28 CFR Part 35, Appendix B: 1991 ADA Title II Regulations Preamble and Section-by-Section Analysis

A ‘‘direct threat’’ is a significant risk to the health or safety of others that cannot be eliminated by a modification of policies, practices, or procedures, or by the provision of auxiliary aids or services. In School Board of Nassau County v. Arline, 480 U.S. 273 (1987), the Supreme Court recognized that there is a need to balance the interests of people with disabilities against legitimate concerns for public safety. Although persons with disabilities are generally entitled to the protection of this part, a person who poses a significant risk to others will not be ‘‘qualified,’’ if reasonable modifications to the public entity’s policies, practices, or procedures will not eliminate that risk.

The determination that a person poses a direct threat to the health or safety of others may not be based on generalizations or stereotypes about the effects of a particular disability. It must be based on an individualized assessment, based on reasonable judgment that relies on current medical evidence or on the best available objective evidence, to determine: the nature, duration, and severity of the risk; the probability that the potential injury will actually occur; and whether reasonable modifications of policies, practices, or procedures will mitigate the risk. This is the test established by the Supreme Court in Arline. Such an inquiry is essential if the law is to achieve its goal of protecting disabled individuals from discrimination based on prejudice, stereotypes, or unfounded fear, while giving appropriate weight to legitimate concerns, such as the need to avoid exposing others to significant health and safety risks. Making this assessment will not usually require the services of a physician. Sources for medical knowledge include guidance from public health authorities, such as the U.S. Public Health Service, the Centers for Disease Control, and the National Institutes of Health, including the National Institute of Mental Health.