Call for a free consultation

Paraquat Toxicity and Poisoning

Paraquat is a highly toxic herbicide used to control weeds and grass. The compound was first synthesized in 1882, and its plant-killing properties were discovered in 1955 by what was then Imperial Chemical Industries (ICI), a British chemical company.

Paraquat is now manufactured by many companies, including:

  • Altitude Crop Innovations, LLC
  • Chevron Chemical Company
  • Drexel Chemical Company
  • Helm Agro
  • Syngenta
  • United Phosphorous

Paraquat has been used in the United States since the early 1960s. It is sold under dozens of trade names, alone or in combination products with other herbicides. Popular trade names for paraquat include:

  • Firestorm®
  • Gramoxone®
  • Helmquat®
  • Ortho-Paraquat
  • Para-SHOT
  • Parazone
  • Quick-Quat™

Gramoxone, now manufactured by Swiss-based Syngenta, was the first commercial paraquat product (sold since 1962) and is the most common trade name for paraquat. Syngenta is owned by China National Chemical Company.

Paraquat is used as an herbicide, to kill unwanted weeds and grasses; a desiccant (drying agent); a defoliant, to cause the leaves to fall off unwanted plants; and a plant growth regulator. It has been used to control broadleaf weeds and grasses in the cultivation of more than 100 different crops worldwide, including:

  • Apples
  • Cocoa
  • Coffee
  • Cotton
  • Maize
  • Rubber
  • Soybeans
  • Potatoes
  • Rice
  • Wheat

Paraquat has also been used as a pre-harvest defoliant or desiccant on crops such as beans, hops, pineapple, and sugar cane, and as a post-harvest desiccant to speed removal of spent plants, such as tomatoes. It is used in no-till agriculture to kill grasses and weeds and, by doing so, minimizes plowing and help prevent soil erosion. Despite its strength as an herbicide, paraquat breaks down quickly once it enters the soil.

Paraquat Is Highly Toxic

Paraquat is extremely poisonous—highly toxic to all mammals including humans. Paraquat most commonly enters the body by swallowing or through damaged skin but can also be inhaled when it is being sprayed or shortly afterwards. Paraquat is corrosive to skin. One farmer died after spending 3 and a half hours spraying diluted paraquat from a leaking knapsack, and others have died after spilling it on their skin.

Swallowing even a small amount of paraquat is lethal; there is no antidote. Paraquat kills by causing respiratory failure, which can take days or as long as a month after the fatal exposure. Paraquat poisoning also damages the:

  • Adrenal glands
  • Central nervous system
  • Heart
  • Kidneys
  • Liver
  • Lungs
  • Muscles
  • Spleen

Paraquat causes multiple-organ failure and damages the skin and eyes.

Common symptoms of paraquat exposure include:

  • Abdominal pain
  • Acute respiratory distress
  • Burns to the mouth
  • Diarrhea
  • Fever
  • Headache
  • Loss of appetite
  • Muscle pain
  • Nausea
  • Thirst
  • Shortness of breath
  • Vomiting

Studies have also linked paraquat exposure to Parkinson’s disease.

To prevent accidental exposure and to respond if accidental exposure occurs, the U.S. Centers for Disease Control and Prevention (CDC) advises:

  • Never put paraquat in food or drink containers
  • Quickly remove any clothing with paraquat on it, place it in a bag, and let state health department or emergency personnel dispose of it
  • Avoid touching contaminated surfaces
  • Quickly wash paraquat off skin with soap and water
  • Rinse eyes out with water for 15 to 20 minutes
  • Seek emergency medical treatment immediately if you suspect you’ve ingested or been exposed to paraquat and have symptoms

Paraquat Deaths

There is not accurate or complete data about how many people have died from swallowing paraquat since its 1962 debut, but at least one source estimates there have been tens of thousands of paraquat deaths. Some of those deaths have been accidents while others have been  suicides. In the mid-1980s, Japan had more than 1,000 paraquat deaths a year. China, South Korea, Sri Lanka, and Taiwan have recorded hundreds of paraquat-related deaths in some years.

Syngenta exports thousands of tons of paraquat annually and has publicly maintained that its product is safe when used as directed. Syngenta also cites the fact that it has added “safening” agents to Gramoxone (its paraquat brand-name) since the 1970s—a dye to prevent the liquid from being confused with beverages, a sharp odor to make it undesirable, and an emetic drug to induce vomiting if paraquat is ingested. However, internal company documents unearthed in a U.S. lawsuit  reveal that Syngenta and its predecessors have known for decades that the emetic in Gramoxone doesn’t prevent poisoning. Simply put, paraquat is so toxic that it poisons the body before the body can throw it back up.

Paraquat Bans and Restrictions

Paraquat is still widely used throughout the world, but it has now been banned in more than 50 countries, including throughout the European Union.

Many international organizations have voluntarily banned paraquat use in their production systems, including the Rainforest Alliance, Fairtrade, the Forest Stewardship Council, and Dole, the well-known multinational agricultural corporation.

In the United States, paraquat use is restricted and those who apply the herbicide must be specially trained and certified.

Per the United States Environmental Protection Agency (EPA), quoted here:

Who is required to take [paraquat] training?

Any person who intends to use paraquat must be a certified applicator and is required to take the training. ‘Use’ includes pre-application activities involving mixing and loading the pesticide; applying the pesticide; and other pesticide-related activities, including, but not limited to, transporting or storing opened pesticide containers, cleaning equipment, and disposing of excess pesticides, spray mix, equipment wash waters, pesticide containers, and other paraquat-containing materials.

Who is permitted to use paraquat?

 The use of paraquat, which is a restricted use pesticide, is restricted to certified pesticide applicators only; noncertified persons working under the supervision of a certified applicator are prohibited from using paraquat, including mixing, loading, applying the pesticide, and other pesticide-related activities.

Because paraquat it is not available to individual consumers in the United States, those most at risk for paraquat exposure in the U.S. work on farms where paraquat is used, and include:

  • Licensed paraquat applicators
  • Farmers
  • Growers
  • Pickers
  • Other agricultural workers


  >    >    >  Toxicity