​Ozone As A Pesticide Alternative: Mechanisms for Reducing Chemical Residues​​

Ozone as a Pesticide Alternative: Mechanisms for Reducing Chemical Residues

The mechanisms and applications of ozone as a pesticide alternative to reduce chemical residues have been widely studied, with its technical advantages primarily reflected in efficient sterilization, residue degradation, and environmental friendliness.

Direct Oxidation to Destroy Microorganisms and Pests

First, ozone exerts its bactericidal effect by disrupting the cell membranes and nucleic acids (e.g., DNA/RNA) of bacteria and fungi through strong oxidation, leading to their inactivation. For example, at a concentration of 0.5 ppm, ozone achieves a spore inactivation rate of over 99% against Botrytis cinerea (gray mold).

Second, its insecticidal action involves ozone gas penetrating pests’ respiratory systems, damaging their enzyme systems and mitochondrial functions, thereby inhibiting egg hatching.

Pesticide Residue Degradation

Ozone reacts with pesticides such as organophosphates and pyrethroids, oxidizing and decomposing them into low-toxicity or non-toxic byproducts (e.g., CO₂, H₂O). Experiments show that 10 minutes of ozone treatment can reduce chlorpyrifos residues on fruits and vegetables by 70%–90%.

Inducing Plant Disease Resistance

Low-concentration ozone activates plants’ systemic acquired resistance (SAR), promoting the synthesis of defensive enzymes (e.g., peroxidase, superoxide dismutase) and enhancing resistance to diseases.

• A water ozone irrigation system developed by the Chinese Academy of Agricultural Sciences, tested in Shouguang vegetable greenhouses (Shandong), reduced cucumber powdery mildew incidence by 60% and cut pesticide use by 40%.

• Research from South China Agricultural University indicates that ozone fumigation extends lychee shelf life by 7 days and degrades dimethoate residues by 75%.

• Hokkaido University (Japan) found that ozone water irrigation reduces tomato leaf mold incidence by 80% while lowering fungicide usage by 50%.

• The Spanish Agricultural Technology Center (IRTA) demonstrated that ozone treatment degrades 85% of carbendazim residues on grape surfaces without compromising fruit quality.

International Recognition & Standards

• The U.S. FDA has certified ozone as GRAS (Generally Recognized as Safe), permitting its use in food processing and agriculture.

• The International Organization for Standardization (ISO) issued ISO 22412:2020 to regulate safe ozone concentrations in agricultural applications.

• The World Health Organization (WHO) acknowledges ozone’s sterilization and environmental benefits in its Guidelines for Drinking-Water Quality.