All sorts of behavior can create what employees deem to be a "hostile work environment". But, in the legal sense, a hostile work environment is caused by unwelcome conduct in the workplace, in the form of discriminatory harassment toward one or more employees based on inclusion in a protected class.

The harasser might be an employee, such as a Supervisor or a coworker, or even a non-employee, i.e. a Contractor. But who the workplace harasser is doesn't matter as much in the legal sense, as does the fact that he or she is creating an intimidating, offensive, abusive, or hostile work environment through discriminatory workplace harassment. 

• Conduct that interferes with an individual’s work performance, i.e., conduct that makes it hard for you to concentrate and focus on your work, etc.
• Conduct that creates an intimidating, hostile, or offensive work environment.
• Verbal or physical repeated conduct, i.e., yelling, screaming, slamming fist or items on desks, etc.
• Conduct that causes an individual to suffer with respect to a term, condition, or privilege of employment, i.e., receiving a Letter of Caution, etc.

There are no Federal "hostile work environment laws" or "hostile workplace laws" named as such. Creating a hostile workplace is prohibited under certain Federal discrimination laws (listed below).

• Title VII of the Civil Rights Act of 1964 (Title VII) 
• Age Discrimination in Employment Act of 1967 (ADEA)
• Americans with Disabilities Act Amendment Act of 2008 (ADAA)
• Genetic Information Nondiscrimination Act of 2008 (GINA)

Subsequently, to be illegal under one of the laws in the eyes of the courts, a hostile work environment typically must be caused by discriminatory workplace harassment based on race, color, sex, age, religion, national origin, disability, genetics; or it must be caused by retaliation in violation of a discrimination law.

Additionally, the harassment typically must be intentional, severe, recurring, and pervasive, and interfere with an employee's ability to perform his or her job.

Lastly, the victim or witnesses typically must reasonably believe that tolerating the hostile work environment is a condition of continued employment. In other words, the victim or witnesses typically must reasonably believe that they have no choice, but to endure a hostile workplace in order to keep their jobs.

PENTAGON OFFICE
HQMC EEO Office
Pentagon, Room 2A262
Washington DC 20350-3000

MCB QUANTICO OFFICE
HQMC EEO Office
Marine Corps Association Building Annex
715A Broadway Street, 1st Floor
Quantico, VA, 22134

Phone: 703-784-4772
Email: SMBHQMCARHEEO@usmc.mil