Bags of heroin are displayed at a press conference in New York City, Sept. 23, 2016. Getty Images

The newly discovered street drug dubbed "Gray Death" is so potent that merely touching the powdery substance is risky. Nicknamed by the investigators who detected it, the drug is merely the latest opioid combination emerging from the nation’s rampant opioid problem.

"Gray Death" comprises of a mixture of multiple opioids including heroin, fentanyl, a synthetic opioid called U-47700 and carfentanil, a drug often used to tranquilize large animals like elephants. Much more potent than heroin alone, investigators have seen the drug injected, swallowed, smoked and snorted.

"Gray Death is one of the scariest combinations that I have ever seen in nearly 20 years of forensic chemistry drug analysis," Deneen Kilcrease, manager of the chemistry section at the Bureau of Investigation, told the Associated Press.

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The already lethal mixture is made more so because the exact composition and concentration are unknown to users.

“Normally, we would be able to walk by one of our scientists and say, ‘What are you testing?’ and they’ll tell you heroin or ‘We’re testing fentanyl,’” Ohio attorney general Mike DeWine told the AP. “Now, sometimes they’re looking at it, at least initially, and say ‘Well, we don’t know.’”

Michael Stone, a recovering heroin addict, told Georgia television station WSB-TV in February that the new drug cocktail would be enticing to users. Georgia reported multiple deaths as a result of “Gray Death,” prompting the state's Bureau of Investigation to declare it a threat to public safety.

“From my own experience, when you’re that addicted and it gets to that level, you don’t care and it’s all about getting high,” Stone told WSBT-TV. “I remember saying to myself several times, ‘If I die, I do and If I don’t wake up, I’m dying. Hey, I’m happy.’”

Investigators have detected the drug, which looks similar to concrete mix, in overdoses in Alabama, Georgia and Ohio. A similar mixture was seen by the coroner’s office in Cincinnati, Ohio. Part of the mixture contains a synthetic opioid known as U-47700, a substance classified as one of the most dangerous by the U.S. Drug Enforcement Administration in November.

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“Because substances like U-47700 are often manufactured in illicit labs overseas, the identity, purity and quantity are unknown, creating a “Russian Roulette” scenario for any user,” the DEA said in a press release.

The addition of “Gray Death” is another roadblock in the battle against the heroin epidemic in the United States. On an average day in the U.S., 78 people die from an opioid-related overdose, according to the Department of Health and Human Services. Heroin-related overdoses more than quadrupled since 2010, with death rates increasing by more than 20 percent from 2014 to 2015 alone.

Bags of heroin are displayed at a press conference in New York City, Sept. 23, 2016. Getty Images