Cosmetic Product Safety Testing: Heavy Metals, PFAS, Formaldehyde, Phthalates, and More

Understanding chemical contaminants, microbiological risks, and safety documentation for cosmetics and personal care products

Cosmetic and personal care product safety involves more than evaluating individual ingredients. Manufacturers and brands must also consider potential contaminants, manufacturing impurities, microbial risks, and the overall safety of finished formulations.

As regulatory requirements and consumer expectations continue to evolve, analytical testing and safety assessments play an important role in product development, quality assurance, and regulatory compliance.

From heavy metals and formaldehyde to PFAS and phthalates, understanding potential chemical hazards helps manufacturers make informed decisions about their products.

At Pentyl Labs, we provide analytical testing and safety assessment services to support cosmetic brands, formulators, manufacturers, and distributors.

1. Heavy Metals Testing in Cosmetics

Heavy metals may occur in cosmetic products as trace contaminants originating from raw materials, pigments, minerals, manufacturing equipment, or environmental sources.

Common metals evaluated in cosmetics include:

• Lead (Pb)

• Arsenic (As)

• Cadmium (Cd)

• Mercury (Hg)

• Antimony (Sb), where applicable

Products containing mineral-based ingredients, pigments, clays, and botanical materials may warrant particular attention.

Heavy metals testing commonly uses Inductively Coupled Plasma Mass Spectrometry (ICP-MS), an analytical technique capable of detecting trace concentrations of metals.

Testing helps manufacturers identify potential contamination, assess raw material quality, and evaluate finished products against applicable regulatory requirements and safety criteria.

Importantly, acceptable concentrations depend on the specific metal, product type, jurisdiction, and exposure considerations.

2. Water Activity Testing and Microbial Risk

Water activity (aw) measures the availability of water within a product for microbial growth. Unlike moisture content, which measures the total amount of water present, water activity indicates how much water is available to support microorganisms.

Water activity is particularly relevant for:

• Anhydrous cosmetics

• Lip balms and body butters

• Sugar and salt scrubs

• Powdered cosmetics

• Solid personal care products

• Low-water formulations

Products with lower water activity generally present a reduced risk of microbial proliferation. However, low water activity does not necessarily mean a product is free from contamination or incapable of supporting microbial growth under all conditions.

For example, consumer use may introduce water into an otherwise low-water formulation.

Water activity measurements can support microbiological risk assessments and help determine appropriate preservation strategies.

Depending on the formulation and intended use, additional microbial limits testing or preservative efficacy testing may still be necessary.

3. Formaldehyde Testing in Cosmetics

Formaldehyde is a chemical of concern because of its toxicological properties and potential to cause skin sensitization.

Although formaldehyde may not be intentionally added to a formulation, it can be released by certain formaldehyde-donating preservatives or arise from other sources.

Examples of formaldehyde-releasing preservatives include:

• DMDM Hydantoin

• Imidazolidinyl Urea

• Diazolidinyl Urea

• Quaternium-15

Formaldehyde testing can help manufacturers evaluate potential exposure and determine whether a finished product meets applicable requirements.

Testing may involve measuring free formaldehyde or other defined forms, depending on the analytical method and regulatory objective.

This distinction is important because different methods may produce different results depending on how formaldehyde is released or measured.

4. 1,4-Dioxane Testing

1,4-Dioxane is a manufacturing byproduct that may occur in products containing certain ethoxylated ingredients.

It is not generally added intentionally to cosmetic formulations.

Potential sources include ingredients such as:

• Polyethylene glycols (PEGs)

• Certain polysorbates

• Sodium Laureth Sulfate (SLES)

• Other ethoxylated surfactants

The presence of these ingredients does not automatically indicate that a product contains measurable 1,4-dioxane.

However, testing can help verify impurity concentrations in raw materials and finished products.

Gas Chromatography–Mass Spectrometry (GC-MS) is commonly used for 1,4-dioxane analysis.

Testing is especially relevant for manufacturers evaluating New York State’s restrictions on 1,4-dioxane in certain personal care and household products.

Routine testing can also support supplier qualification, formulation improvements, and manufacturing process controls.

5. Parabens Testing

Parabens are preservatives used in certain cosmetic and personal care formulations to help prevent microbial growth.

Common examples include:

• Methylparaben

• Ethylparaben

• Propylparaben

• Butylparaben

Different parabens have different toxicological profiles and regulatory restrictions. Therefore, they should not be treated as a single substance when evaluating product safety or compliance.

Paraben testing can help manufacturers confirm preservative identity, measure concentrations, and verify formulation specifications.

Analytical methods such as High-Performance Liquid Chromatography (HPLC) may be used to quantify individual parabens.

Testing is particularly useful when confirming compliance with market-specific restrictions or substantiating claims regarding the absence of specified parabens.

6. PFAS Testing in Cosmetics

Per- and polyfluoroalkyl substances (PFAS) are a broad group of fluorinated chemicals that have attracted increased regulatory and scientific attention.

Certain PFAS have historically been used in cosmetic formulations to provide properties such as improved texture, durability, water resistance, or film formation.

PFAS may also be present through contamination or impurities.

Products that may warrant evaluation include:

• Waterproof makeup

• Long-wear foundations

• Mascara and eyeliner

• Lip products

• Other formulations containing fluorinated ingredients

Targeted PFAS analysis can identify and quantify specific compounds included in the analytical method.

However, because PFAS represent a large and chemically diverse group, no single targeted method detects every PFAS compound.

Manufacturers should select testing methods based on their ingredients, potential exposure pathways, and applicable regulatory requirements.

7. Total Organic Fluorine (TOF) Testing

Total Organic Fluorine (TOF) testing provides a broader screening approach for organofluorine-containing substances.

Unlike targeted PFAS testing, which measures specific compounds, TOF testing evaluates an aggregate fluorine measurement associated with organic substances.

This makes it a useful screening tool when investigating potential fluorinated ingredients or contamination.

TOF testing and targeted PFAS testing serve different purposes.

A positive TOF result does not automatically establish the presence of a specific PFAS compound. Other organic fluorine-containing substances may contribute to the result.

Similarly, a low or nondetectable TOF result does not guarantee the absence of every PFAS substance.

Analytical approaches, including methods based on combustion ion chromatography, may be used to evaluate fluorine content.

For manufacturers, TOF screening can help identify products requiring additional investigation or targeted chemical analysis.

It is also important to distinguish TOF from total fluorine measurements, which may include inorganic fluorine depending on the method.

8. Phthalates Testing

Phthalates are a group of chemicals used in various industrial applications, including as plasticizers and, historically, in certain fragrance-related applications.

Potential phthalate exposure in cosmetic products may arise from ingredients, fragrance materials, packaging, or manufacturing processes.

Common phthalates of interest include:

• Diethyl Phthalate (DEP)

• Dibutyl Phthalate (DBP)

• Di(2-ethylhexyl) Phthalate (DEHP)

• Benzyl Butyl Phthalate (BBP)

Regulatory requirements vary by jurisdiction and by individual compound.

Phthalate testing may be performed using chromatographic methods such as GC-MS.

Testing helps manufacturers verify ingredient specifications, investigate potential contamination, and evaluate products against applicable chemical restrictions.

It may also support product claims when appropriate analytical methods and detection limits are established.

9. Toxicological Risk Assessment (TRA) and Safety Documentation

Analytical testing provides valuable information about a cosmetic product, but chemical testing alone does not establish overall product safety.

A Toxicological Risk Assessment (TRA) evaluates the safety of a formulation based on its ingredients, concentrations, intended use, exposure conditions, and available toxicological information.

A typical cosmetic safety assessment may consider:

• Complete quantitative ingredient composition

• Toxicological profiles of ingredients

• Potential chemical impurities

• Product application area and frequency of use

• Estimated consumer exposure

• Dermal and other relevant exposure routes

• Margin of Safety (MoS), where appropriate

• Potential sensitization and irritation concerns

• Intended consumer population

Under the U.S. Modernization of Cosmetics Regulation Act of 2022 (MoCRA), responsible persons must ensure that adequate safety substantiation records are maintained for cosmetic products, subject to applicable requirements and exemptions.

MoCRA does not require every cosmetic product to undergo the same prescribed laboratory tests or use a specific TRA format.

Instead, the appropriate safety substantiation should reflect the product’s characteristics, intended use, and available scientific evidence.

Safety documentation may include toxicological assessments, analytical testing reports, microbiological evaluations, stability studies, and other relevant supporting information.

For companies selling products internationally, additional documentation may be necessary. For example, cosmetics marketed in the European Union generally require a Cosmetic Product Safety Report (CPSR) as part of the Product Information File (PIF).

10. Developing a Risk-Based Cosmetic Testing Program

Not every cosmetic product requires every analytical test.

A well-designed testing program should consider the formulation, raw materials, manufacturing process, packaging, intended use, and target market.

For example, a mineral-based cosmetic may warrant heavy metals testing, while a product containing ethoxylated surfactants may benefit from 1,4-dioxane analysis.

Similarly, an anhydrous scrub may benefit from water activity testing, while a waterproof cosmetic containing fluorinated ingredients may require additional PFAS-related evaluation.

Combining analytical testing with appropriate toxicological assessment helps manufacturers identify potential risks before products reach consumers.

This risk-based approach can improve product quality, support regulatory compliance, and reduce the likelihood of costly reformulations or market disruptions.

Cosmetic Testing and Safety Assessment Services at Pentyl Labs

Pentyl Labs supports cosmetic and personal care manufacturers through analytical testing, chemical contaminant screening, and product safety assessments.

Our services help brands evaluate raw materials, investigate potential impurities, support regulatory documentation, and make informed product safety decisions.

Whether you are developing a new formulation, reviewing an existing product, or preparing for market entry, selecting the appropriate testing strategy is an important step.

Need assistance selecting the right tests for your cosmetic product?

Visit www.pentyllabs.com to explore available testing services or contact Pentyl Labs to discuss your formulation and testing requirements.

Disclaimer: Testing recommendations and regulatory requirements vary by product, jurisdiction, and intended use. Analytical results should be interpreted in the context of the applicable method, reporting limits, and product-specific safety assessment.