HHS Proposes Changes to Federal Workplace Drug Testing. Medical Review Officers Get Fewer pH Calls.
Oct. 29 notices would raise the invalid urine pH cutoff from 9.0 to 9.5 and let MROs order biomarker tests for substitution. Comments are due Dec. 28.
The Department of Health and Human Services has proposed revising the mandatory guidelines for federal workplace drug testing, in two Federal Register notices published Oct. 29, with comments due Dec. 28. The most practical change for physicians who serve as medical review officers (MROs) is a higher pH cutoff for invalid urine specimens.
One notice covers urine testing and the other oral fluid testing. Both would revise guidelines last updated Oct. 12, 2023. HHS estimates that federal agencies test 275,000 urine specimens a year. The oral fluid notice says no laboratory has yet been certified to test oral fluid.
What changes for medical review officers?
Fewer reviews for mildly alkaline urine. Today, a specimen with a pH of 9.0 or higher goes to laboratory confirmation, and a confirmed pH from 9.0 to 9.5 goes to the MRO to look for an explanation. Without one, or when the test needs a valid negative result, as with pre-employment, return-to-duty and follow-up tests, the specimen must be recollected. HHS proposes to move the invalid cutoff to 9.5 and delete the MRO step for the 9.0 to 9.5 range, calling the current process "a significant burden" that "does not result in identifying additional adulterated specimens."
The urine notice would also let an MRO authorize testing for an HHS-authorized biomarker when a specimen is invalid based on creatinine and specific gravity, to check for substitution. Laboratories would need MRO authorization before running that test or sending the specimen elsewhere. A split-specimen laboratory could reconfirm substitution using a different authorized biomarker.
HHS's own data point to heat and shipping time, not adulteration, as the usual reason urine lands between pH 9.0 and 9.5.
What is the evidence behind the cutoff?
HHS cites data presented to the Substance Abuse and Mental Health Services Administration's Drug Testing Advisory Board in December 2024. Those data show that time at high temperature after collection can push normal urine to pH 9.1 to 9.3, that results in the 9.0 to 9.5 range rise in summer, and that a pH above 9.5 does not occur from heat or shipping time alone. Specimens in that range make up about 0.2 percent of results, or roughly 15,000 a year. By The Script Pad's arithmetic, 15,000 at 0.2 percent implies a base of about 7.5 million specimens, far more than the federal agency total, so the figure appears to describe all testing at HHS-certified laboratories rather than federal programs alone.
There is one caveat in the notice itself. Alkaline pH lowers concentrations of benzoylecgonine, phencyclidine and 6-acetylmorphine, with losses over one to three days of shipping ranging from 13 percent to 58 percent, and 6-acetylmorphine losses were significant at a pH as low as 8.0. HHS says it found no difference in loss between pH 9.0 to 9.5 and 9.5 to 10.0 for benzoylecgonine and phencyclidine, and that split specimens with inconsistent concentrations of those analytes had no pH of 9.0 or higher.
What else is in the notices?
Laboratories would run fewer quality controls in each initial test batch, 4 percent of controls and specimens instead of 10 percent. HHS would publish drug testing panels only when they change, not every year. The notices delete the term "gender identity" and refer to the sex of the observer and donor in direct observed collections. Pre-employment testing would explicitly cover current federal employees applying for testing-designated positions.
What MROs and occupational medicine practices should do now
Review the urine and oral fluid notices before the Dec. 28 deadline, especially the revised MRO actions for invalid results, which vary by reason for the test. Practices that review many pre-employment or return-to-duty results may see fewer recollection orders if the 9.5 cutoff is finalized, and should comment if their own experience differs from HHS's data. This site has also covered the DEA's plan to schedule concentrated 7-OH and CMS's proposed CLIA rules for laboratory directors.
Reported, fact-checked and edited by The Script Pad's editorial staff. See How we use AI.
This article is for professional education and does not replace clinical judgment. Treatment decisions should be based on the individual patient and current guidelines.
