The federal construction rule at 29 CFR 1926.51 requires toilet facilities on job sites, and its table sets the count by crew size. The widely repeated line about one toilet per 20 workers is a paraphrase of the first tier, not the table. OSHA has also said that an unsanitary toilet does not count toward the minimum.
Key takeaways
- Table D-1 in 29 CFR 1926.51(c) sets the toilet count by crew size, and its first tier is one facility for 20 or less workers.
- Above that tier the table calls for one toilet seat and one urinal per 40 workers.
- Paragraph (c)(2) requires that at least one toilet facility be available under temporary field conditions.
- Mobile crews with transportation readily available to nearby toilets may be exempt under paragraph (c)(4).
- OSHA has said a toilet in an unsanitary condition does not count toward the minimum.
- Washing facilities are a separate requirement under 1926.51(f), and a handwash station is one way to meet it.
What does the federal rule require on a job site?
The rule requires toilet facilities on construction sites and sets a minimum count based on crew size. It is a federal OSHA standard, and the employer on the site is the party it binds.
Section 1926.51 of the federal construction rules deals with sanitation on job sites. Paragraph (c) sets the toilet count, and that count is tied to a table rather than a single ratio. Reading the table alongside the paragraphs around it gives the full picture, and a planner should keep a copy of the rule with the site file so the count can be checked on paper. The point of the table is that a small crew and a large one need different numbers of facilities, and the minimum rises with the size of the crew. A planner who reads only one line of the rule will miss the parts that change the answer.
Paragraph (c)(2) adds a floor that applies on every site: at least one toilet facility must be available under temporary field conditions. That matters most on a new build, where there may be no fixed plumbing for months and the only facilities are the ones brought onto the site. Temporary units are the usual way to meet that need, which is why the construction site portable toilets page covers placement and service for the whole build. The sensible order is to plan the units before the first crew arrives, not after the first complaint. A site that starts work with no facility in place has a problem on day one that no later delivery fully solves, and the planner who maps the crew's first week is the one who avoids it.
How is the crew counted for the toilet table?
The table counts workers, so the crew size on the site drives the count. Planners should count the people who will be working there, not the total headcount of the company.
The table is written around the number of workers at a site, meaning the people actually performing the work. A crew split across several locations on the same job has to be counted by where its workers are. The planner's job is to get that number from the superintendent or foreman early, because the count is what sets the facilities. Subcontractors working on the same site are a common source of confusion, so the headcount should be agreed across all of the trades before the units are ordered, and the agreed figure written into the site plan so it can be checked later.
The first tier is simple: one facility covers a crew of 20 or fewer workers. Above 20, the count rises under the rest of the table, and the description of that next tier is one toilet seat and one urinal per 40 workers. A crew that grows during the job should trigger a review of the count, not a single check at the start.
Where does the one-per-20 line come from?
The widely repeated one-per-20 line is a paraphrase of the first tier. It is not the table, and it leaves out the tiers above it, which is why it misleads on a larger crew.
Rental companies and safety blogs often repeat a short version of the rule, and the short version is easy to remember. The problem is that it reads as if the rule were one toilet for every 20 people at all times, which is not what the table says. The first tier is one facility for 20 or fewer workers, and the larger tiers have their own counts that a short slogan cannot carry.
The practical lesson is to work from the table itself. Look up the crew size, check the tier, and then confirm the count with the sanitation provider, who can match units to the site. A shortcut that is right for a small crew can be wrong for a larger one, and that is the mistake the paraphrase invites. Keep the calculation on paper so an inspector or the site manager can see how the count was reached.
What is the mobile crew exception?
Paragraph (c)(4) exempts mobile crews that have transportation readily available to nearby toilets. The exception depends on real access to those toilets, not on the idea that a toilet exists somewhere nearby.
Some crews move from place to place all day, such as a utility crew working one block at a time or a survey team. Paragraph (c)(4) recognizes that such crews may not need a toilet at each stop, as long as transportation is readily available to nearby toilets. The exception is for mobile work, so it does not describe a crew that stays on one site for months. A roadwork and utility crew setup is the usual case for it.
The limit on the exception is access. OSHA's letter on the point indicates that toilets too slow to reach are not treated as provided. A planner who relies on the exception should be able to show that a toilet can be reached quickly during the workday, and should record the route. For a crew that stays in one place, the exception usually does not fit, and a unit on site is the simpler and more defensible choice. Keep a copy of the crew's usual route and the nearest toilet on the site plan, so the reasoning is visible to anyone who checks the site later. A route that changes every week needs its own note, because the nearest toilet on Monday may not be the nearest one by Friday.
Does an unsanitary toilet count toward the minimum?
No. OSHA's 2006 interpretation answers no to whether toilets in an unsanitary condition count toward the minimum. A unit has to be usable to count.
A facility on the site only meets the rule if it can be used. A unit that is full, unstocked or unsafe to enter does not give the crew what the standard is for, and OSHA's interpretation answers no to whether such toilets count toward the minimum. That makes servicing a compliance question as well as a comfort question.
The planning consequence is direct. A service schedule that lets a unit fill before the next visit leaves the site short in practice, even if the unit is still standing on the ground. Ask the provider for a schedule that matches the crew's hours and the size of the work, and check the units during the job. A short walk-through once a week, with the site superintendent, is enough to catch a unit that is filling faster than planned. If a unit cannot be serviced in time, add one rather than hoping the crew will manage.
What are the washing facilities requirement?
Paragraph 1926.51(f) requires washing facilities on construction sites. A handwash station is one way to meet that need, and it is planned alongside the toilets rather than as an afterthought.
Washing facilities are a separate requirement from the toilet count. The rule sits in paragraph (f), and it means a site with toilets still needs a place for workers to wash. A handwash station is one practical way to provide that, and it can sit beside the toilet units so workers do not walk far between the two.
Handwash stations need a water supply and a way to deal with what they collect, so they should be placed where the service truck can reach them as well as the toilets. Check the supply on each visit, and treat the washing plan as part of the same site layout as the toilet count, since both are checked against the same site. The handwash station rental page covers the product itself.
Are construction-only units exempt from accessibility rules?
Portable toilets used exclusively by construction personnel are fully exempt from the accessibility requirement under the federal guidance. Units used by the public at an event are not exempt, so the two situations should be kept apart.
Federal guidance on accessible portable toilets comes from the Justice Department and the Access Board. Under that guidance, units used only by construction personnel are exempt, so a site used only by its own crew does not need an accessible share for that crew. The exemption does not change the washing facility requirement, which applies to the crew whether or not any toilet on the site is accessible. The exemption is narrow. It covers units used exclusively by construction personnel, not units shared with the public.
A construction site that also hosts visitors, a tour or an event on the same grounds should separate its units accordingly, because the exemption no longer covers a unit the public uses. Planners who manage both should read the guidance and confirm the arrangement with the permitting office. Accessible portable toilets are available if a site needs them.
Frequently asked questions
How many toilets does a crew of 20 need?
Under the table's first tier, one facility covers a crew of 20 or fewer workers. Confirm the crew size with the site superintendent, since the count changes if the crew grows, and keep the calculation written down.
Is one toilet per 20 workers the rule?
No. That phrase paraphrases the first tier of Table D-1, not the table itself. The table has more tiers, so a short slogan cannot give the full count for a larger crew.
Does a mobile crew need a toilet on site?
Paragraph (c)(4) may exempt mobile crews that have transportation readily available to nearby toilets. The toilets have to be reachable in practice, and a toilet too slow to reach does not count as provided.
Do washing facilities count as toilets?
No. Washing facilities are a separate requirement under paragraph (f). A handwash station can meet that need, and it should be planned together with the toilet units.
Does an unsanitary unit still count?
OSHA has answered no to that question. A toilet that is not usable does not count toward the minimum, so servicing has to keep pace with how much the crew uses it.
Do construction units need accessible toilets?
Units used exclusively by construction personnel are fully exempt from the accessibility requirement under federal guidance. Units shared with the public are not exempt, so keep them clearly separate on any mixed site.
Sources
This guide is general information for Franklin County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.