“Some of the pigments used in ink contain metallic substances which are harmful to human health and the environment such as cadmium, chromium, lead and mercury. Conventional printing inks are petroleum-based and used with alcohol-based solvents. As alcohol and petroleum evaporate Volatile Organic Compounds (VOCs) are emitted. VOCs represent environmental pollution and a health hazard to pressroom workers. In terms of atmospheric pollution, VOCs react with nitrogen oxides in the presence of sunlight to create ozone pollution or photochemical smog.” (EcoGraphic.co.uk)
But don’t worry; printing inks have evolved over the last few years. Vegetable-based printing inks contain significantly lower levels of VOCs and are considered to be non-hazardous. As well, their production (from sustainable sources) requires a lot less energy than mineral inks. At the end of the life of a printed product, vegetable inks break down much more easily than traditional pigments, thus requiring less energy during the de-inking stage of recycling.