OSHA Porta Potty Requirements for Construction Sites
What OSHA actually requires on a job site, how to count units for your crew, and where the legal minimum ends and good practice starts.
By Kingston, owner of Kingston Portable Toilets Rental. Reviewed October 13, 2026.
How many toilets does OSHA require on a job site?
OSHA 29 CFR 1926.51 Table D-1 requires at least 1 toilet for 20 or fewer workers, 1 toilet seat and 1 urinal per 40 workers for 20 to 199 workers, and 1 toilet seat and 1 urinal per 50 workers for 200 or more. Missouri and Illinois private construction sites follow federal OSHA.
| Workers | Requirement | Standard units |
|---|---|---|
| 20 or fewer | 1 toilet | 1 |
| 20 to 199 | 1 seat + 1 urinal per 40 workers | workers ÷ 40, rounded up |
| 200 or more | 1 seat + 1 urinal per 50 workers | workers ÷ 50, rounded up |
Official text: OSHA 29 CFR 1926.51.
Does OSHA require handwashing on construction sites?
OSHA 29 CFR 1926.51(f) requires washing facilities where workers are exposed to harmful contaminants such as paint, coatings, herbicides or insecticides, and the facilities must be near the work. A portable handwashing station with soap, water and towels meets that need on most St. Louis-area sites.
What about farm crews?
Agricultural employers with 11 or more field workers follow OSHA 29 CFR 1928.110: 1 toilet and 1 handwashing facility for every 20 workers, located within a quarter-mile walk of each worker. Units can move with the crew on a towable trailer.
Official text: OSHA 29 CFR 1928.110.
Is the OSHA minimum enough?
The OSHA count is the legal floor. A unit holds roughly 200 uses between pumpings, so a crew of 15 working 50-hour weeks can fill one before the weekly service. In that case add a mid-week service visit rather than a second unit, which usually costs less.
Quick answers
Do subcontractors count toward the total?
OSHA counts the employees on site, so general contractors usually size for every trade present at peak.
Do I need separate units for men and women?
Table D-1 allows shared units when each locks from the inside. Separate units are good practice on large sites.
Does a single-worker site need a toilet?
Sites near a usable restroom may meet the rule another way. Ask your safety officer.
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