Toxins in Coffee: What Pesticides and Herbicides Could Be In Your Morning Cup?

As much as 60% of America enjoys a cup of coffee every morning. And, coffee enthusiasts usually have more than one cup a day.

While most people enjoy a morning brew for the flavor, many of the chemicals found in coffee, such as chlorogenic acid and caffeine, also have or may have health and productivity benefits. 

But the substances in and on coffee aren’t all the same, and many standard grocery store coffees contain ingredients most of us wouldn't be thrilled to be ingesting, including pesticides, mycotoxins, and herbicides, all of which CAN be toxic in large enough quantities.

Chemicals In Coffee

Let's set one thing straight: the term "chemicals" doesn't necessarily mean "bad". A chemical is any substance that has a defined composition: water is a chemical (a naturally formed chemical), while chlorine is a man-made chemical.

There are many "chemicals" in coffee, from oils to acids like caffeic acid, to antioxidants or the revered caffeine, which is a Xanthine (the technical name is indeed scary). The point is that you shouldn’t be scared simply because your coffee contains chemicals. 

You should be worried, perhaps, about toxins, which by definition can negatively impact your health. 

The main toxins in coffee are those that are added or increase during the production process. These are most commonly pesticides and herbicides. Others, like fungal toxins, develop after harvesting. Some can even form during the roasting process. 

Pesticides, Herbicides, and Fungicides: Oh My!

The following are all common man-made or synthetic substances used in large-scale farming:

• Pesticides are chemicals sprayed on coffee plants to kill insects or similar organisms that might be harmful to the growth of the crop
• Herbicides kill or prevent the formation of counter-productive weeds and can be sprayed on or below the plant to prevent weed formation
• Fungicides prevent fungi and molds from forming on the plant or plant product

Because coffee is such a high-priced commodity, and coffee farmers tend to be in poorer, more rural areas of the world, it’s natural that they try to ensure the safety of the coffee plant at all costs: synthetic chemicals are a common go-to worldwide.

But that's not the case everywhere, and choosing certified organic coffee is one way to reduce or eliminate the amount of synthetic chemicals and potential toxins on and in your coffee.

Common Man-Made Chemicals In and On Coffee Beans

Farmers use dozens of pesticides, herbicides, and fungicides in conventional coffee agriculture. Here are some of the most commonly used and found in and on coffee.

1. Glyphosate: a common herbicide used to control unwanted weeds, also known in the U.S. and Roundup®
2. Mancozeb: used to prevent fungal disease in plants
3. Endosulfan: an insecticide used mainly to kill coffee borer beetles
4. Atrazine: an herbicide applied on broadleaf weeds
5. Chlorpyrifos: a standard herbicide used to control insect infestations

What's the problem with pesticides on coffee you ask?

The World Health Organization classified glyphosate as a probable carcinogen in 2015. Other studies have concluded that this herbicide disrupts endocrine function and can alter the reproductive system. 

It doesn’t stop there though. Many man-made herbicides and pesticides may not only be toxic for you, but also tend to damage the environment. Glyphosate contaminates the water supply and may have a half-life of more than three months, meaning it remains unaltered and circulating in the environment for far longer than scientists anticipated when we started using it. It also appears to contribute to diminished soil quality.

Unfortunately, the bad news is that pesticide and herbicide use is on the rise: as plants and insects become more resistant, farmers respond by spraying more to get the same results. 

Mycotoxins in Coffee

Mycotoxin is the umbrella term for compounds produced by molds and fungi, which sometimes form after or during the coffee harvesting process. 

Technically speaking, they’re called metabolites. Just like we produce sweat, fungi produce metabolites that can have widely different effects on us. Some can be beneficial, like the proposed anti-cancer properties of turkey tail mushrooms, but in the case of many molds, they are frequently always toxic to us.

One of the most prevalent mycotoxins found on coffee is Ochratoxin A, which studies show is toxic to your kidneys, brain, and immune system. It is a metabolite of certain fungi that are prevalent on coffee plantations. Aflatoxin B1 is another mycotoxin that is highly carcinogenic.

Why are these fungi there? Molds love heat, humidity, and organic material! The areas where coffee grows are basically the world’s perfect fungal breeding grounds.

The good news is that studies have repeatedly shown the concentration of these mycotoxins is so low that we can barely measure it. This 2015 study concluded that there is no potential risk for consumers. This is not only due to the low amount naturally found in coffee, but also due to the fact that the roasting process destroys many mycotoxins. 

Still, your best bet to avoid unwanted contaminants is to buy organic coffee beans from certified organic farms or roasters.

Does Roasting Create Toxins In Coffee?

Quick answer, yes.

There are a few potential toxins that appear during the roasting process, the most important of which is acrylamide, a lethal neurotoxin and carcinogen to mammals like us. 

It isn’t only in coffee though, and it’s in most roasted foods(!), particularly starchy foods. It forms when sugars react with amino-acids, and coffee develops it in trace amounts during the roasting process.

A quick review of the research suggests that scientists can’t agree on just how much extra acrylamide we ingest due to coffee. A small 2020 study conducted in Turkey concluded that the exposure levels merit no concern. A more recent study concluded that acrylamide levels in coffee were higher than the European Reference level, warranting some level of concern and monitoring due to its high toxicity.

With this conflicting evidence, what can you do apart from buying certified organic coffee?

You’re in luck. Studies show that choosing high quality coffee beans, roasting at higher temperatures, and using shorter brewing methods all contribute to less acrylamide in your coffee.

Pesticide Regulations and Standards

This is a key point in the quest to reduce your exposure to harmful chemicals, and sadly one that not many people fully understand.

The U.S. has fairly lax standards for the Maximum Residue Levels (MRLs) or Maximum Residue Limits of pesticides and herbicides in coffee beans compared to much of the world.

Imported green coffee beans can have a maximum glyphosate level of 1 part per million (1PPM) in coffee. 

There is also the problem of the MRL gap between exporting and importing countries. For example, a coffee-growing country like Brazil might have an internal standard of 5mg of pesticides per kilogram of green coffee beans, and an importing country like the United Kingdom might have a standard of 1mg per kilogram.

This all goes to say that coffee regulations are not standardized worldwide. Some coffee growing countries in less developed regions still use enormous amounts of pesticides and chemical fertilizers, while others have banned them completely.

Chemicals in Your Coffee

Let’s do a quick roundup of the primary toxic (or potentially toxic) chemicals that could be in your coffee.

1. Herbicides like glyphosate
2. Mycotoxins like Ochratoxin A: due to the natural climate of the coffee belt, coffee may be more susceptible to molds that produce these potentially carcinogenic and neurotoxic compounds
3. Acrylamide: roasting creates this toxin out of sugars and proteins present in most foods, and coffee tends to have higher levels

How Organic Coffee Beans Can Help

When it comes to coffee, the single best thing you can do to protect yourself and reduce exposure to toxins is buying certified organic coffee from reputable vendors.

While USDA organic isn't perfect, it prohibits the use of synthetic inputs. Broadly speaking, organic farms are more sustainable and friendly to the surrounding biosphere and worldwide community than conventional farming practices. 

Ideally, we think your morning cup of brewed coffee should be largely free of the synthetic inputs that conventional coffee production processes often rely on!

And while organic farming isn't a perfect solution – which is why we work hard to partner with growers focused on more than just certification – it's a great step in the right direction.

If all these things concern you, focus on sourcing trusted, organic coffee from roasters who have direct relationships with their coffee growers.

Start Your Day With The Best Organic Coffees From Philly Fair Trade

With all this in mind, here are some Philly Fair Trade top picks for the best organic coffees.

Philly Fair Trade’s Peru Coffee

Our Peru coffee beans are grown in the famous Cajamarca region by families who have been following traditional farming practices for centuries. These coffee farms use a model of organic agriculture and organic farming that aims to reduce our collective impact on the environment. Our darker french roasting process highlights its smokey toasted walnut and cinnamon flavors.

Philly Fair Trade’s Colombia Coffee

If you prefer a brighter flavor, look no further than our Colombia blend, which has tart and bright notes with a fragrance of toasted almond. This one is grown in the Kachalu region, known for growing coffee to the water-saving and anti-deforestation standards of the Rainforest Alliance, ensuring farmers are being socially responsible as well as environmentally friendly. You can buy this organic coffee ground as coarse or fine as you like – for a perfect coffee cup no matter how you do your brew.

Looking to Learn More?

We're a Central PA coffee roaster committed to fair trade and sustainable coffees. Learn more about our commitments and get wholesale coffee pricing by clicking here.