The world of chemistry, like life, is full of things that may appear straightforward at first glance, but upon deeper inspection reveal more nuance and a disregard for rigid “rules.” Contrast that with the world of chemical and pesticide regulations, and you have a recipe for confusion. The straightforward explanation of active and inert chemicals is right there in the names and definitions. However, names and definitions may not (and usually don’t) tell the whole story as to why or how a particular chemical performs.

The EPA defines active ingredients as the chemicals in a pesticide product that act to control pests. There are three categories of active ingredients for EPA-registered products:

  1. Conventional – all ingredients other than biological pesticides and antimicrobial pesticides
  2. Antimicrobial – substances or mixtures of substances used to prevent, destroy, repel or mitigate any pest (Pests can include bacteria, viruses or fungi.)
  3. Biopesticides – types of ingredients derived from certain natural materials

Conversely, anything that is not an active ingredient is considered an inert ingredient by the federal government. The name and definition suggests that inert chemicals don’t play an active role in pesticide management. And while inert chemicals may not act directly on an organism, they may provide crucial effects on the solution or environment that the pesticide needs to be fully effective. Examples of inert functions are:

  • Buffer solution water to protect chemistry from adverse pH or hardness
  • Improve contact time by increasing foaming
  • Improve the ease of application by preventing caking or foaming
  • Improve material compatibility
  • Extend the product’s shelf life
  • Improve safety for the applicator
  • Protect the pesticide from degradation due to exposure to sunlight

So, what’s a real-world example of how inert ingredients can enhance a product’s performance? Let’s take a closer look at our PerQuat® technology, the chemistry powering a line of enhanced disinfectants and biofilm removal and control agents. On the label for Sterilex Ultra Disinfectant Cleaner Solution 1 and Sterilex Ultra Activator Solution, quaternary ammonium and hydrogen peroxide are listed as the active ingredients. However, that doesn’t tell the whole story of how the product works. The inert chemicals in Sterilex Ultra Disinfectant Cleaner Solution 1 and Sterilex Ultra Activator Solution enhance stability and aid in end-use application. These key chemistries are formulated to help buffer and control water characteristics like hardness, pH and alkalinity. In addition, products like the Ultra Soft Metal Activator have corrosion inhibitors formulated into the solution to ensure the protection of metals such as aluminum.

Reading the active chemical list is a quick way to get an overview of how a potential pesticide works and how many active chemicals are in the formula. However, understanding that there are very important ingredients in pesticide formulations that may not be listed as direct actives is a key part of selecting the right chemical formulation for any task: from controlling biofilm in food plants to eradicating pathogens and inactivating viruses on hard surfaces.