Whether you’re new to the recruiting industry or not, conducting pre-employment drug or alcohol testing is a complicated business.

Consider that the federal government doesn’t regulate drug testing in the private sector. The Drug-Free Workplace Act does not require or restrict testing in any way. Since drug abuse is not considered a disability, neither does the Americans with Disabilities Act.

Still, each state supports its own drug testing laws that vary across state lines. California laws, for example, only apply to employees in sensitive positions at state agencies. Laws in Alabama, Hawaii and Idaho apply to all employers. But in Connecticut, they only pertain to private employers.

As a national hiring manager or recruiter, it can be difficult to remember which laws each state observes. For a state-by-state chart of drug and alcohol testing laws, click here.

Meanwhile, there are still basic questions some recruiters may have about the pre-employment testing process. Consider this partial list of FAQs designed by A Worksafe Service, Inc., to help you better navigate your way through an industry that is often confusing, complex and constantly evolving.

  1. What drugs should I test for?

Most employers test for marijuana (THC), cocaine, opiates, amphetamines (including methamphetamine) and phencyclidine (PCP).

  1. What about testing for alcohol?

A breath alcohol test provides immediate results and is directly correlated to a blood alcohol test result. But attorneys argue that if employees know their job offer will be withdrawn if they refuse to take the test, then taking the test is no longer an option. In other words, they don’t freely give their consent. So avoid pre-employment alcohol testing for nongovernment-regulated employers.

  1. What happens when an applicant fails a pre-employment test?

This test is not any different than other employment tests. If job applicants flunk, they do not meet your hiring standards or criteria. In most cases, organizations rescind the job offer.

  1. What is DOT testing?

The U.S. Department of Transportation and the United States Coast Guard have alcohol and drug-testing requirements of safety-sensitive workers employed in the aviation, public transit, trucking, maritime, and pipeline industries.

  1. If job applicants fail a DOT drug test, can they dispute the results?

Federal regulations permit job applicants to request that the split specimen, which was collected at the time of the original specimen, be sent to another laboratory for testing. Companies cannot deny this request. However, it must be made within 72 hours of the applicant being notified of the positive test result.

  1. If a company receives a negative/dilute test result –when the urine is diluted – does the applicant have to retest?

No, employers can accept the result as a negative result. But employers can retest if it’s stated in their policy but must then retest all applicants that have a negative/dilute result in the same testing category. For example, an employer may choose to retest on pre-employment tests only. If so, all applicants with these results will be required to retest.

There’s another key question that every recruiter should pay attention to: Are drug tests reliable?

Drug screens used by most companies are not always reliable, according to the National Workrights Institute. At least 10 percent of common drug tests yield false positive results. That number can quickly rise to as much as 30 percent if job applicants use over-the-counter medicines. Formula 44-M, for instance, has proven positive results for heroin, Advil for marijuana, and Nyquil for amphetamines. Other substances that have caused false positives include Sudafed, certain herbal teas and poppy seeds.

Still, drug testing may be the best approach we have for identifying job applicants who may be drug users or abusers. It offers recruiters and employers another layer of protection and information about a candidate’s background that could potentially impact workplace productivity and safety.

It’s one more tool that can help employers make the most informed hiring decisions.