Answer from perplexity ai: "Gum is illegal in Singapore due to the potential damage it could cause to public infrastructure and the environment. The ban was introduced in 1992 to address issues such as gum stuck on subway door sensors, elevator buttons, and public bus seats, which increased maintenance costs and disrupted public transportation. Additionally, gum littering was seen as a threat to the country's goal of maintaining a clean and orderly environment. The ban has since been partially lifted, allowing for the sale of therapeutic and dental chewing gum, but the importation and sale of regular chewing gum remain illegal"