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Commonly Used Disinfecting QACs

November 2021

Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA categorizes QACs into four main groups. Multiple individual chemicals with unique CAS numbers fall within each of these groups. This fact sheet will focus on the representative substances for Group I and Group II QACs:

  • Didecyl dimethyl ammonium chloride (DDAC)
  • Alkyl dimethyl benzyl ammonium chloride (ADBAC)


Group I consists of five individually registered compounds[3] and Group II consists of 19 compounds;[4] see Table 1 and Table 2 in the Regulation of QACs section for complete lists of individual compounds. Within these groups, the Toxics Use Reduction Act (TURA) Science Advisory Board (SAB) looked in detail at DDAC and a common ADBAC as the representative compound of each group. Both of these example compounds were selected because they are among the most commonly used in disinfecting products, have the highest number of active registrations, and are often found together in mixtures. The table below summarizes key properties for each of the representative substances.

Properties of DDAC and ADBAC*

Quats chart

*Properties sourced from EPA Registration Documents and Final Work Plans unless otherwise noted.

Use Information

In the U.S., ADBAC and DDAC were some of the first QACs to be used as antimicrobials, registered as active ingredients under FIFRA in 1947 and 1962 respectively. ADBAC and DDAC are considered High Production Volume chemicals, which means more than one million pounds are manufactured or imported into the U.S. each year. Data for the years 2011 through 2014 indicate that approximately 198 million pounds of ADBAC and 99 million pounds of DDAC are sold per year in the U.S.3,4 QAC use increased dramatically during the pandemic, accounting for the highest revenue share of the U.S. antiseptics and disinfectants market in 2020.[8]

There are over 600 EPA-registered products that contain ADBAC as an active ingredient. DDAC is registered as the active ingredient in almost 300 antimicrobial EPA-registered products. Many DDAC and ADBAC products contain several ingredients, including other DDAC- and ADBAC-related compounds, isopropyl alcohol, glutaraldehyde, chlorine dioxide, and fragrances.