The U.S. Drug Enforcement Administration has issued an emergency order banning three chemicals used to make street drugs known as "bath salts" and "plant food."

The DEA exercised its emergency scheduling authority to control the synthetic stimulants mephedrone, 3,4 methylenedioxypyrovalerone (MDPV) and methylone.

The DEA temporarily banned the chemicals, and the products that contain them, to "prevent an imminent threat to the public safety," according to the agency. The temporary action remains in effect for at least one year, while the DEA and U.S. Department of Health and Human Services (DHHS) conduct additional studies about whether these chemicals should be permanently controlled.

"This action demonstrates our commitment to keeping our streets safe from these and other new and emerging drugs that have decimated families, ruined lives, and caused havoc in communities across the country," said Michele M. Leonhart, DEA administrator. "These chemicals pose a direct and significant threat, regardless of how they are marketed, and we will aggressively pursue those who attempt their manufacture and sale."

The chemicals will be illegal for at least 12 months, and could be banned for another six months. They've been designated as Schedule I substances, which is the most restrictive category under the federal Controlled Substances Act. Schedule I status is reserved for those substances with a high potential for abuse, no accepted treatment use, and a lack of accepted safe use of the drug under medical supervision.

Over the past several months, there has been a growing use of, and interest in, synthetic stimulants sold under the guise of "bath salts" or "plant food." These products are sold under names such as "Ivory Wave," "Purple Wave," "Vanilla Sky," or "Bliss." They are comprised of a class of chemicals perceived as mimics of cocaine, LSD, MDMA, or methamphetamine.

Users report impaired perception, reduced motor control, disorientation, extreme paranoia, and violent episodes. The long-term physical and psychological effects of using the drugs are unknown and potentially severe. These products have become increasingly popular among teens and young adults, and are usually head shops or online.

They've not been approved by the FDA for human consumption or for medical use, and there's no oversight of the manufacturing process.

In the past six months, the DEA has received an increasing number of reports from poison control centers, hospitals and law enforcement agencies regarding products containing one or more of these chemicals. Also, 37 states have taken action to control or ban these or other synthetic stimulants.