A couple years ago, the presence of diketones in e-liquid made by industry-leading California manufacturer Five Pawns led to something of a scandal in vaping. Not only were some of Five Pawns’ products shown to contain levels of AP that far exceeded government workplace standards, but the company appeared to mislead customers about the situation.
Dr. Konstantinos Farsalinos, in a 2014 study, translated the U.S. National Institute for Occupational Safety and Health (NIOSH) guidelines for occupational diacetyl exposure into vaping terms. Farsalinos determined that the safe limit for AP was 137 micrograms a day. But some of the Five Pawns liquids — in test results they published themselves — far exceeded that number.
One flavor tested at over 600 micrograms per milliliter. For someone vaping just five mL a day, that would mean an intake of over 3,000 micrograms of AP — 22 times the safe daily exposure for AP inhalation, according to Dr. Farsalinos’s scale. Some retailers balked and removed Five Pawns from their shelves, including all members of the Electronic Cigarette Trade Association (ECTA), the Canadian standards group.
And beyond the high levels of the flavoring agent, Five Pawns had apparently lied to retailers about the presence of diketones. There was an outcry from many vapers, including Russ Wishtart, who used his online program Click,Bang! as a platform to crusade against Five Pawns and its apparent deception. Wishtart had been an early opponent of diketones in e-liquid. He had created controversy previously by testing Suicide Bunny e-liquids and finding high levels of AP in that brand too.
After the Five Pawns AP debacle, more retailers began demanding testing from e-liquid manufacturers. But we still don’t know exactly where the theoretical danger of vaping diacetyl and acetyl propionyl becomes a real risk. Until there is a consensus on the standards for testing and consumption, no one really knows how much diacetyl is too much.