Isothiazolinone Content of US Consumer Adhesives: Ultrahigh-Performance Liquid Chromatographic Mass Spectrometry...

There are limited data regarding the prevalence and concentration of isothiazolinone preservatives in consumer adhesives.

The aim of this study was to determine the prevalence and concentration of 5 specific isothiazolinones (methylisothiazolinone [MI], methylchloroisothiazolinone [MCI], benzisothiazolinone [BIT], butyl BIT, and octylisothiazolinone) in US adhesives.

Thirty-eight consumer adhesives were analyzed using ultrahigh-performance liquid chromatographic-mass spectrometry. Fisher exact tests were used to test for isothiazolinone content and: 1) glue format (2) application purpose and 3) extraction method.

Nineteen adhesives (50%) had at least 1 isothiazolinone, and 15 contained 2 isothiazolinones. Frequencies and concentrations were as follows: MI (44.7%; 4-133 ppm), MCI (31.6%; 7-27 ppm), BIT (15.8%; 10-86 ppm), and octylisothiazolinone (2.6%; 1 ppm). Butyl BIT was not detected in any of the adhesives. Format (stick vs liquid) was not statistically associated with isothiazolinone presence. At least half of adhesives in the following application purposes had at least 1 isothiazolinone: shoe, craft, fabric, and school. All-purpose glues had a statistically significant lower concentration of MI and MCI, whereas craft glues were associated with higher concentrations of MI and MCI. Compared with other glues, fabric adhesives were associated with a higher risk of containing BIT.

Half of the tested adhesives contained at least 1 isothiazolinone. Methylisothiazolinone and MCI were the most common. Consumers and dermatologists should be aware of adhesives as a source of isothiazolinones.