In January 2024, the detection of an unexpected phthalate metabolite in samples from children aged 2 to 6 years was reported by the Federal State Office for Nature, the Environment and Consumer Protection in North Rhine Westphalia, Germany (LANUV). Over 60% of the 250 children tested in 2020/21 had mono-n-hexyl phthalate (MnHxP, CAS 24539-57-9) in their urine.
These findings generated considerable media coverage across Germany (e.g., here, here and here) as MnHxP is a metabolite of di-n-hexyl phthalate (DnHxP, CAS 84-75-3), a substance of very high concern (SVHC) due to its reprotoxicity. In 2020, DnHxP was included in the EU REACH authorization list, essentially banning it in the EU unless one has special permission for its use. Since no applications for authorization were submitted, the detection of MnHxP was not anticipated and is a cause for concern due to its toxicity.
Analyses of samples retained from a study in 2017/18 showed that fewer children were affected in previous years (26% compared to 61% in 2020/21). The average MnHxP concentration was 0.28 μg/l in 2017/18, compared to 2.09 μg/l in 2020/21.
“It’s a problem on a larger scale,” said Marike Kolossa-Gehring, head of section toxicology and health related environmental monitoring at the German Environment Agency (UBA). Currently, additional human samples are being analyzed for MnHxP to understand time-trends and duration of exposure. Initial results show that MnHxP is detected in a significant proportion of the samples, which indicates widespread human exposure.
The exact sources of exposure to MnHxP in humans are currently unknown. One hypothesis under investigation is whether a UV filter used in sunscreen (diethylamino hydroxybenzoyl hexyl benzoate, DHHB, CAS 302776-68-7) has been contaminated with DnHxP, but other sources are being discussed.
According to FPF’s FCCmigex database, DnHxP can sometimes be found in food contact materials (FCMs), such as packaging items made of polylactic acid (PLA), adhesive labels used on fruits and vegetables, PET bottles, and take-out food containers made of polypropylene, polystyrene, and paper. However, DnHxP is not authorized for use in plastic FCMs in the EU and a 2022 amendment of the food additive regulation in the US removed its authorization for food contact use (FPF reported). Since many other phthalates have been shown to migrate from FCMs into foods, it can be expected that FCMs contribute to human exposure to MnHxP.
References
LANUV (2024). “Bestimmung von Schadstoffen und Schadstoffmetaboliten im Urin von 2- bis 6-jährigen Kindern aus Nordrhein-Westfalen.” (pdf, in German)
UBA (2024). “Fund eines Weichmachers in Urinproben – Fragen & Antworten.“ (in German)
BfR (2024). “MnHexP in Urinproben: Erste Einschätzungen zu gesundheitlichen Wirkungen.“ (pdf, in German)
Akoueson, F. et al. (2023). “Additives in polypropylene and polylactic acid food packaging: Chemical analysis and bioassays provide complementary tools for risk assessment.” Science of The Total Environment. DOI: 10.1016/j.scitotenv.2022.159318
Hou, H. et al. (2021). “Occurrence and migration of phthalates in adhesive materials to fruits and vegetables.“ Journal of Hazardous Materials. DOI: 10.1016/j.jhazmat.2021.126277
Li, H. et al. (2018). “Phthalate esters in bottled drinking water and their human exposure in Beijing, China.” Food Additives & Contaminants B. DOI: 10.1080/19393210.2018.1495272
Han, Y. et al. (2021). “Widespread occurrence of phthalates in popular take-out food containers from China and the implications for human exposure.” Journal of Cleaner Production. DOI: 10.1016/j.jclepro.2021.125851
Read more
ARD Tagesschau (February 3, 2024). “Weichmacher in zahlreichen Urinproben.” (in German)
The European Conservative (February 5, 2024). “Germany Finds Increasing Levels of Long-Banned Substance in Humans, Including Children.”
Deutschlandfunk (February 8, 2024). “Umweltbundesamt hat Sonnenschutzmittel als Quelle für hohe Konzentration eigentlich verbotener Weichmacher im Urin im Verdacht.“ (in German)
WDR (February 14, 2024). “Hier und heute.“ Interview with Sonja Kolonko (start at 13:15 and 1:32:00, in German)
DAZ (February 26, 2024). “ Was man über Weichmacher in Kinderurin weiß – und was nicht.“ (in German)
RTL (February 28, 2024). “Weichmacher-Skandal: Neue Spur führt zu UV-Filter in Sonnencremes.“ (in German)
