E X T O X N E T
Extension Toxicology Network
A Pesticide Information Project of Cooperative Extension Offices of
Cornell University, Michigan State University, Oregon State University, and
University of California at Davis. Major support and funding was provided
by the USDA/Extension Service/National Agricultural Pesticide Impact
Assessment Program.
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Pesticide
Information
Profile
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Chlorpropham
Publication Date: 9/93
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TRADE OR OTHER NAMES
Beet-Kleen, Bud Nip, Chloro IPC, CIPC, Furloe, Sprout Nip, Spud-Nic,
Taterpex, Triherbide-CIPC and Unicrop CIPC.
REGULATORY STATUS
Products containing chlorpropham must bear the signal word "Caution"
(1).
INTRODUCTION
Chlorpropham is a plant growth regulator used for preemergence control
of grass weeds in alfalfa, lima and snap beans, blueberries, cane berries,
carrots, cranberries, ladino clover, garlic, seed grass, onions, spinach,
sugar beets, tomatoes, safflower, soybeans, gladioli and woody nursery stock.
It is also used to inhibit potato sprouting and for sucker control in tobacco
(1). Chlorpropham is available in emulsifiable concentrate and liquid
formulations.
TOXICOLOGICAL EFFECTS
ACUTE TOXICITY
Chlorpropham is moderately toxic by ingestion (2). It may cause
irritation of the eyes or skin (2). Symptoms of poisoning in laboratory
animals have included listlessness, incoordination, nose bleeds, protruding
eyes, bloody tears, difficulty in breathing, prostration, inability to
urinate, high fevers, and death. Autopsies of animals have shown
inflammation of the stomach and intestinal lining, congestion of the brain,
lungs and other organs, and degenerative changes in the kidneys and liver
(2)
The oral LD50 for chlorpropham in rats ranges from 1,200 mg/kg to 3,800
mg/kg (1, 2), and in rabbits is 5,000 mg/kg (2). The 4-hour inhalation LC50
in rats is > 32 mg/l (4).
CHRONIC TOXICITY
Chronic exposure of laboratory animals has caused retarded growth,
increased liver, kidney and spleen weights, congestion of the spleen and
death (2). No deaths or micropathological abnormalities occurred in rats
given diets containing 2% chlorpropham for 90 days (4).
Reproductive Effects
Long-term exposure to chlorpropham may cause adverse reproductive
effects (2). Chlorpropham may cross the placenta (2). In reproductive
studies with rats, 500 mg/kg, the highest dose tested, produced no adverse
effects (5).
Teratogenic Effects
No birth defects occurred in a 3-generation study with rats (4).
Mutagenic Effects
EPA states that, "The single acceptable mutagenicity study (gene
mutation) was negative" (5).
Carcinogenic Effects
Long-term exposure to chlorpropham may cause tumors (2). In one
experiment chlorpropham initiated skin cancer in mice, but this result was
not confirmed by a later study (2).
Organ Toxicity
No information was found.
Fate in Humans and Animals
No information was found.
ECOLOGICAL EFFECTS
Effects on Birds
Chlorpropham is practically non-toxic to waterfowl (5). Its LD50 in
mallards is > 2,000 mg/kg (1, 4).
Effects on Aquatic Organisms
Chlorpropham is moderately toxic to cold and warm water freshwater fish
(5). The LC50 for chlorpropham in rainbow trout is 3 to 6 ppm, and 6.3 to 6.8
ppm in bluegill sunfish (1).
Chlorpropham accumulated in the skinned fillet of bluegill sunfish to 100
times the levels in surrounding water (5).
Effects on Other Animals (Nontarget species)
No information was found.
ENVIRONMENTAL FATE
Breakdown of Chemical in Soil and Groundwater
Chlorpropham has some potential to contaminate groundwater because
it is highly soluble in water and it has only a moderate tendency to
adsorb to soil particles (3, 5). Chlorpropham adsorbs strongly to organic
matter, so it is unlikely to leach through soils high in organic matter.
Chlorpropham does not readily adsorb to montmorillonite or kaolinite clays
(4).
Chlorpropham is subject to degradation by soil microbes.
Photodegradation and volatilization do not readily occur. Increasing
temperatures above 35 degrees C and increasing soil moisture capacity may
increase volatilization (4). Soil half-lives from 35 days (3) to 65 days
at 15 degrees C or 30 days at 29 degrees C (4) have been reported.
Degradation rates are affected by microbial activity and soil moisture
levels (4).
Breakdown of Chemical in Surface Water
Chlorpropham is not subject to hydrolysis in aqueous solution (5).
Breakdown of Chemical in Vegetation
Chlorpropham is absorbed by the roots of susceptible grass seedlings and
transported throughout the plant. It is absorbed more slowly by leaves (4).
It suppresses plant transpiration and respiration and inhibits root and
epicotyl growth (5).
PHYSICAL PROPERTIES AND GUIDELINES
Technical chlorpropham is a white to light brown crystalline solid (2,
5). It is stable under normal temperatures and pressures, but poses a slight
fire hazard if exposed to heat or flame, and a fire and explosion hazard in
the presence of strong oxidizers. It may burn but will not readily ignite.
Avoid contact with strong oxidizers, excessive heat, sparks or open flame.
Thermal decomposition may release highly toxic fumes of phosgene, toxic and
corrosive fumes of chlorides, and oxides of carbon (2). Workers handling
chlorpropham should avoid breathing vapors, wear goggles to prevent eye
contact and protective clothing to prevent prolonged skin contact (2, 3).
Exposure Guidelines:
No occupational exposure limits have been established for pendimethalin
by OSHA, NIOSH or ACGIH (2).
Physical Properties:
| CAS #: | 101-21-3 |
| Chemical name: | isopropyl m-chlorocarbanilate, or isopropyl-N-(3-chlorophenyl) carbamate |
| Chemical Class/Use: | carbamate herbicide and plant growth regulator |
| Specific gravity: | 1.180 at 30 degrees C (2) |
| H20 solubility: | 89 ppm at 25 degrees C (2) |
| Solubility in other solvents: | soluble in butyrolactone, benzene, xylene, chloroform, ketones, acetone, methanol, ethanol, isopropyl alcohol, kerosene, esters, heavy aromatic naphtha, aromatic hydrocarbons, most organic solvents and oils (2). |
| Melting point: | 106 degrees F (41degrees C) (2) |
| Boiling point: | 300 degrees F (149 degrees C) at 2 mm Hg (2) |
| Decomposition temperature: | 150 degrees C and above (4) |
| Vapor pressure: | negligible at 25 degrees C (2) |
| Koc: | 1150 (3) |
BASIC MANUFACTURER
Atochem North America, Inc.
Three Parkway
Philadelphia, PA 19102
Emergency: 215-587-7885
Review by Basic Manufacturer:
Comments solicited: April, 1993
Comments received:
REFERENCES
Meister, R.T. (ed.). 1992. Farm Chemicals Handbook '92. Meister
Publishing Company, Willoughby, OH.
Occupational Health Services, Inc. 1992 (Nov. 11). MSDS for
Chlorpropham. OHS Inc., Secaucus, NJ.
U. S. Department of Agriculture, Soil Conservation Service. 1990
(Nov.). SCS/ARS/CES Pesticide Properties Database: Version 2.0
(Summary). USDA - Soil Conservation Service, Syracuse, NY.
WSSA Herbicide Handbook Committee. 1989. Herbicide Handbook of the
Weed Science Society of America, 6th Ed. WSSA, Champaign, IL.
U.S. Environmental Protection Agency. Dec, 1987. Pesticide Fact
Sheet Number 150: Chlorpropham. US EPA, Office of Pesticide Programs,
Registration Div., Washington, DC.
