Ontario proposed new legislation on Tuesday to get companies to cut back on their use of toxic chemicals.

Environment Minister John Gerretsen said the legislation, if passed, would make Ontario the first province in Canada to require big companies to track and report on their use of toxic chemicals, as well as develop plans to cut their use of the substances, he said.

While keeping track and coming up with a plan to cut chemical use would be mandatory, the proposed law will not force companies to actually implement their plans. It will be up to businesses to decide whether they want to follow through, Gerretsen said.

"They do not have to follow that plan immediately," he acknowledged. "But as a result of the public pressures that will be applied from the reporting of those plans, et cetera, we feel that in the long run, that is the better way to go than to come up with mandatory targets."

That doesn't worry Aaron Freeman, policy director with Environmental Defence.

"It sounds troublesome, because we know that voluntary regulation doesn't work in a wide range of environmental areas," Freeman said, "but a model of mandatory reporting and then voluntary target-setting actually works very well."

The state of Massachusetts, for example, passed a similar law in 1989 and 10 years later, companies there had collectively cut back by half the amount of toxic waste they produced. The Ontario law is reportedly based on the one in Massachusetts.

If passed, Ontario's law would be more effective than federal legislation on toxic chemicals, Freeman said.

Currently, Ottawa requires big polluters to report how much is coming out of the smokestack, but not what is going into the products they're making.

"Much of the pollution that we're exposed to doesn't come out of a smokestack. Quite a bit of it is in products themselves — things that are common every day items, in many cases that are found around the home," Freeman said.

Sarah Miller, a spokesperson with the Canadian Environmental Law Association, is optimistic about the pending announcement, saying companies that reduce their use of dangerous substances often find it helps their bottom line.

"They see the wisdom of reducing the cost of getting rid of hazardous waste," she said.

Miller says manufacturers also find they are better able to market their wares in Europe, where there are stricter standards for dangerous substances in consumer products.

With files from the Canadian Press