Gov. Mitch Daniels (search) signed legislation Tuesday requiring many stores to keep cold medicines in a locked case or behind a counter if they contain ingredients used to make methamphetamine.

The new law, approved unanimously by the General Assembly last month, places restrictions on the sale and purchase of drugs containing ephedrine (search) or pseudoephedrine, which are commonly found in over-the-counter cold and allergy remedies.

"There are campers, kids, hunters, conservation officers tripping over meth labs in the course of their daily work," the governor said, calling Vigo County the "epicenter of a scourge, which has now touched every corner of Indiana."

Stores without pharmacies will be required to keep the drugs in a locked case or behind a counter. Those with pharmacies can have the drugs within sight of an employee, if the store has 24-hour video surveillance.

Customers will be limited to 3 grams — about 100 tablets — of the medicines per week and must show ID and sign a logbook. The restrictions take effect July 1.

Daniels called the new law one of the toughest in the country — similar to one in Oklahoma that has led to a dramatic reduction in meth production in that state.

Several other states also have restricted access — either by allowing only pharmacies to sell drugs with pseudoephedrine or making retailers lock up the products or sell them from staffed counters.

Pseudoephedrine, a main ingredient in a number of over-the-counter drugs such as Sudafed and Sinutab, can be extracted by boiling down cold medicines. Toxic chemicals are then used to turn the substance into meth.

Also on Tuesday, Wisconsin lawmakers approved a similar bill requiring consumers to buy medications containing pseudoephedrine from a pharmacist or pharmacy technician. Customers would have to show a picture ID and sign a logbook.

The bill now goes to Gov. Jim Doyle (search), who supports it.

Several large retailers, including Wal-Mart, Kmart and Walgreens, say they will move medications with pseudoephedrine behind pharmacy counters, and Target already has done so.