On construction job sites OSHA requires you have 1 porta potty for every 10 construction workers. According to the United States Department of Labor (Occupational Safety and Health Administration). Sanitary standard must meet the requirements fo 29 CFR 1926.51(c). OSHA requirements on whether toilet at construction job sites are in sanitary conditions. The rule of thumb is to have 1 portable toilet available for every 10 construction workers. Toilet must be clean, sanitized and in operating condition.
https://www.osha.gov/laws-regs/standardinterpretations/2006-05-17-0