A Foodie’s Guide to Avoiding Glyphosate (And Other Bad Stuff) – Grain Overview



When glyphosate is used for “pre-harvest desiccation,” it is sprayed on the crop after it has already matured. The goal is to totally kill the crop, so that it dries out faster and can be harvested a few weeks sooner, thus lessening the risk that it will be destroyed through bad weather or rot.

The use of glyphosate to kill crops just before harvest originated in Scotland in the 1980’s. To my understanding, it is mostly used in colder and damper areas where short growing seasons and wet conditions make farming riskier.

The practice is now extremely prevalent in Canada, with reports suggesting that the vast majority of non-organic oats, wheat, buckwheat, and various other grains originating from that country are substantially contaminated with glyphosate as a result.

In the U.S., glyphosate usage as a pre-harvest desiccant is apparently mostly restricted to the upper regions of the Midwest and Northwest. (Although I have heard of some rumors that farmers in other areas of the country, such as the Southeast, also may use glyphosate as a desiccant just prior to harvest, I am not certain how frequently that actually occurs.)

Glyphosate is also frequently used as a pre-harvest desiccant in Scotland, Ireland and England (with UK farmers’ insistence on continuing to use the herbicide in this way being one of the many factors that led to the Brexit decision).

Although farmers in some other European countries such as Germany also sometimes have used glyphosate as a pre-harvest desiccant, this seems to be being phased out due to the general opposition to glyphosate usage in the EU.

Certain European countries, such as Austria, prohibited this usage of the product a number of years ago.

To my understanding, glyphosate is not officially approved for pre-harvest use in Australia or New Zealand but may be used for such purposes by some farmers anyway.

The problem with spraying glyphosate on crops just before harvest is that the matured grain can absorb the chemical like a sponge.

The outside part of the grain – the bran – tends to be the most affected when this occurs.

Certain grains – such as oats and buckwheat – are especially likely to be treated with glyphosate just prior to harvest, as a result of their usually being grown in northern locations.

While wheat also may be treated with glyphosate as a pre-harvest desiccant, this tends to be somewhat less common.

An additional problem with pre-harvest desiccation is that since it is done during the harvest season, any pesticide drift that may occur will have the potential of being absorbed into the mature grains of other farmers’ crops, including crops being grown organically.

As a result, oats and other grains grown in areas where pre-harvest desiccation with glyphosate is common often have measurable levels of glyphosate themselves, even if everything else was done according to accepted organic practices.

In most cases, from what I have seen, the glyphosate levels in organic grains are tend to be lower than 50 ppb (parts per billion) – compared to the 1,000+ ppb that typically are found in non-organic oats from companies like Quaker Oats.

Largely due to concern about glyphosate cross-contamination of their own food products, a group of food companies (including Nature’s Path, One Degree, GrandyOats, Clif Bar and a number of others) have joined EWG’s petition to the EPA requesting that the practice of using glyphosate as a pre-harvest desiccant be eliminated and that maximum allowable glyphosate residue levels in oats be dropped from the current level of 30,000 ppb back to the 1993 level of 100 ppb.

The EPA’s only response so far has been to issue a general Proposed Interim Decision stating that it does not believe that glyphosate poses a public health threat and does not intend to change its regulation of the product.


Pre-Harvest Desiccation Info: 

EWG Oat Petition – March 28, 2019

The Western Producer – August 16, 2018

Irish Farmers Journal – February 24, 2018

ABC Australia – October 31, 2016

EcoWatch – March 5, 2016

Glyphosate EU – January 8, 2014

Glyphosate EU

New Zealand Food Safety



Corn is by far the biggest crop  grown in the U.S. in terms of both weight (more than 350 million tons per year) and dollar value (more than $50 billion).

About 85% of U.S. corn is genetically modified, with the large majority of it having the trait of being resistant to being killed when Roundup or other glyphosate-based products are sprayed on it. Since glyphosate kills virtually all other plants, this means that farmers can easily rid the field of weeds while still producing a sellable crop.

The majority of U.S. corn also has been genetically engineered to contain genes from the soil bacterium Bacillus thuringiensis (BT). This results in the plant itself being able to produce “insecticidal proteins” that make it resistant to being eaten by certain kinds of worms.

While some genetically modified corn has only the insecticidal attribute or only the herbicidal tolerance, the large majority is now “stacked” to be both resistant to the herbicides and capable of manufacturing its own insecticides.

Two other brands of herbicide-tolerant corn are Bayer CropScience’s Liberty Link Corn (resistant to an herbicide called glufosinate) and Pioneer Hi Bred’s Clearfield (resistant to the herbicide imidazoline). The herbicide-tolerance trait in these products was bred using “tissue culture selection and the chemical mutagen ethyl methanesulfonate, not genetic engineering.”

The vast majority of U.S. GMO corn and other herbicide-tolerant field corn is used to make ethanol (used in gasoline and other fuels) and to feed livestock.

Only a small fraction of it is consumed directly by humans, primarily in breakfast cereals, snack products and Mexican foods.

Genetically modified sweet corn also is available in the U.S., but it is not Roundup Ready or otherwise herbicide-tolerant. Rather, it is insect-resistant corn sold under the trade names Attribute (from Syngenta) and Performance Series (Monsanto).

Note that there are no other approved grain products grown in the U.S. or elsewhere that are Roundup Ready tolerant or otherwise genetically engineered.

While Roundup Ready Wheat has been developed, it never has been granted government approval. To my understanding, this is due to U.S. wheat farmers’ fears that negative attitudes about GMO products in other countries would cause them to boycott all U.S. wheat and thus cause farmers in this country economic harm.

Although substantial amounts of glyphosate are used in growing corn, the reports that I have seen so far suggest that non-organic corn sold for human consumption tends to have only moderate levels of glyphosate contamination, such as under 100 ppb (compared to the levels of 1,000 ppb or more often seen in non-organic oats).

Apparently, the fact that glyphosate is applied earlier in the growing process for Roundup Ready corn than it is when it is used as a drying agent for oats results in less of the glyphosate being present in the final product.

In addition, the husk of the corn may serve to protect the grains from spraying or pesticide drift.

Despite the fact that glyphosate levels in non-organic field corn appear to be fairly low, I would not suggest eating non-organic corn cereal, snack products or tortillas under any circumstances.

For one thing, I am not convinced that consuming grain that manufactures its own Bt toxin is a very good idea. To my understanding, some research suggests that it can be harmful to the digestive tract and no research provides much evidence that it is safe.

In addition, Roundup and other glyphosate products change the microbiome of the soil, killing off good bacteria and allowing molds that produce aflatoxins, trichothecenes and other toxins to take over.

This is problematic with regard to agriculture in general, but it is especially concerning when it comes to corn since (compared to other grains) corn is especially likely to be contaminated with toxic mold.

A reason sometimes given for why Bt corn is a good idea is that this controls insects who otherwise would nibble into the corn ears, thus making the corn more vulnerable to mold.

Personally, I do not especially buy this concept since it sounds safer to me to apply the Bt toxin to the plant in a spray (as organic farmers do) or to use an insect growth regulator such as methoprene (which is not organic but seems to have a pretty good safety record) rather than to be eating grains that manufacture their own Bt pesticides.


USDA – Genetic Engineering


While glyphosate currently may be used as a weed killer by farmers in France, even this usage is scheduled to be made illegal within the next several years.


A third way that glyphosate may be used is as a weed killer in fields that are growing plants that are not “Roundup Ready.”

In this case, the herbicide is not sprayed directly onto the plant since this will kill it. Rather, it may be sprayed on the edges of the field, in between the rows, or directly on growing weeds.

In some countries, such as Japan, this is the only accepted usage of Roundup since the idea of spraying a plant that is to be eaten with a toxic chemical is perceived to be unacceptable.

Even if these plants are not sprayed directly with glyphosate, enough of the herbicide to be measurable in lab tests may end up in them anyway.

Usually the levels in these cases are low to moderate (such as less than 200 ppb), rather than extremely high as may occur when glyphosate is used as a pre-harvest desiccant.


Harvest time for a Wheat Montana farm, where no glyphosate is used.


A variety of mycotoxins have the potential of being present in food and to potentially cause harm to humans and other animals that consume that food.

In the U.S., only aflatoxin and patulin are regulated by the government with regard to maximum levels being allowed in human food. In the EU and in certain other countries, other mycotoxins have maximum allowable levels.

Contamination of foods with aflatoxin and certain other mycotoxins is considered to be a major health problem in certain parts of Africa, leading to high rates of conditions such as liver disease, kidney disease and cancer.

In the U.S. and other cooler countries, contamination of foods with Fusarium toxins tends to be especially common. Although these toxins appear to be less deadly than aflatoxin, they still may have major health effects.

Experts in the field of mycotoxins suggest that contamination of human foods with these toxins is much lower than contamination of agricultural animals’ feed or of pet foods, however.

One topic that I think deserves more exploration is the connection between glyphosate use in agriculture and the presence of mycotoxins in foods.

Since glyphosate use is known to cause toxic molds such as Fusarium and Aspergillus flavus to grow in fields, it makes sense that foods that were grown with the use of glyphosate might end up being more contaminated with mycotoxins.

From what I have been able to find, the question of whether glyphosate in particular causes grains to be more likely to be contaminated with substantial amounts of mycotoxins has not been specifically considered in the peer-reviewed literature.

Quite a few studies have been done on the question of whether non-organic foods in general are less likely vs. more likely to be contaminated with mycotoxins, however.

For non-grain products, non-organic products often are more contaminated with mycotoxins than organic products are.

For instance, non-organic apple products tend to have less patulin, presumably because the lack of fungicides in organic apples allow more mold growth to occur.

(The propensity of fungicides to lead to resistant fungal infections such as Candida auris to have problematic in recent years suggests that their use in agricultural is not necessarily a good idea even if it makes the foods less likely to be contaminated with mycotoxins, however.)

For grain products, the tendency seems to be for the conventional products to have more toxic mold contamination (especially with regard to Fusarium toxins) than the organic ones.

This seems to be consistent with the theory that the glyphosate that is usually used on conventional grains may be causing more mycotoxins to be present in the food products.

This is particularly concerning in light of a substantial body of work by Professor Pauline Jolly (of the University of Alabama at Birmingham) and co-authors suggesting that the AIDS epidemic in Africa is at least in part being driven by high levels of contamination of the food supply with mycotoxins.

Those study suggest that individuals with high levels of mycotoxins in their urine are more likely to acquire HIV from others and also are more likely to have it multiply to problematic levels in their bodies.

The research also suggests that the disease is more problematic in parts of Africa where people tend to eat more corn and peanuts (which often are high in mycotoxins) and less rice (which tends to be low in mycotoxins).

Although not much research apparently has been done on the topic, it does seem that glyphosate is a popular product in Africa.

I therefore have been wondering to what extent glyphosate may be playing a role in the AIDS epidemic there.

In general, my feeling is that if I am going to eat corn products (which I do occasionally), then it seems reasonable that they should not only be organic but also that I should try to find higher quality products since those may be less likely to be contaminated with mycotoxins as well as chemicals.

I also feel better with regard to the state of the planet when I eat foods not contaminated with glyphosate (including animal products that have not consumed glyphosate-contaminated grains).

Since ethanol is almost always derived from GMO corn, I do resent the fact that I seem to be able to find any gasoline that does  not contain this chemical though.

While it’s possible that using corn as a fuel source is a good idea, I see no reason why glyphosate should be used to grow it or why Monsanto/Bayer should get a piece of the profits from the production of it.

I’ve yet to hear anyone else express any concern about the connection between ethanol and glyphosate, but I think that likely will change soon as the negative effects of glyphosate on the microbiome as well as the insect population becomes more understood.


Mycotoxin Info:

Stephanie Seneff & Dave AspreyJune 2015

Dave Asprey – November 10, 2012


An oat field.


While glyphosate seems that it may be one of the most problematic chemicals currently being used in the agricultural industry at present, a wide variety of other chemicals used in non-organic grains may not be safe at all either.

I thought about this recently when I recently read an article about agriculture in Brazil – a country that apparently already is the world’s largest user of pesticides and recently in the process of approving hundreds of additional extremely controversial pesticides for use there.

I found this to be especially relevant since I had previously been trying to find out more information about tapioca and cassava products – products that are very often imported from Brazil and that often (even when supposedly organic) feel very toxic to me.

Cassava chips, for instance, have become very popular as a supposedly Paleo alternative to other kinds of snack chips but have felt problematic to me. When I contacted a major manufacturer, they responded:

Cassava is native to and widely grown in Brazil, where we currently source our cassava from. We focus on finding sustainable ingredients and do our best to do right by the environment and of course, our customers. To this point, we may change suppliers periodically so please keep in touch for future changes.


Of course, I don’t want to suggest that the U.S. is much better than Brazil with regard to the use of pesticides, since a wide variety of chemicals are also in use here and the Trump Administration EPA seems to have the agenda of allowing others to be used without research to find out of if they are safe for children (or adults) as well.


Moreover, virtually all grains – including organic grains – sold in the U.S. today have been treated with some kinds of chemicals. While it seems that on average the organic chemicals may be safer than the non-organic ones, whether there has been enough safety testing done to determine what the real long-term effects are is debatable.

In addition, there are some agricultural chemicals that are synthetic rather than naturally derived and therefore that cannot be used on “organic” products even though they may be just as safe or even safer than the ones that can be used on organic products.

For those individuals who have chemical sensitivities, it seems entirely possible that they may end up reacting to certain organic chemicals, even if those chemicals are not especially dangerous in general.

In other words, there may be some individual variation in terms of what products are tolerated that will mandate some trial-and-error being done.

Despite all of this, I tend to think that with grains especially, sticking with organic products rather than taking a chance on non-organic is usually going to be a good idea, at least when it comes to grains that are grown in North America or the UK, due to the fact that if a product is not marked as “organic” then there is generally no commitment on the part of the growers to follow any specific procedures at all.

I learned this the hard way when, a number of years ago, I had some good experiences with McCann’s oatmeal products and concluded – based on information on their website as well as reports from a number of members of the Mold Avoiders group – that the company’s products seemed cleaner to me than many U.S. oatmeal products marked as organic.

More recently, though, the company’s products started feeling problematic enough to me that I stopped eating oatmeal entirely, and I got some reports of people experiencing negative reactions from the Mold Avoiders group. Eventually the Taiwanese government was reported in the news media as rejected a bunch of foreign oatmeal products, including some McCann’s oatmeal, because it violated the country’s 100 ppb maximum level of allowable glyphosate contamination.

For the most part, I do think that when it comes to grain products from North America or from UK/Ireland, it is a good idea to stick with products that are labeled as “certified organic” as a minimum standard, if only to reduce the likelihood that glyphosate contamination will be present.

There are a few exceptions to this, but they are pretty few and far between.

For instance, I experimented with some non-organic oat products

For instance, Montana Gluten Free states on its website that no glyphosate at all is used on any of its products and that every lot of oats is tested for glyphosate residues both in-house and by an outside lab.

I asked the company how their non-organic oats differed from the organic ones, and this was their response:

Our conventional oats (aka not organic) are treated with a mild herbicide when the plant is quite small. It doesn’t translocate – which means it doesn’t move through or stay with the plant. There is no trace of it in the adult plant or the seeds – which we use to make our products. None of our growers use glyphosate at any point in the growing process.


I tried a sampler of this company’s non-organic products and thought that they felt fine – that is, quite a lot better than most company’s so-called organic oats and plenty good enough for me to order again.

The company’s organic oats, which are about 50% more expensive than the non-organic ones, felt at least as good and possibly better to me. While I likely will just buy the organic products when I order again, it was nice to find that this company is able to produce a non-organic product at a good price that I would not have any problems eating myself.

Although I usually buy organic rice from Lundberg Family Farms, some of their products (such as the snack chips) area available only with non-organic rice but still have felt fine to me.

This is what the company states about the topic on its website:

Many years ago, we developed our “Eco-Farmed” growing system as an improvement on many typical conventional rice growing practices. This system blends organic practices and integrated pest management techniques with minimal application of synthetic fertilizers, herbicides, and pesticides, only as needed. Additionally, many of our growers are transitioning their non-organic fields to organic – a 3 year process required by organic certification standards. During this 3 year period, a field and its crop are treated as organic, but are not able to be certified organic. In this instance, offering the rice as Eco-Farmed benefits not only the environment and price conscious consumer but also the farmer and the growth of organic farmland in the US. We think that you will find the growing system of our Eco-Farmed rice above and beyond that of conventional rice.


Glyphosate is not generally used on rice at all (with the maximum allowable limit in the U.S. still being a low 100 ppb), and based on this description heavy metals (the biggest rice hazard) do not seem to me to be more likely to be present in Lundberg’s “Eco-Farmed” rice than in its organic rice. It therefore does make some sense to me that this rice would feel okay to me.

A final non-organic grain product that I am willing to eat on occasion is popcorn.

Like rice, popcorn appears to be pretty much untainted with glyphosate (with maximum U.S. levels at 100 ppb). In addition, although many brands of popcorn are now labeled as being “Non-GMO,” this is purely for marketing purposes since no GMO popcorn has been approved.

Virtually all popcorn is treated with some kind of pesticide, however. The reason for this is that if worms gnaw into the ears, then mold (likely toxic mold) will be much more likely to get into the corn and contaminate it.

The question here, therefore, is not whether pesticides are being used, but rather whether we believe the organic pesticides are safer than the non-organic ones.

In some cases, the pesticides being used have enough of an established safety record or appear to be being used carefully enough that they seem to me that they are likely fine even though they are not organic.

For instance, a few years ago I tried a bunch of different popcorn brands and really liked Lakota Popcorn, which was grown in an area of South Dakota that felt really good to me by a Native American company.

When I called Lakota Foods to inquire about their growing practices, they informed me that the only chemical used on the popcorn was a product called Diacon, which has as its active ingredient the insect-growth regulator methoprene.

Methoprene has been on the market since 1975 and EPA materials suggest that it has a very good safety profile. No harm was reported to mammals in laboratory studies even at the levels of the highest doses, for instance.

A book called The Organic Gardener’s Handbook of Natural Insect and Disease Control states the following about methoprene and other insect growth regulators:

Insect growth and reproduction is controlled by hormones that must be present in the right place at the right time and at the right concentration. Most insects shed their external skeletons periodically as they grow and develop. Juvenile hormone (JH) is one of the chemicals that help to regulate this process. However, if insects are exposed to it at the wrong time, they do not mature. Scientists have used this and similar concepts to develop insecticides that control several different important insect pests. Most available products use synthetic versions of naturally occurring insect growth-regulating hormones. 

Since humans do not have the same chemical processes as insects, insect growth regulators are considered among the safest of pest-control products. They don’t irritate the skin or eyes, and since the growth-regulating hormones must be eaten by the insects to be effective, they are not as likely to affect beneficial and non-target insects. 


I bring all this up because it reinforced my belief that in general Native Americans tend to be extremely good stewards of the land and to be making wise decisions with regard to how to use it even if they sometimes deviate from white people’s conceptions what should be considered “organic.”

What I honestly (!) wish is that we could give all the land in the whole country back to the Native Americans with an apology and let them do with it as they see fit, since that seems to me that it would solve a great many problems and that everyone would be much better off as a result.

And so it’s pretty heartbreaking to me that Lakota seems to have suspended its business operations, at least for the time being.

Another brand of non-organic popcorn that I have felt good about is Tiny But Mighty, which is an heirloom product grown in Iowa. Their website states:

Some of what we’re doing with the growing methods and soil building is actually beyond organic standards, but this unique heirloom can’t produce well enough without some help….We do not use pesticides in any aspect of growing or producing Tiny But Mighty Popcorn. Farmer Gene performs seed selections every year and over time has made sure the seeds that are used carry the best traits for natural insect resistance. However, our variety is particularly susceptible to being destroyed by weeds or grasses during the first stage of each growing season, Therefore, we do use an herbicide that is “non-residual” or “non-systemic” – meaning that it never actually enters the popcorn plant. It only targets the grasses and broadleaf weeds on contact. There is only one application early in the season. We also use a special organic fertilizer blend that includes trace minerals and other positive elements for plants and soils. Once the corn gets past this early growth it becomes tall enough to form a leaf canopy that is sufficient to fight off weed and grass growth. There are no herbicides used in the second part of the season when the ears/kernels are actually developing.


In truth, though, I seem to do fine with most non-organic popcorn, as long as it does not have toxic oils or other components added to it and as long as the quality is high enough that mold contamination is not a problem.

Even the non-microwave versions of really mainstream brands like Amish Country (which acknowledged to me that they use “herbicides, fungicides and pesticides” during the growing process) and Orville Redenbacher’s have felt okay to me. I’ve also done fine with the already-popped snack foods sold by Popcorn, Indiana (which use GMO-free oils but suggest nothing about the popcorn itself being organic).

I’m still not crazy about the idea of these brands using agricultural fungicides (which seem to be to blame for the emergence of dangerous drug-resistant fungal infections such as Candida auris), and so would tend to avoid them for that reason alone. Still, when I consider all the food choices available in most ordinary grocery stores or convenience stores, popcorn often seems one of the safest bets by far (as long as toxic oils are not accompanying it, of course).

There are also are a few countries – including France, Italy and Japan – that produce grains that are rarely labeled as organic but that nonetheless usually feel good to me.

Although glyphosate is used in these countries, it is only for weed-killing purposes and apparently only in pretty small amounts. France seems to be committed to eliminating the chemical from its agriculture entirely within the next few years, and Italy and Japan also seem to be increasingly circumspect in terms of how much of the chemical is used.

My hope is that as the use of glyphosate decreases around the world, the number of countries on this list will increase.

I also would like to see more flours and whole grains – rather than just cookies and pastas – from these countries being sold in the U.S. The efforts of Healthy Traditions to import oats and wheat flour from Italy is a good start to this, for instance.


A field of rice being grown by Massa Organic.


Allowable glyphosate levels for rice in the U.S. are low (maximum 100 ppb), and it seems that farmers rarely use glyphosate on their rice fields even as a weed killer.

Some brown rice – including brown organic rice – may have low levels of glyphosate contamination, however. This usually is for rice originating in Canada and presumably is a result of pre-harvest desiccation of other crops with the chemical.

In most cases, though, white rice especially but even brown rice comes up free of glyphosate contamination on tests.

A much bigger problem with rice is that it tends to be contaminated by whatever heavy metals happen to be in the soil and water in the area.

Although arsenic contamination issues have gotten the most media attention, other kinds of heavy metals such as cadmium also may be present in high levels in rice.

Although in some cases the heavy metal contamination of the soil occurred naturally, in other cases it is due to activities such as agriculture or mining.

For instance, arsenic is often added to chicken food as an antiparasitical, with the chicken droppings then used as fertilizer. Pesticides used for certain crops, such as cotton, also have contained arsenic and thus contaminated those areas with the metal.

I have had problems with metals toxicity as part of my chronic illness, and so it likely should not be surprising that metals contamination of rice seems to be almost as problematic for me as glyphosate contamination of other food products.

The rice products that have felt the most toxic to me have also been among the most expensive ones that I have encountered – a heavily promoted black rice grown in China and a wild rice grown in a lake in Canada.

I also tend to do really poorly with almost all gluten-free products (such as baking mixes or gluten-free breads) that include rice flour, even when they are organic. My guess is that this is due to the use of inexpensive ingredients that are especially contaminated with metals.

The only rice company that I have seen discussing the arsenic problem openly is Lundgren Family Farms, which is located in California and has a whole section devoted to the topic on its website. The company has many of its products tested and they do seem to mostly come up as less problematic than many  other brands of rice on the market.

I do feel like the Lundgren rice feels pretty clean to me. I also like the brown rice that is produced by Massa Organics, which is a small soil-oriented farm located very close Lundgren’s operations in central California.

Still, even that rice is not something that I eat very often. A few servings per month seem more than enough.


Chris Kresser – February 28, 2019

Wellness Mama – January 23, 2019

Food Revolution – March 2, 2018

Consumer Reports – November 18, 2014

The New York Times – April 18, 2014


Popcorn is clean enough with regard to toxicity that I consider it to be a dietary staple rather than a junk food. 


Following is an overview summary of allowable and typical glyphosate levels per type of grain (listed in parts per billion/ppb), as well as my own general strategy with regard to consuming products of each type.


Oats (U.S. Limit – 30,000 ppb):

Non-organic oats have consistently quite high levels of glyphosate contamination, generally between 300 ppb and 2000 ppb. Of the public reports released so far, organic oats have been clear about half the time and having low levels (less than 30  ppb) the rest. Oats from Canada, the U.S. and the British Isles all tend to be problematic.

My feeling has been that eating a bowl of oatmeal or other oat products regularly (even every day) seems to be a good thing for me with regard to detoxification and general health, but only if I can get super-clean oatmeal. Fortunately, I recently have managed to find several different brands of oatmeal that I feel consistently good about, and so no longer feel the need to limit my oatmeal consumption due to toxicity issues.


Wheat (U.S. Limit – 30,000 ppb): 

Glyphosate contamination of wheat occurs when the chemical lands on the outer part of the wheat kernel, which then is polished away in order to make white flour. Non-organic wheat bran often has extremely high levels of glyphosate residue, such as in the neighborhood of 4,000 ppb or even higher. Non-organic refined (white) wheat flour also tends to be fairly consistently contaminated but at lower levels (usually less than 1,000 ppb). Organic wheat products appear to be contaminated with glyphosate at low levels (such as below 30 ppb) about one-third to half the time. Wheat products from certain other countries such as France or Italy may be less contaminated than those from the U.S., Canada or the U.K.

For the most part, my wheat consumption is limited to a few slices of white sourdough bread per week. I also seem to do perfectly fine with other wheat products such as European cookies, but don’t eat them too often because they tend to be high in sugar. Occasionally (such as once a month), I may eat durum semolina pasta from Italy and seem to do fine with it, regardless of whether it is organic or not. I also have recently found some good wheat flour and have done a bit of experimenting with that for baking.


Spelt (U.S. Limit – 30,000 ppb):

The Canadian study suggests that spelt may be a little less likely to be contaminated than regular wheat. Many of the non-organic as well as organic samples were not found to have any contamination. Some samples of non-organic and organic spelt were contaminated, but at low levels of 50 ppb or below. One whole-grain spelt sample was contaminated at a level of 166 ppb, though.

Newman’s Own Organics makes a spelt pretzel that I have done well with, though I only buy a bag maybe once a year (usually when planning a long car trip). I recently made some cookies using One Degree spelt flour and they seemed fine.


Corn (U.S. Limit – 30,000 ppb):

Non-organic corn is usually a GMO Roundup Ready crop and so is treated with glyphosate as an herbicide rather than as a pre-harvest desiccant. Most of this corn is also genetically modified to manufacture its own pesticide (Bt corn), which manufactures its own pesticide. An additional problem with corn is that even more than most other kinds of grains, it may have the potential of being moldy (with the trichothecene-producing toxic mold Fusarium being especially likely to be present when glyphosate has been used on the land). As a result of all of these problems, avoiding non-organic corn may be considered especially important even though measured glyphosate residue levels on corn tend to be lower than for many other grains (from what I have seen so far, less than 50 ppb for non-organic corn and approximately 0 ppb for organic corn). It is possible that non-organic corn from places like Mexico or Italy may be less problematic, but I am not sure about that based on the data. Organic corn tends to be very low in glyphosate residue but may be contaminated with mycotoxins such as aflatoxins or trichothecenes.

Recently I have been eating the corn or maize cold cereals from One Degree and really enjoying them. I also occasionally eat specific brands of corn chips. I have some good corn flour (from Healthy Traditions) on hand but use it only occasionally, such as a coating for fried chicken or fried green tomatoes or (rarely) to make corn muffins.


Rye (U.S. Limit – 30,000 ppb): 

The Canadian study looked at just a few rye samples. Some non-organic rye products were highly contaminated with glyphosate (more than 500 ppb), but others had very low levels of contamination or were clean. The organic rye samples were contaminated at very low levels or were clean.

There was a time in my  life when I really liked rye bread, but it is has been many years since I have eaten any. Now that One Degree is offering rye flour, conceivably I could use it to make homemade sourdough rye bread. That sounds like a lot of work, but maybe it would be worth it.


Buckwheat (U.S. Limit – 30,000):

The Canadian study looked at a large number of buckwheat samples from the U.S. and Canada. Most of these were organic, and all of them were contaminated – the majority at fairly high levels of more than 50 ppb. In some cases, the levels were higher than 300 ppb. It therefore seems that people who are concerned about glyphosate contamination may do well to avoid even organic buckwheat North America. On the other hand, of the seven samples of buckwheat from China that were analyzed in that study, six came up negative for glyphosate and one had a very low level (6 ppb). Potentially products from China could be contaminated with something else such as heavy metals, however.

While I like clean buckwheat quite a lot, my experiences with North American buckwheat have been consistently terrible and I have given up on it. The buckwheat soba noodles from Eden (imported from Japan) and from King Soba (imported from China) have seemed okay though, and so I do occasionally eat those.


Farro (U.S. Limit 30,000 ppb):

The Canadian study looked at several samples of farro. While most came up as negative for glyphosate, one non-organic one from Italy had a level of 30 ppb.

I bought a bag of organic farro to try when writing this article but was not very impressed.


Millet (U.S. Limit – 30,000 ppb):

Millet is not listed specifically on the U.S. allowable glyphosate limits chart, but I am guessing that it is classified as a grain (with the limit therefore being 30,000 ppb). Based on the Canadian report, non-organic millet seems similar to non-organic oats in terms of glyphosate contamination, with most samples in the 50-1500 ppb range. Although some organic samples were clean, others were fairly heftily contaminated in the 50-150 ppb range.

Mostly I like millet in bread, and probably would need to start making my own sourdough bread if I were going to be motivated to eat this very often. I seem to have done okay with the Eden brand.


Amaranth (U.S. Limit – 30,000 ppb): 

Amaranth is officially classified as a pseudo-grain and is not listed on the

Amaranth also is not listed on the chart but may also be classified as a grain. The Canadian study looked at a number of non-organic and organic amaranth samples. While most came up negative for glyphosate, a few of the organic amaranth flour samples were contaminated at levels less than 50 ppb.

I tried amaranth (Arrowhead Mills brand) for the first time while writing this blog article. It seemed quite clean to me and tasted slightly like spinach, which is not necessarily a bad thing. I might eat it again.


Kamut (U.S. Limit – 30,000 ppb?): 

Kamut is a brand of khourasan ancient wheat originating in the Middle East and now grown mostly in North America. It is supposed to be grown only organically. In the Canadian report, one sample from Canada had a glyphosate level of 61 ppb. A handful of other samples had levels under 20 ppb, and the remaining 30 or so samples were negative.

I tried some puffed Kamut breakfast cereal from Arrowhead Mills when writing this article and thought that it felt fine to me. Basically like the Super Sugar Crisp (now renamed Golden Crisp) that I ate as a kid, but without the sugar. I might buy it again.


Sorghum (U.S. Limit – 30,000 ppb?):

Sorghum is sometimes used for gluten-free baking (as well as being used as animal feed or processed into a sweetener). I have not seen any reports about sorghum flour being tested for glyphosate contamination, but an article in Organic Lifestyle magazine speculates that it may be one of those grains where glyphosate is used as a pre-harvest desiccant.

Silver Hills Bakery from Canada used to make a gluten-free bread that included sorghum that felt okay to me, but it has been discontinued and I don’t think I have ever eaten sorghum flour in anything else.


Legume Flour (U.S. Limit – 5,000-8,000 ppb):

The Canadian study looked at many samples of chick pea flour and virtually all of them – including the organic ones – were contaminated at relatively high levels. Many samples had contamination between 1,000 and 8,000 ppb, and one amazingly high sample was tested with a level of 12,699 ppb. U.S., Canadian and “unknown” samples all had similar problems. Some soy flour also was tested as very high, with levels of more than 4,000 ppb.

I used to be a falafel fan and recently tried it again at a local all-organic restaurant. On some occasions, it seemed almost the best meal I had had in years. On other occasions, I could not eat even a bite because of how toxic it felt to me. So my own experience is definitely consistent with the idea that even organic chickpea flour often can be super-contaminated. I occasionally have sampled energy bars with soy flour in them, and those always feel very toxic to me. So in general, until clean sources of legume flour can be found, I don’t really think it is safe for anyone to be eating these types of foods, and I certainly am not planning to eat them myself.


Quinoa (U.S. Limit – 5,000 ppb):

Quinoa is a grain-like seed grown mostly in South America, with smaller amounts being cultivated in the U.S. and Europe. In the Canadian study, almost all the organic samples tested negative for glyphosate, with the exception coming up at 27 ppb. All 20 of the samples from Peru (many of them non-organic) were free of contamination, as were 11 of the 14 organic and non-organic samples from Bolivia (the others had levels below 40 ppm). Some of the non-organic samples from unspecified countries had substantial contamination (one at more than 500 ppb), however.

Quinoa is a prepared food that I occasionally have eaten in healthy food restaurants and it always has felt pretty good to me. I don’t prepare it at home very often but it seems pretty clean when I do.


Teff (U.S. Limit – 5,000 ppb): 

The Canadian study looked at a number of non-organic and organic teff samples. While most were free of glyphosate contamination, a few (including one organic sample) had a low level of contamination (below 20 ppb).

I don’t think that I ever have eaten teff except a long time ago in the injera bread in an Ethiopian restaurant. I do remember really liking that spongy bread though, and so maybe it would be worthwhile buying some teff to try to make it.


Tree Nuts (U.S. Limit – 1,000 ppb):

Tree nuts (such as may be used in almond flour) are subject to the fairly low limit on glyphosate usage of 1,000 ppb. Coconut is not listed on the U.S. guidelines, and I wonder if they may be classified as tree nuts. I’ve yet to see any evidence of coconut products or tree nut products (including flours) having any glyphosate contamination at all and have usually not had problems with these sorts of products myself, even when they are not organic. Problems that I have had seem to have been more with mold than with glyphosate contamination and to have been limited to lower-priced products rather than ones from reputable companies.

I just simply do not bake very often and so rarely have used nut flours or coconut flours. I seem to have done okay with the brands that I have tried, however.


Cassava/Tapioca (U.S. Limit – 200 ppb?)

Cassava and tapioca are not mentioned specifically on the U.S. government’s list of allowable glyphosate limits, but I think that it may be classified as a tuber and thus subject to the 200 ppb guideline. Cassava was mentioned a few times in the Canadian report, with low amounts of glyphosate contamination for some of them (less than 10 ppb).

I’ve been a fan of tapioca pudding since childhood and still occasionally make some of that (using the Let’s Do Organic product from Edward & Sons). Recently, though, the use of cassava or tapioca as a replacement for wheat/corn/rice (such as in tortillas or baking mixes) has become popular, especially among those people pursuing grain-free diets. Regardless of whether the products have been labeled as organic, I seem to be doing less well with those products and to be disinclined to eat very much of them. Although I suspect that the issue is heavy metal contamination or obscenely high pesticide use in countries like Brazil (where a high percentage of cassava is grown), low levels of glyphosate also could be a factor. Maybe in time some good versions of this kind of product will emerge though.


Popcorn (U.S. Limit – 100 ppb):

Although I cannot find where the report lists them individually, the Canadian study is stated as having tested 22 samples of popcorn and having them all come up clean of glyphosate. This is consistent with the low legal limit of glyphosate residue on popcorn. Popcorn does have the potential of becoming moldy, though, and non-organic popcorn may be treated with pesticides, herbicides and fungicides.

Although I know that most people consider popcorn as junk food, I personally feel that the nutritional levels seem comparable to that of other grains and that the low toxicity levels may make it worth considering as a regular part of the diet. I eat popcorn myself pretty often, such as every few weeks or so.


Rice (U.S. Limit – 100 ppb): 

Allowable levels of glyphosate contamination in rice are relatively low, and none of the samples in the Canadian study exceeded the U.S. standard. Brown rice tended to be more contaminated across the board than white rice, but organic vs. non-organic seemed to make little difference.  Canadian samples tended to be especially likely to be contaminated, with a few brown rice samples from Canada exceeding 40 ppb. Rice from the U.S. seemed a little better, with most samples showing no contamination and a few being tested at 25 ppb or below. All 18 rice samples from Thailand, 9/10 rice samples from India, and three rice samples from Pakistan came up as clean. (The one exception from India had slight contamination at 6 ppb.) Undoubtedly a much bigger problem in rice, however, is contamination with arsenic and other heavy metals, which can be a problem in organic as well as non-organic rice.

Increasingly, I am feeling like I am finding clean versions of other grains that I can feel really good about eating. The heavy metal problem in rice, on the other hand, seems impossible to get around – that is, that even though the levels in the better brand are comparatively low, they are still not low enough that I do not see them as a problem. I therefore do not think it is a good idea to remove other grains from my diet and replace them with rice, as some people seem wont to do. I do enjoy rice on occasion as a side dish though, and so eat it maybe a few times a month.


Snack bars made from One Degree oatmeal and crispy rice cereal, which are “non-glyphosate certified” by BioChecked.


There are two companies that are currently offering certifications regarding glyphosate in foods.

The Detox Project offers a “Glyphosate Residue Free” certification, earned as a result of having several product samples come up as free of glyposate. The maximum amount that is viewed as acceptable is 0.01 ppm (or 10 ppb). At present, the only product from the categories discussed on this page that is listed as certified is Foodstirs baking mixes.

BioChecked offers a number of different certifications including a “Non Glyphosate Certified” one. Products that are tested also must have a residue limit of 0.01 ppm (10 ppb). One Degree (and also the bread company Food For Life) are grain companies that have earned BioChecked certification with regard to glyphosate levels.

The Healthy Traditions website sells only products that have come up as totally clean in their own glyphosate testing. The only grain products that they seem to be selling at present, though, are a few from Bionaturae/Jovial as well as a number of additional items items that they have acquired from farmers and are selling under their own label.

In October 2018, the FDA released the results of glyphosate testing that it did from 2015-2016. About two-thirds of the corn samples (and about the same percentage of the soy samples) were contaminated with glyphosate. Information on contamination of oat and wheat products (which have shown up with higher levels in other testing than soy or corn) were not included in the FDA report.

The Environmental Working Group (EWG) released a highly publicized study of glyphosate contamination in oat products in August 2018. Contamination was found to be present in all of the non-organic brands tested, and in some cases (especially for Quaker Oats products) the levels were quite high (such as 1000 ppb or higher). Some of the organic oat products (including ones from Bob’s Red Mill and Nature’s Path) had low levels of contamination, whereas others (including ones from Cascadian Farms, Simple Truth, Kashi and Whole Foods 365) came up as clean.

A follow-up EWG study found relatively high levels in every tested brand of children’s cereal (all of them non-organic).

A US EPA memo from 2015 (but not released until 2018) listed the percentage of a list of a variety of different crops treated with glyphosate.

In 2017, the Canadian Food Inspection Agency (CFIA) released a glyphosate testing report. Of the 869 products tested, about 37% were found to be contaminated with the herbicide.

Also in 2017, Tony Mitra published a book – Poison Foods of North America – summarizing information obtained from the CFIA as a result of a freedom of information request on 8000 different products (unfortunately not listed by name) that were tested for glyphosate. (Note: Although this is a long and dense and somewhat disorganized book, I have found it to be tremendously valuable in allowing me to get a better understanding of this subject and recommend it to others who also really want to get a good grasp of what is going on.)

In 2016, Taiwan’s Food and Drug Administration rejected several brands of imported non-organic oats (including products from Quaker, McCann’s and Bob’s Red Mill) due to glyphosate contamination surpassing their maximum allowed level of 1000 ppb.

In 2016, the Alliance for Natural Health released a report on glyphosate levels in a number of different organic and non-organic breakfast foods. Although the product names were not revealed in the first report, a list later was made available from Natural News. So-called “organic” products registering at more than 100 ppb included Dave’s Killer Whole Wheat Bread and Rudio’s Multibagels. In the non-organic foods, the highest levels were found in Quaker instant oatmeal (1327 ppb), Thomas’ whole wheat bagels (491 ppb) and Pepperidge Farm whole-wheat bread (403 ppb).

In 2014, Food Democracy Now found elevated glyphosate levels in a wide variety of grain products from major companies, with the highest levels in Cheerios cereal, Stacy’s pita chips, Lays potato chips, Doritos corn chips, Lucy’s oatmeal cookies and Back To Nature cheddar crackers. Although most of the products tested were non-organic, two products labeled as organic (Kashi Organic Promise cereal and Whole Foods 365 Golden Round crackers) also came up as contaminated.


Taiwan Articles:

Taiwan News – August 11, 2018

Eco Watch – May 27, 2016

Taipei Times – May 27, 2016


Testing Articles:

Dr. Mercola – February 19, 2019

EWG – October 24, 2018

NYT – August 15, 2018

CNN – August 15, 2018

EWG – August 15, 2018


An Oat Fruit Bread made a baking mix from Montana Gluten Free.


One issue that I have been pondering is the extent to which companies that sell products that are labeled as “organic” or “healthful” or “gluten-free” have the responsibility to be acting in those customers’ best interests, rather than just solely to make as much money as they can.

For instance, while living in California in 2011, I purchased a product called Dave’s Killer Bread, which was a heavily seeded, reasonably priced, supposedly organic bread that was almost literally flying off the shelves at a local grocery store chain. The company making the bread was based in Oregon and staffed by many individuals with criminal backgrounds.

Although I liked the idea of supporting an organization giving people a second chance, that bread made me feel remarkably sick – that is, basically the same as I did when eating various non-organic food. Being still young and naive at the time, I concluded that since organic food “couldn’t be contaminated with glyphosate,” the problem instead must have been that the company was buying cheap organic flour contaminated with mycotoxins and that I was reacting to that.

In 2016, however, a report of glyphosate testing in various breakfast foods revealed that a whole-wheat organic loaf of Dave’s Killer Bread had tested at 136.4 ppb. While this was not nearly as high as the non-organic Quaker instant oatmeal also tested in the study (1327.1 ppb), it is still what I consider to be unacceptably high (e.g. high enough to exceed the maximum allowable limit for glyphosate contamination of grain in Taiwan and other countries).

Now that I have looked at large amounts of glyphosate testing data, it seems to me that this is a level that is unlikely to have occurred just through pesticide drift or rainwater contamination. Rather, it seems to me more likely that there is some kind of systematic problem going on, where flour that is grown non-organically is somehow making its way into the bread.

A little more than a year ago, while still young and naive, I spent a more than an hour at an agricultural conference talking to a local organics inspector about his work. He told me that it was like being a sheriff in a small town, like Mayberry on the old Andy Griffith show – that is, that even though you were keeping your eye out for problems, it was not too hard of a job because there really was no crime to begin with.

Right after that, though, I read about a $140 million scam in which non-organic corn and soybeans from Nebraska were successfully sold as organic for a period of more than seven years by a Missouri businessman.

Which does make me wonder: Is the organic industry really like a small town where there is no crime? Or is it instead that there is actually a lot of crime going on, but that it is going unnoticed because no one is really looking for it?

I thought of this just the other day, when I tried an organic cake mix product that felt so toxic to me that I felt obliged to spit it out into the garbage can. Even though I felt like it was contaminated with glyphosate, there was not any easy way for me to prove it, and even if I did get it tested and the level came up really high, there likely would not be any consequences for the cake manufacturer at all. (Or at any rate, there don’t seem to have been any consequences for Dave’s Killer Bread having been revealed as having a lot of glyphosate contamination.)

Another news story that caught my attention recently was a lawsuit filed by a consumer against Bob’s Red Mill, with regard to glyphosate contamination in its oat products. The plaintiffs suggested that since the company was making health claims on its label, it also should have revealed the presence of the chemical so that consumers could make an informed decision:

Instead, they say, the Oregon-based company labeled the products with phrases such as “gluten free,” “wheat free” and “purity tested,” leading consumers to believe them to be healthy.

“Consumers have a reasonable expectation that material product information, such as the presence of a probable carcinogen like glyphosate, will be provided by a product manufacturer, especially when the manufacturer affirmatively identifies the health-related attributes of its products such as “Gluten Free”, “Whole Grain”, and “Friend of the Heart,” the complaint states, adding that the labeling amounts to “misleading half-truths.”


Despite the fact that that case was settled out of court (without terms being disclosed) a few months ago, I still have quite a few concerns about Bob’s Red Mill products of my own. For instance, I have yet to come across any grain products from the company that have felt good to me, and I also am not very happy about the fact that the company was selling oats treated with glyphosate as a pre-harvest desiccant until 2016 (and then only changed its policy after customers insisted that it do so).

Pamela’s – another company with a strong focus on gluten-free grain grain products with a few organic items – appears to be even less concerned about glyphosate contamination than Bob’s Red Mill.  Their initial response to my initial query was to just state that they were in compliance with FDA requirements, and then when I expressed some concern that 30,0000 ppb was a huge amount of contamination, the response from the customer service department was as follows:

The health and well-being of our consumers is our utmost priority, and Pamela’s Products sources quality ingredients for all of our products. We are very aware of the glyphosate concerns and challenges regarding growing crops today. Per our request, our vendors test the oats supplied to Pamela’s. Both the organic and conventional oats supplied by our vendors are well within the allowable standards set by the FDA. The most recent shipments came in at less than 0.33 parts per million while the FDA standard is up to 310 parts per million. We are hopeful that the government will disallow Glyphosate to be used as a desiccant in oat farming in the near future.


Unless I have missed something, I don’t think that they are right that the FDA standard for food intended for human consumption is up to 310 ppm (which would be 310,000 ppb); to my understanding it is actually 30 ppm (30,000 ppb).

In addition, I don’t think that 0.33 ppm (which is 330 ppb) is even close to a level that I consider to be acceptable in a food product that is targeted at people with chronic health concerns such as gluten sensitivities.

The fact that Pamela’s is not even making a nominal effort to keep contaminated grain out of their products does explain to me they the items of theirs that I have tried over the past several years have felt so bad to me, however.

Although the lack of concern with regard to glyphosate contamination demonstrated by supposedly health-oriented companies like Pamela’s is unfortunate, when taken in context of the position of the agricultural industry in general it is not a very big surprise at all though.

For instance, as of this writing (5/25/19), the Prairie Oat Growers Association continued to promote on its website a “fact sheet” insisting that people should not be concerned about glyphosate contamination at all:

Canadian oat growers aim to produce the best quality oats, and it all starts in the field. Oat farmers work to grow a quality crop that is sustainable and safe.

Glyphosate is one product commonly used by farmers to effectively control grass weeds prior to planting or after wheat is harvested. It also reduces disease and natural contaminants. Using this product also makes it possible to use reduce ploughing, which protects soil and water.

Soil quality and good water use is important around the world. The Keep it Clean campaign reminds farmers to only use crop protection products (pesticides) that have been registered for use in Canada and to always follow the rates and timing listed on the label. Canadian farmers continue to look for ways to reduce chemical use on their farms, as it is an added cost to them and therefore it is only used when necessary. Canadian oat growers take consumer health seriously. 

Any levels of glyphosate that may remain after processing are trace amounts and significantly below any limits which have been set by the Environmental Protection Agency (EPA) and international bodies as safe for human consumption.

Glyphosate is much safer than many things found in most kitchen cupboards. For example, research demonstrates that the potential toxicity of common products like vinegar, baking soda, and coffee are higher than that of glyphosate. As research has shown, there are trace amounts of glyphosate found in many products. While not zero, it is important to note that one in a billion is the equivalent of 1 second in 32 years, or an incredibly small amount of the product.


On the other hand, Nature’s Path – a huge organic grain producer based in Canada – is in many ways a model company. For instance, all of its products are organic; it was instrumental in the development of the Non-GMO Project Verified label; has put quite a lot of money and effort into lobbying against GMO’s, glyphosate and pesticides in general; and produces some non-oat products that I really like.

And yet, as is also the case with Bob’s Red Mill’s organic oat products, Nature’s Path oat products often test positive for low levels of glyphosate and almost always have felt problematic enough that I do not want to each much or any of them when I have tried them.

While I am not sure what is going on with Bob’s Red Mill, I feel pretty sure with Nature’s Path that the company is doing everything that it can to keep glyphosate out of its products and that the contamination is due to the crops being hit by pesticide drift or rainwater due to the large amount of glyphosate being used in Canada as a pre-harvest desiccant during the fall months.


Company Website Discussion:

Bob’s Red Mill

Nature’s Path


Mycotoxins & Cholesterol