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| | 2,2-Dichloropropionic acid Basic information |
| | 2,2-Dichloropropionic acid Chemical Properties |
| Melting point | 166°C (dec.) | | Boiling point | 202°C | | density | 1.4014 | | refractive index | 1.4544 | | Fp | >110°C | | storage temp. | 0-6°C | | solubility | Acetonitrile (Slightly), Chloroform (Sparingly), Methanol (Slightly) | | form | Liquid | | pka | pK1:2.06 (25°C) | | color | Colorless to Light yellow | | Water Solubility | 50.2 g/100 mL | | Sensitive | Moisture Sensitive | | Merck | 14,2802 | | BRN | 1750149 | | Stability: | Hygroscopic | | CAS DataBase Reference | 75-99-0(CAS DataBase Reference) | | NIST Chemistry Reference | Propanoic acid, 2,2-dichloro-(75-99-0) | | EPA Substance Registry System | Dalapon (75-99-0) |
| | 2,2-Dichloropropionic acid Usage And Synthesis |
| Description | 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. | | Chemical Properties | clear yellow liquid | | Uses | 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. | | Uses | Dalapon is used as an herbicide primarily to control annual
and perennial grasses, including Bermuda grass and Johnson
grass. Use of dalapon on food crops is primarily with sugarcane
and sugar beets. Dalapon is also used on fruits, potatoes,
carrots, asparagus, alfalfa, and flax, and in forestry, home
gardening, and to control reed and sedge growth in aquatic
environments. | | Uses | Herbicide marketed as the sodium salt
or a mixture of the sodium and magnesium salts
used to control grasses in a wide variety of
crops and in a number of noncrop applications,
such as along drainage ditches and railroads
and in industrial areas. | | Definition | ChEBI: Dalapon is a carboxylic acid and an organohalogen compound. | | General Description | A colorless liquid. Soluble in water. Density 11.6 lb /gal. Corrosive to metals and tissue. Used as a herbicide. | | Air & Water Reactions | Soluble in water. Reacts slowly in water to form hydrochloric and pyruvic acids. | | Health Hazard | VAPOR: Irritating to eyes, nose and throat. LIQUID: Will burn skin and eyes. Harmful if swallowed. | | Fire Hazard | Combustible. Irritating fumes of hydrochloric acid may form in fire. Volatilizes with steam. | | Safety Profile | A corrosive with low
toxicity by skin contact. A skin irritant.
Mutation data reported. When heated to
decomposition it emits toxic fumes of Cl- | | Environmental Fate | 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. | | Toxicity evaluation | Dalapon is somewhat persistent in soil but does not readily
adsorb to soil particles. It can remain active in soil for several
months when applied at high rates. In general, dalapon is
considered to have low to moderate persistence with detection
in soil for 2–8 weeks. Due to its inability to bind to soil
particles, dalapon has a relatively high mobility in soil, with
leaching possible. Microorganisms in the soil are very efficient
at degrading dalapon. The herbicide is usually not found below
the first 6 inches of soil layer. Breakdown is relatively rapid and
complete, leading to the production of compounds that are not
naturally occurring. Soil microorganisms are efficient at
degrading dalapon, however, such that dalapon is not typically
found in groundwater. High temperatures and increased
moisture accelerate dalapon degradation in soil. Dalapon can
also be degraded by ultraviolet light. In aquatic environments,
dalapon is degraded by microorganisms (most important),
hydrolysis, and photolysis. In the absence of microbial degradation,
the half-life of dalapon is several months or longer if
the water temperature is below 25°C, with the primary
hydrolysis product being pyruvate. Dalapon is absorbed by
both plant roots and leaves followed by translocation. With
high applications, dalapon precipitates and leads to local
corrosive effects on plants. Due to the ability of dalapon to be
rapidly metabolized and degraded by microorganisms,
hydrolyzed to pyruvate, rapidly translocated to plants, and
quickly moved through the environment, it is not expected that
dalapon will constitute any bioaccumulation hazard. |
| | 2,2-Dichloropropionic acid Preparation Products And Raw materials |
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