A new report from the American Association of Poison Control Centers says people are legally and increasingly selling bath salts laced with a dangerous drug stimulant.

Typically, bath salts are products sold in stores like Bath and Body Works that relax someone's muscles when they are taking a bath. However, the American Association of Poison Control Centers says criminals are increasingly lacing products marketed as bath salts with a dangerous chemical that causes increased blood pressure and heart rate, agitation, hallucinations, extreme paranoia and delusions.

The chemical is Methylenedioxypyrovalerone, or MPDV. It is not approved for medical use in the United States.

The number of reported calls due to use of these bath salts has increased tenfold over the past year. In 2010, there were 303 calls. This year so far there have been 3,740 calls.

The American Association of Poison Control Centers says many people are using the bath salts on purpose to get a high.' The use is similar to how some people use synthetic marijuana marketed as herbal incense to get high. In both cases, the effects of using these stimulants are dangerous.

The products are being sold in gas stations, other stores and primarily online. They have typical bath salt names like Red Dove, Blue Silk, Bloom, Cloud Nine and Vanilla Sky.

 We are incredibly concerned about the extreme paranoia being reported by people who are taking these drugs, Mark Ryan, director of the Louisiana Poison Center, said in a statement. The products are being used, he said, by some as a cocaine substitute.

Another poison center director, Henry A. Spiller, director of the Kentucky Regional Poison Center, said patients being treated for using the bath salts have completely lost it.

The association says patients are snorting the substance, ignoring label warnings that say the salts are not for human consumption.

READ: Bath Salts Drug 'Unusually Dangerous', Induces Psychosis