Workplace violence, violence in the workplace, or occupational violence refers to violence, usually in the form of physical abuse or threat, that creates a risk to the health and safety of an employee or multiple employees. The National Institute for Occupational Safety and Health defines worker on worker, personal relationship, customer/client, and criminal intent all as categories of violence in the workplace. These four categories are further broken down into three levels: Level one displays early warning signs of violence, Level two is slightly more violent, and level three is significantly violent. Many workplaces have initiated programs and protocols to protect their workers as the Occupational Health Act of 1970 states that employers must provide an environment in which employees are free of harm or harmful conditions.