Today, several manufactured herbicides contain specially formulated adjuvants pre-mixed in the herbicide container. Or, herbicide applicators may select and mix adjuvants themselves to meet site specific needs. Modern adjuvants are made from complex synthetic formulations that are designed for specific purposes. Most have no toxic effect on the plants or the environment. In the United States, there are several hundred name brand adjuvants that have various effects on aquatic herbicides. The EPA regulates ingredients (“inert ingredients”) that are added to pesticide products but adjuvants, by themselves, do not require testing by the Environmental Protection Agency or the Florida Department of Agriculture and Consumer Services in order to be used. There are generally three categories of adjuvants.

General Adjuvant Types

Activator Adjuvants	Activator adjuvants increase the effectiveness of herbicide by altering spray droplet size, distribution and/or viscosity of the spray, evaporation rate, rate of uptake (absorption) by the plant, and solubility of the herbicide.
Surfactants (surface-active agents)	promote the penetration of the chemical into the leaves of the plant.
Wetting agents	increase the ability of water to displace air or liquid from the plant's surface so the herbicide will spread more evenly over the plant.
Oils	increase the retention time of the sprayed material on the plant and enhance uptake though the leaf surface.
Spray Modifier Adjuvants	Spray-modifier adjuvants affect the delivery and placement of the spray solution. They make the herbicide spray easier to aim, reduce herbicide drift in the air, and cause the spray to more readily adhere to the plant.
Stickers and spreaders	are made of gels, oils, and waxes that help herbicide spray droplets spread and adhere to foliage.
Foams	make it easier to control drift so non-target damage is less likely.
Polymers	are used for drift control and to help break surface tension on the water, thus allowing the herbicide to sink onto submersed aquatic weeds.
Inverting oils	form a viscous blend that reduces drift during application, increases contact time on the plant, and sinks the herbicide onto submersed plants.
Utility-modifier Adjuvants	Utility-modifier adjuvants make the herbicide more useful in certain environmental conditions.
Buffering agents	adjust the pH of the herbicide spray solution for alkaline or acidic water.
Anti-foam agents	enable the herbicide to mix with soft water.