In this Aug. 9, 2016, photo, a vial containing 2mg of fentanyl, which will kill a human if ingested into the body, is displayed at the Drug Enforcement Administration (DEA) Special Testing and Research Laboratory in Sterling, Va. A 2mg dose of fentanyl is fatal to 99 percent of humans. A novel class of deadly drugs is exploding across the country, with many manufactured in China for export around the world. The drugs, synthetic opioids, are fueling the deadliest addiction crisis the U.S. has ever seen. (AP Photo/Cliff Owen)
