Hidden Risks in Natural Cosmetics: PAHs in Shea Butter and Other Nut-Derived Ingredients
- annolim
- Sep 1
- 5 min read
Updated: Sep 2
The Hidden Side of “Natural” Beauty
In the clean beauty era, many consumers reach for products boasting natural ingredients such as Butyrospermum parkii (shea) butter, cocoa butter, or almond oil. These plant-derived butters and oils are praised for their nourishing, moisturizing, and antioxidant properties. But “natural” does not always mean “risk-free.”
Recent research has highlighted a concerning issue: polycyclic aromatic hydrocarbons (PAHs)—a class of chemicals with known carcinogenic and mutagenic potential—can contaminate raw cosmetic materials like shea butter. While the levels and risks vary, the presence of PAHs raises important questions about consumer safety, manufacturing standards, and regulatory compliance in cosmetics.
What Are PAHs and Why Do They Matter?
Polycyclic Aromatic Hydrocarbons (PAHs) are a group of over 100 chemicals formed during the incomplete combustion of organic matter, such as wood, coal, or oil. They are found in polluted air, contaminated soil, and sometimes in foods and oils.
Key points about PAHs:
Several PAHs are classified by the International Agency for Research on Cancer (IARC) as probable or known human carcinogens.
Long-term exposure has been linked to skin, lung, and bladder cancers, as well as DNA damage.
Although cosmetics are applied topically, PAHs can penetrate the skin barrier and accumulate over time, especially with daily use.
How Do PAHs Enter Cosmetic Raw Materials?
Botanical butters and oils—especially those derived from nuts and seeds—can become contaminated with PAHs at multiple stages:
Environmental exposure
Plants grown in polluted regions may absorb PAHs from soil, air, and water.
Processing & drying methods
Traditional drying or roasting of nuts over open fires is a common practice in rural production areas for shea and cocoa. This direct smoke exposure can dramatically increase PAH content.
Supply chain vulnerabilities
Without strict quality control, cosmetic manufacturers may unknowingly source raw materials contaminated during collection, storage, or transportation.
For example, a study in Nigeria analyzing food-grade shea butter found PAH concentrations ranging from 126 to 865 μg/kg, far exceeding EU safety thresholds for oils. While these figures refer to edible shea butter, they highlight the potential contamination risks in cosmetic-grade materials if stringent safeguards are not in place.
The Health Risks of PAHs in Cosmetics
Although the risk from cosmetics is typically lower than from food or tobacco smoke, the issue cannot be ignored:
Carcinogenic potential: Some PAHs, including benzo[a]pyrene, are classified as Group 1 carcinogens.
Skin penetration: Scientific evidence shows that lipophilic (fat-loving) PAHs can be absorbed through the skin.
Cumulative exposure: Cosmetics are used daily and often remain on the skin for long periods. Even low-level contamination can add up over years.
This cumulative risk becomes particularly relevant when consumers unknowingly layer multiple products—lotions, creams, lip balms—all containing nut-derived butters or oils.
Regulatory and Safety Oversight
The good news: regulators and scientific bodies are aware of the issue and have set frameworks to minimize risk.
Cosmetic Ingredient Review (CIR)
The CIR Expert Panel has evaluated shea butter and related derivatives, concluding that they are safe for use in cosmetics—but only when manufactured according to Good Manufacturing Practices (GMP) that control impurities like PAHs.
EU Cosmetics Regulation
The European Union prohibits carcinogenic, mutagenic, or reprotoxic (CMR) substances in cosmetics, including PAHs. Cosmetic ingredients must meet purity criteria, and contamination must be minimized.
Industry Standards
Certifications such as ECOCERT and COSMOS also require testing for contaminants, including PAHs, to guarantee safe, high-quality raw materials.
The takeaway: PAHs themselves are not allowed in cosmetics. But contamination can slip through if raw materials are poorly processed or inadequately tested.
EU – laws, guidance, and official lists
Core law: EU Cosmetics Regulation (EC) No 1223/2009 – full text (Articles 3, 10, 15, 17, Annexes). Article 17 clarifies when traces of prohibited substances (e.g., PAHs) can be tolerated if technically unavoidable and safe.
How to build the Cosmetic Product Safety Report (CPSR): EU Commission Implementing Decision 2013/674/EU explains expectations for safety assessments and reiterates the “technically unavoidable traces” principle.
PAHs on the EU cosmetics prohibited list: Annex II entry for benzo[a]pyrene (benzo[def]chrysene) appears on the Annex II list of substances prohibited in cosmetics.
“Traces” concept explained (useful explanatory references): official UK/EU publishing of Article 17 text and industry explainer summarizing Articles 3 & 17.
REACH restriction on PAHs in consumer articles (rubber/plastic) – not cosmetics, but good context for EU hazard recognition of PAHs (Annex XVII, Entry 50).
EU—food/oils contamination limits (useful benchmarks for natural oils)
PAH limits in foods/fats & oils (often used as a reference point for raw plant oils): Commission Regulation (EU) No 835/2011 sets limits for BaP (2 μg/kg) and PAH4 (10 μg/kg) in fats and oils, among other matrices.
Scientific Studies & Analytical Methods
Sensitive analysis of PAHs in cosmetics A 2025 study developed a GC-MS/MS method to assess 18 PAH compounds in cosmetic products and raw materials. Among 73 samples (including over 40 lipsticks), the most carcinogenic PAHs—benzo[a]pyrene (BaP) and dibenzo[a,h]anthracene (DBA)—were not detected. Other PAHs were present at 0.08 to 0.27 mg/kg. This method provides a robust tool for screening cosmetic materials for PAH contamination.
Early method validation for PAHs in cosmetic materials
A 2019 study introduced a sensitive method for detecting 18 representative PAHs in cosmetic raw materials, reinforcing the relevance of rigorous analytical testing in safety assessments.
PAHs from traditional processing of shea butter
A study on volatile compounds in shea butter revealed significant PAH contamination caused by smoking during traditional processing, highlighting a key contamination pathway.
PAHs in edible shea butter (food-grade context)
Research from Nigeria measured the concentrations of the 16 EPA-listed PAHs in edible oils and shea butter, underscoring potential health risks from contaminated edible oils—which may mirror risks in cosmetic-grade materials if not properly managed.
What Brands and Manufacturers Should Do
For cosmetic companies, vigilance is essential to protect consumers and maintain compliance:
Source Responsibly
Work with suppliers who use refined, cosmetic-grade butters rather than raw or food-grade alternatives.
Demand Transparency
Require documentation on processing methods and Certificates of Analysis (CoA) confirming PAH-free status.
Test, Test, Test
Conduct regular third-party lab testing for PAHs, particularly when sourcing raw materials from regions with traditional fire-drying practices.
Educate Teams and Consumers
Transparency builds trust. Communicate safety protocols and certifications openly.
What Consumers Can Do
While much of the responsibility lies with manufacturers, consumers also play a role:
Choose Trusted Brands Support companies that prioritize quality control and safety testing. Many ethical beauty brands already highlight this in their marketing.
Check for Certifications
ECOCERT, COSMOS, and similar seals indicate that raw materials have been screened for contaminants.
Be Cautious with DIY Products
Unrefined shea butter from local markets may not meet cosmetic safety standards. If you enjoy DIY cosmetics, source only from reputable suppliers.
Ask Questions
Don’t hesitate to ask brands if their shea butter or nut-derived ingredients are tested for PAHs and other impurities. Consumer demand often drives industry change.
Awareness is the First Step
Shea butter, cocoa butter, and other nut-derived oils are powerful, nourishing ingredients that have been used safely for centuries. But in today’s industrialized, globalized supply chains, hidden risks like PAH contamination cannot be overlooked.
The science is clear: PAHs are carcinogenic, and while their presence in cosmetics is unintended, contamination can happen. The solution lies in rigorous sourcing, testing, and manufacturing practices—as well as consumer awareness.
By asking questions, supporting transparent brands, and demanding stronger safety standards, we can enjoy the benefits of natural cosmetic ingredients without compromising on health or compliance.
Reference sources
Commission Regulation (EU) 2023/915
ResearchGate Cancer Prevention and Risk Assessment
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