Fox and Mehler are partners in the Los Angeles-based law firm of Hogan Lovells, which was hired by the AKA, an organization of kratom consumers that receives some of its funding from kratom vendors.

In their 35-page letter to Rosenberg, Fox and Mehler said much of the evidence used by DEA to justify the emergency scheduling was “fundamentally flawed” because it relies on reports that “are inadequate and unreliable.”

In the emergency scheduling notice published in the Federal Register, DEA cited a July 2016 report from the CDC that claimed kratom was “an emerging public health threat.” The CDC said kratom related calls to U.S. poison control centers rose from 26 calls in 2010 to 263 in 2015 – a total of 660 calls over a six year period.

Fox and Mehler said that pales in comparison to the number of calls to poison centers received about other common household items, including caffeine (23,303 calls in 6 years) and essential oils (66,300 calls).

The CDC report also cited two published research reports that “associated kratom exposure with psychosis, seizures, and deaths.”

“The CDC publication appears to have either misidentified its sources or been mistaken in its conclusions, as both sources reported no deaths from kratom,” wrote Fox and Mehler. “Likewise, the CDC report also stated that ‘deaths have been attributed to kratom in the United States,’ but it cited for that proposition a single report in a newspaper article. The newspaper article reported the suicide of a 22-year old male by self-inflicted gunshot wound.”

The assertion that CDC research is faulty is not a new one. Similar complaints were raised about the weak evidence used by CDC to justify its guidelines for opioid prescribing. Critics have also faulted the agency for “incomplete and biased” reports about the risks associated with opioid pain medication, and misleading reports about the number of deaths caused by prescription opioids.

“Nowhere does DEA rely on the scientific, epidemiological, and public health sources that normally undergird the assertion that a substance poses a high potential for abuse, let alone an imminent public health threat,” said Fox and Mehler. “The proposed use of the emergency scheduling provisions in this case is unprecedented, contrary to the law and public interest, violates fundamental principles of regulatory procedure, and implicates serious constitutional questions.”

The DEA has not publicly responded to the AKA letter. The agency could have classified kratom as a Schedule I controlled substance on September 30, but caved into political pressure from some members of Congress to leave the legal status of the herb unchanged for the time being.

Under the DEA’s emergency scheduling order, no public notice or comment period was allowed. But according to Wisconsin Rep. Mark Pocan’s office, the agency will allow for a “modified comment process” about the scheduling of kratom, although that has not yet been confirmed by the agency.

Kratom activists believe the DEA will announce its decision soon.

“We’ve heard through the grapevine that as early as Tuesday, the DEA is going to be making an announcement about where they go from notice of intent to saying that they’re going to allow for a public comment process,” said Susan Ash, founder of AKA.

“Our concern is that it will be a very brief amount of time to be able to get enough comments from the scientific community, the medical community and the public at large to really have an impact on this decision. So the question is this just an attempt to save face by the DEA when they still have full intent of banning it? Or are they really going to be opening up a true comment process?”

In a survey of over 6,000 kratom consumers by Pain News Network and the American Kratom Association, over 95 percent said banning the herb would have a harmful effect on society. Many predicted it would lead to more addiction and illegal drug abuse.