General Motors, Anheuser-Busch, BMW and Rubbermaid are among the more than 1,000 companies employing the test. Hair testing is also used by the police departments of several major cities. Less Dangerous Than The One They Make. The controversy surrounding hair testing stems from years of scientific research. The scientific consensus is that the process is not sufficiently reliable for widespread use.
Evidence also points to a possible bias against people with dark hair.
Althea Jones, an African-American mother of two, says she is a victim of hair testing's inaccuracy. Her lifelong dream was to be a police officer, but when she applied for admission to the Chicago Police Academy, it requested a sample of her hair. The results came back positive for drug use. I was shocked. I don't even smoke or drink.