Security guards and workers in related security service occupations guard and implement security measures to protect property against theft, vandalism and fire; to control access to establishments; to maintain order and enforce regulations at public events and within establishments; to perform screening of passengers, luggage or cargo; to conduct private investigations for clients or employers and to provide other protective services not elsewhere classified. They are employed by public or private security agencies, residential complexes, educational, cultural, financial and health institutions, retail establishments, investigation service companies, transportation facilities, and organizations throughout the public and private sectors, or they may be self-employed.