A lazy summer day turned deadly for 16-year-old Ricky Stem of Old Hickory, and the ''harmless fun'' that killed him is becoming more popular among youth.

Ricky was on summer break from high school nearly 10 years ago when his father came home and found him lying dead on his bedroom floor. Ricky was ''huffing,'' or inhaling household chemicals to get a dizzying high.

While overall drug use among teens is declining, inhalant use is on the rise. It's especially prevalent in Tennessee, which ranks seventh in the nation for inhalant use.

Experts say ignorance is the reason huffing is so popular: Parents often don't know what huffing is - let alone the warning signs - and children vastly underestimate the risks.

''Many times kids that would not try an illegal drug would try an inhalant, thinking it's harmless fun,'' Ricky Stem Sr. says. ''And it's this 'harmless fun' that killed our son.''

Parents unaware, access easy

Ricky Stem was inhaling Freon that he tapped from his parents' home air-conditioning system, but he literally could have used more than a thousand other products. Nearly any type of solvent can be used as an inhalant.

According to the non-profit National Inhalant Prevention Coalition, some common inhalants include compressed air used to remove dust on computers, rubber cement, spray paint, nail polish remover, lighter fluid and the aerosol from vegetable cooking spray and dessert topping. Anesthetics such as nitrous oxide or ether can be abused as well.

The products are sprayed into plastic bags or soda cans or onto rags, then inhaled.

Ricky's parents learned that their son had experimented with inhalants with a friend, and that the boys would take turns pulling a Freon-filled bag off each other's head. When Ricky died, he was alone; no one was there to pull the bag off. He died instantly of cardiac arrest in what's often referred to as sudden sniffing death syndrome.

Ricky's parents had warned their son about illegal drug use, smoking and alcohol but had never even heard the word ''huffing'' until their son died.

That day, a friend called the house to ask for Ricky, and Ricky's father, Ricky Sr., told him the news. The teen's immediate reaction was to ask, ''Was he huffing?''

''The kids know about huffing,'' Ricky Stem Sr. says. ''The parents do not.''

A growing problem

Huffing - also called bagging or sniffing - isn't a new problem. But it is a growing one.

The annual Monitoring the Future Survey, a survey of 50,000 American eighth-, 10th- and 12th-graders sponsored by the National Institute on Drug Abuse, found that in 2004, 17% of eighth graders surveyed said they had used inhalants. Unlike other drugs, inhalants are used more by younger adolescents.

That number is up 1.5% from the year before, and experts fear it signals the start of a steady rise. Inhalant use peaked at 21% in the 1996 - the year Ricky died - and 1997. Harvey Weiss, executive director for NIPC, says inhalant rates began to drop after several large awareness campaigns warned about the dangers. Those campaigns have tapered off, and inhalant use has risen accordingly.

''Schools need to talk about it, parents need to talk about it and kids need to understand that these are poisons,'' Weiss says.

Like alcohol, inhalants act as central nervous system depressants. They give users a quick euphoric rush followed by a bit of wooziness. The effects fade quickly, which makes inhalant use difficult to detect and also gives children the misconception that inhalants aren't dangerous.

Users also can choke on plastic bags or suffocate, and inhalants can cause the heart to beat irregularly, and - as in Ricky's case - lead to cardiac arrest.

''Any episode, whether it be the first or the fifth episode, can be a fatal episode,'' Weiss says.

Because of this risk of sudden sniffing death syndrome, Weiss says parents should never startle or confront children while they're using inhalants.

Since many death certificates list accidental death as the cause of death for inhalant users, there are no reliable statistics on inhalant death rates. Weiss says he hears of about 100 to 125 youth every year who die from inhalants.

Even if they avoid sudden death, inhalant users risk causing severe and permanent damage to their brain, heart, kidney, brain, liver, bone marrow and other organs. Inhalants can also be physically and psychologically addictive.

Education, awareness crucial

In response to the problem of inhalant abuse, some products, such as CleanSafe Dust Remover, have added an ingredient that gives the spray a bitter taste to deter intentional inhalation. Some retailers such as Wal-Mart require that people be over age 18 to buy certain products.

But the sheer variety of products that can be inhaled means that those efforts won't eliminate the problem.

Most states have adopted legislation designed to reduce inhalant abuse. In Tennessee, using inhalants or possessing products with the intention of using them as inhalants is a misdemeanor punishable by a maximum sentence of up to a year in prison and a maximum fine of $2,500. Knowingly selling or giving away products that will be used as inhalants is a felony punishable by a minimum of one year in prison.

Weiss says Tennessee's law is a relatively tough one, but argues that legislation alone won't solve the problem.

''Education and awareness are the keys for inhalant prevention,'' he says. ''You can't legislate the problem away. If we could, no one would be smoking pot.''

Last month, Weiss had a meeting in Nashville to brainstorm ways to raise awareness of inhalant abuse. Nearly 20 people showed up.

At the meeting, the Tennessee Poison Center agreed to send inhalant information next year as part of its Poison Prevention Week package, which reaches 600,000 people. Metro Nashville police agreed to work to get information to officers on how to identify inhalant abusers. A pediatrician offered to distribute inhalant information to other pediatricians.

It's this kind of grassroots effort, Weiss says, that can make a difference.

At the meeting, Stem shared her story as she's done countless times before. She speaks to churches, schools, community groups and businesses, and has appeared on Good Morning America. She makes it a point to remind people that her story isn't just another sad tale. She says that inhalant abuse can be stopped if parents and the community will take the time to educate youth.

''I always use the acronym R-I-C-K-Y,'' Stem says. ''Remember inhalants can kill you.''