Construction sites: OSHA Table D-1
For construction work, OSHA 29 CFR 1926.51 sets minimum toilet facilities by the number of employees on site. At 20 or fewer workers, at least one toilet is required. Above 20 workers, the table calls for one toilet seat and one urinal per 40 workers. At 200 or more workers, it calls for one toilet seat and one urinal per 50 workers.
Treat the table as a minimum. Shift changes, long breaks and a single start time push real demand above it, so many sites plan for more.
A worked example
Take a construction crew of 120 workers on site at the same time. Under Table D-1, 120 divided by 40 is 3, so the minimum is three toilet seats and three urinals. If everyone starts and breaks together, adding a margin keeps lines short.
Employer-provided housing: temporary labor camps
When a camp is housing provided for workers, OSHA 29 CFR 1910.142 can apply. It covers shelter space, water supply, toilets, sewage, washing, bathing and laundry facilities, and food handling. Read the current text for the ratios that apply, and check whether your arrangement counts as a temporary labor camp.
State, local and contract rules
Health departments, state agencies, project owners and contracts often set stricter ratios than OSHA, or require specific facilities such as accessible stalls. Ask which rules apply to your site before you size the order.
Matching the rule to equipment
- Restroom trailers come in 12, 14, 20 and 30 ft sizes with flush toilets, handwashing sinks, lighting and ventilation.
- Shower trailers: a 22 ft trailer with 10 stalls, and a 20 ft shower container with 5 stalls.
- Shower and restroom combinations run from 3 to 8 stalls, with configurations that add an ADA stall.
- Hands-free handwashing stations use a foot pump and a basin with soap and paper-towel dispensers.
- Laundry trailers hold eight to ten stackable washers and dryers.
Service and supplies
Trailers with water and waste tanks need refilling and pump-out on a schedule that depends on headcount and use. Ask how service is handled and who to call when a tank is nearly full.
This is general information
This guide summarizes public rules and is not legal or safety advice. Regulations change, so confirm requirements with your safety professional and the authority that governs your site.