Contact Dermatitis • Original Article
Isothiazolinones are still widely used in paints purchased in ve
European countries: a follow-up study
Andreas V. Thomsen
, Jakob F. Schwensen
, Rossana Bossi
, Piu Banerjee
, Elena Giménez-Arnau
, Carola Lidén
, Wolfgang Uter
, Ian R. White
and Jeanne D. Johansen
Department of Dermatology and Allergy, National Allergy Research Centre, Copenhagen University Hospital Herlev and Gentofte, 2900 Hellerup, Denmark,
Department of Environmental Science, Aarhus University, 4000 Roskilde, Denmark,
St John’s Institute of Dermatology, Guy’s Hospital, London SE1 9RT, UK,
Laboratoire de Dermatochimie, CNRS and University of Strasbourg, 67091 Strasbourg, France,
Institute of Environmental Medicine, Karolinska Institutet,
171 77 Stockholm, Sweden and
Department of Medical Informatics, Biometry and Epidemiology, Friedrich-Alexander University, 91054 Erlangen, Germany
Background. An increasing incidence of contact allergy to methylisothiazolinone (MI)
has been seen, caused, in particular, by cosmetic products and paints. A study from
2015 showed that 93.0% of paints bought in ve European countries contained MI. New
regulations have been discussed for paints in the EU, which may have inuenced this
Objectives. To re-evaluate the use and concentrations of MI and four other isothiazoli-
nones in water-based wall paints.
Methods. Water-based white wall paints (n = 60) were purchased in retail stores in ve
European countries: Denmark, France, Germany, Sweden, and the United Kingdom. The
paints were analysed for isothiazolione content by the use of high-performance liquid
chromatography coupled to ultraviolet detection, and the results were conrmed with
high-performance liquid chromatography–tandem mass spectrometry.
Results. MI was identied in 55 (91.7%) of the paints, with concentrations rang-
ing from 1.1 to 142.7 ppm. The other isothiazolinones were identied in 20.0%
[methylchloroisothiazolinone (MCI)] to 88.3% [benzisothiazolinone (BIT)] of the paints.
BIT concentrations varied signicantly between countries, whereas MI and MCI concen-
trations did not. There were no statistically signicant differences in MI, MCI and BIT
concentrations between the current study and the 2015 study.
Conclusions. MI and other isothiazolinones are widely used in paints available in
Europe. Their use does not seem to be decreasing.
Key words: benzisothiazolinone; dichlorooctylisothiazolinone; environmental label;
exposure analysis; methylchloroisothiazolinone; methylisothiazolinone;
octylisothiazolinone; paint; safety data sheet.
The isothiazolinones methylisothiazolinone (MI),
methylchloroisothiazolinone (MCI), MCI/MI 3:1, ben-
zisothiazolinone (BIT), octylisothiazolinone (OIT) and
dichlorooctylisothiazolinone (DCOIT) (see Table 1 for
further information) are preservatives used in a wide
Correspondence: Andreas V. Thomsen, MB, Department of Dermatology and Allergy, National Allergy Research Centre, Copenhagen University Hospital
Herlev-Gentofte, Kildegårdsvej 28, DK-2900 Hellerup, Denmark. Tel: +45 38 67 39 60; Fax: +45 39 77 71 18.
Conﬂicts of interests: All authors declare no conﬂicts of interests pertinent to the present study.
Accepted for publication 24 October 2017
range of industrial chemical products (as biocides) and
partly (MCI and MI) in cosmetic and household products,
owing to their activity against bacteria and fungi (1–5).
Although isothiazolinones have been recognized since
the 1970s as contact allergens, and the use of MCI/MI
© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Contact Dermatitis, 78, 246–253