Every time we publish a new set of test results, we see the same arguments pop up on Facebook.
One recent comment claimed:
“Glyphosate does NOT bio-accumulate! Glyphosate is 95% excreted in urine and stools with a half-life of hours, the rest metabolized by a specific cytochrome p450 in the liver. The residual amounts of glyphosate detected in foods are in parts per billion — infinitesimal! Glyphosate is less toxic than table salt, so what are you afraid of?”
It sounds convincing. But is it accurate? Let’s break it down.
Claim 1: Glyphosate does not bioaccumulate
What’s true:
Glyphosate is often excreted relatively quickly and mostly unchanged — true. Much of an oral dose is not absorbed, and a large portion is eliminated in urine and feces.
What’s missing:
- “Not bioaccumulative” does not mean “harmless.” Substances can still cause damage while circulating through the body.
- Animal studies show tissue-specific retention phases, with the longest half-life reported in bone.
- Human biomonitoring shows glyphosate in the urine of the majority of people tested in the U.S., which indicates ongoing, frequent exposure rather than one-off doses.
See our article: Glyphosate Urine Testing in NZ: Barriers and Options
Claim 2: Glyphosate has a short half-life in the body
What’s true:
Yes — human studies estimate a biological half-life of around 5–10 hours.
What’s missing:
- Half-life refers to how quickly blood concentrations fall by half. It doesn’t mean the chemical “disappears.”
- If exposure is daily (through bread, cereals, honey, oats, fruit, and water), that short half-life no longer matters — each dose stacks on the last, creating a steady background level. Biomonitoring confirms this.
See our results: Honey tests, Breakfast cereals, Bread testing
Claim 3: The amounts detected are in parts per billion (ppb) — infinitesimal!
What’s true:
Glyphosate residues are often measured in parts per billion (ppb).
What’s missing:
- The “1 second in 32 years” analogy is a rhetorical trick. It assumes one exposure, once, ever. Real life doesn’t work that way.
- Residues show up across many foods, so small amounts add up across a lifetime.
- Endocrine disruptors like glyphosate can act at very low levels, sometimes below what regulators once considered safe.
Coming soon: our article on Glyphosate as an Endocrine Disruptor
Claim 4: Glyphosate is less toxic than table salt
What’s true:
In acute toxicity tests, glyphosate appears less deadly than salt.
What’s missing:
- Acute LD₅₀ (lethal dose, 50%) tests only measure how much of a substance it takes to kill half of a group of lab animals in a single, high-dose exposure. They don’t measure chronic, low-dose effects — the kind that matter when people are exposed to glyphosate residues day after day.
- Long-term studies link glyphosate and its formulations to oxidative stress, endocrine disruption, microbiome changes, and cancer risk.
- That’s why the International Agency for Research on Cancer (IARC) classified glyphosate as “probably carcinogenic to humans” (Group 2A).
Claim 5: Glyphosate passes harmlessly through pregnancy
What’s true:
Ex vivo human-placenta models show limited but measurable transfer of glyphosate to the fetal side . Separate work indicates glyphosate-based formulations can impair placental function in this model.
What’s missing:
- The prospective Indiana birth cohort found glyphosate in over 90% of pregnant women studied, with higher levels linked to shorter pregnancies.
- “Short half-life” is no comfort when exposures are daily and outcomes may be subtle but significant.
Where This Leaves Us
The Facebook commenter’s claims are half-truths dressed up as reassurance. Yes, glyphosate may leave the body quickly. Yes, residues are often measured in ppb. But what these arguments ignore is the bigger picture:
- We aren’t exposed once — we’re exposed constantly.
- “Low doses” across a lifetime can add up to real harm.
- Independent science continues to show concerning effects at levels regulators dismiss as “safe.”
The real question isn’t whether glyphosate is “as safe as salt.” It’s whether we want a chemical designed to kill plants and microbes showing up on our breakfast tables at all.
Resources & References
Fact-checking only works if readers can see the evidence for themselves. Too often, reassuring claims are repeated without sources, or worse, with cherry-picked figures stripped of context.
Below you’ll find a mix of independent studies, international reviews, and biomonitoring data that cut through the spin. By no means is this a complete set of references — rather a small, random selection and a place to start if you want to dig deeper.
IARC Monograph on Glyphosate (2015)
The International Agency for Research on Cancer classified glyphosate as “probably carcinogenic to humans” (Group 2A), raising global concern about long-term exposure.
CDC National Biomonitoring Program: Diet Is a Factor in Contact with Glyphosate (Apr 2024)
New analysis from NHANES data found that around 81% of the U.S. population had recent exposure to glyphosate, showing how widespread daily exposure really is.
Environmental Health, 15 (19): Concerns over glyphosate-based herbicides and risks associated with exposures: a consensus statement.
An expert panel reviewing evidence of endocrine disruption, oxidative stress, and microbiome impacts at levels far below regulatory limits.
Facts and Fallacies in the Debate on Glyphosate Toxicity
Frontiers in Public Health, 5:316.
Highlights flaws in the “glyphosate is safe as table salt” narrative and explains why chronic low-dose effects cannot be dismissed.
Glyphosate exposure in pregnancy and shortened gestational length: a prospective Indiana birth cohort study.
Environmental Health, 17(23).
Shows glyphosate detected in over 90% of pregnant women studied, with higher levels linked to shorter pregnancies.
Environmental and health effects of the herbicide glyphosate.
Science of the Total Environment, 616–617, 255–268.
A broad review linking glyphosate use to soil health impacts, microbial changes, and possible human health risks.
Potential toxic effects of glyphosate and its commercial formulations below regulatory safety limits.
Food and Chemical Toxicology, 84, 133–153.
Demonstrates adverse effects at doses regulators claim are “safe,” including endocrine disruption and oxidative stress.
This is the crucial difference between slogans and science: slogans simplify, science complicates. When someone says “glyphosate is safer than salt,” it sounds tidy, but the research tells a much messier story — one of low-dose effects, multiple exposure pathways, and ongoing uncertainty. Fact-checking doesn’t give us all the answers, but it reminds us to test the easy lines against real evidence. Only then can we see past the one-liners to the bigger picture.
Image Source & Attribution
A big thank you to the creators at Unsplash for making their images freely available for projects like ours. The image featured on this page is by Lachlan. You can explore more of their work here: https://unsplash.com/@lachlancormie.
