The Future of Synthetic Inerts


Guest post by Peter Bungum, the Technical Coordinator at Organic Materials Review InstituteIf you have questions pertaining to this article, please contact author.

In 1947, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) created a distinction between two types of pesticide ingredients: “active” ingredients that kill, repel, or otherwise mitigate pests; and “inerts,” which are any other ingredients intentionally added to pesticide formulations other than the active ingredient. Inerts perform a variety of functions, such as to modify pesticides so that they can be sprayed through equipment, improve adhesion to plant surfaces, and act as carriers so that materials can be usefully applied. Enforcing FIFRA became the responsibility of the Environmental Protection Agency (EPA) after it was established in 1970. When the National Organic Program (NOP) Final Rule was published in 2000, the regulations deferred to the EPA’s definition of an inert and based the allowance of inerts on a specific classification system used by the EPA. Eventually, the relationship between these two sets of regulations created a problem.

The National Organic Standards Board (NOSB), which provides recommendations to the NOP, has been attempting to align the regulation of inert ingredients used in organic compliant pesticides with the Organic Foods Production Act of 1990 (OFPA) for over a decade. Section 6517(c)(1)(b)(ii) of OFPA provides an exemption for materials otherwise prohibited in organic agriculture to be used as inerts, so long as they are not classified by the EPA as “inerts of toxicological concern.” Currently, the NOP regulations base the allowance of inerts on obsolete EPA lists, which are no longer updated. If the EPA were to reclassify the toxicological risk of a substance, they would not update the obsolete lists and the current NOP regulations would not be able to enforce the requirements of the law (OFPA). The EPA has requested that the NOP remove language that refers to these obsolete lists.

The NOP and NOSB have investigated various approaches to listing allowed inerts, including deferring to assessments made by the EPA’s Safer Chemical Ingredients List program and materials that are determined to be legally exempt from pesticide registration under FIFRA. In October 2015, the NOSB passed a recommendation to amend the NOP regulations at 205.601(m) and 205.603(e) by removing references to EPA List 3 and 4, and replacing them with the new language italicized below:

[In accordance with restrictions specified in this section, the following synthetic substances may be used ….]

As synthetic inert ingredients as classified by the Environmental Protection Agency (EPA), for use with nonsynthetic substances or synthetic substances listed in this section and used as an active pesticide ingredient in accordance with any limitations on the use of such substances.

(i) Substances permitted for use as inerts in minimal risk products exempt from pesticide registration under FIFRA section 25(b).

(ii) Substances included on the EPA’s Safer Chemical Ingredient List.

(iii) Inert ingredients that are exempt from the requirement of a tolerance under 40 CFR 180.1122 – for use only in passive pheromone dispensers.

(iv) [Reserved] (for any other inerts individually petitioned and reviewed)

Despite outward indications that the NOP intends to move forward with this approach, official rulemaking procedures to implement the NOSB’s recommendation have yet to occur. Additionally, in order for the NOP to rely on the EPA’s Safer Chemical Ingredients List, the NOP has indicated that they need to establish a memorandum of understanding (MOU) with the EPA to formalize their relationship. The NOSB will also need to establish a procedure for incorporating elements of OFPA criteria that are not specifically addressed by the EPA’s health risk assessments and substance classifications. Once a final rule is published, there may be an implementation period of three to five years.

The NOSB has reviewed the allowance for synthetic inerts during sunset reviews and recommended that the NOP continue to use the current annotations until the NOP implements the new language through rulemaking. The NOP regulations currently allow for synthetic inerts to be used in conjunction with approved active pesticide ingredients, provided that the synthetic inert substances are:

• specifically listed on the 2004 EPA List 4 – Inerts of Minimal Concern and not prohibited as described within Guidance NOP 5008; or

• substances on EPA List 3 – Inerts of Unknown Toxicity; allowed only for use in passive pheromone dispensers.

Nonsynthetic materials may also be used as inerts so long as they are not specifically prohibited. These regulations remain in place until the NOP amends the relevant annotations at 7 CFR §205.601(m) and §205.603(e).

Peter Bungum is the Technical Coordinator for Organic Materials Review Institute. He earned his B.S. and M.S. in Biology from the University of Oregon. He has worked as a college instructor for three different community colleges in the Willamette Valley, as a Biological Technician for the U.S. Forest Service (working with fungal pathogens), and at Oregon State University as a Research Assistant in the Botany and Plant Pathology department. Peter has also owned a metal fabrication business since 2007.

Leave a Reply