A record number of U.S. workers are cheating on employer drug tests by tampering with urine samples or using other means to evade detection, new research shows. 

The percentage of employees who tried to fake the results of workplace drug screenings jumped more than six-fold in 2023 from the previous year, according to Quest Diagnostics, a national drug testing company. 

The surge in workers trying to hide their drug use comes as more states across the U.S. legalize recreational marijuana use. The shifting legal environment and changing societal norms around cannabis use is forcing employers to review their drug-testing policies. The chief aim of employer-mandated drug tests is to ensure a safe workplace, while recreational drug use can also affect worker productivity. 

"Workforce drug testing exists because it's intended as a deterrence mechanism," Dr. Suhash Harwani, senior director of science for workforce health solutions at Quest, told CBS MoneyWatch. "That's why it was founded — to ensure workplace safety."

Quest's analysis of lab data also found that the drug positivity rate for the overall U.S. workforce remained at a record high of 4.6%, up from a low of 3.5% between 2010 and 2012. 

As of April 2024, recreational marijuana is legal in 24 states, or nearly half the country, according to the Pew Research Center. 

How workers cheat

Workers typically used one of two methods to foil an employer's drug testing protocols: substituting their urine specimens by replacing them with synthetic formulas or even animal urine, or submitting invalid specimens, suggesting they'd been tampered with in order to conceal drug use. 

"Given the growing acceptance and use of some drugs, particularly marijuana, it may be unsurprising that some people feel it necessary to try and cheat a drug test," Dr. Harwani said in a statement. "It is possible that our society's normalization of drug use is fostering environments in which some employees feel it is acceptable to use such drugs without truly understanding the impact they have on workplace safety."

Some experts expressed concern about the findings, saying they underline a need to improve drug testing policies and procedures.

"Drug tests are an important tool employers have to keep everyone in communities safe," Katie Mueller, senior program manager at the National Safety Council, told CBS MoneyWatch. "When policy and procedure fails us or people make decisions to alter their tests for whatever reason, it puts everyone at risk."

Regarding the widening push to legalize cannabis, Mueller added that "we need to have a really open dialogue with employees, employers and lawmakers about the impacts of legalization, and how it's trickling down to the workplace." 

Dr. Harwani said there could be better ways of testing employees and job candidates for drug use than relying on urine samples. For example, the U.S. Department of Transportation recently approved oral fluid testing to detect drug use, in addition to using urine samples. 

Whereas urine samples are submitted in a private space, oral fluids are collected directly by lab technicians. And while drugs can take time to show up in a donor's urine sample, they can be detected in saliva immediately after they are used.