The bill, passed last week by the House of Representatives, would restrict the sale of thermometers and other products containing mercury. It also would prohibit schools from buying or using mercury items in bulk and require manufacturers to label products containing mercury.
The measure was one of a series of proposals pushed through the Senate on Monday that now must go to the governor for approval.
Last spring, the mercury bill died quietly, overshadowed by budgetary concerns and other environmental proposals. It was resurrected this year with backing from the state Department of Environmental Protection and softer language - including a more liberal phase-in - that legislators said would help manufacturers comply more easily.
State Sen. Gary LeBeau, D-East Hartford, said lawmakers have become more "fully aware of the problems of mercury dangers."
"It's a dangerous chemical. It's a dangerous substance. It's something we have to do something about," LeBeau said.
Chris Cooper, spokesman for Gov. John G. Rowland, said the governor as of Monday had not yet seen the bill. If he signs it, Connecticut would follow the lead of other New England states now pushing proposals that address the dangers of mercury contamination. Nationwide, New England and the Great Lakes region have the highest amounts of mercury in soil and waterways.
Mercury is a potent neurotoxin that is released into the environment mainly through coal-burning plants. Legislation to restrict its use follows recommendations by the Conference of New England Governors and Eastern Canadian Premiers, a group in which Rowland has been active.
Rhode Island passed comprehensive mercury-reduction legislation last summer, while other states have adopted pieces of that package. The restrictions have drawn opposition from some manufacturers of mercury products, such as thermostats, light switches in automobiles and computer display screens.
John H. Gurley, project associate for Connecticut's CleanWater Action group, said the bill's comeback marked a victory for environmentalists.
"They're starting to understand that people don't want to be exposed to it," Gurley said.