Last updated
How Many Porta Potties Does OSHA Require on a Jobsite?
OSHA 1926.51(c) sets the baseline: one toilet facility for 20 workers or fewer, then it steps up. From 20 to 200 workers, add one toilet seat and one urinal per 40 employees. Above 200, the ratio drops to one seat and one urinal per 50. A 35-person crew working outside Spokane needs two units minimum under that bracket, not one. Crews doing paint, coatings or pesticide work also trigger washing facilities under OSHA 1926.51(f)(1), separate from the toilet count. If your site runs potable water for drinking per OSHA 1926.51(a)(1), that's a different requirement than toilet ratios, so don't conflate the two when you're budgeting units. For a full breakdown by crew size, see OSHA portable toilet requirements and price it out with standard porta potty rental or check the porta potty rental cost page for day and week rates.
| Crew size | Units required (OSHA 1926.51(c)) |
|---|---|
| 1 to 20 | 1 |
| 21 to 60 | 2 |
| 61 to 100 | 3 |
| 101 to 140 | 4 |
| 141 to 200 | 5 |
How Many Porta Potties Do I Need for an Event?
Events don't follow OSHA's jobsite ratios, they run on guest count and hours. A rough industry rule most Spokane planners use: one unit per 50 guests for a 4 hour event. Stretch the event to 8 hours, or serve alcohol, and that ratio tightens fast because people drink more and stay longer. A wedding of 150 guests over 6 hours needs at least three standard units, plus one ADA-compliant unit under ADA Standards section 213.2, which requires at least 5 percent of clustered units be accessible.
| Guest count | 4 hour event | 8 hour event |
|---|---|---|
| 50 | 1 unit | 2 units |
| 100 | 2 units | 3 units |
| 150 | 3 units | 5 units |
| 250 | 5 units | 8 units |
Standard units run in the 100 to 350 dollar day range, and event-day pricing for a cluster typically lands between 200 and 800 dollars depending on scope. Browse event restroom rental or look at dedicated pages for wedding restroom rental and festival restroom rental if you're planning something bigger than a backyard gathering.
Worked Example: A 40 Person Construction Crew
Take a 40 person crew building a subdivision near Town and Country, about 4.6 miles north of Spokane. Under OSHA 1926.51(c), that crew falls in the 21 to 200 bracket, so it needs one toilet seat and one urinal per 40 workers on top of the base unit. That works out to two standard units for the site. If the crew is coating steel or applying sealants, add a handwashing station to satisfy OSHA 1926.51(f)(1), since that rule kicks in specifically for paints, coatings, herbicides or insecticides work, not general use. A two-unit setup on a month-long job runs in the 125 to 325 dollar per unit monthly range. Pair that with handwashing station rental and check construction site services for the rest of what a jobsite near Spokane typically needs, including fencing and a dumpster.
Worked Example: A 200 Guest Outdoor Wedding
A 200 guest wedding over 6 hours near Fairwood, roughly 7.7 miles north of Spokane, lands between the 4 hour and 8 hour brackets. Round up: plan for four to five standard units, plus one ADA unit meeting ADA Standards section 304.3.1, which calls for a 60 inch turning circle inside the unit. If the reception serves alcohol, add one more unit to the count, since alcohol consumption is the single biggest driver of higher usage per guest at any event. A deluxe flushable option often makes sense for a wedding budget, and those run 150 to 290 dollars for a week rental. See deluxe flushable porta potty or start with portable restroom rental to compare unit types side by side.
How Do Alcohol and Multi-Day Events Change the Count?
Alcohol service pushes usage up because people drink more fluid and use the restroom more often per hour. Add roughly 20 percent more units to your base headcount ratio if the event pours alcohol for more than 2 hours. Multi-day events, like a county fair or a multi-day festival, need service visits built into the plan rather than a single drop-off. ANSI/PSAI Z4.3 sets a baseline of one service visit per week for up to 10 users over a 40 hour week, but a 3-day outdoor event with heavy traffic needs daily servicing, not weekly. Check county fair restrooms or golf tournament restrooms for examples of multi-day setups, and if the event runs long enough to need a manned trailer instead of standalone units, look at restroom trailer rental and the 2 stall restroom trailer option for smaller headcounts.
How Many Cubic Feet and Tons Does a Dumpster Hold for Site Cleanup?
Once you've sorted restrooms, most Spokane jobsites also need debris hauled off, and dumpster sizing runs on cubic feet and tons rather than headcount. Asking how many cubic feet in a 10 yard dumpster gets you about 270 cubic feet, suited for a small remodel. How many cubic feet in a 20 yard dumpster comes out to close to 540 cubic feet, and that box typically handles 2 to 3 tons of mixed debris, which answers how many tons does a 20 yard dumpster hold for most jobs. Step up to a 30 yard dumpster and you're looking at around 810 cubic feet, with how many tons can a 30 yard dumpster hold landing near 3 to 4 tons depending on material density. How many cubic feet in a 40 yard dumpster works out to roughly 1,080 cubic feet, and how many tons does a 40 yard dumpster hold comes in around 4 to 5 tons on a typical construction cleanout. Weekly dumpster rental in Spokane runs 426 to 778 dollars depending on size and haul distance. Compare exact dimensions on dumpster sizes and dimensions, check dumpster weight limits before you load it, and pick a size from 10 yard dumpster rental, 20 yard dumpster rental, 30 yard dumpster rental or 40 yard dumpster rental.
Should I Order Extra Units for Winter or Remote Sites?
Yes, if the site sits far from a service route or the job runs through winter. A jobsite near Cheney, about 17.4 miles southwest of Spokane, or one out toward Post Falls, ID, roughly 27 miles east, costs more to service because of drive time, and that shows up in the delivery fee more than the unit price. Delivery fees for a single trip typically run 100 to 500 dollars depending on distance and rush timing. Cold weather also slows tank turnover, so an extra unit per crew segment reduces backup risk during freeze events. Read porta potty in winter for servicing details, and if you're outside Spokane proper, check service areas or look at nearby coverage like porta potty rental in Mead and porta potty rental in Airway Heights to confirm delivery logistics before you commit to a count.
How many porta potties do I need per 100 guests?
Plan on two standard units per 100 guests for a 4 hour event, three if alcohol is served or the event runs longer. Add one ADA-compliant unit regardless of headcount if you're clustering multiple units, per ADA Standards section 213.2. Check how many porta potties do I need for the full breakdown by hours and headcount.
Does OSHA require separate toilets for men and women?
OSHA 1926.51(c) sets ratios by total headcount, not gender-separated counts, though many Spokane jobsites still separate facilities as a practical matter. The rule cares about total seats and urinals per worker bracket. See OSHA portable toilet requirements for the full bracket table.
How many tons does a 30 yard dumpster hold?
A 30 yard dumpster typically holds 3 to 4 tons of mixed construction debris, though heavier material like concrete or shingles fills the weight limit long before the cubic footage does. Check dumpster weight limits before loading dense debris to avoid overage charges.
How many feet is a 20 yard dumpster?
A 20 yard dumpster runs about 20 feet long, 8 feet wide, and 4 feet tall, holding roughly 540 cubic feet of debris. See dumpster sizes and dimensions for exact measurements across all sizes.
Do I need more units if the event serves alcohol?
Yes. Alcohol service increases restroom usage per guest, so add roughly 20 percent more units above your base headcount ratio. A 150 guest event that would normally need three units should plan for four if drinks are flowing for more than 2 hours.
What if my Spokane jobsite has fewer than 20 workers?
One standard unit satisfies OSHA 1926.51(c) for crews of 20 or fewer. Confirm placement location works with your site layout using the porta potty placement guide, and request a quote through request a quote once you know your count.
Next step
Get a delivery date
Tell us the address, the dates and the headcount. We size the order and confirm the route.