Gym floor and school track manufacturers for schools will face tighter regulations, after the discovery of mercury-tainted fumes closed gymnasiums in districts across the state

This month, the New Jersey Schools Development Authority reported it would, for the first time, require certification from rubberized or urethane floors floor manufacturers that their products do not contain mercury.

The mercury fumes are given off by certain rubberized or synthetic polyurethane flooring that contain the chemical phenyl mercuric acetate, known as PMA. The chemical, found in gym, cafeteria and multipurpose room floors, as well as indoor and outdoor running tracks, has been used in floors since the 1960s, according to the New Jersey Education Association, the state’s largest teacher’s union. The chemical breaks down over time and emits mercury fumes, according to the union. The chemical is not found in gym floors made of wood or vinyl tile, according to the NJEA.