For many years, isothiazolinones have proven themselves as biocidal agents for in-can preservation and film preservation in aqueous pigment pastes, paints and varnishes. The new Biocides Regulation (EU No. 528/2012) has set in motion a process of revision and re-evaluation of biocidal active substances, the effects of which are gradually being felt in a wide range of applications.
This concerns, inter alia, the active substance 2-methyl-2(H)-isothiazol-3-one (MIT), which is classified by the EU as having skin sensitizing properties according to category 1A. For this reason, as of 05.01.2020, products containing 15 ppm or more MIT must be labeled as skin sensitizing (H317 "May cause allergic skin reactions"). For professional paint and varnish applications, a marking such as this is permissible, but unwelcome. Heubach has therefore addressed the idea of developing alternatives at an early stage within the framework of the Responsible Cares.
Under this framework, our team of experts tested various active ingredients and active ingredient systems, and evaluated them in close cooperation with suppliers. The results of this first stage were further improvements to operational hygiene and a new biocide package consisting of a bactericide preservation based on 1,2-benzisothiazol-3-one (BIT), a co-component and a booster.
From extensive testing and a large number of base colors, unchanged compatibility profiles and the usual high application properties were confirmed.
The plan, after consultation with customers, is for products from the AQUIS™, HEUCOTINT™ W and HEUCOTINT™ UN series to be successively equipped with the new biocide package and delivered. In this way, we can ensure that our customers will be supplied with label-free and still biocidally stable products beyond 05.01.2020.
A further development project to replace BIT, which may be necessary in the future, has already been launched. This project deals with medium- and long-term solutions that may well lead to a change in thinking in terms of conservation.