Propham

Chemical Properties

White to gray crystalline needles; odorless when pure. Mp 84C (technical grade). Soluble in alcohol, acetone, isopropyl alcohol; insoluble in water.

Chemical Properties

Propham is a colorless crystalline solid.

Uses

Inhibitor of plant metabolism

Uses

Preemergence and postemergence herbicide used to control annual grass weeds in peas, beet crops, lucerne, clover, sugar beet, beans, lettuce, flax, safflowers and lentils.

Uses

Herbicide, applied as a spray to the soil.

Definition

ChEBI: Propham is a carbamate ester that is the isopropyl ester of phenylcarbamic acid. It is a selective herbicide used for the control of annual grasses and some broad-leaf weeds and is also a growth regulator for control of sprouting in stored potatoes. It has a role as a herbicide and a plant growth retardant. It is a carbamate ester and a member of benzenes.

General Description

Colorless crystalline solid.

Reactivity Profile

Propham is a carbamate ester. Carbamates are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates.

Hazard

Toxic by ingestion.

Health Hazard

Moderately toxic herbicide; exhibited low tomoderate toxicity in experimental animalswhen administered by oral, intraperitoneal,intravenous, and subcutaneous routes; skinabsorption is slow; cholinesterase inhibitor;in human ingestion can cause carbamatepoisoning, which can be lethal when takenin large amount; probable lethal oral dosein adult human estimated to be larger thanother carbamate insecticides within the range35–50 g.

Safety Profile

Poison by intraperitoneal route. Moderately toxic to humans by ingestion. Moderately toxic experimentally by ingestion and possibly other routes. An experimental teratogen. Human mutation data reported. Questionable carcinogen with experimental neoplastigenic data. An herbicide. When heated to decomposition it emits toxic fumes of NO,. See also CARBAMATES.

Potential Exposure

A potential danger to those involved in the manufacture, formulation and application of this car- bamate/organonitrogen grass-control herbicide.

Environmental Fate

Biological. Rajagopal et al. (1989) reported that Achromobacter sp. and an Arthrobacter sp. utilized propham as a sole carbon source. Metabolites identified were Nphenylcarbamic acid, aniline, catechol, monoisopropyl carbonate, 2-propanol and carbon dioxide (Rajagopal et al., 1989).
Soil. Readily degraded by soil microorganisms forming aniline and carbon dioxide (Humburg et al., 1989). The reported half-life in soil is approximately 15 and 5 days at 16 and 29°C, respectively (Hartley and Kidd, 1987).
Groundwater. According to the U.S. EPA (1986) propham has a high potential to leach to groundwater.
Plant. The major plant metabolite which was identified from soybean plants is isopropyl N-2-hydroxycarbanilate (Hartley and Kidd, 1987; Humburg et al., 1989).
Chemical/Physical. Hydrolysis of propham yields N-phenylcarbamic acid and 2-propanol. The acid is very unstable and is spontaneously decomposed to form aniline and carbon dioxide (Still and Herrett, 1976). Emits toxic fumes of nitrogen oxides when heated to decomposition (Sax and Lewis, 1987).

Shipping

UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous haz- ardous material, Technical Name Required. UN2757 Carbamate pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Incompatibilities

Carbamates are incompatible with reduc- ing agents, strong acids, oxidizing acids, peroxides, and bases. Contact with active metals or nitrides cause the release of flammable, and potentially explosive, hydrogen gas. May react violently with bromine, ketones. Incompatible with azo dyes, caustics, ammonia, amines, boranes, hydrazines, strong

Waste Disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. In accordance with 40CFR165, follow recom- mendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following pack- age label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office.