Quats

Are Quaternary Ammonium Compounds allowed for use in my certified organic operation?

By Doug Currier

Quaternary Ammonium Cations (NR4+) are a group of powerful surfactants used in a variety of industries for their hydrophobic and anti-microbial properties. Often referred to as “quats” or QACs (Quaternary Ammonium Compounds), these materials are found in products ranging from shampoos, to corrosion inhibitors used in the oil and gas industry, to formulation ingredients for pesticides.

Quats are synthetic materials manufactured through a process called quaternization, in which a tertiary amine is reacted with an alkylating reagent (e.g., methyl chloride or benzyl chloride). The resulting quats are permanently positively charged and stable, with a long shelf life.

Due to their strong attraction to surfaces, quats are commonly used in the food and beverage industry for their disinfectant qualities, and their ability to create a surface monolayer which inhibits microbial activity. This monolayer acts as a persistent antimicrobial film which is bacteriostatic, fungistatic and sporistatic. The strong attraction which creates this monolayer is due to most surfaces being negatively charged, which attracts the positively charged quats.

It is this persistent nature of quats which creates a problem for certifiers. As a synthetic material used in operations producing, handling or processing certified organic food or fiber, quats would need to appear on the National List of Allowed Synthetics either at §205.601, §205.603 or §205.605(b) to be used in certified organic operations. Since quats do not appear as an allowed synthetic on any of these lists, there needs to be an intervening event to effectively remove quat residue and prevent contact with organic produce. This may be difficult to accomplish, because a typical hot water rinse is not effective to remove the residue. Some certifiers may require low level quat testing to demonstrate removal of the residue from food contact surfaces.

Given the persistence of this synthetic material, and the need for certifiers to evaluate the use of quats on a case-by-case, site-by-site basis, OMRI currently considers any products that contain quats out of our scope of review in each of our review classes.

OMRI’s policy on quats is recorded in the Generic Materials List© as follows: "Quaternary Ammonia: Also known as quats. Persistent materials that are likely to leave a prohibited residue will not be Listed by OMRI. Certification agent must determine if and how the material may be used."

This article was originally printed in the fall 2012 edition of the OMRI Materials Review newsletter, and was reviewed and updated in May 2020 by Technical Director Doug Currier.