Thu, Nov 13
|William Stokes Centre
Jack Eustace Lecture - Evening event
Using Human Biomonitoring as an Early Warning System: A Case Study of Di-n-Hexyl Phthalate Exposure Caused by a Contaminated UV Filter in Sunscreens. Includes drinks reception, tea, coffee, & finger food.
Time & Location
Nov 13, 2025, 6:30 PM – 7:30 PM
William Stokes Centre, St James's Hospital, Saint James, Dublin 8, D08 NHY1, Ireland
About the event
The OHSI programme presents:
Using Human Biomonitoring as an Early Warning System: A Case Study of Di-n-Hexyl Phthalate Exposure Caused by a Contaminated UV Filter in Sunscreens.
Dr. rer. nat. Holger M. Koch
Division Head Human-Biomonitoring
Institute for Prevention and Occupational Medicine of the German Social Accident Insurance - Institute of the Ruhr-University Bochum (IPA)
Bürkle-de-la-Camp-Platz 1
44789 Bochum, Germany
Fon: +49 (0)30 13001 4415
E-Mail: holger.koch@dguv.de
Human biomonitoring (HBM) is increasingly accepted as the gold standard for chemical risk assessment. It is based on the analysis of human samples (e.g. blood, urine) to quantify chemical exposures.
This case study investigates di-n-hexyl-phthalate (DnHexP), a compound that is not authorised in the EU under REACH, as it is classified toxic to reproduction and listed as a “substance of very high concern” (SVHC). Surprisingly, though, its metabolite, mono-n-hexyl-phthalate (MnHexP), has been detected in a considerable fraction of urine samples collected in Germany and Denmark. This talk will take you on a detective’s journey, tracking down the source of DnHexP through the analysis of questionnaires filled out during urine sample collections, product analyses, and patent information. First hints on the potential source were given when urinary MnHexP was found to be associated with previous sunscreen use. Shortly thereafter, patents revealed that DnHexP can be an impurity during the synthesis of diethylamino-hydroxybenzoyl-hexyl-benzoate (DHHB), an increasingly used UV filter. State lab analyses indeed detected DnHexP in ~50% of DHHB-containing sunscreens, but only those. By applying DHHB containing sunscreens in a human trial, we could indeed simulate the previously observed urinary MnHexP levels. An immediately initiated risk assessment by the German HBM-Commission revealed that upper exposures could exceed safe levels, especially in children; immediate measures were needed to eliminate DnHexP from DHHB-containing sunscreens.
Overall, this case study unveils the power of Human Biomonitoring to detect and track down exposures to harmful chemicals, but also to evaluate actual exposures in a risk context.
Dr. rer. nat. Holger M. Koch
Dr. rer. nat. Holger M. Koch has actively been involved in conducting exposure and risk assessments of chemicals through both ambient and human monitoring for the past 25 years. He received his doctorate in occupational toxicology in 2006 from the University of Erlangen-Nuremberg, Germany, with a dissertation on human metabolism, human biomonitoring, and exposure/risk assessment of the plasticiser DEHP (Di(2-ethylhexyl) phthalate). Prior to this, he graduated as a Certified Food Chemist at the Bavarian Health and Food Safety Authority, Erlangen, Germany, in 1999, after a year at the NYS Department of Health (Wadsworth Center, Albany) and the State University of New York at Albany (SUNY) in 1996/97.
Since 2006, Dr Koch has served as Head of the Human Biomonitoring Laboratories at the Institute for Prevention and Occupational Medicine (IPA) - an institute of Ruhr University Bochum, Germany. Together with his active research group and in numerous national and international collaborations, he has already authored over 250 peer-reviewed publications on the exposure and risk assessment of occupational and environmental chemicals, including plasticisers, bisphenols, parabens, UV filters, and pesticides. The speciality of his research group is the study of human metabolism and excretion of novel chemicals, the identification of appropriate exposure biomarkers and the development of sensitive analytical methods to measure these novel chemicals and their biomarkers in both occupational and general population studies. He has been actively involved in renowned projects, including the German National Surveys (GerES), the German Environmental Specimen Bank (ESB), the European Human Biomonitoring Initiative (HBM4EU), and the Partnership for the Assessment of Risks from Chemicals (PARC).
Dr Koch is an Honorary Professor at The University of Queensland, Australia (QAEHS). Since 2010, Dr Koch has been a member of the Human Biomonitoring Commission of the German Environment Agency (UBA), chairing it since 2024. From 2010 to 2015, he was a member of the Chronic Hazard Advisory Panel on Phthalates (CHAP) of the U.S. Consumer Product Safety Commission (CPSC). Since 2017, Dr Koch is co-Editor-in-Chief of the International Journal of Hygiene and Environmental Health (IJHEH) and serves on the Editorial Board of Environment International. According to GoogleScholar, he is currently (October 2025) listed with an h-index of 74 and an i10-index of 208.
Breathe Freely Ireland, the OHSI campaign to improve awareness of respiratory health hazards among construction workers.
The Jack Eustace Lecture is named after Dr Jack Eustace, a pioneer of occupational medicine in Ireland, and one of the founding members in 1972 of a group of Irish 'company doctors' with a dedicated interest in occupational medicine known as the Eustaceans.
The tradition of the Jack Eustace Lecture continues as an annual event, with hosting duties rotating each year between:
Faculty of Occupational Medicine
Occupational Hygiene Society of Ireland,
Irish Society of Occupational Medicine,
Occupational Health Nurses Association of Ireland,
Irish Society of Toxicology.
This event is free for members from each of the five societies.