At least three people have died from vaping-related illnesses, the Centers for Disease Control and Prevention said Friday.
Many of those affected had recently used marijuana oil products, initial CDC findings show, though officials said they could not yet blame one particular product.
The CDC said it is examining 120 samples from state health officials.
"The FDA is analyzing these for a broad range of chemicals but no one substance, including Vitamin E acetate, has been identified in all of the samples tested," acting FDA Commissioner Ned Sharpless said. "Importantly, identifying any compounds present in the samples will be one piece of the puzzle but won’t necessarily answer questions about causality, which makes our ongoing work critical."
Cases have been reported in 25 states.
The vaping industry is coming under more government scrutiny, as North Carolina's attorney general is suing Juul and eight of its competitors, Beard Vape, Direct eLiquid, Electric Lotus, Electric Tobacconist, Eonsmoke, Juice Man, Tinted Brew and VapeCo.
Juul Labs CEO Kevin Burns told “CBS This Morning” last month that the recent cases involving the use of e-cigarettes were “worrisome.”