Potential harmfulness of solvent flexographic inks for flexible packaging printing

flexible packaging for food and pharmaceutical products. Printing inks based on organic solvents hold the lead in application, especially in the packaging industry. The analysis of world tendencies is carried out concerning the restriction of harmful substances at manufacturing alcohol-solvent flexographic printing inks and the accepted regulatory documents. The examples of possible migration of printing ink components in the process of packaging production are described. Contamination can occur due to the contact of the film reverse side with the printed one, penetration (diffusion) of the ink components both on the surface of the ink layer and through the printed material, evaporation of the ink layer components into the environment. A significant amount of organic solvents, organic and inorganic pigments and plasticizers, for which carcinogenic and toxic effects on living organisms are established, are prohibited or minimally used in the component composition of alcohol-solvent flexographic inks. The following factors are identified, on which the process of diffusion of substances from the applied ink layer depends. In particular, they are the structure of molecules and the molecular weight of ink components, the operating temperature of printed packaging, thickness and ability of printed materials to prevent diffusion of molecules. The appropriate measures are described to prevent the process of migration of printing ink components during the packaging operation. The analysis has made it possible to form the classification of measures to minimize the harmful effects of alcohol-solvent printing inks. The measures can be divided into two directions: chemical one, when the components of the ink composition are carefully selected, and physical one, with the creation of effective barriers, taking into account the operational characteristics of flexible packaging.