The US Centers for Disease Control and Prevention said Friday it’s still investigating the cause of the illnesses, and cautioned that no single chemical has been linked to all patients. However, it updated its warning to consumers to avoid vaping all products, particularly marijuana, adding that the cause “might be related” to pre-filled cartridges containing THC, the psychoactive chemical in cannabis.

“I’m not familiar with the most recent release, but ‘most’ is not ‘all,’ ” Baker said, while speaking at an unrelated news conference in Lawrence. He said earlier that the four-month ban on sales is necessary to allow medical experts to determine the source of an outbreak of vaping-related lung injuries, which has sickened 805 people and killed 12 nationwide.

Governor Charlie Baker stood by his temporary ban on nicotine and marijuana vape sales on Friday, after two new reports signaled mounting evidence that most vaping-related lung illnesses were linked to illicit pot products.

New reports released by the CDC Friday help clarify what may have caused the majority of patients to become sick.


About 77 percent of the 514 patients interviewed nationwide reported using vaping products containing THC, according to the CDC report. Anne Schuchat, CDC’s principal deputy director, testified this week that most patients reported purchasing products from people they knew, rather than a store.

About 16 percent of patients nationally said they used nicotine e-cigarettes exclusively, and many reported vaping both tobacco and THC products.

A separate CDC report released Friday showed that the majority of patients who fell ill in Wisconsin and Illinois reported vaping marijuana bought from friends, family, illicit dealers, or off the street. Almost 70 percent of those patients used a black-market brand called Dank Vapes.

Baker earlier this week declared a public health emergency and implemented the four-month ban on all vaping sales, the first and only one in the country. Rhode Island, Michigan, and New York are banning flavored vapes.


On Friday, Baker cited the death of a man in Oregon who had visited a licensed marijuana retail store. A second death in Oregon was reported Thursday, and health authorities said that man, too, had purchased products at a licensed dispensary.

Baker spokesman Terry MacCormack said the governor’s office “will continue to work with medical experts and federal and state officials to better understand why vaping is causing lung-related illnesses and consider all options as next steps.”

The Massachusetts Department of Public Health is investigating at least 66 possible cases of the illness. No deaths have been reported in the state. The agency said it has received five to 10 new reports of possible vaping-related lung illnesses per day, “an alarming rate.”

Baker’s ban has drawn criticism from some consumer and industry advocates, who fear it could drive marijuana consumers and patients to the black market, where products are likely far more dangerous.

“Why are we making harmful bootleg products the only option, at the time when regulation is most critically necessary?” said Cannabis Control Commissioner Shaleen Title, who noted that no evidence has suggested that any licensed vape products in Massachusetts caused harm.

She said the government should respond to the cluster of ailments by enacting strict regulatory standards including restricting the use of additives and other ingredients in legal vape cartridges.

“The other 49 states have acted relatively reasonably,” Title said. “We are the only state to have taken such an extreme measure.”


Other common black-market brands that were used by patients in Wisconsin and Illinois: TKO, Off White, Moon Rocks, Chronic Carts, Cookies, Smart Carts, and Kingpen.

Michael Levenson of the Globe Staff contributed to this report. Naomi Martin can be reached at naomi.martin@globe.com. Follow her on Twitter at @NaomiMartin.