Title VII's broad prohibitions against discrimination specifically cover
"hostile environment" when the hostile environment is motivated by animus based upon sex, race, color, national origin or religion (the same prohibition applies under different legislation for age, and disability)

Generally, the action of the few ignorant, arrogant or obnoxious employers that is not motivated by the "suspect" classes referenced above will not support a law suit.  (In other words, a hostile environment created by an equal opportunity SOB is not against the law)

In the event that a person has made false statements defaming of another's character, there may be a cause of action for defamation/libel.  In the work place, the person has a qualified privilege--that is they will not be liable for statements made to persons who have a reason to know, provided the statements were not knowingly false.

Finally, keep in mind that UNLESS you complain about one of the suspect classifications, alleging discrimination based upon sex, race, color, national origin, religion, age, or disability, etc. your employer may terminate you for complaining, or for no reason at all (called at-will employment). (Unless otherwise covered by a contract, including but not limited to a collective bargaining agreement)

To prove a prima facie case of hostile work environment based on racial harassment, a plaintiff must show:

1) there was unwelcome harassment; 

3) the harassment was so severe or so pervasive that it altered the conditions of employment and created an abusive atmosphere; and 

4) there is some basis for imposing liability on the employer. 

Causey v. Balog, 162 F.3d 795, 801 (4th Cir. 1998). In determining if the third element of the prima facie case is met, the Court must consider the frequency and severity of the harassment, whether it was physically threatening or humiliating, whether it reasonably interfered with work performance, and whether it resulted in physical harm. Harris v. Forklift Sys., Inc., 510 U.S. 17, 21, 126 L. Ed. 2d 295, 114 S. Ct. 367 (1993). A mere utterance "'which engenders offensive feelings in an employee'" does not satisfy the element. Id. (quoting Meritor Savings Bank FSB v. Vinson, 477 U.S. 57, 67, 91 L. Ed. 2d 49, 106 S. Ct. 2399 (1986)). The severity of the harassment should be judged from "the perspective of a reasonable person in plaintiff's position, considering 'all the circumstances.'" Oncale v. Sundowner Offshore Servs., Inc., 523 U.S. 75, 81, 140 L. Ed. 2d 201, 118 [*455] S. Ct. 998 (1998) (quoting Harris, 510 U.S. at 23).Greene v. Swain County P'ship for Health, 342 F. Supp. 2d 442, 454-455 (D.N.C., 2004) Far more than a "mere offensive utterance," the word "nigger" is pure anathema to African-Americans. "Perhaps no single act can more quickly alter the conditions of employment and create an abusive working environment than the use of an unambiguously racial epithet such as 'nigger' by a supervisor in the presence of his subordinates." Rodgers v. Western-Southern Life Ins. Co., 12 F.3d 668, 675 (7th Cir. 1993) (citation and internal quotation marks omitted).White v. BFI Waste Servs., LLC, 375 F.3d 288, 298 (4th Cir., 2004) Some words are so offensive that, when uttered repeatedly, they can foster "an abusive working environment" even if they are not accompanied by threat of physical injury. Spriggs, 242 F.3d at 185. The presence of race-based physical threats undeniably strengthens a hostile work environment claim. The absence of such, however, is in no way dispositive, when there is sufficient evidence from which a reasonable jury could conclude that allegedly harassing conduct was otherwise "humiliating." See Harris v. Forklift Sys., Inc., 510 U.S. 17, 23, 126 L. Ed. 2d 295, 114 S. Ct. 367 (1993).

See Title VII Summary

Discrimination Q & A