How Many Portable Restrooms? OSHA's Actual Ratio
OSHA's rule is simple on paper. The misses happen in the details — hand-wash stations, seasonal crew spikes, and who counts as a 'worker' for the math.
The ratio, from the reg
OSHA 29 CFR 1926.51(c)(1) — one toilet per 20 employees working fewer than 40 hours. One toilet per 10 employees plus one urinal per 40 when the crew is on a full 40-hour workweek.
Practical translation for most jobsites:
| Crew size | Toilets required | Hand-wash stations (recommended) |
|---|---|---|
| 1–10 | 1 | 1 |
| 11–20 | 2 | 1 |
| 21–30 | 3 | 2 |
| 31–40 | 4 | 2 |
| 41–50 | 5 | 3 |
Every additional 10 workers adds another unit.
ADA requirements
If you have any worker (or jobsite visitor) who requires accessible facilities, you need at least one ADA-compliant unit on site. Not optional. Most inspectors check for one on commercial sites regardless.
The hand-wash question
OSHA doesn't require hand-wash stations at every site — but if your crew is working with concrete, chemicals, or any food service is present, you need them. If you're in Harris County, the health department has layered rules on food-present sites that go further than OSHA.
Practical rule: add one hand-wash station per 10 workers and you'll never fail a walk.
Service frequency
Weekly pump, restock, and deodorize is the standard. Heavy-use sites (over 40 workers) should bump to twice-weekly — it's cheaper than the alternative (a unit that smells, a crew that won't use it, a safety citation for "inadequate facilities").
The mistakes we see
- Counting crew instead of daily presence. Subs on site only Tuesdays count toward Tuesday's total.
- Skipping weekend servicing. Saturday work means Monday morning walks into a bad unit.
- Placing units 200+ feet from the work area. If it's inconvenient, crews won't use it — which defeats the point.
- Forgetting ADA. A $50 upsell that saves a citation.
Booking the right count
Tell dispatch your peak crew size, work schedule, and whether ADA is required. We'll size the unit count and service schedule, deliver them staged against your site plan, and keep them clean without you chasing us.