In this category of protection, the STAA contains this limit:
an employee's apprehension of serious injury is reasonable only if a reasonable individual in the circumstances then confronting the employee would conclude that the unsafe condition establishes a real danger of accident, injury, or serious impairment to health. To qualify for protection, the employee must have sought from the employer, and been unable to obtain, correction of the unsafe condition. This means that you must try to have your employer correct the unsafe condition before refusing to drive.