Application of the incorporation of cigarette butts into building materials: a review

Trillions of cigarette butts are discarded annually worldwide, releasing over 7000 toxic chemicals and becoming one of the most prevalent solid wastes in society. Cigarette filters are composed primarily of cellulose acetate fibers, a nonbiodegradable material that poses significant environmental challenges. This systematic review surveyed the ScienceDirect, Web of Science, and Scopus databases to evaluate recent research on the incorporation of cigarette butt fibers into building materials such as mortar, concrete, gypsum composites, asphalt, and bricks. Few studies were found in these areas, and their results were analyzed and compared, allowing for the identification of gaps in the literature. It was observed that, in small proportions, the incorporation of cigarette butts can reduce density, improve thermal insulation, and decrease energy consumption. On the other hand, higher levels compromise mechanical strength and durability, and there is still a lack of fundamental tests that limit the practical application of these materials.