The technological method in the field of foundry production is described, which combines additive manufacturing (AM) of disposable foundry polymer patterns with waste polystyrene (EPS) waste disposal. It was created to switch to the method of Lost Foam casting on gasified patterns (LFC), from the current method of casting on printed patterns of fired. The latter method is used because modern printed patterns have a high density and ash content, which degrades the quality of metal castings when used for LFC. EPS disposal gives an environmental effect, and AM patterns are an example of the spread of digitalization and automation of foundry production. Examples of EPS disposal, examples of castings after firing additively manufactured patterns and the ash residue, consisting of carbon, found in the working cavities of molds after firing such patterns are described. Examples of printing patterns with a cellular core and a ventilation channel are shown, an unsuccessful example of aluminum casting by the LFC method in a vacuumed sand mold, as well as an example of a 3D printer for printing using crushed plastic or plastic granules. The developed method of printing one-time foundry patterns for gasification in sand foundry mold corresponds to the trend of spreading AM in foundry production. If the specific weight of the printed pattern is too high, then new LFC methods are used with the removal of excess gases from the gasification of the pattern through the ventilation duct in the pattern and tubular evaporation outside the mold and their oxidation, in particular by our method. Such neutralization of gaseous waste at LFC rightly complements the utilization of EPS solid waste as a raw material for AM foundry patterns, together these methods give a synergistic effect on environmental protection, improving the working conditions of foundries and reducing the cost of cast products while improving its quality. Keywords: Lost Foam casting; gasified patterns; 3D printing; additive manufacturing; one-time patterns; burning patterns; expanded polystyrene; disposal of polymer waste.