Why Homosalate in Sunscreens Is Being Re-Examined in Australia

What homosalate is and why it matters?

Homosalate is a chemical UV filter that has been used in sunscreens for many years and is currently permitted in Australia at concentrations of up to 15 percent. Like many ingredients approved decades ago, it entered widespread use at a time when assumptions about skin absorption and internal exposure were limited. Advances in toxicology and biomonitoring have since changed how these substances are evaluated, prompting renewed scientific attention.

What newer studies are showing?

Recent research indicates that homosalate does not remain on the skin surface. After topical application, it is absorbed into the body and can be measured in blood plasma, urine, and breast milk. Human toxicokinetic studies have also shown that it can persist internally for days or weeks after repeated use. These findings are particularly relevant in countries where sunscreen is applied frequently and to large areas of the body.

How international regulators have responded?

Several international scientific and regulatory bodies have reassessed homosalate in light of this evidence. In the European Union, reviews led to strict limits on how and where it can be used, with higher concentrations allowed only in limited product types. In the United States, homosalate remains under ongoing review because available data were not considered sufficient to confirm safety under high-use conditions. Other jurisdictions have adopted similarly cautious positions.

Why Australia is a unique case?

Australia’s sunscreen use patterns differ from those assumed in many overseas risk assessments. Public health guidance encourages full-body application, frequent reapplication, and daily use due to high ultraviolet exposure. When these real-world conditions are applied to safety calculations, systemic exposure to homosalate increases substantially, making safety margins highly sensitive to concentration and modelling assumptions.

Why safety margins are under scrutiny?

Risk assessments for sunscreen ingredients rely on margins of safety that compare internal exposure with toxicological reference points. For homosalate, different regulators have selected different reference values from the same underlying studies, leading to very different conclusions. Sensitivity analyses show that under high-use scenarios, small changes in assumptions can shift safety margins from acceptable to very low, highlighting uncertainty rather than clear reassurance.

What the current regulatory submission seeks?

In response to these issues, a formal submission has been made requesting that homosalate’s status in Australian therapeutic sunscreens be re-evaluated, alongside the TGA’s 2025 proposal to introduce precautionary restrictions following its safety review. The submission draws on updated human absorption data, international regulatory assessments, and Australian-specific exposure modelling. It does not question the importance of sunscreen for skin cancer prevention, but asks whether existing ingredient limits remain appropriate under current scientific understanding.

What possible outcomes are being considered?

Two pathways are outlined. The primary position is that removal should be considered if safety cannot be if safety cannot be confidently assured under widespread, high-frequency use, with restriction to lower concentrations presented as a secondary regulatory pathway. A secondary option proposes a much lower concentration that aligns with conservative exposure modelling and achieves commonly used safety benchmarks. Both approaches aim to align regulation with contemporary evidence.

Why this review is part of a broader trend?

Re-examining long-standing ingredients as science evolves is a normal part of modern regulation. This process reflects growing recognition that real-world exposure patterns, cumulative use, and updated toxicology need to be considered together. The current review focuses on evidence, transparency, and ensuring that everyday products continue to meet modern safety expectations as knowledge advances.

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About the Australian Sunscreen Council

The Australian Sunscreen Council (ASC) is dedicated to protecting public health by championing the highest standards in sunscreen safety, testing, use and transparency.

Our mission is to ensure that all sunscreen and related products available to Australians meet or exceed the latest scientific evidence on ultraviolet (UV) protection and human health.

We promote balanced, evidence-based sun safety guidance, recognising that sunscreen is only a small part of the overall picture when it comes to sun safety and health. Our approach is holistic: effective UV protection includes shade, clothing, behaviour, and thoughtful timing of exposure—not sunscreen alone.

The ASC also supports greater public awareness of the documented benefits of moderate sun exposure, including vitamin D synthesis, improved mental wellbeing, and nitric oxide release—a process linked to healthier cardiovascular function and improved blood pressure regulation. We believe Australians deserve clear, science-backed advice that helps them understand how to obtain these benefits safely.

The ASC works collaboratively with government agencies, dermatologists, and public health experts to improve sunscreen standards and to support balanced, science-driven sun safety advice for all Australians.

Learn more at www.australiansunscreencouncil.org