Federal prosecutors in Colorado are warning the public about the dangers of fentanyl.

“Your next high could be your last,” Deborah Takahara, a spokeswoman for the U.S. attorney’s office, said in a video released on Twitter. “… People are playing Russian roulette with fentanyl and other illicit street drugs that are laced with it.”

“Fentanyl is killing our neighbors and our children at an alarming rate,” U.S. Attorney Cole Finegan said.

The Drug Enforcement Administration warns that just 2 milligrams of fentanyl can be lethal. This means that if a single sugar packet were filled with fentanyl, it would be enough to kill 500 people, Finegan said.

A DEA analysis found 42% of pills tested for fentanyl contain at least 2 milligrams. Finegan said his office is going after manufacturers and dealers “who are poisoning and killing people.” Should they be prosecuted for a death caused by fentanyl, they could face at least 20 years and up to life in prison.

“We cannot do this alone,” Takahara said. “We need everyone (in) the community to take this seriously, have tough talks with your loved ones and please help us share the message: Fentanyl kills.”