that are allowed in organic production, look for labels that say “OMRI Listed” or “For Organic Gardening.” OMRI (Organic Materials Review Institute) evaluates inputs (such as fertilizers, pesticides, and livestock care products) used in organic agriculture. The USDA and the EPA created the “For Organic Gardening” logo to indicate the pesticide is permitted for use in organic gardening or agriculture. If the pesticide is OMRI-listed or intended for certified organic production, these logos will appear on the front panel of the label (fig. 2). Some products may have one or both logos.

Care When Using Pesticides

Whether organic or synthetic, all pesticides are intended to kill or control pests and must be used with respect and caution. Read the pesticide label and follow the directions for use. Make sure the pest you intend to control and the intended application site are listed on the product label. Use the recommended dose, wear the personal protective clothing and equipment listed, and take note of environmental hazards.

Reminder to Practice IPM

Integrated pest management (IPM) is highly encouraged in both organic and conventional production. IPM is a holistic approach that combines multiple control methods to reduce pest damage while minimizing harm. These controls may be cultural, mechanical/physical, biological, or chemical. Depending on the pest and situation, some control methods may be more effective than others. By integrating several approaches, IPM provides flexible and effective pest management options while protecting people, animals, and the environment. For more information, see the Extension publication, An Introduction to Integrated Pest Management.

Any pesticide products named or displayed in this publication are included for informational purposes only. Virginia Cooperative Extension, Virginia Department of Agriculture and Consumer Services, and Virginia Tech Pesticide Programs do not endorse these products and do not intend discrimination against other products that may also be suitable.