Mike Redmond says the only chemical that has been banned is 2,4-D.
He says lawn-care companies still have access to wide range of similar chemicals, which are banned in other provinces.
Redmond says there's ample evidence the chemicals being sprayed on P.E.I. lawns can cause a wide range of medial problems.
The party leader says Newfoundland, Nova Scotia, Ontario, Manitoba and Quebec already have broader bans in place.