How Much Exposure to Roundup Is Dangerous?

Roundup has been marketed for decades as a simple weedkiller for lawns, gardens, farms, and public spaces. But growing scientific evidence, lawsuits, and public concern have raised an urgent question: 

How much exposure to Roundup is dangerous? 

The troubling reality is that scientists still do not know exactly how much Roundup exposure is “safe” — especially with repeated use over time. 

What we do know is this: 

• Long-term exposure to Roundup has been linked to serious health concerns, including cancer 
• The World Health Organization’s International Agency for Research on Cancer classified glyphosate — historically the main active ingredient in all Roundup products, and still present in many to this day— as a “probable human carcinogen” 
• Bayer, the company that now owns Monsanto and manufactures Roundup, has paid out billions to settle lawsuits from people who say Roundup exposure caused their non-Hodgkin lymphoma 
• New Roundup formulas sold to consumers may be even more toxic than older versions 

At Friends of the Earth, we believe people deserve clear answers and safer alternatives — not more toxic chemicals hidden behind familiar brand names. 

Is Any Amount of Roundup Exposure Safe? 

There is no universal agreement about a “safe” amount of Roundup exposure. 

Regulators like the EPA have continued to approve glyphosate use in the United States, while other scientific bodies and courts have raised serious concerns about cancer risks and environmental harm. Studies have linked glyphosate or other Roundup active ingredients to: 

• Non-Hodgkin lymphoma 
• Endocrine disruption 
• DNA damage 
• Reproductive harm 
• Kidney and liver damage 
• Harm to pollinators and aquatic life 

The risk often depends on several factors: 

Frequency of exposure 

People exposed repeatedly over months or years — such as farmers, landscapers, and groundskeepers — face higher risks than someone exposed once. How much exposure to Roundup is dangerous can vary based on the frequency.

Amount of exposure 

Higher doses generally increase risk. Occupational exposure involving spraying large areas is especially concerning. 

Type of Roundup product used 

Many consumers assume all Roundup products contain glyphosate. But Bayer has replaced glyphosate in several home and garden Roundup products sold in the U.S. with other chemicals, including diquat dibromide and triclopyr. 

Friends of the Earth’s analysis found that newer Roundup formulations sold to consumers are, on average, 45 times more toxic to human health following long-term exposure than older glyphosate-based products. 

How exposure happens 

People may be exposed through: 

• Skin contact 
• Breathing spray mist 
• Contaminated food or water 
• Drift from nearby spraying 

When thinking about how much exposure to Roundup is dangerous, it’s important to note that children may be especially vulnerable because their bodies are still developing. 

Why Experts Are Concerned About Long-Term Exposure 

One of the biggest concerns about Roundup is chronic exposure — small or moderate amounts over long periods of time. 

Many of the lawsuits against Bayer involve people who used Roundup regularly for years before developing cancer. And research has raised concerns about cumulative exposure from glyphosate residues in food and water,  or lawn, garden, or agricultural use of glyphosate.  

The chemicals in Roundup can also persist in the environment and spread beyond where they are sprayed. 

New Roundup Formulas May Be Even More Dangerous 

How much exposure to Roundup is dangerous? Many people do not realize that home and garden Roundup products sold today may contain different chemicals than older versions. 

In response to mounting cancer lawsuits, Bayer announced it would remove glyphosate from some consumer Roundup products. But instead of making products safer, many new formulas contain chemicals associated with even greater toxicity concerns. 

Friends of the Earth found that some new Roundup products contain: 

• Diquat dibromide 
• Fluazifop-P-butyl 
• Triclopyr 
• Imazapic 

Some of these chemicals are banned in the European Union due to health and environmental concerns. 

Diquat dibromide, now found in several Roundup lawn and garden products, is considered dramatically more toxic than glyphosate in long-term exposure scenarios. 

Risks of Roundup Exposure 

Short-term exposure to active ingredients in some Roundup products have been linked to:  

• Skin irritation 
• Eye irritation 
• Nausea 
• Vomiting 
• Respiratory irritation 

Long-term exposure concerns linked to active ingredients in some Roundup products include: 

• Increased cancer risk 
• Liver or kidney damage 
• Hormone disruption 
• Reproductive and developmental effects 

How to Reduce Exposure to Roundup 

The safest way to reduce risk is to avoid toxic herbicides altogether by buying organic or OMRI-certified pest products as well as plants, soil, and seeds that have not been treated with pesticides. Many of the seeds, soil, and plants you’ll find at a nursery are pre-treated with pesticides, which can continue to contaminate your soil and plants at home. Buying untreated garden items helps avoid this.   

Additionally, eating organic food whenever possible can help avoid dietary exposure to Roundup. Organic farming prohibits the use of glyphosate and more than 900 additional synthetic pesticides otherwise allowed in agriculture. Research suggests that one week on an organic diet can reduce levels of pesticides in your body by up to 95%. 

You can also:  

• Keep your lawn longer – Just a few extra inches of growth can help shade out weeds and grow stronger roots.   
• Identify your weeds. This can help you figure out what your soil needs to prevent growth without applying harmful chemicals.   
• Weed by hand. This can be a great way to spend some more time outdoors, and a way for other family members and children to get involved. Make sure to remove the whole plant (roots and all) not just the sprouted part.  
• Use a flame weeder or a mechanical tool  like a weedwhacker on weeds in driveways or gravel areas.  
• Encourage native species. Native species are naturally hardy and compete well with weeds. Choose insect- and disease-resistant plant varieties. 

When purchasing lawn or garden products, look for: 

• OMRI-certified products 
• Non-chemical weed management solutions 

Why Friends of the Earth Is Fighting Back 

Friends of the Earth is calling on major retailers like Home Depot and Lowe’s to stop selling harmful Roundup products and replace them with safer organic alternatives. 

Consumers should not have to decode ingredient labels or navigate hidden chemical substitutions to protect their health. 

We need: 

• Stronger pesticide regulations 
• Full transparency about ingredients 
• Protection for farmworkers and communities 
• Safer organic alternatives in stores 
• An end to toxic pesticide dependency 

Roundup’s legacy is not just about one chemical. It’s about a system that continues putting corporate profits ahead of public health and the environment. 

Take Action 

You can help protect your family, pollinators, and communities by: 

• Avoiding Roundup and toxic pesticides 
• Choosing organic lawn and garden care 
• Asking retailers to stop selling hazardous weedkillers 
• Support organic farmers by eating organic whenever possible 
• Supporting policies that phase out toxic pesticides 

Together, we can build a healthier future without toxic chemicals in our homes, food system, and environment.