What makes a paint environmentally preferable?
Paint is made from three basic ingredients: pigment, binder and solvent. In addition to these it can contain a variety of additives, including biocides (to prevent bacteria or fungal growth in the can or on the painted surface). Each of these ingredients can have an impact on the environment during the life cycle of the paint.
The solvent can be thought of as the carrier. It evaporates as the paint dries on the surface. Water is obviously the preferable solvent as it causes no environmental problems as it evaporates, whereas organic solvents release volatile organic compounds (VOCs) into the surrounding environment. Solvent-based paint also contains around 50 per cent more embodied energy than water-based paint.
Pigments provide the colour, the opacity and the protective barrier in the paint. Titanium dioxide is used widely in the paint industry for this purpose. Unlike the organic solvents its major environmental impact is in its manufacture. It has high embodied energy, is a limited resource and its production results in both air and water emissions that carry an environmental impact.
The other components of paints can contain ingredients that are toxic to those producing the paint and those applying it. Many chemicals are used as biocides, and these are necessary. However, it is important to exclude those that are carcinogenic or cause mutations. GECA Paints and Coatings standard excludes the use of chemicals that fall into these categories and limits other potentially dangerous compounds.
GECA certifies only water based paints and places limits on the amount of titanium dioxide that can be used in paint. It also has criteria which address the amount of VOCs released, as even water based paints will emit these from ingredients like the biocides.
See GECA’s Paints and Coatings standard