Are microplastics in olive oil harmful?

The research on long-term health effects is still developing, so the honest answer is caution rather than alarm. The smallest particles may be absorbed into tissues, and the plastics they come from can carry additives such as phthalates and bisphenols that are studied as endocrine disruptors. For a food many people consume daily, reducing avoidable exposure is a sensible default while the science matures.

How do microplastics get into olive oil?

Mostly during milling and processing, not from the bottle. Conventional production often runs the oil through plastic hoses, valves, and storage that can shed particles, and some contamination is already present in the environment before harvest. This is why a 2024 study found no significant difference between glass and plastic packaging.

Does glass olive oil contain fewer microplastics than plastic?

Not according to the current evidence. The 2024 analysis of oils from Italy and Spain found no statistically significant difference in microplastic content between glass and plastic packaging, because most of the contamination enters upstream rather than from the container.

Can microplastics be filtered out of olive oil?

There is no practical way for a consumer to remove them, and filtering finished oil is not a reliable answer. The real lever is preventing contamination during production, by keeping plastic out of contact with the oil at the mill, and then testing the finished oil to confirm it.

How do I choose an olive oil with fewer microplastics?

Ask how the oil is milled and stored rather than only what the bottle is made of, look for a producer that tests for contaminants, and favour transparency about production methods and lab results.

Are There Microplastics in Your Olive Oil?

Nicolas Netien
May 12, 2025
4 min read

Updated: Jul 15

By Nicolas Netien, Chief Scientist and co-founder of Oleaphen.

Quick answer:

Yes, microplastics are found in almost every olive oil tested, and the bottle is not the main source. A 2024 study found no meaningful difference between glass and plastic packaging, which means most of the contamination happens earlier, during milling and processing. A separate problem, chemical plasticizers leaching out of bottle caps, is where packaging genuinely matters, and it is one I have measured myself. The way to get a clean oil is to control the mill, keep plastic out of contact with the oil, and test the finished product rather than trusting the container.

Why I take this seriously

In more than fifteen years working with olive oil, I have visited a lot of mills. Enough to know that the gap between how olive oil is imagined and how it is actually made is wide. People picture stone presses and clean tanks. The reality is often plastic hoses, plastic valves, and plastic storage, all in contact with an oil that happens to be one of the best solvents for plastic additives you could design. That is the context for the recent research on microplastics, and it is why the findings did not surprise me.

What the research found on microplastics in olive oil

A 2024 analysis of commercial vegetable oils from Italy and Spain, including extra virgin olive oil, examined oils in both glass and plastic packaging. Every sample contained microplastics, at a mean of 1,140 particles per litre. Most were fragments smaller than 100 micrometres, and polyethylene and polypropylene, the plastics common in food packaging, made up the majority.

The result that changes how you should read this: there was no statistically significant difference between glass and plastic packaging. The bottle, in other words, is not the main culprit. The oil is picking up plastic earlier, during production and processing.

A separate 2023 study of oils in PET bottles reported far higher counts, between roughly 134,000 and 580,000 particles per litre, with over 80 percent of the particles smaller than 10 micrometres.

Why it matters

Research on the long-term health effects is still developing, so my position is caution rather than alarm. The smallest particles may be absorbed into tissues, and plastics carry additives such as phthalates and bisphenols that are studied as endocrine disruptors. For a food many of us consume every day precisely for its health value, reducing avoidable exposure is a sensible default while the science matures.

What I found in our own testing

This is the part that shaped how we package. We run a plastic-free production process, so I expected our oil to come back clean. To check the container side, we took that oil and stored it in glass bottles, the packaging most people assume is the safe choice. When we tested it, we found plasticizer in the oil. It had migrated out of the lining of the cap.

The glass was innocent. The closure was not. That is the point almost everyone misses about glass: a glass bottle cannot seal itself. It needs a cap, and the cap is usually a plastic-lined gasket sitting in direct contact with the oil for months. Because olive oil draws these compounds out of plastic far more readily than a water-based food would, the closure becomes the weak point even when the bottle is perfect.

The wider literature backs this up. European enforcement laboratories have repeatedly documented plasticizers migrating from lid gaskets into oily foods in glass jars, in some cases above the legal limit. I have written about that record in detail in a companion piece on what actually contaminates olive oil.

How we approach purity at Oleaphen

We built our process around the parts that actually drive contamination rather than around the bottle.

Our extraction and storage are plastic-free, which is the highest-leverage step given that most contamination is upstream of packaging. We hold the oil under a continuous cold chain, which protects the polyphenols and slows the chemistry of any migration. And we test the finished oil for contaminants, rather than asking you to take purity on trust.

The packaging follows the same logic. We moved away from bottles years ago, so there is no separate plastic cap resting in the oil. For the harvest ahead, our monodose format is made from 100 percent recycled aluminium with a food-grade internal coating, so the oil never touches the metal, and it opens with a snap-off tip. No plastic anywhere. If you would like to be notified when it is available, you can join the waitlist.

How to choose a cleaner olive oil

Whether you choose Oleaphen or another producer, a few practical guidelines help:

Ask how the oil is milled and stored, not just what the bottle is made of, since most contamination is upstream of packaging.
Ask what sits in contact with the oil, including the cap liner, which is where plasticizers usually enter.
Look for real testing, both for contaminants and for polyphenol content, ideally by an independent laboratory.
Store oil away from light and heat to protect the polyphenols and slow migration from any surface it contacts.
Favour transparency, and producers who openly share their methods and their lab results.

The real question

Learning that microplastics are in almost every olive oil is unsettling, but it also clarifies what to ask. The bottle is a decision about one surface. A clean oil is a decision about every surface the oil touches, from the grove to your hand. After fifteen years, that is the difference I care about most, and it is the one you cannot see on a label. You have to test for it.

About the author

Nicolas Netien is the Chief Scientific Officer and co-founder of Oleaphen. He has worked with olive oil for over fifteen years, visiting mills across the Mediterranean and building a production process designed to protect the polyphenols that give high-phenolic olive oil its value. He oversees cultivation, extraction and preservation and interprets the laboratory analysis behind every harvest. He holds the world record for the highest polyphenol concentration ever measured in olive oil, at 4,943 mg/kg, set with the 2018 harvest.