Police and public health officials say that much of the U.S. fentanyl supply is mass-manufactured in Mexico and moves up the U.S. West Coast. A Sinaloa cartel cook massages blue dye into a bucket of fentanyl powder in Culiacan, Mexico, on Dec. 19, 2024.MERIDITH KOHUT/The New York Times News Service
In North America, tracking the flow of illicit fentanyl, a deadly opioid that can be synthesized in a lab, is difficult. But the changing chemistry of the drug may offer clues.
Recently, police and public health officials have taken note of a mysterious toxic industrial chemical that is showing up in street fentanyl in the United States – but not in Canada, despite U.S. President Donald Trump’s assertion that the drug is flowing south in massive quantities.
The industrial chemical, which is used in plastic manufacturing, is called BTMPS (pronounced “bee-temps”). The reason some traffickers appear to be adding BTMPS to their fentanyl mixes is unclear.
Studies led by a researcher at the University of California in Los Angeles last year tested hundreds of fentanyl doses and found the additive came out of nowhere to become prevalent across many states. What started as a filler in minute quantities was suddenly present in many or even most dose samples collected by several researchers – in some instances, much of the weight of any given pill.
“It showed up at basically the same time, basically all over the place,” said Dr. Chelsea Shover, an assistant professor-in-residence at UCLA who co-authored the study. In an interview, she said the additive has gotten traction a lot faster than other fillers that scientists have seen spread across the United States.
“The high ratios of BTMPS to fentanyl may indicate a change in synthesis methods, possibly to stabilize a precursor,” said the study, published last month in the Journal of the American Medical Association. Some samples, the study noted, “exceeded the amount of fentanyl, sometimes by orders of magnitude,” which “is concerning given lethality and health risks in animal studies.”
The plastic-making chemical has never been tested on humans. The Philadelphia Department of Public Health put out a warning last year saying drug users who had consumed it reported ringing ears, blurring vision and bloody coughs.
The chemical “is not approved for human use and is often used in plastics to block UV rays and listed as a component of fragrances and candles,” the health unit said in a bulletin last September. It added that the chemical has also been found in North Carolina, Wisconsin, Maine, Oregon, Colorado, New York, Washington State, Ohio, Michigan, California and New Mexico.
But north of the border, in Canada, health officials say they are simply not seeing it.
“We are aware of BTMPS presenting in the U.S. unregulated drug supply, but we have not found it in any samples checked by our service,” said Hayley Thompson, managing director of Toronto’s Drug Checking Service.
Health Canada, which tests drugs seized by police across the country, has not identified BTMPS in any samples, according to spokesperson Tammy Jabareau.
The presence of BTMPS in fentanyl is “a very distinguishing feature, that’s not found here, and it’s found in abundance in the United States. Which are contrary to some of the allegations that are being made that Canadian fentanyl is flooding the U.S.,” said RCMP Corporal Arash Seyed, a spokesperson for the Mounties in B.C.
Mr. Trump has repeatedly claimed that fentanyl is pouring into the U.S. from Canada and has used that claim to justify triggering a trade war between the two countries.
Citing data from the federal U.S. Customs and Border Protection agency, the White House has asserted that 43 pounds of fentanyl was intercepted in its northern border region in the past fiscal year, compared with just two pounds the previous year.
While that number represents less than 1 per cent of all fentanyl seized by U.S. border officials, a recent investigation by The Globe and Mail has found that even those statistics are misleading.
The investigation revealed that the designation of “northern border” only means that the drugs were seized by border agents assigned to the northern part of the U.S. – sometimes hundreds of kilometres inland – and may not have anything to do with the border, or Canada, at all.
Of the 43-pound tally The Globe found that nearly 15 pounds had, in fact, originated in Mexico. An additional 5.5 pounds was identified as having crossed the Canadian border. U.S. authorities did not speak to the other fentanyl seizures.
CBP acknowledges that its methodology for drug seizures – the data that the White House is citing – does not hinge on whether the fentanyl was intercepted at the border or whether it came from Canada.
RCMP Commissioner Michael Duheme has also said he sees no evidence that significant volumes of fentanyl from Canada are being smuggled into the United States.
Police and public health officials say that much of the U.S. fentanyl supply is mass-manufactured in Mexico and moves up the U.S. West Coast.
The growing presence of BTMPS in illicit fentanyl in the U.S. speaks to the dangers of a new era where more people use synthesized drugs, said Alex Caudarella, a family physician and the chief executive officer of the Canadian Centre on Substance Use and Addiction.
“Whatever you think you’re buying – you are not buying,” he said.
Fentanyl is at the core of a wider overdose crisis that killed 107,000 people in the U.S. and 8,600 people in Canada in 2023, according to public health officials. Powders and pills are increasingly unpredictable, given that what is bought and sold as fentanyl is actually an increasingly complex array of opioids, stimulants, veterinary tranquillizers and industrial chemicals.
Dr. Caudarella predicts that borders will matter less as more crime gangs learn how to manufacture drugs.
“We’ve seen a big shift,” he said. “Fentanyl is so easy to make these days. You don’t need it to come from Canada. That’s the reality of the synthetic drug era.”