Paraquat

General Information

Concentrated liquid paraquat preparations (e.g. Gramoxone®), available to farmers and horticulturists, contain 10–20% paraquat and are extremely toxic. Granular preparations, for garden use, contain only 2.5% paraquat and have caused few deaths.

Paraquat has local and systemic effects. Splashes in the eyes irritate and ulcerate the cornea and conjunctiva. Copious washing of the eye should aid healing but it may be a long process. Skin irritation, blistering, and ulceration can occur from prolonged contact both with the concentrated and dilute forms. Inhalation of spray, mist, or dust containing paraquat may cause nose bleeding and sore throat but not systemic toxicity.

Ingestion of concentrated paraquat solutions is followed by nausea, vomiting, and diarrhoea. Painful ulceration of the tongue, lips, and fauces may appear after 36 to 48 hours together with renal failure. Some days later there may be dyspnoea with pulmonary fibrosis due to proliferative alveolitis and bronchiolitis.