Some jobs types may need drug screening more than others, and that's OK
Q Can we mandate a drug screening upon hire for some job types and not others?
Yes. There's no federal law prohibiting you from screening some employees but not others based on the type of job they will hold. Generally, state laws follow this trend because job type isn't typically recognized as a protected class for purposes of antidiscrimination laws.
In fact, you should consider an employee's job type when determining whether to require her to submit to a drug screening upon hire. There are economic risks and rewards to consider when determining whether to mandate a drug screening upon hire, and her job type plays a significant role in the determination.
Screening employees for drugs upon hire can be beneficial for employers. Drug screenings can be effective in preventing accidents and litigation. They can also be used to improve productivity by identifying employees who may be under the influence while on the job or suffering from performance issues due to drug use.
On the other hand, drug screening can be expensive, slow down the hiring process, and negatively affect the candidate's experience, even for those who don't use drugs. Beyond the illicit user who avoids companies that drug test, most clean and sober people hardly cherish the opportunity to prove they aren't a drug user.