Hostile work environment
In United States labor law, a hostile work environment exists when an employee experiences workplace harassment based on a legally protected class as defined by the Equal Employment Opportunity Commission (EEOC). According to the EEOC, protected classes are age (over 40), disability (including pregnancy), genetic information, national origin, race/color, religion, gender, or sex. Furthermore, the acts done must be "severe or pervasive enough to create a work environment that a reasonable person would consider intimidating, hostile, or abusive."
Workplace harassment or bullying, in itself, is generally legal so long as it is not done due to an employee's membership in a protected class. As the United States Supreme Court stated in Oncale v. Sundowner Offshore Services, Title VII "does not prohibit all verbal or physical harassment in the workplace."