Employers are usually familiar with the language of the Americans with Disabilities Act (ADA), which allows an employer to decline to provide requested accommodation to an individual with a disability if the accommodation would impose an undue hardship on the operation of the company's business. For many employers, it's less common to consider the ADA's language permitting employers to apply job-related qualification standards that require an employee not to pose a direct threat to the health or safety of other individuals in the workplace.  

The Eighth Circuit recently produced a thorough discussion of the direct threat defense in the case of Christensen v. Union Pacific Railroad Co. In Christensen, both the district court (in granting summary judgment for Union Pacific) and the Eighth Circuit went directly to an analysis of the employer's affirmative defense to the plaintiff's disparate treatment claim under the ADA. Union Pacific created a solid case by following textbook procedure to support its direct threat defense, including fitness-for-duty evaluations and comprehensive review of extensive medical records by multiple physicians acting on the best and most current medical knowledge.  

Christensen argued that his own personal physician's opinion that he should be cleared to return to work created a fact issue that precluded summary judgment. But the Eighth Circuit noted that a difference of opinion between physicians did not automatically mean that Union Pacific's decision was objectively unreasonable.  

The Christensen case highlights that, especially for employees in safety-sensitive positions, employers should consider whether the direct threat defense applies to the analysis of an employee's disability accommodation request.