Oregon OSHA adopts 29 CFR 1926.51. Here is what it requires.
One toilet. A standard porta potty with a urinal counts as one seat and one urinal.
One seat and one urinal per 40 workers. Two units cover a crew of 80.
Section 1926.51(f): washing facilities where crews handle harmful materials. A station at the lunch area covers it.
Crews with ready transportation to a nearby toilet are exempt. A framing crew parked for three weeks is not mobile.
28-day jobsite cycles with weekly pump and restock. Read the full guide at bendportapottyrentals.com or call (541) 208-0264.