Plasticizers in sunscreen – What you need to know

Sunscreens and other sun protection products are considered essential for preventing skin cancer and premature skin aging. However, studies show that certain ingredients not only offer benefits but can also release byproducts that are harmful to health, such as plasticizers. The discussion focused on the UV filter DHHB (diethylhexylbutamidotriazone), which can break down in the body to form the metabolite mono-n-hexylphthalate (MnHexP). Mono-n-hexyl phthalate (MnHexP) is a plasticizer degradation product classified as a substance hazardous to reproduction and health.

In 2024, the State Agency for Nature, Environment, and Consumer Protection of North Rhine-Westphalia (LANUV) and the Federal Environment Agency (UBA) detected traces of MnHexP in children’s urine. The findings from these urine samples suggest that children are unintentionally exposed to a phthalate breakdown product (plasticizer) when applying sunscreen. Manufacturers of sunscreen and sun protection products emphasize that MnHexP is not actually an ingredient in their products, but rather an “unavoidable” byproduct of certain UV filters.

However, the Federal Institute for Risk Assessment (BfR) has given the all-clear and points out that there is no immediate health risk. Nevertheless, exposure to a substance that may be harmful to reproduction remains a sensitive issue. Stiftung Warentest has tested sunscreens and confirmed that the products tested provide reliable protection against UV radiation. According to experts, the risks should be viewed in a realistic light: While even low concentrations of phthalate breakdown products in children’s urine should be monitored closely, the health risk posed by skin cancer from unprotected sun exposure is significantly higher.

How does the plasticizer end up in sunscreen?

The plasticizer in sunscreens is not intentionally added; rather, it is a byproduct of a specific UV filter. Many sunscreens use the chemical filter DHHB because it reliably protects the skin from long-wave UVA radiation, thereby reducing the risk of sunburn and skin cancer. Studies have shown that when sunscreen products containing DHHB are used, the metabolite mono-n-hexyl phthalate is formed from di-n-hexyl phthalate (DnHP, DnHexP). This breakdown product belongs to the group of phthalates, which are otherwise primarily known as plasticizers in plastics. MnHexP is therefore not an actual ingredient in sunscreen, but rather a byproduct that is formed within the body.

The different ways sunscreens work

Sunscreens work in different ways depending on the type of UV filters they contain. Basically, there are two types: soluble (chemical, organic) filters and insoluble (physical, mineral) filters. Chemical filters penetrate the outermost layer of the skin, where they absorb high-energy UV radiation and convert it into longer-wavelength, lower-energy heat radiation. This protects the skin from damage caused by sunlight without allowing the rays to reach the cells directly. Physical filters, on the other hand (e.g., made of titanium or zinc oxide), remain on the skin’s surface and act as a protective shield. They not only absorb some of the radiation but also scatter and reflect UV rays. This prevents them from penetrating deeper into the skin.

In addition to conventional products, natural cosmetics and alternative sun protection methods are also gaining attention. Natural sunscreen products typically use mineral filters, as many chemical filters are avoided due to environmental and health concerns. Products such as coconut oil or other vegetable oils, on the other hand, are often touted as “natural” alternatives, but they offer very little protection on their own and do not come close to matching the effectiveness of approved sunscreens. Dermatological associations expressly warn against using oils as a substitute for approved sunscreens.

Which sunscreens contain the undesirable plasticizer?

Not all sunscreens contain this undesirable plasticizer; only those that use the UV filter diethylamino hydroxybenzoyl hexyl benzoate (DHHB) do. This chemical filter is particularly valued for its strong and stable protection against long-wave UVA radiation and is therefore found in many products.

Limits and other legal regulations for plasticizers in sunscreen

Regulation (EU) 2026/909, published on April 28, 2026, establishes a limit value for di-n-hexyl phthalate (DnHP) as an unavoidable trace impurity in DHHB, such that the concentration of this impurity in the DHHB UV filter used must not exceed 10 ppm.

Cosmetic products may only contain ingredients listed on the positive lists in the annexes to the Cosmetics Regulation (EC) No. 1223/2009, or ingredients that are not prohibited. Ingredients classified as toxic to reproduction, such as DnHexP or other phthalates, must not be used; impurities that are technically unavoidable and result from natural or synthetic components, the manufacturing process, storage, or migration from packaging are permitted but must be taken into account in the safety assessment.

In its statement, the BfR also makes it clear that, even though there are currently no specific legal limits or guideline values for MnHexP or other phthalates, it is recommended that exposure to these substances—particularly among children and from all relevant sources—be reduced as much as possible.

Methods for detecting plasticizers

Detecting plasticizers in sunscreens or their raw materials requires highly sensitive analytical methods, as the concentrations are typically very low and the matrices are complex. In practice, gas chromatography (GC) and high-performance liquid chromatography (HPLC) are the primary methods used for this purpose, each coupled with mass spectrometry (MS). This combination makes it possible to unambiguously identify individual substances and reliably quantify them even in trace amounts. While GC-MS is particularly well-suited for volatile and thermally stable compounds, HPLC-MS enables the analysis of heavier or less volatile molecules, such as those commonly found in cosmetic products.

Such detection methods are primarily suited for specialized testing laboratories and research institutes, as they require sophisticated equipment, trained personnel, and standardized sample preparation. For cosmetics manufacturers, however, they are indispensable when it comes to ensuring product safety and compliance with legal requirements. As a rule, the analysis is conducted on a random basis, for example as part of quality assurance or when there is a specific suspicion of contamination.

Tentamus is here to help

The Tentamus Group’s analyses cover not only finished cosmetic products such as sunscreens, but also the raw materials and ingredients used to manufacture these products. This makes it possible to check at an early stage of production whether any prohibited or restricted substances might end up in the formulations. The methods used include modern analytical techniques such as gas chromatography and high-performance liquid chromatography in combination with mass spectrometry, which enable the highly accurate identification and quantification of even the smallest traces.

The Tentamus Group’s testing is based on the requirements of the EU Cosmetics Regulation (EC No. 1223/2009) as well as other regulatory frameworks. The goal is both to ensure compliance with legal requirements and to provide manufacturers with reliable data for their quality assurance processes. In this way, manufacturers can not only demonstrate that their sunscreen products meet applicable safety requirements, but also build consumer confidence.

We conduct comprehensive testing of sunscreen products for plasticizers and phthalates, including mono-n-hexyl phthalate (MnHexP) and di-n-hexyl phthalate (DnHexP).