A newly proposed federal rule would expand workplace drug testing programs by allowing certain employers to collect and analyze samples of workers’ hair, a move critics say would lead to disproportionate job-related punishments for people of color.

Federal agencies can already test workers’ urine and saliva, which provide evidence of more recent drug use, but “hair testing potentially offers several benefits when compared to urine, including directly observed collections, ease of transport and storage, increased specimen stability, and a longer window of drug detection,” the Substance Abuse and Mental Health Services Administration (SAMHSA) argued in a notice of proposed rulemaking published in the Federal Register on Thursday.

If adopted, the change would affect thousands of government employees as well as private workers in certain federally regulated industries such as those who work in transportation or at nuclear power plants.

Drug reform advocates are skeptical about the move.

“It’s shameful that these harmful federal drug testing guidelines are even being considered again,” Rep. Barbara Lee (D-CA), co-chair of the Congressional Cannabis Caucus, told Marijuana Moment. “Not only is hair follicle testing discriminatory against people of color due to its sensitivity to melanin and darker hair, it gives no indication of someone being impaired on the job. This just goes to show how far behind the federal government is on cannabis policy.”

Paul Armentano, deputy director for the advocacy group NORML, said it is “mind-boggling that, in 2020, SAMHSA is considering expanding federal drug testing guidelines.”

“Hair follicle testing is highly problematic,” Armentano said. “A positive test, even when confirmed, provides neither evidence of behavioral impairment nor recent drug exposure. Moreover, the sensitivity and accuracy of the test is highly variable.”

Because hair exists outside a person’s body, for example, it’s more vulnerable to contamination—including secondhand smoke and other chemicals—than other sample types. That can put workers at risk of false positives unless results are checked through another testing method.

“Arguably most problematic,” Armentano said in an email, “is the reality that these tests discriminate against certain ethnicities because it is influenced by melanin content and is thus more sensitive to those with darker hair—while far less sensitive to those with gray hair.”

Other factors, such as humidity and hormones, could also affect test outcomes, Armentano added.

SAMHSA in its proposal acknowledges that numerous studies “provide scientific evidence that melanin pigments may influence the amount of drug incorporated into hair,” as well as that hair products more commonly used by people of color could lead to false positives. “As noted,” the filing says, “the Department wishes to solicit feedback on scientific studies comparing drug results and hair color and comparing urine to hair.”

The proposal is the latest effort by SAMHSA to expand federal drug screening to include specimens besides urine, including hair, saliva and even sweat. SAMHSA initially floated the idea of hair-based testing in 1997, and the agency put forward a rulemaking proposal along those lines in 2004. Regulators ultimately rejected that proposal amid concerns over accuracy, but SAMHSA has pursued the plan ever since. In recent years, the agency expanded testing to include saliva.

Unlike urine and saliva, hair can take up to a week to show evidence of drug use, rendering it especially useless as a measure of a worker’s immediate impairment. SAMHSA is proposing that hair testing be used only in pre-employment drug screening and random testing—not in cases where workers are suspected of recent use.

In an effort to protect workers from false positives and ensure that hair tests hold up in court, the proposal includes a directive that an alternate specimen, such as urine or saliva, be collected in order to verify a positive hair-test result. “This two-test approach,” SAMHSA’s summary says, “is intended to protect federal workers from issues that have been identified as limitations of hair testing, and related legal deficiencies.”

Marijuana-related cases, however, may not qualify for that additional layer of scrutiny. “The Department is specifically requesting comments, including support from the recent scientific literature, on whether hair tests that are positive for the marijuana analyte, delta-9-tetrahydrocannabinol-9-carboxylic acid (THCA), should be excluded from the requirement to test an alternate authorized specimen,” the proposal says.

Workers, some labor unions and even a Federal Drug Testing Advisory Board (DTAB) member have criticized the SAMHSA proposal as misguided, warning that the proposal is getting away from the science.

As reported in the trade publication Freight Waves, which covers the shipping and logistics industries, independent truck drivers are opposed to the rule, citing bias toward hair color and texture as well as a general lack of evidence that hair testing would improve driver safety. Major trucking companies, however, generally support the change.

DTAB member Michael Schaffer criticized the rulemaking process as “fatally flawed” because the board was left out of discussions.

“This means that these proposed guidelines were developed without the expertise needed to ensure that they are scientifically accurate and defensible,” said Schaffer, a toxicologist at a drug-testing lab, according to a Freight Waves report. “I fear that these proposed guidelines are going to unnecessarily restrict the use of hair drug testing, an incredibly effective tool at detecting drug use, for reasons which have no scientific basis.”

Armentano at NORML said that doubling down on a testing procedure that could exacerbate racial disparities simply doesn’t make sense, especially given today’s political climate.

“Given the heightened awareness surrounding the need for social and racial equity,” he said, “the idea of proposing a testing procedure that will inherently deny more people of color opportunities than it would others who have engaged in exactly the same activities is beyond tone deaf and counterproductive.”

SAMHSA estimates that about one percent of the 275,000 drug tests it expects federal agencies to do every year will be for hair specimens. When it comes to workers in jobs regulated by the Department of Transportation, the agency anticipates that 1.53 million of a total 6.1 million drug tests will be hair-focused. For nuclear workers, 15,000 of 150,000 total tests would be of hair specimens.

“These projected numbers are based on existing annual pre-employment testing that currently occurs in the regulated industries and current hair testing being conducted,” SAMHSA wrote

The agency is accepting public comments on the proposal through November 9.

This story was updated to add comment from Lee.

Photo courtesy of Markus Spiske