What is the test for determining whether an individual poses a direct threat to the health or safety of others?

The entity asserting a direct threat' as a basis for excluding an individual bears a heavy burden of demonstrating that the individual poses a significant risk to the health and safety of others. Lockett v. Catalina Channel Exp., Inc., 496 F.3d 1061, 1066 (9th Cir. 2007). In determining whether an individual poses a direct threat to the health or safety of others, a public entity must make an individualized assessment

29 C.F.R. 36.208(b).