Published in Environment International, the study examined how common cosmetic ingredients and product contaminants contribute to measurable internal exposure to endocrine-disrupting chemicals — including parabens, phthalates, Bisphenol A (BPA), and phenoxyethanol.
The findings are difficult to ignore.
Within just five days of changing personal care products, participants experienced significant reductions in several harmful chemical biomarkers detected in their urine.
This means the products applied to the skin every day are not simply remaining on the surface — they are entering the body.
The Study
Researchers from several leading European institutions recruited 103 women aged 18–30 and asked them to temporarily stop using their normal personal care products.
For five days, participants replaced their usual skincare, deodorants, shampoos, toothpaste and cosmetics with alternative products specifically selected to avoid certain chemicals of concern.
The researchers then measured chemical metabolites in 24-hour urine collections before and after the intervention.
The results showed rapid reductions in multiple chemical exposures linked directly to personal care product use.
The observed reductions included:
Phenoxyethanol exposure: ↓ 64%
Bisphenol A (BPA): ↓ 39%
Methylparaben: ↓ 30%
Phthalate exposure (MEP): ↓ 22%
The study demonstrates that personal care products are a major and highly modifiable source of chemical exposure in daily life.
Why These Chemicals Matter
Parabens
Parabens are commonly used preservatives found in skincare and cosmetics to prevent microbial contamination and extend shelf life.
The study found significant reductions in methylparaben and propylparaben exposure after participants switched products.
Why does this matter?
Parabens are known endocrine-active compounds, meaning they can interfere with hormonal signalling pathways within the body. Growing scientific concern has linked chronic exposure to potential reproductive, developmental and hormonal effects.
And because skincare is used daily — often multiple times per day — exposure becomes cumulative over time.
Phthalates
Phthalates are frequently associated with synthetic fragrance systems and are often hidden under vague ingredient terms like:
“Fragrance”
“Parfum”
“Aroma”
This means consumers are often exposed without realising it.
The study observed measurable reductions in monoethyl phthalate (MEP), a marker of exposure to diethyl phthalate (DEP), after participants changed their personal care routines.
Phthalates are among the most studied endocrine-disrupting chemicals and have been associated with concerns surrounding fertility, hormonal health, reproduction and development.
Bisphenol A (BPA)
One of the most striking findings involved BPA.
Despite BPA being prohibited in cosmetic formulations in the European Union, the study still detected measurable exposure linked to personal care product use.
Researchers suggest contamination may occur through:
Plastic packaging
Manufacturing equipment
Storage containers
Supply chain contamination
In other words, harmful exposure may occur even when BPA is not intentionally listed as an ingredient.
The study also conducted a health impact assessment, estimating that lowering BPA exposure during pregnancy could potentially:
Reduce childhood asthma cases
Reduce wheezing prevalence
Help prevent IQ decline associated with prenatal exposure
This is significant because it connects skincare-related chemical exposure not only to absorption, but to potential long-term developmental health outcomes.
Phenoxyethanol
Phenoxyethanol is often marketed as a “safer alternative” to parabens and is now extremely common in modern skincare formulations.
However, this study found the largest reduction of all measured compounds was linked to phenoxyethanol exposure.
Researchers measured phenoxyacetic acid — a biomarker of phenoxyethanol exposure — and observed a reduction exceeding 60% after product changes.
The study also referenced previous research associating glycol ethers and related compounds with developmental and neurodevelopmental concerns.
This does not automatically mean all phenoxyethanol-containing products are unsafe.
But it does reinforce a broader issue:
Modern consumers are exposed to low doses of multiple biologically active chemicals every single day, often from numerous products simultaneously.
Side note: Phenoxyethanol is known to cause contact dermatitis, burning, redness, and itching in people with sensitive skin or existing conditions like eczema. I personally cannot use products containing this ingredient.
The Bigger Problem: Cumulative Exposure
Perhaps the most important takeaway from this study is not one individual ingredient.
It is the concept of cumulative exposure.
Participants in the study used a median of 12 personal care products per day before the intervention. Take a moment and think about that!
Cleanser. Serum. Moisturiser. SPF. Foundation. Shampoo. Conditioner. Deodorant. Fragrance. Body wash. Hair styling products.
Each individual product may appear compliant with regulations in isolation. But humans are not exposed to these compounds in isolation. We are exposed continuously, cumulatively and chronically.
And increasingly, research is suggesting that long-term low-dose exposure — particularly to endocrine-disrupting compounds — deserves far more attention than it currently receives.
Why This Matters for Consumers
This study is important because it confirms several realities many consumers are only beginning to understand:
What goes on the skin can enter the body
The chemicals measured were not theoretical. They were found inside participants after routine product use.
Product choices can rapidly alter exposure
Internal chemical levels changed significantly within only five days.
“Legal” does not necessarily mean harmless. Many of these substances remain permitted in cosmetics under current regulations.
Packaging matters too
Contamination can occur through manufacturing systems and packaging materials — not only through ingredient lists.
Transparency matters
Consumers deserve clearer insight into what they are repeatedly applying to their skin and bodies every day.
A Shift in the Conversation Around Beauty
For years, the beauty industry has focused heavily on aesthetics, performance and trends.
But studies like this are shifting the conversation toward something deeper:
Long-term biological impact
Hormonal health
Environmental toxicology
Chronic cumulative exposure
Skin health as part of overall health
Consumers are becoming increasingly aware that skincare is not just cosmetic.
It is a daily biological interface with the body, and what we repeatedly apply matters.
Practical Ways Consumers Can Reduce Exposure
This study also highlights something empowering:
Exposure can be reduced. And often, relatively quickly.
While no product or lifestyle is completely exposure-free, there are practical ways consumers can lessen cumulative chemical burden from skincare and self-care products.
1. Learn to Read the INCI List
The INCI (International Nomenclature of Cosmetic Ingredients) list is one of the most important tools consumers have.
Look for ingredients such as:
Parabens
Methylparaben
Propylparaben
Butylparaben
Ethylparaben
Phthalate-associated terms
Fragrance
Parfum
Aroma
(Phthalates are often hidden within fragrance blends.)
Phenoxyethanol
Phenoxyethanol
Bisphenol-related concerns
BPA is rarely listed directly, making packaging and manufacturing transparency equally important.
2. Reduce Fragrance Exposure
Synthetic fragrance is one of the largest hidden sources of unnecessary chemical exposure.
Consider limiting:
Perfumed skincare
Synthetic fragrances
Scented body products
Heavily fragranced haircare
Air fresheners and room sprays
Fragrance-free or naturally low-odour formulations can significantly reduce exposure to phthalates and other volatile compounds.
3. Simplify Your Routine
More products generally mean more cumulative exposure.
Conscious consumers are increasingly moving toward:
Fewer products
Multi-functional formulations
Barrier-supportive skincare
Minimalist routines
The goal is not fear — it is reducing unnecessary chemical load where possible.
4. Pay Attention to Packaging
Packaging is an overlooked part of the exposure conversation.
Whenever possible:
Choose glass over plastic
Avoid prolonged heat exposure of products in plastic packaging
Be cautious with products stored in soft plastics
Avoid leaving products in hot cars or bathrooms
This is particularly relevant for compounds like BPA and other plastic-associated contaminants.
5. Be Wary of “Clean Beauty” Marketing Alone
“Natural” and “clean” are not regulated scientific terms in many markets.
A product marketed as clean may still contain:
Synthetic fragrance
Phenoxyethanol
Endocrine-active preservatives
Problematic packaging
Ingredient transparency matters more than marketing language.
6. Support Brands Focused on Full Formulation Integrity
Increasingly, consumers are looking beyond hero ingredients and asking broader formulation questions:
What preservative systems are being used?
Is fragrance included?
What is the packaging made from?
Are ingredients bioaccumulative?
Does the formulation minimise unnecessary endocrine disruptors?
This represents a broader shift toward formulation transparency and long-term skin health and longevity. Ask questions - always!
All FIFTY7KIND ingredients are COSMOS approved - this means that petrochemicals, synthetic preservatives and fragrance are prohibited. All FIFTY7KIND products are formulated to the highest cosmetic regulations of the EU Cosmetics Regulation 1223/2009 and are EU Certified.