It can be difficult for store clerks to figure out someone's age just by looking, said Shirley Barnhart, owner of Barnhart's Supermarkets in the Eastern Panhandle of West Virginia.
"I've told 'em (employees) to card them unless they have gray hair," she said.
Some stores, including Terrace Liquors in Hagerstown, have put up signs to notify customers that things will change today.
"It's the law. You gotta do what you gotta do," said Manager Steve Morozek, who said he cards anyone who looks younger than 18.
Patsy McBee, owner of Sandie's News Agency in Berkeley Springs, W.Va., said she asks customers she doesn't know for identification when they buy tobacco or alcohol.
"We have four young people of our own so I know how parents feel," McBee said. "When we were raising them we didn't think very highly of people who sell to underage."
Pharmhouse Drugstore, because it is close to South Hagerstown High School, is a prime target for underage smokers.
But Assistant Manager Mary Lynch said clerks there already have an eagle eye.
"They card anyone that comes through with cigarettes. And they haven't gotten punched yet," she said with a laugh.
At Pharmhouse, warning signs are posted on the front doors, at the customer service counter and around the cigarette display.
Barbara Orlando, community development coordinator at Trans Potomac Prevention Coalition in Hagerstown, said she likes the new rules.
"This is not designed to punish people who already use it, it's to deter the youth from starting," she said.
The older someone is when they start smoking, the less likely they are to become a long-term smoker, she said.
Despite the tightened regulations, teenagers say they think cigarettes will remain easy to get.
One 16-year-old boy said his 18-year-old brother buys him cigarettes.
"I don't really care (whether clerks ask for identification). I ain't got to worry about it," he said.
Others say they will sneak them from parents or get them from friends.
Even though he doesn't smoke, one 14-year-old said he doesn't like the new rules.
"You should be able to make your own decision," he said.
The new rules are a result of the Food and Drug Administration's declaration last year that nicotine is a drug.
Although state laws already outlaw selling tobacco to anyone under age 18, government figures show minors buy $1.6 billion in tobacco annually, and 75 percent of teen smokers say they've never been carded, the Associated Press reported.
The FDA, in the first of sweeping new tobacco regulations, ordered retailers to card all customers younger than 27 to prevent mature-looking minors from buying tobacco. Store owners caught selling to teens face federal fines of $250 per violation.
In August, the FDA will ban cigarette vending machines and self-service displays, except in places where no one under 18 is permitted.
Police agencies have said it is difficult to crack down on underage smoking because so many more crimes take precedence.
Hagerstown City Police Lt. Dick Mumma expects this law to be no different.
"We don't have the manpower. Let's be honest here," Mumma said. "They make the laws, but they have no concept of how it will be enforced."
Police will check out complaints that the law is being broken, he said.
- The FDA has set up a toll-free number for customers to report violations: 1-888-FDA-4KIDS.