CHESTERFIELD — Gov. Matt Blunt signed legislation Tuesday that will require stores to electronically track purchases of pseudoephedrine products and called it a big step in the fight against methamphetamine.

Local police and prosecutors aren't sure whether it will be enough.

The plan calls for the creation of a statewide electronic database to catalog every purchase of pseudoephedrine, which is meth's key ingredient found in allergy and cold medications such as Sudafed.

Missouri legislators pushed the products behind pharmacy counters in 2005 and required signatures of those buying them. Federal laws also set legal limits on pseudoephedrine products. But police have struggled to keep track of signature logs at stores. The logs can contain hundreds of names at any time, said Jefferson County sheriff's Cpl. Scott Poe.

By sometime in 2009, the database should allow police to access every transaction involving pseudoephedrine as they occur statewide.

"I believe it's a step in the right direction," said Poe, who leads a drug task force in Missouri's meth epicenter. "But time will have to tell, as we've seen the resourcefulness of meth cooks in the past and their ability to work their way around the laws."

The database will make it easier to tell whether known meth cooks and addicts have been buying pills, but it won't stop them, Poe said.

Missouri will be one of three states to have a database. Addicts will go to other states to buy the products, Poe predicted. Illinois has no database.

Assistant Jefferson County Prosecuting Attorney Trisha Stefanski said the database will make offenders easier to find and charge. But she said Oregon's approach is the best. Oregon declared pseudoephedrine a prescription in 2006 and has seen its meth lab problem virtually vanish.

"Prescription status is the only way you're completely going to stop it," Stefanski said.

Blunt disagrees. "We think this is going to be enough," he said Tuesday at the St. Louis County police emergency operations center.

In 2007, Missouri led the nation in meth labs busted with 1,185.