The prevalence of pre-employment drug testing varies across industries, with only a small percentage of US job postings mentioning required testing in 2019. Companies are increasingly requiring employees to comply with testing policies due to rising workforce positivity rates. Drug tests determine whether prospective employees use illicit substances or medications inappropriately and can be conducted through various methods, including urine, hair, oral fluid, breath alcohol, and blood testing. While pre-employment screening is rarely a blanket requirement, it's often restricted to safety-sensitive positions or government roles where public endangerment risks are high. The use of pre-employment drug testing is regulated by federal laws, such as the Omnibus Transportation Employee Testing Act and Executive Order 12564, which prohibit the use of illegal drugs by federal employees and transportation workers. Certain industries, including government, healthcare, transportation, construction, aerospace, education, IT, and private security, are more likely to conduct pre-employment screening.