Newer technologies, caused by tighter regulations on the disposal of fluorescent lights containing mercury, are reducing sales to one of the liquid metal's last high-volume end-use markets.

Mercury sales will total less than 500 metric tons again this year, compared to 1,000 metric tons in 1994. Hospitals are phasing out thermometers, automakers are replacing switches in trunk and hood lights, producers of measuring and control instruments are using digital equipment, and makers of chlorine and caustic soda have made a commitment to cut mercury use 50% by 2002.