Is Using K-Cups Unhealthy? Toxic Single Serve Coffee Pods
Don't get microplastics percolating in your coffee. Avoid single-serve plastic coffee pods. Hot water and coffee acidity can cause microplastics to leach into your brew. Learn more about making a safe cup of coffee so you can avoid microplastics in K-cups.

For millions of people, nothing gets the day going quicker than a cup of coffee.
Keurig has made this even faster with the invention of K-cups. These disposable coffee pods may get you perky in the morning, but there are very few perks to consuming a hot mug of K-cup coffee. Consuming K-cups and microplastics has become a growing concern, with these tiny plastic particles potentially leaching into our morning brew. Not to mention, coffeemakers are susceptible to mold growth, which has caused what many are calling “Keurig sickness.” So ditch the K-cups for good and learn how to brew a safe cup of coffee with us!
What Are K-Cups and Keurig?
Keurig is a brand that produces coffee makers that can brew coffees from single-use containers, known as “pods.” Anything that fits into a Keurig pod and is used to make coffee is known as a K-cup.
Keurig also makes coffee in pods that are known as K-cups. So, K-cups are often referred to interchangeably in a way that Kleenex is used to describe a tissue, even if you’re using a Puff’s.
In this article, we refer to K-cups as any pod that fits into a Keurig machine or any single-serve coffee machine. This is an important distinction because Keurig’s coffee pods are not made with BPA. However, other coffee pod brands may use BPA or other bisphenols.
So, when we are referring to K-cups in this article, we are not talking about Keurig’s coffee or product. We are talking about plastic pods, which are dangerous to your health.
Why Plastic K-Cups Are Dangerous
Single-serve coffee pods have revolutionized the way millions of people consume coffee daily. They provide unparalleled convenience and a wide variety of flavors at the touch of a button.
The ability to brew a single cup of coffee quickly, without the hassle of measuring grounds or cleaning filters, has made Keurig machines a staple in homes and offices across the country. However, the truth about K-cups is far more concerning than their convenience might suggest.
K-Cups are typically made of:
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A plastic outer shell
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An aluminum lid with colored ink
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A filter made with paper and plastics that holds coffee grounds
When a Keurig machine operates, it punctures the K-Cup and forces hot water through it at high pressure. This process, while efficient for brewing, creates an environment where chemicals from the plastic, ink, and aluminum components can potentially leach into your drink.
The combination of heat, pressure, and the acidic nature of coffee increases the likelihood of harmful substances, including microplastics, making their way into your cup. K-cups and microplastics have become a growing concern, with these tiny plastic particles potentially affecting our health over time.
Beyond the potential health risks, K-Cups pose a significant environmental hazard. It was estimated that over 9 billion K-Cup pods ended up in landfills in 2014 [1].
These disposable coffee pods aren’t biodegradable. It can take hundreds of years for these plastic pods to decompose. Over time, the chemicals used to create K-cups can contaminate water, air, and soil in the process.
As they break down, they release harmful chemicals and microplastics into the environment, further exacerbating pollution issues. The sheer volume of waste generated by these single-use pods has led some cities to ban their use in government buildings, highlighting the urgent need for more sustainable coffee consumption practices.
Health Concerns Over K-Cup Chemicals
Don’t inject your coffee with harmful chemicals. Kick your K-cup habit to the curb.
K-Cups and other coffee pods have raised significant health concerns due to the potential leaching of harmful chemicals into brewed coffee. While many K-Cups are now made from BPA-free plastic, even "safe plastics" can release potentially harmful substances when exposed to hot water. Let’s take a closer look at the chemicals used in K-cups and potential health concerns.
@million_marker Ditch the plastic and give French Presses, Drip/Pour Over Coffee, and Espresso makers a try! #coffee #coffeetiktok #health #science #plasticfree #fyp #tiktokban #viral #trending ♬ original sound - Million Marker
Microplastics and Endocrine-Disrupting Chemicals
Prior to 2020, K-cups were created using #7 plastic. This is a catch-all category for mixed plastics, which means that a large variety of harmful chemicals could be present in old K-cups.
However, Keurig has transitioned to #5 plastic, which is polypropylene. The reason for this change was to address the 9 billion K-cups in landfills. #5 plastic is easier to recycle than #7, making it a seemingly more eco-friendly choice [2].
However, polypropylene breaks down into microplastics quite readily. In fact, propylene releases a substantial amount of microplastics when introduced to hot water at boiling point, which is 212°F [3]. While Keurig machines typically reach 192° F, these are still extremely high temperatures that are capable of causing chemical reactions that alter plastics [4].
Not to mention, water also increases the release of microplastics from polypropylene. One study found that water increased the biodegradation of polypropylene to microplastics threefold [5]! Seeing as water is the primary ingredient, this puts K-cup drinkers at a significant risk of drinking microplastics.
Microplastics are a significant source of endocrine-disrupting chemicals (EDCs) that can interfere with the body's hormone systems. These tiny plastic particles can leach harmful chemicals such as bisphenols, phthalates, and other additives used in plastic production, which have been linked to various health issues [6].
The health effects of microplastic-associated EDCs include:
- Reproductive disorders
- Cancer
- Diabetes
- Obesity
- Metabolic disorders
- Thyroid problems
- Neurodevelopmental issues in fetuses and children
Alarmingly, microplastics can not only release their own chemical additives but also absorb and accumulate other toxic compounds from the environment, potentially amplifying their harmful effects on human health. And microplastic particles themselves have been shown to be damaging to health [7].
Filters Made of Polyethylene and Polypropylene
Filters are essential for making a smooth cup of coffee, free from coarse grounds. In K-cups, paper filters are made with the support of polypropylene (which we’ve discussed) and polyethylene.
These plastics are fused together with the paper filter using heat. So, chemicals may already have started leaching into the grounds before you’ve even added hot water!
Aluminum Exposure and Neurotoxicity
Many disposable coffee pods are constructed with an aluminum lid. This lid is punctured so that hot water can steep over the grounds and percolate a hot cup of joe.
When this happens, aluminum chemicals can get mixed in the water and coffee ground combo, causing drinkers to sip down some extra aluminum.
There are increasing concerns about aluminum and neurotoxicity [8]. While research is still ongoing, it might be best to err on the side of caution when it comes to consuming heated aluminum.
Bisphenols in Ink and Hormone Disruption
Bisphenols, including bisphenol A (BPA), are commonly used in the production of printing inks and overprint varnishes for food packaging materials. These chemicals can be found in the plastic components of single-serve coffee pods.
When hot water punctures the aluminum lid of a K-cup, it creates an opportunity for bisphenols to leach from the plastic into the brewing coffee. This process is exacerbated by the high temperature of the water and the acidic nature of coffee.
Exposure to bisphenols has been linked to various health concerns, including endocrine disruption, reproductive disorders, developmental issues, and increased risk of certain cancers [9].
Do K-Cups Leach Chemicals?
Yes, K-Cups may leach chemicals into coffee during brewing. Hot water passing through the plastic cup can cause microplastics to enter the coffee and EDCs to contaminate your beverage.
This can happen even with BPA-free K-Cups. While Keurig says their products are safe and meet FDA rules, some experts advise caution.
This is especially true for people who drink multiple K-Cup coffees daily, as long-term exposure to these chemicals might have cumulative effects.
Are Plasitc-Free K-Cups Safe?
Plastic-free K-Cups, known as K-Rounds, have emerged as a promising alternative to traditional plastic pods. K-Rounds offer a seemingly safer option for coffee lovers.
Marketed as eco-friendly single-serve coffee pods, K-Rounds are typically made from a variety of plant-based materials, including compressed cornstarch, sugar cane, coffee bean skins, and paper pulp.
Some companies now use special plant-based plastics called PLA or PHA. These are different from regular plastic.
To make these materials stick together, they use:
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Special plant-based coatings
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Wrappers made from plant fibers
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Glues that break down naturally
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A method using sound waves to join pieces
Many people think these new materials are safer than regular plastic. However, there is still some cause for concern.
Some studies show that these plant-based plastics can have many different chemicals mixed together. Just like regular plastic, some of these chemicals could be harmful [10]. So, while these new materials seem better, we still need to be careful about using them.
Are Keurig Coffee Machines Toxic?
Keurig coffee machines have raised concerns about potential toxicity, primarily due to their plastic components coming into contact with hot water. Many coffee makers, including Keurigs, use plastic tubing and parts in their internal mechanisms. When hot water passes through these plastic components, there's a risk of chemicals leaching into your coffee.
The main issue lies in the interaction between heat and plastic. Hot water can cause plastic to degrade more quickly, potentially releasing harmful substances into your beverage.
Additionally, Keurig machines can harbor mold and bacteria if not cleaned regularly. A 2011 study found that 50% of coffee maker reservoirs contained mold or yeast [11]. Some people may experience adverse reactions to mold exposure, including stomach aches, respiratory issues, and other health problems.
Furthermore, the cleaning products recommended for Keurig machines often contain harsh chemicals and fragrances, which may include phthalates. These substances can potentially add more toxicants to your brewing process.
Considering these factors, it's generally advisable to opt for coffee-making methods that minimize plastic contact with hot water.
What Is Keurig Sickness?
It’s hard to shine while you rise when you’re downing toxic chemicals. "Keurig sickness" is an unofficial condition that refers to a range of symptoms that some people experience after consuming coffee from Keurig machines [12]. Some of the most common symptoms of Keurig sickness are due to mold and bacteria growth inside the coffee maker.
Keurig sickness symptoms can include:
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Headaches
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Nausea and vomiting
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Fatigue
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Skin rashes
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Eye irritation
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Stomach cramps
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Coughing
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Nasal congestion
The primary cause of Keurig sickness is the growth of mold and bacteria inside the machine's water reservoir and internal components. Keurig machines provide an ideal environment for mold growth due to the constant presence of moisture and lack of sunlight.
Mold can begin to grow in as little as 24 to 48 hours in a moist environment, and even allowing the machine to sit idle for a few days can lead to mold growth. The problem is worsened by the fact that many of the internal components of Keurig machines are difficult to access and clean thoroughly.
If you suspect that your Keurig machine may be harboring mold, it's best to err on the side of caution. While regular cleaning and maintenance can help prevent mold growth, once mold has established itself inside the machine, it can be challenging to eliminate completely. In such cases, it's advisable to replace your Keurig with a new coffee maker or consider alternative brewing methods that are easier to clean and maintain, such as a French press or pour-over setup.
Safe Alternatives to K-Cups for Brewing Coffee
Looking to move away from K-Cups due to health or environmental concerns? Swig safely with the peace of mind of brewing a low-tox cup of coffee.
There are many ways to make coffee without using K-Cups. Here are some easy options:
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French Press: This is a simple way to make coffee. You can get one made of steel or glass. It's easy to clean and lets you control how strong your coffee is.
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Pour-Over: This method uses a special cup with holes. You can change how fine you grind the coffee and how hot the water is. This makes a clean-tasting coffee.
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Percolator: This makes strong coffee. It's good for making a lot of coffee at once. They're usually made of steel and easy to clean.
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Cold Brew: This makes smooth coffee that's less bitter. You can make a lot at once using a glass jar or a special cold brew maker.
These methods are better for your health and the environment than K-Cups. Try different ways to find the one you like best!
Also, there are attachments to single-serve coffee makers made of stainless steel that can act as a pod for your coffee. These are a great way to get the same K-cup experience without swallowing potentially harmful chemicals.
Test Yourself for BPA and Phthalates
Disposable coffee pods, including K-Cups, have raised concerns about potential exposure to BPA and other EDCs. While many manufacturers now claim their products are BPA-free, they may still contain other bisphenols or harmful chemicals that can leach into your coffee. However, these pods are not the only source of exposure to such substances in our daily lives.
To understand your overall exposure to harmful chemicals, consider using Million Marker's Detect & Detox Test Kit. This mail-in test allows you to measure your levels of BPA, phthalates, and other EDCs through a simple urine sample.
After analysis, you'll receive personalized recommendations to help reduce your exposure to these chemicals. By identifying and addressing various sources of EDCs in your environment, you can take proactive steps to minimize your overall chemical burden and potentially improve your health.
Is It Safe to Drink from a Keurig?
Drinking from a Keurig may pose potential health risks. Recent studies suggest that K-Cups can leach chemicals, including EDCs and microplastics, into your coffee when exposed to hot water. While Keurig maintains their products are safe, some experts recommend caution, especially for frequent users, due to the cumulative effects of long-term exposure. Additionally, K-Cups may contain additives and artificial ingredients linked to various health issues and can harbor harmful mold. Given these concerns, it's advisable to consider alternative brewing methods.
Resources
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC7280196/
[2] https://www.keurig.com/recyclable
[3] https://www.sciencedirect.com/science/article/abs/pii/S0048969721067619
[4] https://support.keurig.com/?kmContentId=1012526&page=shell&shell=knowledge-article
[5] https://www.nature.com/articles/s41598-022-23435-y
[6] https://pubmed.ncbi.nlm.nih.gov/36726457/
[7] https://link.springer.com/article/10.1007/S13280-021-01589-9
[8] https://www.sciencedirect.com/science/article/abs/pii/S0048969723060801
[9] https://pmc.ncbi.nlm.nih.gov/articles/PMC6864600/
[10] https://phys.org/news/2020-10-bioplastics-substances-toxic-ordinary-plastics.html
[11] https://d2evkimvhatqav.cloudfront.net/documents/2011_NSF_Household_Germ_Study_exec-summary.pdf
[12] https://www.cnet.com/home/kitchen-and-household/coffee-lovers-its-time-to-clean-your-dirty-keurig-asap/