Glyphosate, Atrazine, Phthalates: What Two Farmers Want You to Know

Between the two of us, Shane and Clayton, we have spent the better part of our adult lives in agriculture. Shane farmed for 15 years after college. Clayton grew up around it and has spent 18 years selling the equipment that applies the chemicals we are going to talk about today. We are not outsiders looking in. We are two people who know what anhydrous ammonia smells like at 6 in the morning, what chemical drift looks like when it hits a neighboring field, and what a chemical SDS sheet actually means in practice. That background is exactly why we wanted to write this together.

Neither of us is anti-farmer. Most of the farmers we know personally do not want to use chemicals. They use them because the economics of modern agriculture make it the only financially viable option. We get that. This blog is not an attack on farming. It is an honest conversation about what these chemicals are, where they end up, and why - when we started making soap - we became very deliberate about what goes into ours.

The history of agricultural chemicals stretches back to the late 1800s, accelerating dramatically through World War I and World War II, when chemical weapons research and pesticide development became deeply intertwined. The same science that was used to develop nerve agents and chemical weapons was later redirected toward killing insects and weeds. That is not an exaggeration, it is documented history. The important thing to understand, though, is that the scientists behind these developments were not villains. Chemicals were introduced with genuinely good intentions: to prevent famine, to eradicate disease, to feed a growing world. They solved real problems. The issue, as Frank Von Hippel documents thoroughly in his book The Chemical Age, is that these compounds were deployed at massive scale before anyone fully understood their long-term consequences. And the pattern has kept repeating ever since.

We are not going to go back and re-litigate all of it. What happened in the past has happened. What we can do is look honestly at the chemicals most relevant to our lives right now, understand where they end up, and make better decisions going forward. That is what this blog is about.

Glyphosate and Roundup

Glyphosate was first synthesized in 1950 by Henri Martin in Switzerland, but its herbicidal properties were not discovered until 1970 by John Franz at Monsanto. Roundup was introduced to the market in 1974. It became the most widely used herbicide in history, particularly after Monsanto introduced Roundup Ready GMO crops in the mid-1990s, crops genetically engineered to tolerate glyphosate, which meant farmers could spray entire fields without killing their crop. This is when usage exploded. By 2014, glyphosate use in the United States had risen to approximately 275 million pounds, a 15-fold increase since the 1970s.

Glyphosate-resistant weeds began appearing in the mid-1990s, directly tied to the widespread adoption of those GMO crops. The more glyphosate was used, the faster resistance developed. Today there are dozens of documented glyphosate-resistant weed species, which is pushing farmers toward using multiple herbicides in combination and at higher rates. That is exactly the opposite of what was promised when Roundup Ready technology was introduced.

A UCSF biomonitoring study found glyphosate in 93 percent of individuals tested. It has been found in 60 percent of surface water in the Midwest. It has been detected in rain, air samples, honey, oat products, wheat flour, breast milk, and in urine samples from children living in agricultural areas at rates above 95 percent in some studies. Glyphosate contamination is present even in certified organic food, though at significantly lower levels, because of drift and soil persistence. It is genuinely everywhere.

One use of glyphosate that most people are not aware of is desiccation. Farmers spray glyphosate directly on wheat, oats, beans, and other crops shortly before harvest, not to kill weeds, but to dry the crop uniformly so harvesting equipment can run more efficiently. Because the crop is sprayed directly in the days before it is cut, glyphosate residues in desiccated wheat and oats are significantly higher than in crops where it was only used for weed control during the growing season. Independent studies have identified this practice as a primary driver of elevated glyphosate residues in flour, bread, and oat products. Regulators have consistently responded by raising the legal limits for glyphosate in food rather than restricting the practice itself.

Glyphosate's mechanism of action in plants is to inhibit an enzyme called EPSPS in the shikimate pathway. Humans do not have this pathway, which is why Monsanto initially claimed it was safe for human exposure. What that claim ignored is that gut bacteria do have this pathway. Multiple peer-reviewed studies have shown glyphosate disrupts gut microbiome composition, potentially contributing to intestinal dysbiosis, inflammation, and leaky gut syndrome. This research is still developing, but it is not fringe science. It is published in peer-reviewed journals and the conversation in the scientific community is growing, not shrinking.

There is also something glyphosate does beyond killing weeds that does not get discussed nearly enough. It is a chelating agent, meaning it chemically binds to minerals in the soil, iron, manganese, zinc, and boron among them, forming compounds that plant roots cannot absorb. The magnet analogy is a reasonable one. The chemical grabs onto nutrients and locks them up. It also functions as a broad-spectrum antibiotic in soil, killing the beneficial microorganisms that cycle nutrients and make them available to plant roots in the first place. The combination of these two effects has contributed to something documented across multiple studies: a meaningful and measurable decline in the nutritional density of our food over the past several decades. Some common fruits and vegetables have lost 25 to 50 percent of certain minerals and nutrients compared to what they contained 50 to 70 years ago. The causes are multiple. Breeding for yield over nutrition, soil depletion from intensive farming, synthetic fertilizers that replace only nitrogen, phosphorus, and potassium while neglecting trace minerals. But glyphosate's chelating and antimicrobial effects are a documented part of that picture.

We are growing more food than ever. It just contains less nutrition per bite than it used to.

Atrazine: The Most Used Herbicide You Have Never Heard Of

Atrazine has been the most commonly used herbicide in the United States since the 1970s. It is used primarily on corn, which means it is applied across enormous swaths of the Midwest every single year. It is the most frequently detected pesticide contaminant in groundwater and drinking water in the US. It is also highly estrogenic.

Dr. Tyrone Hayes at UC Berkeley published landmark research in 2002 and 2010 in the Proceedings of the National Academy of Sciences. His findings: male frogs exposed to atrazine at concentrations as low as 0.1 parts per billion, below what is legally allowed in US drinking water, developed hermaphroditic characteristics, including ovarian tissue in their testes. A 2010 follow-up study found that 75 percent of male frogs exposed to atrazine were chemically castrated and 10 percent were completely feminized, able to produce viable eggs. Hayes measured a ten-fold decrease in testosterone in exposed males.

The frogs were not the only animals telling this story. In 1980 a chemical spill released large quantities of DDT and its breakdown compounds into Lake Apopka in central Florida. The alligator population on the lake crashed over the following seven years. Researchers investigating why found that juvenile male alligators from Lake Apopka had testosterone levels 70 percent lower than alligators of similar size from a nearby uncontaminated lake, and their penis size was on average 24 percent smaller. Some alligators were intersexed. Females were laying clutches of dead eggs. The population was being reproductively destroyed by the chemical contamination in the water and sediment they lived in. The research was published in peer-reviewed journals and became one of the foundational studies in endocrine disruption science. Dr. Shanna Swan references this type of cross-species evidence in her book Countdown and her appearances on The Joe Rogan Experience as part of the broader pattern she has spent her career documenting: endocrine-disrupting chemicals alter reproductive development not just in frogs and alligators, but in humans. The chemicals change. The mechanism is the same.

A point of contention worth mentioning honestly: Hayes's research has been contested by Syngenta, the company that manufactures atrazine, which funded counter-studies. Some independent Japanese researchers were also unable to replicate his results. The European Union banned atrazine in 2004. The US has not. This is the same pattern we saw with glyphosate. The manufacturer disputes the independent research, the US regulatory body sides with the manufacturer, and other countries act more cautiously. We are not in a position to settle that scientific debate. What we can say is that the research raising concerns was published in the Proceedings of the National Academy of Sciences, one of the most prestigious scientific journals in the world, and that the chemical responsible has been in the ground, in the water, and in the food supply of the American Midwest for over 50 years. Studies have also found possible links between atrazine exposure and human birth defects, low birth weight, and endocrine disruption at environmentally relevant concentrations. Whether Hayes's specific findings are fully replicable or not, the broader concern about atrazine's estrogenic properties is not going away.

Phthalates and the Hidden Ingredients in Your Herbicide

The term phthalates refers to a specific class of chemical compounds, esters of phthalic acid, that are widely used as plasticizers in plastics and as fixatives in fragrances and cosmetics. They are documented endocrine disruptors.

Most people assume that when a herbicide is evaluated for safety, all of its ingredients are evaluated. That is not how it works. Herbicide formulations contain adjuvants and surfactants designed to help the chemical penetrate plant cells more effectively. These are classified as inert ingredients, which sounds reassuring but simply means they are not the active herbicidal compound. It does not mean they are biologically inactive or safe. Regulators largely do not require these formulants to be fully disclosed or independently safety-tested. The surfactant POEA, polyoxyethylene tallow amine, used in Roundup formulations has been found in some studies to be more toxic to human cells than glyphosate itself. This is a documented and published criticism of current regulatory practice, not a fringe claim.

Dr. Shanna Swan noted on The Joe Rogan Experience that phthalates have been identified in some pesticide formulations specifically because of their ability to increase absorption into plant cells. The mechanism is the same one that makes phthalates useful in cosmetics and personal care products. They reduce surface tension and increase cellular permeability. In a pesticide you want the herbicide to penetrate the plant. In a lotion you want the active ingredient to penetrate the skin. The chemistry is identical. What this means practically is that agricultural workers and rural communities near spray operations are not just potentially exposed to the active herbicidal ingredient during drift events. They may be exposed to phthalates as well.

Swan's research documents that phthalate exposure, even at low levels and particularly during fetal development, has measurable effects on reproductive health across generations. In one of her studies, men in agricultural Missouri had half the motile sperm of men in urban Minneapolis. Swan attributed this finding to pesticide exposure, which was confirmed through urine analysis. The men were not living near a chemical plant or working directly with pesticides. They were simply living in an agricultural region of the American Midwest.

Chemical Drift and Volatilization

Most people think of pesticide exposure as something that happens to farmers and farmworkers. That assumption does not hold up to scrutiny. Pesticide drift occurs in two ways. The first is particle drift, the physical movement of spray droplets during application carried by wind. The second, and more insidious, is volatilization drift, where chemicals evaporate from soil and plant surfaces hours or even days after application and become airborne gases. Research from Scientific American citing Pesticide Action Network found that upward of 95 percent of applied pesticides miss their target, reaching nearby people, wildlife, waterways, soil, and air instead.

Volatilization is documented to occur 25 times more frequently than surface runoff as a chemical transport mechanism. Up to 25 percent of applied pesticides are carried by air currents, and during summer months that figure can reach 60 percent. Once pesticides enter the upper atmosphere they can travel hundreds to thousands of miles from where they were applied. This is not a theoretical concern. Pesticides have been documented in Antarctic air, water, and soil despite no agricultural activity on the continent. They have been found in Arctic snow, in ice cores from Greenland, in Rocky Mountain National Park, and in remote mountain ecosystems in Brazil. A European atmospheric study detected 58 different pesticides across monitoring sites that included polar and mountain locations. Atrazine, the most used herbicide in the American Midwest, has been detected at Arctic monitoring stations. DDT has been found in Antarctic snow for more than 40 years. Everywhere researchers have looked, they have found these chemicals. The reach of agricultural chemicals is not regional. It is planetary.

There is one more exposure pathway worth addressing directly, because it is something Clayton and I have both experienced firsthand. Temperature inversions, weather conditions where a layer of warm air traps cooler air near the ground, are a documented mechanism for concentrated chemical exposure in agricultural areas. When chemicals are applied and an inversion sets in, those compounds do not disperse upward the way they normally would. They stay low and concentrated. If you have ever driven past a field being sprayed and thought about rolling up your windows, that instinct is correct. Whether the concentration reaching you through a car vent during a brief drive-by is at a harmful level depends on the chemical, the application rate, and how close you are. But the exposure is real. There is also a simple rule worth remembering: if you can smell it, you are breathing it. Odor detection means chemical molecules are physically contacting your olfactory receptors, which means they are already in your respiratory system. That is not alarmism. It is basic chemistry.

Skin Absorption

Skin is the largest organ in the human body, covering roughly 20 square feet, about the size of a standard interior door, and accounting for more than 6 percent of total body mass. It is the primary route of pesticide exposure for most people who are not directly applying chemicals.

Peer-reviewed research and EPA guidance both confirm that absorption rates vary dramatically by body location. The documented order from highest to lowest is the scrotal area, forehead and scalp, armpits, back and abdomen, palms, and soles of the feet. Think about that list for a moment. The areas of highest chemical absorption are the exact areas of the body most in contact with soap during bathing. If your soap contains synthetic chemicals, you are applying them directly to the parts of your body most capable of absorbing whatever they carry.

Research has found that surfactants like SLS, sodium lauryl sulfate, actually increase skin permeability for other chemicals. SLS damages the stratum corneum, the skin's outer protective layer. This means a soap containing SLS does not just strip your skin's natural oils. It potentially increases your skin's absorption of whatever else comes into contact with it afterward, including the environmental chemical residues we have been discussing throughout this entire blog. You are not just absorbing the soap. You may be absorbing the world it is washing off.

Some pesticides absorbed through high-absorption skin areas can reach bloodstream concentrations approximating direct injection. The EPA's dermal absorption guidance explicitly notes this for certain compounds.

Insecticides

Insecticides are, by design, more acutely toxic to living organisms than herbicides because they have to kill creatures that have evolved genuine biological defenses: nervous systems, exoskeletons, and behavioral adaptations that have developed over millions of years. Herbicides kill plants. Insecticides have to overcome biology that actively resists being killed.

Many insecticides work by disrupting neurological function through a mechanism called acetylcholinesterase inhibition, which prevents nerve signals from switching off properly, causing continuous nerve firing that leads to paralysis and death in the target organism. These same mechanisms affect human neurological function at sufficient exposure levels. The human nervous system is not as different from an insect's as we might like to think when it comes to the chemistry involved. Organophosphate insecticides are the most well-documented example of this. They are chemically related to nerve agents developed for warfare. The same science that was weaponized in World War I was later reformulated and sold as agricultural pest control.

Neonicotinoids deserve specific mention. These are systemic insecticides, meaning they are absorbed throughout the entire plant, including its pollen and nectar, rather than sitting on the surface where they might be washed off. Bees and other pollinators that feed on treated plants ingest the chemical with every visit. Neonicotinoids are the primary documented driver of bee colony collapse disorder, a phenomenon that has wiped out a significant percentage of managed honeybee colonies in the United States and Europe over the past two decades. This matters beyond the bees themselves. Roughly a third of the human food supply depends on pollinator activity.

When insecticide labels describe a product as safe for indoor use, that claim is based on the active ingredient studied in isolation, at specific concentrations, under specific conditions. As we discussed with herbicide formulants, the adjuvants and inert ingredients in insecticide formulations are largely not required to be independently tested or disclosed. The safety claim on the label is not a full picture. It is a partial one.

Organic Does Not Mean Chemical-Free

Organic certification legally prohibits the use of synthetic pesticides on certified crops. However, organic certification does not guarantee zero chemical contamination. Multiple peer-reviewed studies have confirmed that organic foods typically show considerably lower levels of glyphosate compared to conventionally grown counterparts, but avoiding glyphosate entirely is extremely challenging due to its presence in soil, animal manure, rainwater, and airborne drift. You now understand exactly why that is, having read everything above.

The reason Private Oaks uses organic ingredients is not because they are perfectly clean. It is because they represent the best currently achievable standard - the lowest possible chemical load in a world where some level of contamination is unavoidable. That is an honest position and we stand by it.

That sourcing philosophy is also why we get our ingredients where we get them. Our olive oil comes primarily from countries surrounding the Mediterranean Sea, specifically Spain, Italy, Portugal, Tunisia, Morocco, and Turkey. Our coconut oil comes from the Philippines and our shea butter from Burkina Faso. We do not source our oils from the United States, and the reason is straightforward. The US applies more agricultural chemicals per acre than nearly any other country on earth. Fleshy fruits like grapes, olives, berries, plums, and apples absorb chemical residues far too easily for us to be comfortable sourcing from conventional American agriculture.

Wine is a useful example because grapes are among the fleshy fruits with the highest documented glyphosate absorption, and the testing data is well documented across multiple independent studies. In 2016, a group called Moms Across America tested 10 California wines from Napa, Sonoma, and Mendocino counties and found glyphosate in all 10, including a biodynamic organic wine from a vineyard that had never been sprayed. The contamination in that organic wine was attributed to drift from neighboring conventional vineyards. In 2019, U.S. PIRG tested 20 beers and wines and found glyphosate in 19 of the 20, including organic brands. The only product that came back clean was one organic IPA. Neither study found levels exceeding current EPA limits, and that distinction is worth acknowledging. The point is not whether a single glass of wine will harm you. The point is that glyphosate is now present in products made from grapes grown on vineyards that have never been intentionally sprayed with it. The chemical arrived through the air. That is what drift and volatilization look like in the real world.

The regions we source from operate under significantly stricter chemical regulations than the United States. Atrazine, the most widely used herbicide in American corn country and the chemical responsible for the feminization of frogs you read about earlier in this blog, has been banned across the European Union since 2004. Pre-harvest glyphosate desiccation, one of the primary causes of elevated glyphosate residues in American wheat and oats, is prohibited under EU regulations. European allowable residue limits for glyphosate in food are thousands of times lower than US standards. We are not claiming our ingredients are perfectly chemical free. Nobody can make that claim honestly in the world we have just described. What we can say is that we source from regions where the regulatory framework demands significantly lower chemical exposure than what American agriculture currently allows.

Some people ask why we use organic coconut oil and shea butter given that both come encased in shells or husks that are naturally impermeable to chemical penetration. It is a fair question. The answer is that if those shells and husks are sprayed during cultivation, real contamination risk enters the picture during the extraction process. When the shell is cracked or the husk is removed to access the meat inside, any chemical residue on the exterior can come into direct contact with the oil-bearing material we are extracting. The shell protects the fruit. It does not protect the extraction process. Organic certification means the plant was never sprayed in the first place, which eliminates that risk entirely.

Our Thesis

We are already surrounded by chemicals we did not choose. They are in the air during spray season. They drift into our neighborhoods. They are in our food at levels below legal limits but above zero. Organic certification reduces that load but does not eliminate it. Given all of that, the one place you have complete control is what you put directly on the most absorbent areas of your body every single day. That is your soap. That is your skin. That choice is yours. And when you understand what goes into most commercial soap bars - the synthetic surfactants, the undisclosed formulants, the SLS that makes your skin more permeable to everything else - choosing a soap made from organic oils with nothing hidden becomes less of a lifestyle preference and more of a logical conclusion.

We are not in the business of telling people what to be afraid of. But we are in the business of making soap, and we think the people using it deserve to know what the research actually says about what goes on their skin and where it ends up.

For the history of how we arrived at this chemical landscape, Frank A. Von Hippel's book “The Chemical Age” is essential reading. It is not a polemic. It is a documented account of how the same science that saved millions of lives through famine and disease prevention also created the chemical world we are now navigating.

For the human health consequences, specifically what phthalates and other endocrine-disrupting chemicals are doing to reproductive health across generations, Dr. Shanna Swan's book “Countdown” is the most important piece of research you can read on the subject. Dr. Swan has appeared twice on The Joe Rogan Experience, episodes 1638 and 2476, both available on Spotify. If you prefer to listen before you read, start there.

Dr. Shanna Swan's Netflix documentary The Plastic Detox, currently streaming, follows six couples struggling with unexplained infertility through a 90-day effort to reduce their exposure to phthalates and other endocrine-disrupting chemicals. The trailer is below. It is worth your time.

Curious about what goes into every Private Oaks bar? Our ingredients page breaks down every oil, clay, and mineral we use, where it comes from, and why it is there. If you're looking for an even deeper analysis on our ingredients, these blogs have the information you're searching for: Do the Oils Really Matter That Much?, What Clays and Salts Actually Do to Your Skin.