If you’re interested in learning more about agriculture chemical use over time, please see an earlier response I drafted, posted here.
Pesticides in use today have been thoroughly evaluated for environmental and human safety. The Environmental Protection Agency regulates the sale and use of pesticides and requires robust studies and lengthy testing to demonstrate safety before any product reaches the market. Many products on the market today have specific modes of action for a target pest. An example of a class of crop protection chemistry that is marketed by DuPont and remains popular is sulfonylurea herbicides. These herbicides are used at very low rates (often less than one-tenth of a pound per acre) and disrupt an enzymatic pathway found only in plants, and therefore have minimal impact on other organisms (e.g., humans, birds, insects). For all products, strict handling requirements are implemented to limit potential farmworker exposure and also to limit products’ potential exposure to the environment and other non–target organisms.
As for surfactants and inert ingredients that are used in these crop protection products, government regulators maintain tight control and oversight. Ingredients used in any product have undergone a similar level of scrutiny, as has the active ingredient in any product. A substantial number of studies for toxicity and non–target organisms are required before an inert ingredient is approved for use.