Paraquat

Synonyms

1,1'-Dimethyl-4,4'-bipyridinium; 1,1'-Dimethyl-4,4'-bipyridinium cation; 1,1'-Dimethyl-4,4'-bipyridinium salt; 1,1'-Dimethyl-4,4'-bipyridyldiylium; 1,1'-Dimethyl-4,4'-bipyridyldiylium ion (8CI)(9CI); Dextrone; Dextrone X; Dimethyl viologen; Methyl viologen (2+); Methyl viologen ion(2+); N,N'-Dimethyl-4,4'-bipyridinium; N,N'-Dimethyl-4,4'-bipyridinium dication; N,N'-Dimethyl-gamma,gamma'-dipyridylium; Paraquat dication; Paraquat ion; Spraytop-graze; Starfire; Weedol; 4,4'-Bipyridinium, 1,1'-dimethyl-; [ChemIDplus]

Category

Herbicides, Bipyridyl

Description

Yellow, odorless solid; [HSDB] Technical grade is a dark red solution; [CHEMINFO] Commercially available as an aqueous solution with surfactants; [ACGIH]

Sources/Uses

Used as a contact herbicide for weed control in grass seed crops and orchards; a crop desiccant and defoliant on cotton and potato vines; harvest aid for soybeans; [HSDB] A quick-acting herbicide; [ACGIH]

Comments

Contact injuries in workers include skin rashes, burns, eye damage from splashes, nail damage, and nasal bleeding. Parquat absorption through the skin can contribute to systemic toxicity, especially when contacting damaged skin or sensitive areas like the buttocks and genitalia. Toxic ingestion: low doses (<20 mg/kg) cause local irritation to oral and GI mucosa; moderate doses (20-40 mg/kg) cause renal, liver and lung damage with respiratory failure within 2-3 weeks; high doses (>40 mg/kg) cause pulmonary fibroplasia, respiratory failure, and death within 1-7 days. [ACGIH] Highly toxic via ingestion, inhalation, and skin absorption; [Hawley] See "Paraquat dichloride."

Biomedical References

Yes

0.05 mg/m3, inhalable particulate matter, as the cation

0.5 mg/m3, respirable dust

1E-07 mm Hg

Yes

Yes

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Yes

Skin burns

Not Classifiable

Processes

Industrial Processes with risk of exposure:

• Farming (Pesticides)