Phenylmercuric acetate (PMA) has been used against antifungal activity in agriculture and in leather processing and has known to work well. PMA has also been used as an additive in eye-drops and paint in order to preserve them, as a disinfectant, and as a catalyst in polyurethane systems.[4][5] In the 1950s–1970s, PMA was used as a catalyst in the 3M Tartan brand polyurethane flexible floors that were commonly in school gymnasiums.[5] School officials worried that mercury vapor was being released into air above the surface of these floors.