A decade after first appearing in the United States, synthetic marijuana is seen as a growing health danger.

Some marijuana smokers turned to it because it is relatively cheap and not detected in routine drug testing. Dozens of people in New Haven, Connecticut, went to the hospital this week after overdosing on a batch of synthetic pot.

FILE – In this Nov. 14, 2012, file photo, packages of synthetic drugs are displayed in the North Dakota attorney general’s office in the state Capitol in Bismarck, N.D. (AP Photo/Dale Wetzel, File)

A look at the issue:

WHAT IS IT?

While states have moved to legalize traditional marijuana, synthetic marijuana has become a public health threat. Synthetic pot is a mind-altering drug made by taking plant material and spraying it with chemicals that can mimic the high from marijuana. It is sold under names like K2, AK47, Spice, Kush, Kronic, and Scooby Snax.

The chemicals also can also be mixed into a liquid and vaped, and even mixed into tea or food. The substances can produce some similar effects to traditional marijuana including relaxation, elevated mood and altered perception.

WHAT’S IN IT?

Authorities have detected scores of chemicals in synthetic marijuana, and say chemical composition can vary not only from product to product but from batch to batch. Some ingredients are banned by federal or state law. Drug dealers peddle synthetic marijuana, and police say people have been able to buy it online or in convenience stores and gas stations.

FILE – In this Thursday, Aug. 16, 2018 file photo, paramedics and EMT members respond to one of three simultaneous drug overdose victims on the New Haven Green, a city park in New Haven, Conn. Police swarmed a Connecticut park near Yale University and searched people’s homes for drugs Thursday in an effort to prevent more overdoses from a batch of synthetic marijuana blamed for sending more than 70 people to the hospital. (Brian A. Pounds/Hearst Connecticut Media via AP)

Synthetic pot products are not tested for safety and people who use them don’t know exactly what chemicals they’re putting into their bodies.

Earlier this year, more than 160 people in Illinois were sickened and at least four died after using synthetic marijuana tainted with rat poison.

WHAT ARE THE DANGERS?

Synthetic marijuana can cause vomiting, hallucinations, seizures, rapid heartbeat and kidney damage severe enough to put users on dialysis.

It also can be addictive and has been tied to violent behavior and suicidal thoughts.

Health officials track reports of illnesses related to synthetic marijuana through hospital emergency department visits or poison center calls. Poison centers report thousands of cases each year including nearly 8,000 in 2015. This year, as of last month, poison control centers handled about 1,300 synthetic marijuana calls.

The Associated Press Health & Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.