What to Know About Paraquat Poisoning

Medically Reviewed by Sanjay Ponkshe on February 23, 2024
3 min read

Paraquat is a common weed killer used by licensed farmers that can cause severe injury or death. For this reason, it’s dyed blue and has chemicals added to make it smell bad and make you throw up if you drink it. 

Paraquat is a toxic chemical called paraquat dichloride used to kill plants. It’s one of the most commonly used commercial farming herbicides in the U.S. Only licensed and safety-certified individuals can use paraquat. It’s not available for homeowners or public use and it’s not allowed in residential areas.

Paraquat is an active ingredient in some products like Gramoxone, Helmquat, Firestorm, or Parazone. It was first available for purchase in the 1960s and is still used around the world. The most common paraquat uses are for crop farming and controlling weeds.

Some other specific paraquat uses include:

  • Drying out cotton crops before harvest
  • Killing weeds and grasses in fruit orchards 
  • Controlling grass-covering crops
  • Drying out and removing leaves from hops before harvest 
  • Destroying potato stems 

Paraquat must be stored in properly labeled bottles out of reach of children and away from residential areas. It is illegal to transfer the liquid to drink containers or other bottles. Some poisoning cases have happened because leftover paraquat was dumped into a Gatorade container, and someone drank it. 

Only a licensed person can use paraquat. Unlike other restricted chemicals, a licensed applicator can’t supervise someone else applying the chemical. In most cases, the certified applicator is most likely to be at risk for poisoning.

Paraquat is extremely poisonous: as little as 1 teaspoon can cause death. It absorbs quickly into your body and causes toxic chemical reactions that damage your cells. This leads to widespread damage to your liver, kidneys, and lungs. 

Paraquat collects in your lungs, causing them to fill up with fluids, which leads to scarring, internal bleeding, and trouble breathing. As your whole body becomes affected, you can go into cardiogenic shock and multiorgan failure. Cardiogenic shock happens when your heart suddenly can’t pump blood to the rest of your body. 

Paraquat also causes other side effects, especially when it comes into direct contact with your mouth, stomach, or digestive tract linings. These include:

The first signs of paraquat are usually to your digestive system, especially if it’s taken in large amounts by mouth. These symptoms include:

Paraquat poisoning can cause other symptoms, including:

In most cases, drinking paraquat is the most common cause of poisoning. The treatment involves removing the poison from your body and treating other symptoms. Some paraquat poisoning treatments may include:

Some studies suggest using oxygen therapy as a treatment, but this can worsen symptoms and should be avoided. 

If you spill paraquat on your clothes or skin or get it in your eyes, you should:

  • Remove your clothes right away and put them in a plastic bag.
  • Quickly wash the body with lots of soap and water.
  • Remove contacts from your eyes.
  • Rinse your eyes with plain water for 10 to 15 minutes.
  • Go to a hospital right away.

There are no medications or substances that can reverse poisoning from paraquat exposure. Severe poisoning from large amounts can lead to death. Proper handling and storage can prevent exposure. 

Some people can survive severe paraquat poisoning, but it can cause long-term health problems like lung scarring. You might also have kidney failure, leading to permanent dialysis treatment, heart problems, and esophageal scarring and narrowing that makes it hard to swallow. 

If you think you or someone else has been exposed or poisoned, go to the hospital right away.