The ADA allows an employer to refuse to hire individuals who pose a “direct threat” to the health or safety of themselves or others. A direct threat means a “significant risk of substantial harm.” Employers have legitimate concerns about maintaining a safe workplace for all employees and members of the public. In some instances, the nature of a particular person's disability may cause an unacceptable risk of harm from the employer's perspective.
The determination that there is a direct threat must be based on objective evidence and reasonable medical judgment regarding an individual's present ability to perform essential functions of a job. It cannot be based on unfounded fears or generalizations. An employer cannot refuse to hire you because of a slightly increased risk or because of fears that there might be a significant risk sometime in the future. The employer must also consider whether a risk can be eliminated or reduced to an acceptable level with a reasonable accommodation.