Landmark Study Finds Homosalate in Sunscreens Could Be Harming 50% of QLD Children
New Australian study finds 80% of children exceeded the health-based HBM-I guidance value for homosalate, while 53% exceeded the higher HBM-II level where adverse health effects are possible
The findings were published in Environmental Science & Technology in the paper:
Assessing UV Filter Exposure in Queensland, Australia: Human Biomonitoring Evidence Highlighting Homosalate in Children.
A major new peer-reviewed Australian human biomonitoring study has found widespread and concerning exposure to the sunscreen chemical homosalate among Queensland children.
Researchers found that 80% of children’s pooled urine samples exceeded the German HBM-I health-based guidance value for the homosalate metabolite HMS-CA5.
HBM-I represents the concentration at and below which no adverse health effects are expected according to current scientific knowledge and no action is required.
In other words, four out of five children’s pooled samples were above that health-based guidance level.
Even more significantly, 53% of children’s pooled samples exceeded HBM-II — the higher health-based limit at and above which the researchers state that adverse health effects are possible, with an “acute need for exposure reduction” and biomedical advice.
The research analysed 187 pooled urine samples representing approximately 18,700 Australians, collected between 2012 and 2023.
The researchers examined human exposure to three chemical UV filters commonly used in sunscreen:
Homosalate
Octisalate
Octocrylene
By far the most concerning population-level result related to homosalate.
80% of children exceeded the HBM-I health-based guidance value
The scale of the HBM-I exceedance is one of the most important findings of the study.
For the homosalate metabolite HMS-CA5, the researchers found:
80% of children’s pooled urine samples exceeded HBM-I.
For children and men, the HBM-I value for HMS-CA5 is 0.16 µg/L.
The researchers explain that HBM-I is the urinary biomarker concentration “at and below which no health effects are expected according to the current state of knowledge, and no action is required.”
An exceedance therefore means the measured exposure is above the concentration at and below which adverse effects are expected not to occur.
The pattern also became more consistent over time.
From 2018 onwards, every children’s pooled sample exceeded the HBM-I value for HMS-CA5.
That is not simply evidence that a sunscreen ingredient can be detected in children.
It is evidence that a very large proportion of the children represented in these samples had internal concentrations above an established health-based guidance value derived from toxicological evidence.
More than half exceeded HBM-II — where adverse health effects are possible
The higher HBM-II result is more concerning again.
For children and men, the HBM-II value for the homosalate metabolite HMS-CA5 is 0.49 µg/L.
The study defines HBM-II as the:
“limit value at which and above which adverse health effects are possible”
and states that reaching or exceeding that level creates an:
“acute need for exposure reduction”
together with the provision of biomedical advice.
53% of children’s pooled samples exceeded HBM-II.
The first HBM-II exceedances in children appeared as early as 2016.
Put plainly:
More than half of the Queensland children represented by these pooled samples had concentrations of a homosalate metabolite at a level where adverse health effects are considered possible under the German human biomonitoring framework.
That is a critical sunscreen safety finding.
Kidney toxicity is the critical health endpoint
For homosalate, the health-based HBM values used in the study were derived using toxicological evidence identifying adverse effects on the kidneys as the critical endpoint.
The study’s own risk-assessment table lists the critical effect for both cis-homosalate and trans-homosalate as:
“adverse effects in the kidneys.”
This is important because the biomonitoring thresholds are not arbitrary numbers.
They are toxicology-based guidance values derived using human toxicokinetic data and the most sensitive adverse effects identified in experimental studies.
The research therefore connects measured exposure inside Australian children with an established health-based toxicological framework.
Homosalate has also raised endocrine and fertility concerns
Homosalate has also been under regulatory scrutiny because of concerns regarding its potential endocrine effects and reproductive toxicity.
The TGA’s own 2025 safety review states that available information for homosalate and several other UV filters indicates potential endocrine effects, although it concluded that existing data were not adequate to establish causality in humans and that further investigation was warranted.
Documents subsequently obtained from the TGA under Freedom of Information also reveal that its internal consideration of homosalate included concerns relevant to kidney toxicity, fertility and development.
The Australian Sunscreen Council published the ten-document FOI release in July 2026.
According to the released material, the TGA's own nonclinical assessment reviewed a combined repeat-dose and reproductive/developmental toxicity study and established a general toxicity NOAEL of 120 mg/kg/day.
Importantly, the assessment recorded that a reproductive and developmental NOAEL could not be reliably established.
The documents also record TGA consideration of possible effects relevant to the kidneys, fertility and development.
Children had dramatically greater UV-filter exposure
The new study found a striking relationship between age and sunscreen UV-filter exposure.
Children had roughly one order of magnitude higher biomarker concentrations than adolescents and adults for several of the UV-filter biomarkers studied.
In 100% of children’s pooled samples, the most sensitive biomarker for each of the three UV filters investigated was present above the laboratory limit of quantification.
The researchers are calling for stricter Australian regulation
The authors did not describe their results merely as an interesting exposure finding.
They explicitly called for action.
They concluded that:
“These findings indicate the need to reduce HMS exposure in at least some individuals”
and said their results confirmed the:
“necessity for stricter regulations for homosalate in Australia”.
The researchers specifically raised the possibility that tighter restrictions could focus on products intended for children.
The study also highlighted the potential public-health consequences of failing to address legitimate sunscreen ingredient concerns.
Researchers warned that a loss of confidence in sunscreen safety could lead to ineffective sun-protection behaviour.
Initial claims that the TGA is now “looking into” homosalate are misleading.
Following media coverage of the new study, the public may be left with the impression that the TGA is only now beginning to investigate whether homosalate presents a safety concern.
That impression would be incomplete.
The TGA finalised and published its safety review of homosalate more than a year ago, on 8 July 2025.
The TGA recommended regulatory controls for homosalate to restrict its permitted concentration and use in therapeutic sunscreens.
The regulator had already evaluated homosalate.
It had already identified systemic exposure as an issue.
It had already considered its toxicity.
And it had already concluded that the existing conditions of use warranted additional regulatory controls.
The TGA's own Australian exposure model found an insufficient safety margin
The TGA used its Australian Sunscreen Exposure Model, or ASEM, to estimate long-term exposure to sunscreen ingredients by Australian adults and children.
The regulator states that a Margin of Safety of 100 or more is considered satisfactory for controlling risks to human health and safety from long-term use by the Australian population.
For homosalate and oxybenzone, the Margin of Safety was below 100 when general sunscreen was applied to the body at the maximum permitted concentration.
The significance of the new biomonitoring study is therefore particularly striking.
The TGA had already modelled potential homosalate exposure and found an inadequate safety margin under relevant use conditions.
Researchers have now measured actual internal exposure among Australians and found 80% of children's pools above HBM-I and 53% above HBM-II.
FOI documents revealed fertility, developmental and kidney concerns
Documents obtained under the Freedom of Information Act 1982 and published by the Australian Sunscreen Council provide an even clearer picture of what Australian regulators already knew.
The ten documents relate to the TGA's consideration of proposed scheduling restrictions for homosalate.
The material shows the TGA proposed restrictions in July 2025, including listing homosalate in the Poisons Standard and reducing its permitted concentration in therapeutic sunscreens.
A TGA pre-meeting brief recorded that homosalate:
is absorbed through the skin;
is used extensively in Australian sunscreen;
may have effects relevant to the kidneys, fertility and development.
The TGA's nonclinical advice recommended that homosalate be listed in the Poisons Standard with restrictions on its use.
Internal correspondence later examined whether sunscreen could be formulated without homosalate and considered the availability of alternative UV filters following restrictions introduced in Europe.
The Australian Sunscreen Council made the released documents publicly available so researchers, health professionals, industry and consumers could examine the underlying evidence themselves.
The new study turns a modelled concern into human biomonitoring evidence
Until now, much of Australia's debate over homosalate has centred on toxicology studies and mathematical exposure modelling.
This study adds another dimension:
actual measurements from Australian people.
The paper analysed pooled samples representing approximately 18,700 individuals.
Children had the greatest exposure.
For the principal cis-homosalate biomarker:
80% of children’s pools exceeded HBM-I.
53% exceeded HBM-II.
From 2018 onwards:
100% of children's pools exceeded HBM-I.
That is precisely why human biomonitoring matters.
A theoretical exposure calculation attempts to predict how much of a substance may enter the body.
Human biomonitoring measures the chemical or its metabolites after exposure has actually occurred.
Australian doctors respond
Australian Medical Association Queensland President Dr Nick Yim told The Courier-Mail:
“While sunscreen plays a vital role in preventing skin cancer, especially in Queensland, with increasing research we now know that some chemicals could cause harm.”
Zinc oxide is recognised by the FDA as safe and effective
Consumers concerned about homosalate have alternatives.
Most importantly, zinc oxide has a fundamentally different safety-data position under the United States Food and Drug Administration's sunscreen framework.
The FDA has determined that sufficient data are available to support zinc oxide as Generally Recognized as Safe and Effective — GRASE — for sunscreen use.
By contrast, the FDA has stated that the available record does not contain sufficient data to make the same positive GRASE determination for a range of chemical UV filters, including homosalate.
Consumers who wish to avoid homosalate can look for sunscreens labelled “zinc” or “mineral.”
They should also check the product's active-ingredient panel to ensure zinc oxide is being used and determine whether any chemical UV filters are also included in the formulation.
About the researchers
The study brings together researchers with specialist expertise in human biomonitoring, toxicology, environmental exposure science, epidemiology, analytical chemistry and pathology from Australia and Germany.
Katharina E. Ebert
Katharina E. Ebert is based at the Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of Ruhr University Bochum in Germany.
Her research has focused extensively on sunscreen UV filters and, in particular, the metabolism, toxicokinetics and human biomonitoring of homosalate.
Ebert has previously led research examining what happens to homosalate following dermal application in humans and identifying urinary metabolites capable of providing reliable measures of internal homosalate exposure.
That work directly supports the analytical approach used in the new Australian study.
Danielle E. Que
Danielle E. Que is an Australian environmental exposure researcher associated with The University of Queensland's Queensland Alliance for Environmental Health Sciences.
Her research involves human biomonitoring and the use of biological samples to investigate Australians' exposure to environmental and consumer-product chemicals.
She has contributed to research examining population-level chemical exposure and how those exposures change over time.
Anne Lotz
Anne Lotz is a researcher at the Institute for Prevention and Occupational Medicine of the German Social Accident Insurance at Ruhr University Bochum.
Her research encompasses human biomonitoring, occupational and environmental exposure assessment and epidemiology.
She has contributed to investigations measuring internal chemical exposure and assessing the potential health implications of environmental and occupational contaminants.
Professor Thomas Brüning
Professor Thomas Brüning is Director of the Institute for Prevention and Occupational Medicine of the German Social Accident Insurance and Professor of Occupational Medicine at Ruhr University Bochum.
His career spans occupational medicine, environmental medicine, epidemiology and toxicology.
He has published extensively in the fields of chemical exposure and human biomonitoring and has contributed to major research examining the effects of environmental and workplace chemical exposures.
Dr Leisa-Maree Toms
Dr Leisa-Maree Toms is an Australian environmental health and human biomonitoring researcher associated with The University of Queensland.
Her work has examined Australian population exposure to both persistent and emerging environmental chemicals.
She has extensive experience using pooled biological samples to assess exposure patterns across large populations and over long periods.
Peter Hobson
Peter Hobson is associated with Sullivan Nicolaides Pathology in Brisbane and has contributed to Australian human biomonitoring programs using deidentified surplus pathology specimens.
This approach has enabled researchers to examine population-level exposure to environmental chemicals using large numbers of biological samples that would otherwise be discarded.
Heath Glover
Heath Glover is also associated with Sullivan Nicolaides Pathology and has contributed to Australian biomonitoring research examining changing population exposure to consumer and environmental chemicals.
Sullivan Nicolaides Pathology was an important contributor to the biological sample collection underpinning this study.
Dr Holger M. Koch
Dr Holger M. Koch is a leading researcher in human biomonitoring at the Institute for Prevention and Occupational Medicine of the German Social Accident Insurance.
His research has helped develop analytical biomarkers capable of measuring human exposure to numerous chemicals used in consumer products and industry.
His work has included substantial research into UV filters and the human metabolism and toxicokinetics of homosalate.
Professor Jochen F. Mueller
Professor Jochen F. Mueller is a leading Australian environmental exposure scientist at The University of Queensland.
His research focuses on environmental contaminants, chemical exposure pathways and techniques for understanding how human exposure changes over time.
He has played a major role in developing Australia's capacity for long-term human biomonitoring and environmental specimen banking.
Dr Daniel Bury
Dr Daniel Bury is a human biomonitoring and toxicokinetics researcher at the Institute for Prevention and Occupational Medicine of the German Social Accident Insurance at Ruhr University Bochum.
His work focuses on measuring internal chemical exposure and translating biomonitoring concentrations into meaningful estimates of exposure and potential risk.
Bury has published specifically on UV filters and homosalate and is senior author of the new Australian study.
Study
Ebert KE, Que DE, Lotz A, Brüning T, Toms L-ML, Hobson P, Glover H, Koch HM, Mueller JF, Bury D.
Assessing UV Filter Exposure in Queensland, Australia: Human Biomonitoring Evidence Highlighting Homosalate in Children.
Environmental Science & Technology, 2026.
DOI: 10.1021/acs.est.6c09445
