2,2-ДИХЛОРПРОПИОНОВАЯ КИСЛОТА

Dalapon is a commonly used herbicide for the control of annual and perennial grasses in croplands. The US Environmental Protection Agency (EPA) has listed dalapon as a general use pesticide and categorized dalapon as a Class II toxic agent (moderately toxic). As such, any product that contains dalapon would be labeled with ‘warning.’ The moderate toxicity associated with dalapon is confined primarily to workers around dalapon and those individuals who are applying dalapon. Contact with the herbicide can be caustic to human skin, damaging to the conjunctiva of the human eye, and irritating/damaging to the upper respiratory system of humans. When used to control grasses in cropland as well as noncropland, dalapon is distributed via either aerial or ground equipment for foliage application. Some of the common croplands that have benefitted from dalapon application include corn, potatoes, legume crops, citrus, fruit, and nut trees. It is used extensively in the western United States to control a variety of grasses such as Bermuda, Johnson, Crab, and Quack grasses. Dalapon is translocated to the roots where it acts as a growth regulator. Although highly soluble with the ability to readily move through the environment, dalapon is relative safe and instances of dalapon intoxication are rare. The primary sources of toxicity are contact with the sodium or magnesium salt of dalapon, which is an irritant to the eyes, skin, and respiratory system. Cases of elevated levels of dalapon in drinking water or groundwater have also been rare, and little toxicity has been reported following dalapon exposure in water. Individuals who were exposed to high levels for extended periods of time can experience kidney dysfunction. Collectively, dalapon is a relatively safe herbicide for the control of many annual and perennial grasses.

clear yellow liquid

Dalapon is used primarily for the selective control of annual and perennial grass weeds in cropland and noncropland. Dalapon is also used as a selective aquatic herbicide. It is acidic in nature and are not strongly sorbed by soils, and reported to be rapidly degraded in both soil and water by microbial processes.

A colorless liquid. Soluble in water. Density 11.6 lb /gal. Corrosive to metals and tissue. Used as a herbicide.

Soluble in water. Reacts slowly in water to form hydrochloric and pyruvic acids.

VAPOR: Irritating to eyes, nose and throat. LIQUID: Will burn skin and eyes. Harmful if swallowed.

Combustible. Irritating fumes of hydrochloric acid may form in fire. Volatilizes with steam.

A corrosive with low toxicity by skin contact. A skin irritant. Mutation data reported. When heated to decomposition it emits toxic fumes of Cl-

The mechanism of action of dalapon is the same as for most acids. The acid denatures tissue proteins upon contact. At lower concentrations, the dalapon causes nonlethal yellowing of sensitive plants, which clearly distinguished them from resistant plants. The mode of action of chlorinated aliphatic acids is not known but they probably affect many enzyme pathways. Dalapon is readily absorbed into roots and leaves of plants and then translocated. Lower concentrations will inhibit plant growth and cause leaf chlorosis, followed by necrosis and death. Higher concentrations of dalapon will result in significant necrosis of areas of the plant in contact with dalapon. Although the direct mechanism of these effects has remained elusive, it is thought that dalapon may affect lipid, carbohydrate, and nitrogen metabolism as secondary effects. One prevailing hypothesis for the primary dalapon affect is that dalapon exerts direct effects on plant structural proteins leading to these secondary metabolic outcomes.