You are standing in the grocery store, looking at two bottles of olive oil. One is in a dark glass bottle. One is in a clear plastic bottle — or worse, one of those trendy squeeze bottles everyone seems to be using right now. The plastic one is cheaper and easier to handle. So what is the big deal?
The big deal is that plastic packaging and olive oil are a genuinely bad combination — and the research to support that is not fringe science. It is peer-reviewed, published in major food science journals, and the findings are consistent: plastic leaches chemicals into olive oil, and the longer the oil sits in plastic, the worse it gets.
Here is what the science actually says.
What Happens When Olive Oil Sits in Plastic
Plastic containers — particularly PET (polyethylene terephthalate) and PVC — contain chemical compounds called phthalates. Phthalates are plasticizers, added to plastic since the 1930s to make it flexible, durable, and extensible. The critical problem is that phthalates do not form stable chemical bonds with the polymers they are added to. They sit loosely within the plastic matrix, which makes them susceptible to migrating into whatever the plastic is in contact with.
Olive oil is particularly vulnerable. Phthalates are lipophilic — they dissolve readily in fats and oils but have very low solubility in water. This means that when a fatty food like olive oil comes into contact with plastic, phthalates move from the container walls into the oil at a much higher rate than they would into a water-based product. The migration accelerates significantly under heat, UV light exposure, and prolonged storage — exactly the conditions a bottle of olive oil on a grocery store shelf or kitchen counter experiences every day.
What the Research Found
Multiple independent studies have now documented phthalate contamination in commercially sold olive oil.
A study analyzing olive oil samples from the European market found that DEHP and DINP — two of the most common and concerning phthalates — were detected in all samples tested, with average concentrations of 1.31 and 1.52 mg/kg respectively. Four out of 16 samples showed DEHP concentrations exceeding the migration limits established under EU food contact materials regulation. Three of those four samples were extra virgin or virgin olive oils — the highest grade products, which consumers reasonably expect to be the cleanest.
A separate study tracking plasticizer contamination across the entire olive oil production process found that concentrations progressively increased at each stage — from the olive fruit itself through processing and into packaging. Crucially, while glass and plastic bottles showed similar contamination levels at six months, plastic-packaged samples showed significantly higher plasticizer concentrations after 18 months of storage. The researchers concluded that prolonged storage in plastic bottles should be avoided.
A third study on phthalate occurrence in foods confirmed that olive oil's contribution to overall dietary phthalate exposure is relevant, given how frequently and generously it is used, and that contamination can occur at multiple points in the production and storage chain — not just from the final packaging.
Bisphenol A (BPA) Is Also a Concern
Phthalates are not the only chemical compound that migrates from plastic into olive oil. A study examining BPA migration from plastic packaging into Moroccan extra virgin olive oil found BPA levels above the daily intake limits set by the European Food Safety Authority in olive oil stored in both polycarbonate (PC) and polyethylene (PE) plastic bottles — reaching 0.238 ppm in PC bottles and 0.144 ppm in PE bottles.
BPA is a known endocrine disruptor. Even at low levels, it interferes with hormonal signaling. The EFSA has set its tolerable daily intake at 0.2 nanograms per kilogram of body weight per day — an extremely low threshold that reflects how seriously regulators take even trace exposure. The fact that detectable BPA levels persist in human samples globally underscores that dietary exposure through food packaging is a real and ongoing concern.
Why Olive Oil Is Especially Vulnerable
Not all foods are equally affected by plastic packaging. What makes olive oil particularly susceptible is its fat content. Phthalates and BPA are both lipophilic — they preferentially dissolve into fatty substances. The higher the fat content of a food, the more readily these compounds migrate from plastic into it.
Olive oil is essentially pure fat. There is no water content to dilute or slow the migration process. Combined with the fact that olive oil is often stored for months before being used, and that bottles are frequently left near heat sources in the kitchen, the conditions for chemical migration are essentially ideal.
The research on phthalates also notes that migration is accelerated by acidic environments, high temperatures, sunlight exposure, and long-term storage — all of which a plastic bottle of olive oil regularly encounters between the producer, the distributor, the grocery store shelf, and your kitchen counter.
What About the Squeeze Bottle Trend?
If you have been on food social media recently, you have seen the olive oil squeeze bottle — typically a soft plastic bottle designed for easy pouring. The trend is real and the convenience is genuine. But from a chemical safety and quality standpoint, squeeze bottles present compounding problems.
First, most squeeze bottles are made from soft, flexible plastic — exactly the type that requires the highest concentration of plasticizers to achieve that flexibility. More plasticizer content means higher migration potential into the oil inside.
Second, squeeze bottles work by squeezing air out and letting it back in as you use them. Every time air re-enters the bottle, it introduces oxygen — one of the primary drivers of olive oil oxidation. This progressively degrades both the flavor and the polyphenol content of the oil over time. The antioxidants and anti-inflammatory compounds that make extra virgin olive oil nutritionally valuable are among the first things to degrade when the oil is repeatedly exposed to oxygen.
Third, most squeeze bottles are clear or lightly tinted — meaning the oil inside is exposed to light, another major driver of oxidation and polyphenol loss.
The squeeze bottle solves one problem (convenience) while creating three others (chemical migration, oxidation, and light exposure). It is not a trade-off worth making.
What Plastic Does to Olive Oil Quality Beyond Chemistry
The chemical contamination issue is serious on its own. But plastic packaging also degrades olive oil quality in ways that are measurable at the product level.
Research analyzing commercial olive oils across multiple packaging types found that a sample of extra virgin olive oil packaged in PET plastic exceeded the K270 limit for extra virgin classification — meaning the oil had oxidized to the point where it legally should have been classified as lampante, the lowest grade, unfit for direct consumption. It was labeled and sold as extra virgin.
This is not an isolated finding. The mislabeling problem in the olive oil industry is well documented, and plastic packaging that accelerates oxidation is one of the factors that contributes to oils degrading below their labeled grade before they ever reach a consumer.
Why Dark Glass Is the Right Choice
Glass is chemically inert. It does not leach compounds into the oil it contains. It does not interact with the acidity of olive oil or accelerate under heat. A glass bottle of olive oil sitting in the same conditions as a plastic bottle will not contaminate the oil inside with plasticizers, BPA, or any other migrating chemical compound. There is simply no migration pathway.
Dark glass adds another layer of protection. Ultraviolet light degrades polyphenols and accelerates oxidation — the same process that turns a fresh, peppery oil flat and stale. Dark glass blocks UV light, significantly slowing this process and extending the window during which the oil remains at peak quality.
This is why every bottle of EXAU olive oil is packaged in dark, heavy glass. Our bottles weigh approximately two pounds — not because we are trying to make an impression, but because the glass is genuinely thick and protective. It is the right container for a product we have spent a year farming and producing carefully. Putting it in plastic would undermine everything that happens before it reaches you.
We also ship directly to you from our temperature-controlled warehouse in the US — no distributor split, no months under fluorescent lights in a grocery store. The oil travels from our family's groves in Calabria to our US storage facility, where it is held in controlled conditions until it ships to your door. The supply chain is where most olive oil loses its quality. Dark glass and direct-to-consumer shipping are how we protect what we make.
What To Do With the Plastic Bottle You Already Have
If you currently have olive oil in a plastic bottle at home, use it up quickly. Do not store it for months. Keep it away from heat and direct light. And when you replace it, choose dark glass.
If you have a squeeze bottle you love for the convenience, transfer a small amount of oil from your dark glass bottle into a ceramic or stainless steel pourer for daily use. You get the ease of dispensing without leaving your oil sitting in plastic long-term.
Frequently Asked Questions
Is it safe to store olive oil in plastic?
Short-term storage in high-quality food-grade plastic is unlikely to cause immediate harm, but research consistently shows that phthalates and BPA migrate from plastic into olive oil over time, particularly under heat and light. Prolonged storage in plastic should be avoided.
What type of bottle is best for olive oil?
Dark glass is the gold standard. It is chemically inert, does not leach compounds into the oil, and blocks UV light that degrades polyphenols and accelerates oxidation. Tins are also acceptable for storage but cannot be inspected for color or clarity.
Are squeeze bottles bad for olive oil?
Yes, for two reasons. Most squeeze bottles are made from soft plastic with high plasticizer content. They also allow air back into the bottle each time you use them, which progressively oxidizes the oil and degrades its flavor and nutritional value.
What are phthalates and why are they in olive oil?
Phthalates are chemical plasticizers added to plastic to make it flexible. They are not chemically bonded to the plastic, so they migrate into fatty foods like olive oil that come into contact with plastic containers. They are known endocrine disruptors and are regulated in the EU due to health concerns.
Does BPA get into olive oil from plastic bottles?
Research has found BPA levels above EFSA daily intake limits in olive oil stored in both polycarbonate and polyethylene plastic bottles. BPA is a known endocrine disruptor. Dark glass eliminates this risk entirely.
Shop our 100% Italian extra virgin olive oil, bottled in heavy dark glass, shipped direct from Calabria.
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