Olive oil is a fatty product that can remain in direct contact with its packaging for many months. For this reason, choosing a bottle is not simply a matter of appearance. It matters for protecting the oil from light and oxygen, but also for limiting the migration of chemical substances from packaging into food.
One of the most frequently discussed substances is bisphenol A — BPA.
What is bisphenol A?
BPA is a chemical compound used mainly in the production of hard polycarbonate plastics and epoxy resins. These materials have been used in coatings for cans, tanks and some types of food-contact packaging.
Bisphenol A can migrate in small quantities from packaging materials into food or drink. This process is known as migration. It may be increased by:
- long storage times,
- high temperatures,
- exposure to sunlight,
- worn or damaged packaging,
- contact with foods that contain a high proportion of fat.
In one study, olive oils stored in plastic containers contained, on average, more BPA than oils stored in non-plastic packaging. Higher concentrations were also observed after storage lasting more than one year. The authors noted that the estimated exposure at that time remained below the safety limit then in force. Since that study, however, European safety limits have been tightened very substantially.
Important: not every plastic bottle contains BPA
The most common single-use PET bottles are not normally manufactured with bisphenol A. BPA is primarily associated with polycarbonate plastics and epoxy resins.
That does not mean every type of plastic is completely inert. Depending on the polymer, additives, cap, coating, temperature and storage time, different substances may migrate into fatty foods. Research on olive oil stored in PET also indicates that elevated temperature and long storage can influence both migration from the packaging and the deterioration of the oil’s chemical and sensory properties.
The word “plastic” covers many different materials. Nevertheless, for a premium product stored for many months, the precautionary principle supports choosing dark glass or a suitable metal tin made specifically for olive oil.
How can BPA affect the human body?
Bisphenol A is described as an endocrine-disrupting chemical. It may imitate hormones, bind to hormone receptors and interfere with natural signals involved in development, metabolism and reproduction.
The European Chemicals Agency classifies BPA as toxic to reproduction and identifies it as a substance that disrupts the human endocrine system.
1. The hormonal system
Hormones help regulate:
- puberty,
- fertility,
- thyroid function,
- metabolism,
- brain development,
- immune responses.
A hormonally active substance may have effects even at low concentrations, particularly when exposure occurs during critical stages of development such as pregnancy, foetal life and early childhood. Some consequences may not become apparent until years later.
2. The immune system
In its 2023 reassessment, the European Food Safety Authority identified the immune system as the most sensitive to BPA. EFSA established a tolerable daily intake of only 0.2 nanograms per kilogram of body weight per day — 20,000 times lower than the previous temporary value.
EFSA also concluded that estimated dietary exposure raises a health concern for all age groups.
3. Female and male fertility
Research suggests possible links between BPA exposure and changes in ovarian function, ovarian reserve, follicle development and hormonal response. Epidemiological evidence is not equally strong for every condition and does not always prove a direct causal relationship.
In men, a meta-analysis of epidemiological studies found an association between higher BPA exposure and lower sperm concentration, lower total sperm count and changes in sex hormone levels. The authors also emphasised the limitations of the available evidence.
4. Brain development and children’s behaviour
Observational studies have linked prenatal BPA exposure with changes in behaviour, self-control, attention and some aspects of neurological development in children. Findings are not always consistent and may depend on the child’s sex, the timing of exposure and the method of measurement. Even so, they support particular caution during pregnancy.
5. Metabolism
Toxicological and epidemiological studies also indicate a possible association between BPA and disturbances in glucose and fat metabolism, body weight and the risk of metabolic disease. With observational studies, however, a statistical association does not necessarily prove that BPA directly caused the condition.
Who is most at risk?
Pregnant women and the developing foetus
This is the most sensitive group because the hormonal system guides the development of organs, the brain, the reproductive system and the immune system. Even a short exposure during a critical developmental window may matter more than a similar exposure in an adult.
Infants and young children
Children have a lower body weight, rapidly developing organs and immature mechanisms for metabolising certain substances. The same absolute amount of a chemical can therefore represent a higher dose per kilogram of body weight.
People planning a family
This applies to both women and men. Available research indicates that BPA may affect reproductive hormones, egg cells, ovarian function, semen quality and early embryo development.
People exposed regularly from multiple sources
BPA exposure may come not only from food packaging, but also from thermal receipts, can linings, polycarbonate plastics and other everyday products. Total exposure from many sources therefore matters.
Europe has said “no” to BPA
In December 2024, the European Commission adopted a ban on BPA in food-contact materials. The rules cover, among other things, certain plastics, can coatings, reusable bottles and equipment that comes into contact with food. Transitional periods apply to most products.
The ban also addresses other hazardous bisphenols so that BPA is not automatically replaced by a substance with similar endocrine-disrupting or reproductive toxicity.
Why does olive oil deserve glass?
Good extra virgin olive oil is sensitive to light, oxygen and high temperatures. A dark glass bottle:
- reduces the oil’s exposure to light,
- does not require plasticisers,
- is chemically stable,
- does not absorb odours,
- better reflects the character of a premium product,
- can be reused or recycled.
Glass does not solve every problem — olive oil should still be kept in a cool, dark place — but it is a sensible choice for protecting the product and reducing food contact with plastics.
Conclusion
Not every plastic bottle contains BPA, and olive oil sold in plastic is not automatically dangerous. Consumers should not be frightened, and science should not be oversimplified.
At the same time, BPA is officially recognised in Europe as an endocrine disruptor and as toxic to reproduction. EFSA’s latest assessment indicates that current dietary exposure may be a health concern across all age groups, with pregnant women, children and people planning a family deserving particular protection.
For premium olive oil that remains in its packaging for many months, dark glass is a responsible, safe choice that matches the character of the product.
Good olive oil should be protected not only from light and oxygen. It should also be stored in packaging we can trust.