Chlorine Dioxide

Brief Description:

Chlorine Dioxide is used in the winery as an alternative to chlorinated cleaners because of the magnitude of the effect that chlorine has on wine quality through the formation of TCA. Although chlorine is in the name chlorine dioxide, chlorine is not involved in any of chlorine dioxides reaction pathways.  Use of chlorine dioxied does not lead to the same issues of TCA generation as use of chlorine. Like ozone, chlorine dioxide must be generated on site.

Chlorine dioxide (ClO2) is a neutral compound of chlorine in the +IV oxidation state and it disinfects by oxidation.  It is a relatively small, volatile, and highly energetic molecule, and a free radical even while in dilute aqueous solutions. At high concentrations, it reacts violently with reducing agents. However, it is stable in dilute solution in a closed container in the absence of light (AWWA, 1990). Chlorine dioxide functions as a highly selective oxidant due to its unique, one-electron transfer mechanism where it is reduced to chlorite (ClO2-) (Hoehn et al., 1996).

Application in Wine Microbiology:

Chlorine dioxide is used as a disinfectant in wineries for cleaning surfaces as an oxidizing cleaner and sanitizer.