Remediation of residues on stored product surfaces using ozone-based fumgiations

Authors: Walse, Spencer

Submitted to: Controlled Atmosphere & Fumigation in Stored Products International Conference
Publication Type: Proceedings
Publication Acceptance Date: 5/24/2012
Publication Date: 10/21/2012
Citation: Walse, S.S. 2012. Remediation of residues on stored product surfaces using ozone-based fumgiations. International Conference on Controlled Atmosphere and Fumigation in Stored Products, October 21-26, 2012, Antalya, Turkey. p. 678-682.

Interpretive Summary: Evolving environmental and public health concerns surrounding non-target exposure of consumers to pesticide residues, regardless of concomitant toxicological evidence, necessitates the development of safe and effective methodologies for residue minimization. This publication describes technical research that is consistent with the goal of maximizing degradation of pesticide residues in postharvest scenarios, while minimizing unintended toxicity produced by “disinfection/remediation” technologies.

Technical Abstract: Ozone fumigation, alone and in combination with other gases, was explored as a means for degrading “undesirable” organic residues on stored products. Organic residues sorbed onto model abiotic glass surfaces or onto stored products were fumigated separately in a flow-through chamber at 150 - 900 ± 10 ppmv (uLL-1) reagent gas. Heterogeneous rate constants of gaseous ozone, and its mixtures, reacting with a sorbed organic residue, (M-1min^-1), were calculated for all surface types. The kinetics and mechanism of residue removal, supported by gas chromatography- and liquid chromatography-mass spectrometry product analyses, is discussed in the context of facilitating compliance with maximum residue level (MRL) tolerances for stored products. Results indicate that the extent of residue reduction varies with chemical structure; however, most residues can be rapidly degraded via decomposition radicals from ozonide intermediates and subsequent chain reactions involved (e.g., OH, OOR, etc.). Future work will focus on developing ozone fumigation as a remediation technology that is a more universally applicable tool for industries that use chemicals for pest control.