The invention relates to the use of ozone for removing residual phytosanitary molecules contained in plant seeds. According to the invention, plant seeds contaminated by residual phytosanitary molecules can be treated in a method including the steps of: (a) providing plant seeds contaminated by residual phytosanitary molecules (b) adjusting the moisture of the contaminated plant seeds to a rate of at least 10% and at most 21% with respect to the dry material (c) placing the ozone and the contaminated plant seeds in contact with each other and (d) removing the residual ozone. The treated plant seed may be wheat, corn, or rape.
