Superfund Research Program

February 2026

Exposure Assessment

Researchers at Duke University, funded by the NIEHS Superfund Research Program, reported that silicone ankle bands can be used as a practical and noninvasive tool to assess infant’s exposures to harmful compounds.

Infants and children are particularly susceptible to harmful exposures because their bodies are still developing. However, traditional approaches for assessing these exposures is challenging, including difficulties in collecting urine from diapers and in accurately tracing some parent compounds to their metabolites in urine. The research team sought to overcome these challenges by testing and validating silicone bands as a reliable replacement.

Originally developed as wristbands for personal exposure monitoring by researchers at the Oregon State University SRP Center and used by the Duke team in other settings, the team modified the concept into ankle bands to better suit use with infants, who are more likely to put things in their mouths.

Infants aged six to 18 months wore silicone ankle bands for three consecutive days. Then the team analyzed the bands for 20 compounds called organophosphate esters (OPEs) – chemicals used as flame retardants and plasticizers. They also compared the compounds detected on the bands to compounds measured in urine samples from the children.

Seven OPEs were found in over 70% of the ankle bands. TDCIPP and TPHP were the most abundant OPEs on bands. TDCIPP is a flame retardant used in products like furniture and baby products, while TPHP is a used as a flame retardant and a plasticizer in products like nail polish.

There was a strong overlap between the compounds found in urine and the compounds found in the ankle bands, though the bands captured a broader range of parent OPE compounds than were detected in urine.

According to the authors, the bands can reliably capture exposure trends in infants without using urine or other biological samples. Ankle bands also offer advantages over analyzing biological samples because they directly measure parent compounds rather than metabolites that can be difficult to trace to their source.

To learn more, please refer to the following source:

Wise CF, Boxer E, Hurst J, Hoehn RM, Herkert NJ, Hay D, Cooper EM, Stapleton HM, Hoffman K. 2025. Silicone ankle bands as a tool to assess infant exposures to semivolatile organic chemicals in indoor environments. Environ Sci Technol Lett 12(10):1314-1319. doi: 10.1021/acs.estlett.5c00774. PMID: 41112140; PMCID: PMC12529947.