**1. Introduction**

Microorganisms, including fungi, contaminate grains during storage. These fungi do not only reduce grain quality, but also produce mycotoxins which pose health risks to consumers [1, 2]. According to Kady et al. [3], *Aspergillus, Fusarium, Penicillium,* and *Rhizopus* are the most common genera in barley, wheat, maize, and sorghum. These grains serve as staple food worldwide. Nowadays, nanotechnology is advancing in many fields, namely biotechnology, analytical chemistry, agriculture, and others. However, its application in crop protection is still in its early stages [4, 5].

The biocidal activity of nanoparticles is well documented. Herein, we proposed the utilization of nanoparticles to inhibit fungal growth and the production/synthesis of mycotoxins. Therefore, the second part of this chapter aims to discuss other

promising nanoparticles (titanium dioxide nanoparticles, chitosan nanoparticles, ultradisperse humic sapropel suspension (UDHSS) nanoparticles, and carbonbased nanoparticles/nanomaterials) of interest which could be applied during grain storage. The toxicological aspects, as well as the proposed modes of application are discussed.
