Product Storage Stability for EPA FIFRA Registration FAQs

One significant requirement to register an antimicrobial product with EPA is product stability testing. But what sort of testing is required, what is the purpose of that testing, and how is it performed? Find answers to the most frequently asked questions in this article.

Why conduct stability testing?

Storage stability testing is designed to confirm the product’s ability to maintain integrity throughout the intended shelf life, and to identify any potential storage limits your product may have. The end goal is to determine the appropriate storage conditions and expiration dates for the product label.

What EPA guidelines are in place for stability testing under FIFRA?

When the Environmental Protection Agency (EPA) implemented the OPPTS 830.6317 guideline in June of 2002, the framework of how storage stability testing should be conducted for products registered under the federal insecticide, fungicide, and rodenticide act (FIFRA) was established. 

Additional guidance was published in the form of a memo in 2012 that described conditions for accelerated stability studies at elevated temperature for some products.

What is covered in the FIFRA stability guidelines?

These guidelines require that all product packaging maintains integrity, that the product’s active ingredients remain within the nominal range (see below), and that the product be free from significant physical changes that could interfere with its usefulness or safe handling. To confirm these requirements are met, stability testing is performed.

What are the EPA's requirements for products being tested for stability?

EPA requires products to be tested in the intended commercial packaging (or in smaller packaging of the same construction and materials) and evaluated specifically for active ingredient changes over time. The framework of a stability study must resemble one of the strategies below.

What are the common conditions for FIFRA stability studies?

Common stability conditions include shelf life and accelerated conditions. Table 1 details conditions, temperature, and storage intervals.

Table 1. Stability study conditions, temperature, and storage intervals

How do I know which storage conditions are right for my EPA product registration stability study?

Most active ingredients designed for EPA product registration under FIFRA fall under one of these categories:

• Quaternary ammonium compounds (QACs)
• Alcohols (ethanol, isopropanol, etc.)
• Halogen releasing compounds
• Peroxygen-based compounds
• Acids (citric acid, hydrochloric acid, etc.)
• Aldehydes (formaldehyde, glutaraldehyde, etc.)

Most other products not found in those categories can be classified into the remaining categories such as phenols (halogenated or not), alkalis (like sodium hydroxide), and metal ions (like copper or silver). Element primarily focuses on the six listed in the bullets above. However, if your product falls into another category, or if you’re unsure which category it belongs to, please reach out and contact us for additional information and guidance. We’d love to help!

The chart below can help you begin to understand which stability study framework may best work for the active ingredient in your product.

Table 2. Active ingredient stability considerations for EPA stability studies for FIFRA

What is the nominal range for stability testing?

Typically, the nominal range of an active ingredient is determined by a table provided in OPPTS 830.1750 - Certified limits- published in August of 1996. Unless a different limit is proposed by a registrant, the table provides specific upper and lower limits based on the concentration of the active ingredient stated on the label. For example, a 10% hydrogen peroxide solution would have an upper limit of 10.5% and a lower limit of 9.5%, making the nominal range 9.5 to 10.5% hydrogen peroxide.

Why is the nominal range so important for stability studies for FIFRA registration?

It is critical to understand the nominal range when working with stability data as the range defines acceptable stability limits for the active ingredient. For a product to pass stability testing, it needs to maintain active ingredient concentrations within the nominal range at the initial time point and throughout the entirety of the study. If at any time the active ingredient concentration is outside the nominal range, the product may require additional testing, special labeling, a different shelf life or worse, EPA may deny approval.

How do I learn more about Element's antimicrobial testing programs?

Our consultative team has the depth of regulatory and scientific knowledge necessary to assist in developing a testing plan for your product, whether you require stability testing, analytical chemistry or antimicrobial efficacy studies, or more. To start the conversation about partnering with Element’s antimicrobial experts, please reach out today.