Desmedipham

Herbicides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Herbicides, Carbamate

Herbicides

Environmental transformation -> Pesticides (parent, predecessor)

Pesticide (Desmedipham) -> USDA PDB

Warning

H361d: Suspected of damaging the unborn child [Warning Reproductive toxicity]

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

Warning

H361d (66.8%): Suspected of damaging the unborn child [Warning Reproductive toxicity]

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

Commission Regulation No 844/2012

Desmedipham is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

04/58/EC, Reg. (EU) 2017/841, Reg. (EU) 2018/917, Reg. (EU) 2019/1100, Reg. (EU) 2019/707, Reg. (EU) No 540/2011

REACH registered substance: Desmedipham (EC: 237-198-5)

Desmedipham: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

DESMEDIPHAM 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.

Desmedipham

Marine pollutant

Repr. 2 (66.8%)

Reproductive toxicity - category 2

Specific target organ toxicity - Repeated exposure - Category 2 (blood system)

Reproductive toxicity - Category 2

Repr. 2

If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.

Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Chronically high (>10 years) exposure leads to neuropsychological consequences including disturbances in perception and visuo-motor processing. (A15321)

Desmedipham is a cholinesterase or acetylcholinesterase (AChE) inhibitor. Carbamates form unstable complexes with chlolinesterases by carbamoylation of the active sites of the enzymes. This inhibition is reversible. A cholinesterase inhibitor suppresses the action of acetylcholine esterase. Because of its essential function, chemicals that interfere with the action of acetylcholine esterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses. Headache, salivation, nausea, vomiting, abdominal pain and diarrhea are often prominent at higher levels of exposure. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop.

As with organophosphates, the signs and symptoms are based on excessive cholinergic stimulation. Unlike organophosphate poisoning, carbamate poisonings tend to be of shorter duration because the inhibition of nervous tissue acetylcholinesterase is reversible, and carbamates are more rapidly metabolized. Muscle weakness, dizziness, sweating and slight body discomfort are commonly reported early symptoms. Headache, salivation, nausea, vomiting, abdominal pain and diarrhea are often prominent at higher levels of exposure. Contraction of the pupils with blurred vision, incoordination, muscle twitching and slurred speech have been reported. (L795)

LC50 (rat) > 7,400 mg/m3

LD50: 9600 mg/kg (Rat, oral); LD50: >2000 mg/kg (Rabbits, transdermally)

0.1

OPP

0.04

OPP

Desmedipham

0.1

700

Children

0.04

200

Used as selective post-emergence herbicide for sugar beets; Also registered for Special Local Needs in Washington state for table beets and Swiss chard seed production; [Reference #1]

Farming (Pesticides) [Category: Industry]

Desmedipham is a selective, systemic post-emergence herbicide commonly used in beet and strawberry crops to protect against weeds, often in comination with Phenmedipham.

Herbicides

Environmental transformation -> Pesticides (parent, predecessor)