California Personal Injury Lawyers Blog
The Defenses Bayer Uses in Roundup Cases — and How Walch Law Defeats Them
If you developed non-Hodgkin’s lymphoma after using Roundup, you may already sense what you’re up against. Bayer — the company that now owns Monsanto — has vast resources and a team of lawyers whose entire job is to make your case go away. It’s easy to feel like the deck is stacked before you even begin.
Here’s what you should know: these defenses are predictable. We’ve seen them before, juries have rejected them before, and there are proven ways to answer each one. Understanding how Bayer fights back is the first step to feeling confident that your case can stand up to the pressure.
Below, we walk through the five defenses Bayer raises most often in Roundup cases — and exactly how we counter them. Ready to get started for free? Walch Law is standing by– call now.
Defense 1: “The Science Doesn’t Support a Link to Cancer”
This is Bayer’s cornerstone argument. The company insists that glyphosate, the active ingredient in Roundup, does not cause cancer and that no reliable science says otherwise. It’s a bold claim, and it’s designed to make you doubt your own case.
The problem for Bayer is that the science tells a different story. In 2015, the International Agency for Research on Cancer (IARC) — the cancer research arm of the World Health Organization — classified glyphosate as “probably carcinogenic to humans.” That’s a conclusion from one of the most respected scientific bodies in the world, not a plaintiff’s attorney.
We also have something even more powerful: verdicts. Juries who heard the evidence, examined the internal company documents, and listened to experts from both sides have repeatedly sided with plaintiffs. Some of those verdicts reached hundreds of millions of dollars. When we present the same peer-reviewed studies, the IARC findings, and Monsanto’s own internal communications, Bayer’s “no link” argument loses much of its footing.
Defense 2: “You Weren’t Exposed Long Enough or at High Enough Levels”
When Bayer can’t win on the science outright, it pivots to exposure. The company argues that you didn’t use Roundup often enough, long enough, or in high enough amounts for it to have caused your illness. In effect, they try to shrink your history with the product until it looks harmless.
We answer this by building a detailed, documented picture of your actual exposure. That often includes:
- Occupational records for farmworkers, landscapers, groundskeepers, and agricultural applicators who handled Roundup regularly
- Purchase history and product receipts showing how much you bought and how often
- Witness statements from coworkers, family, and neighbors who saw you use it
- Employment and job-site history documenting years of routine spraying
- Expert testimony connecting your specific exposure pattern to your diagnosis
People with heavy occupational exposure — those who sprayed for a living or maintained large properties for years — often have the strongest records here. But even residential users can build a compelling case when the history is gathered carefully. We do the digging so your true exposure comes into full view, not the minimized version Bayer prefers.
Defense 3: “You Have Other Risk Factors for Cancer”
Expect Bayer to comb through your medical history looking for another explanation. Age, family history, other chemical exposures, lifestyle — the company will point to anything it can to argue that something besides Roundup caused your cancer. It’s an attempt to shift blame away from the product.
This defense sounds stronger than it is. Under California’s comparative fault system, the presence of other risk factors does not automatically defeat your claim. The legal question isn’t whether Roundup was the only possible cause — it’s whether Roundup was a substantial factor in causing your illness. A product can be a substantial factor even when other influences exist.
We meet this defense with focused causation evidence. Our medical and scientific experts explain how glyphosate exposure specifically contributes to non-Hodgkin’s lymphoma, and why your exposure fits that pattern. We also push back hard when Bayer tries to inflate the importance of minor or speculative risk factors. Having more than one possible cause is common in cancer cases — and it does not give Bayer a free pass.
Defense 4: “You Filed Too Late”
If Bayer can convince a court that you waited too long, your case can be dismissed before a jury ever hears the facts. So the company often argues that the deadline to sue — the statute of limitations — has already passed. For many worried claimants, this is the scariest defense of all.
Here’s why you shouldn’t count yourself out. California follows the discovery rule, which means the clock generally doesn’t start when you used Roundup — it starts when you knew, or reasonably should have known, that your illness might be linked to it. Many people used Roundup for years and only later connected their diagnosis to the product. That gap matters, and the law accounts for it.
We investigate exactly when you reasonably could have made that connection, then build the timeline that keeps your claim alive. Because these deadlines are fact-specific and unforgiving once they pass, the safest move is to have your situation reviewed promptly rather than assume the door has closed. Often, it hasn’t.
Defense 5: “The EPA Approved Glyphosate”
Bayer leans heavily on regulatory approval. The company argues that because the U.S. Environmental Protection Agency approved glyphosate and did not classify it as a carcinogen, the product must be safe — and it can’t be held liable. On the surface, this sounds convincing.
But regulatory approval is not a liability shield. A government agency clearing a product for sale does not erase a manufacturer’s duty to warn users about known risks, and it does not prevent injured people from holding that company accountable. Courts have repeatedly allowed Roundup cases to move forward despite EPA approval, and juries have returned verdicts against the manufacturer anyway.
There’s more to this story, too. The EPA’s assessment has faced serious criticism, and internal documents raised troubling questions about Monsanto’s influence over the science and the regulatory process. When we present that evidence, the “EPA said it’s fine” defense looks far weaker than Bayer wants the jury to believe. Approval to sell a product is not the same as proof that it’s safe.
You Don’t Have to Face These Defenses Alone
Every one of these arguments is designed to make you give up before you start. But knowing the playbook changes everything. Each defense has a well-established counter, and we’ve spent years learning how to turn Bayer’s tactics against them.
At Walch Law, we investigate your exposure, marshal the scientific and medical evidence, protect your deadlines, and build a case designed to withstand exactly the defenses described above. We handle the fight so you can focus on your health and your family.
We work on a contingency fee basis. You pay nothing out of pocket, and we only collect a fee if we recover compensation for you. There’s no financial risk in simply finding out where you stand.
Contact Walch Law today for a completely free, confidential consultation. Tell us what happened, and we’ll give you an honest assessment of your case and the next steps that make sense for you.