Job-Site Planning Guide
How Many Porta Potties Does a Job Site Need?
OSHA’s construction sanitation standard, 29 CFR 1926.51, sets the minimum number of toilets by crew size. Here is the table, how OSHA applies it, and what else the rule asks for.
From $135 per month
- OSHA Table D-1 minimums
- Servicing and access guidance
- Handwashing rules
The Minimum
OSHA Table D-1: Toilets by Crew Size
29 CFR 1926.51(c)(1) says toilets shall be provided for employees according to this table.
| Number of employees | Minimum number of facilities |
|---|---|
| 20 or less | 1 |
| 20 or more | 1 toilet seat and 1 urinal per 40 workers |
| 200 or more | 1 toilet seat and 1 urinal per 50 workers |
As printed, the first two rows both include 20 employees. In its 2006 interpretation, OSHA reads 20 employees as needing at least one toilet.
What Counts
A Toilet Only Counts If It’s Clean and Close
OSHA has explained in letters of interpretation what “provided” means on a construction site.
Clean, or it doesn’t count
In its May 17, 2006 interpretation, OSHA says a toilet in unsanitary condition is not “provided” and does not count toward Table D-1. As a guide it points to the ANSI Z4.3-1995 servicing schedule, which calls for a toilet used by up to 10 people to be serviced at least once a week. OSHA’s example: with one toilet for 20 employees, servicing it twice a week would likely keep it sanitary. Servicing means emptying the waste and cleaning the unit, and OSHA notes the standard does not require toilets to be immaculate.
Close enough to reach quickly
OSHA reads “provided” as “made available,” and toilets that take too long to get to are not available. Its February 23, 2005 interpretation says that, in general, the starting point is whether it takes employees less than 10 minutes to get to a toilet. OSHA also says one purpose of Table D-1 is timely access, so employees do not have to wait in long lines.
Also in 1926.51
Handwashing, Toilet Types and Exemptions
The same standard covers more than the head count.
Handwashing — 1926.51(f)(3)
Lavatories must be made available in all places of employment. Each needs hot and cold running water, or tepid running water; hand soap or a similar cleansing agent; and individual hand towels or air blowers. Mobile crews and normally unattended locations with transportation readily available to nearby washing facilities are exempt.
Harmful materials — 1926.51(f)(1)
Crews applying paints, coatings, herbicides or insecticides, or working where other contaminants may be harmful, need adequate washing facilities in near proximity to the worksite, equipped so they can remove those substances.
No sewer on site — 1926.51(c)(3)
A job site without a sanitary sewer must have privies (where they will not contaminate ground or surface water), chemical toilets, recirculating toilets or combustion toilets, unless local codes prohibit them. A porta potty is a portable chemical toilet.
Temporary field conditions — 1926.51(c)(2)
Provisions must be made so that not less than one toilet facility is available.
Mobile crews — 1926.51(c)(4)
The toilet requirements do not apply to mobile crews having transportation readily available to nearby toilet facilities. OSHA describes mobile crews as moving from jobsite to jobsite on a daily or hourly basis, and says that is not the normal situation for crews in housing construction.
Drinking water — 1926.51(a)
An adequate supply of potable water must be provided in all places of employment.
Planning
Planning Your Count
OSHA sets the floor. These follow from it on a real job.
- Count your peak day: every crew on site at the same time, not the weekly average.
- Longer shifts and more crews mean more use. Add units or service them more often — OSHA’s servicing example scales with how many people share each toilet.
- On a large or spread-out site, place units so reaching one takes less than 10 minutes, even if that means more than one location.
- Plan handwashing alongside the toilets: 1926.51(f)(3) asks for lavatories in all places of employment.
OSHA’s table is a minimum. Our own planning rule of thumb for crews is more generous: one unit for every 10 workers on a 40-hour week. Standard units start at $135 per month, including service.
Porta potty rental and pricingQuestions
Job-Site Toilet Questions
How many porta potties does OSHA require on a construction site?
OSHA’s construction sanitation standard, 29 CFR 1926.51(c)(1), sets the minimum by headcount: 1 toilet for 20 or fewer employees; 1 toilet seat and 1 urinal per 40 workers for 20 or more; and 1 toilet seat and 1 urinal per 50 workers for 200 or more.
How many porta potties do I need for 20 workers?
At least one. OSHA uses that exact example in a 2006 interpretation, and adds that one toilet for 20 employees, serviced twice a week, would likely be in sanitary condition.
How often does a job-site porta potty need to be serviced?
The standard sets no schedule, but OSHA says a toilet in unsanitary condition does not count as provided. As a guide it points to the ANSI Z4.3-1995 servicing schedule, which calls for a toilet used by up to 10 people to be serviced at least once a week.
How close do porta potties have to be to the crew?
Close enough to reach promptly. OSHA says toilets that take too long to get to are not available, and that in general the starting point is whether it takes employees less than 10 minutes to get to a toilet.
Does a job site need handwashing stations?
OSHA’s construction standard requires lavatories to be made available in all places of employment, with hot and cold running water or tepid running water, hand soap or a similar cleansing agent, and individual hand towels or air blowers. Mobile crews and normally unattended locations with transportation readily available to nearby washing facilities are exempt.
Are mobile crews exempt from the toilet rule?
Only crews with transportation readily available to nearby toilet facilities. OSHA describes mobile crews as moving from jobsite to jobsite on a daily or hourly basis, and says that is not the normal situation for housing construction crews.
Sources
Where This Comes From
Everything above is from OSHA’s construction sanitation standard and OSHA’s letters of interpretation on it. Read the full text before you rely on it.
- 29 CFR 1926.51 — Sanitation (construction)
OSHA, U.S. Department of Labor
- Interpretation, May 17, 2006: toilets at a construction jobsite must be in a sanitary condition
OSHA Directorate of Construction
- Interpretation, February 23, 2005: providing employees with toilet facilities on a construction jobsite
OSHA Directorate of Construction
- Interpretation, April 19, 1993: toilets for mobile crews with transportation to nearby facilities
OSHA Office of Construction and Maritime Compliance Assistance
This guide is general information, not legal advice. Checked against these sources on October 13, 2026; the official text is what counts.