I, also, seem to remember something in recent years of one of the weed control products being banned. Maybe it was the 2,4-D. This may be one of those herbicides that was banned by some states for consumer use but not banned for agricultural or industrial use?
Based on the USGS data, it appear to be increasing in use.
In fact, I may have some 2,4-D + Dicamba somewhere around here.
Despite concerns about potential health risks, in 2014 the U.S. Environmental Protection Agency approved the combined use of 2,4-D and the popular weed killer Roundup (also known as glyphosate, a whole other—and in many ways more worrying—story when it comes to health and the environment). Enlist Duo, as the combo is called, was already legal in several states. It is used mainly on big farms, where it is sprayed on genetically modified crops called Enlist soy and Enlist corn that have been engineered to be resistant to the poisons.
In other words, farmers can now douse their fields with high concentrations of the weed killer without worrying that it will also destroy their crops. Originally, plants genetically engineered to resist Roundup were sprayed with that herbicide alone. But when the weeds it was intended to kill also developed resistance, 2,4-D was added to make the mix more effective. As Pullen puts it, "These chemicals by themselves can be problematic, but when we start combining them with other toxic chemicals, we're just creating a new problem in order to solve another problem."
The U.S. Department of Agriculture estimates that by 2020, the use of 2,4-D on America's farms could rise between 100 percent and 600 percent now that it has been approved as part of Enlist Duo. According to Pullen, "When you combine increased use with the potential for increased developmental, cancer, and other health impacts, you could create a perfect storm of hazard and exposure coming together."