Is Glyphosate Dangerous? Information On Glyphosate Use

By Jackie Carroll

Glyphosate is one of the most widely used herbicides in the U.S., but is it safe? Find out about the safety of glyphosate herbicide in this article.

Glyphosate Herbicide

When you buy an herbicide containing glyphosate, about 49 percent of the liquid is the active ingredient, glyphosate. The other 51 percent is inert ingredients. “Inert” refers to herbicide ingredients that don’t directly kill weeds. Inert ingredients may make the herbicide easier to use, help it spread across the surface of the leaves, or “stick” the herbicide to the targeted plant.

In the case of glyphosate herbicides, the inert ingredients are often more harmful than the glyphosate. Glyphosate is the active ingredient in Roundup.

Is Glyphosate Dangerous?


According to the National Pesticide Information Center, glyphosate is as safe an herbicide as you will find. It is even safer that most organic herbicides. All studies to date done on humans show that there is no link between glyphosate and cancer, though there have been a few studies done on animals that show there may be a link between glyphosate and some rare forms of cancer. These findings have led the WHO to list it as a probable human carcinogen, which is the same classification given to red meat and exposure to professional hair care products. An addition, if ingested in large amounts, it may cause developmental disorders in children or fetuses.

Glyphosate can cause minor skin irritations, which usually last no more than 24 hours. It can also cause painful eye irritations. Inhaling the spray causes nose and throat irritation. All of these irritations are usually caused by the inert ingredients. Ingesting the product causes nausea, vomiting and diarrhea.

Keep pets out of the garden for 24 hours after spraying. Exposure can cause drowsiness, loss of appetite, vomiting and diarrhea. Glyphosate itself isn’t harmful to most wildlife; however, some of the inert ingredients may affect wildlife. It also has the indirect effect of killing plants that wildlife needs to survive.

The safest way to kill weeds is to use mulch, hand pull weeds as they emerge, and use chemicals such as glyphosate as a last resort.

Information on Glyphosate Use

Follow these precautions when using herbicides containing glyphosate:

  • Wear goggles to protect your eyes.
  • Use a face mask to prevent accidental inhalation.
  • Wear long sleeves, long pants and gloves to prevent skin irritation.
  • Avoid touching plants that are wet with glyphosate, and wash your hands thoroughly after use.
  • Spray on a calm day. Wind can carry the spray to other plants and it increases the chances of human contact.

Glyphosate General Fact Sheet Oregon State Extension Service
Master Gardener Column Article on Glyphosate From Illinois Extension Service
Trying to Sift Through the Current Wealth of Information (and Misinformation) About Glyphosate – OSU Extention

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