For years as a consumer, I trusted that ingredients authorized in cosmetics had been extensively evaluated and were safe within established limits. But that's not always the case.
Parabens, used as preservatives to prevent the proliferation of bacteria and fungi, have been present in countless personal care products due to their effectiveness and stability. They are part of the history of modern cosmetics. However, some parabens have shown to have weak estrogenic activity, meaning they can act as endocrine disruptors by interacting with our hormone receptors. And when we talk about hormones, we're talking about an extremely delicate system.
Science has not demonstrated a direct causal link between the use of parabens and hormone-dependent cancer (especially breast cancer), but it is true that there are studies that have raised relevant questions and call for caution. And it was precisely in that space—between what we know and what we don't yet know—where, as the founder of Banbu, I decided to take a stand. And as always, to apply the precautionary principle.
What do the studies that found parabens in breast tumors really say?
When talking about parabens and breast cancer, it is often mentioned that "parabens have been found in tumors." But what exactly does that mean? What was investigated? And what real conclusions can we draw?
The study that opened the debate
In 2004, researcher Philippa Darbre and her team published a study in which they analyzed breast tumor samples and detected the presence of different types of parabens in most of them.
They identified methylparaben, ethylparaben, propylparaben, and butylparaben using very precise analytical techniques. It was a significant finding because it demonstrated something important: parabens could be absorbed and reach breast tissue in intact form.
This study did not say that parabens caused breast cancer. But it did show that they were present. And that was the question that remained open.
Subsequent studies: more data, new questions
In 2012, another study analyzed breast tissue samples taken from different areas of the breast—from the armpit to the sternum—in women undergoing mastectomy. Again, parabens were detected in a significant portion of the samples.
This work provided something interesting: parabens did not appear only in the tumor, but also in other areas of the breast tissue. This reinforced the idea that daily exposure—for example, through products applied to the skin—can lead to a measurable presence in the body.
More recently, some studies have compared tumor tissue with adjacent tissue considered normal in the same patients. This type of design attempts to observe if there are differences in concentration within the body itself. Even so, even these more sophisticated approaches do not allow asserting a causal relationship.
Presence does not mean causation
This point is fundamental. The presence of a substance in tumor tissue does not automatically mean that it caused the tumor. Science clearly distinguishes between:
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Detecting a substance.
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Understanding its biological mechanism.
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Demonstrating that it causes disease under real exposure conditions.
Available studies tell us that parabens can be found in breast tissue. What they don't tell us is that they are responsible for the development of cancer.
So, why does it matter?
Because some parabens have estrogenic activity, even if it's weak. And many breast cancers are hormone-dependent. That combination—presence in tissue + hormonal activity—is what has kept the scientific debate open.
We are not facing conclusive evidence of harm. But neither is it a completely closed issue. And when we talk about chronic exposure, hormonal health, and prevention, for me that difference matters.
What happened next? The regulatory response in Europe
When studies like these begin to raise legitimate questions, the next logical step is to review the available evidence from a regulatory perspective.
In Europe, the body responsible for evaluating the safety of cosmetic ingredients is the Scientific Committee on Consumer Safety (SCCS). Its function is to analyze toxicological data, exposure levels, and possible biological effects to determine if a substance can be considered safe under certain conditions of use.
For many years, parabens were considered safe within specific concentrations. However, as research into endocrine disruptors advanced, the European Union began to review some of them more closely.
In 2014, several parabens were banned due to a lack of sufficient data to guarantee their safety and concern about their possible activity as endocrine disruptors. These included: isopropylparaben, isobutylparaben, phenylparaben, benzylparaben, and pentylparaben.
That same period also brought additional restrictions for propylparaben and butylparaben, limiting their maximum permitted concentration and prohibiting their use in rinse-off products intended for the diaper area in children under three years of age, as this was considered a particularly vulnerable population.
It is important to understand that these decisions were not based on conclusive proof of harm in humans, but on a principle of prudence in the face of scientific uncertainty.
And this is where the debate ceases to be purely scientific and also becomes a matter of judgment: do we wait for absolute certainty or do we act when there are reasonable indications?
Which parabens are still allowed in Europe today?
After the prohibitions and restrictions we have discussed, it is logical to ask: are parabens still used in cosmetics in the European Union?
The answer is yes. Some continue to be authorized because, according to current evaluations, they are considered safe within specific concentrations and under certain conditions of use.
Today, the following are permitted:
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Methylparaben
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Ethylparaben
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Propylparaben (with stricter concentration limits)
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Butylparaben (also with restrictions)
Maximum concentrations are regulated and have been reviewed over the years by the Scientific Committee on Consumer Safety (SCCS), taking into account toxicological data, estimated exposure, and possible endocrine activity.
"Permitted" does not mean there has been no debate. It means that, with the scientific evidence available so far, authorities consider that the risk is acceptable within established limits.
But this is where an interesting reflection arises. Regulatory evaluation analyzes each substance individually and within specific use scenarios. However, in real life, we do not use just one product a day, nor are we exposed to just one potentially active substance from a hormonal point of view.
And that difference between theoretical evaluation and real exposure is what, for many people—including myself—keeps the conversation alive.
Because the question is no longer just "is a specific paraben safe in a specific concentration?" The question is how all of that fits into the whole of our daily and long-term exposure. And that is where the scientific debate remains open.
The ongoing scientific debate
The current debate no longer revolves solely around whether a specific, isolated paraben can pose a risk within a certain concentration. The discussion is more complex and has to do with how our endocrine system actually works and how we are exposed to these substances in real life.
The "cocktail effect"
In regulatory studies, ingredients are evaluated individually. However, in our daily lives, we are exposed to multiple substances with potential hormonal activity: cosmetics, packaging, food, environmental pollution...
Although each one, separately, is considered safe within certain limits, the scientific question is: what happens when they are combined? This phenomenon is known as the "cocktail effect," and it is one of the great current challenges in toxicology.
Chronic and cumulative exposure
Another key point is time.
We are not talking about a one-time exposure, but daily application for years.
Some parabens have weak estrogenic activity compared to natural estrogens. But when we talk about hormones, even small interferences can be relevant depending on the biological context, life stage, or individual sensitivity.
Science is still investigating how these long-term exposures interact.
Individual variability
Not all organisms respond in the same way.
Genetics, pregnancy, puberty, menopause, family history... are factors that can influence how each body processes and responds to endocrine disruptors.
That's why the debate is not black and white. We are not facing conclusive evidence of harm, but neither is it a completely closed issue.
And when the scientific conversation remains open, for me the question ceases to be solely "is it legal?" or "is it allowed?", and becomes:
What level of caution do we want to apply when we talk about hormonal health?
And that's where our decision comes in.
Our decision: applying the precautionary principle
After reviewing studies, understanding regulatory evolution, and following the scientific debate, I came to a very personal conclusion.
I don't need absolute certainty of risk to decide to act with greater caution.
In Europe, there is a key concept in public health: the precautionary principle. This principle states that when there are reasonable indications of possible risk, even if the evidence is not conclusive, preventive measures can be adopted to protect health.
Current regulations allow some parabens within certain limits. And I want to say clearly: I deeply respect the scientific and regulatory work behind these decisions.
But as the founder of Banbu, my reflection went beyond what is strictly legal.
When we talk about substances with hormonal activity, daily exposure, potential accumulation, and still open scientific uncertainty, I decided that I preferred not to use them.
That's why at Banbu:
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We do not formulate with any type of paraben, even if it is permitted.
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We opt for alternative preservative systems.
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We apply a more restrictive criterion than the minimum required by law.
It is not about demonizing ingredients or creating fear. It is about consistency with our values.
If there is a reasonable doubt, even if not definitive, we prefer to opt for the most prudent option.
Because when we talk about health—and especially hormonal health—for me, prevention is not a marketing strategy. It is a responsibility.
