In regard to pesticide regulations, what is required to ensure safety from back siphonage?

The requirement to ensure safety from back siphonage is primarily addressed through the installation of check valves. These devices are crucial because they prevent the reverse flow of liquid, which can occur when there’s a decrease in water pressure. In the context of pesticide application, back siphonage could lead to contaminated water supplies if pesticides inadvertently flow back into the system. Properly installed check valves maintain the integrity of the water system by ensuring that any liquid intended for application does not return from the treated area into the potable water supply.

While the other options contribute to overall safety and efficacy in pesticide handling and application, they do not specifically address the risk associated with back siphonage. Proper containers ensure that pesticides are stored safely, regular training of personnel helps in following best practices, and monitoring pesticide usage is essential to comply with regulations, but none of these directly mitigates the risk of back siphonage. Thus, the installation of check valves stands out as the primary measure necessary to protect against this specific hazard.