October 4, 2010 was more than just an ordinary Monday. It was the day that NEMA members voluntarily began capping the total mercury content in CFLs (compact fluorescent lamps) of less than 25 W at 4 mg per unit. The total mercury content of CFLs that use 25 to 40 W of electricity will be capped at 5 mg per unit.
Mercury is an essential element in CFLs and lets the bulb more efficiently use tube phosphors to generate visible light. The additional milligram for lamps of 25 to 40 W is needed to operate these higher-wattage lamps for higher light-output demands in the U.S.The new agreement builds upon voluntary commitments made by CFL makers in March 2007. That agreement capped average mercury content of CFL models of less than 25 W at 5.0 mg per lamp. CFL models that use 25 to 40 W of electricity had average mercury content capped at 6.0 mg per lamp.