OSHA Portable Toilet Requirements for Job Sites in Oregon and Washington

• Federal OSHA sets a tiered minimum for construction sites, not a flat ratio: 1 toilet for 20 or fewer workers, then 1 toilet seat and 1 urinal per 40 workers, then per 50 workers once a site reaches 200. Source: 29 CFR 1926.51(c), Table D-1.
• A toilet that is dirty, broken, or too far away does not count toward that minimum. OSHA's own letters say so.
• OSHA sets no service frequency. The weekly schedule everyone quotes is an industry standard, ANSI Z4.3, which OSHA points to as one way to stay compliant.
• Oregon uses the federal table and adds its own rules, including flush toilets and warm-water wash basins on any project estimated at $1,000,000 or more.
• Washington does not use the federal table. Its own table requires more units at almost every crew size, warm wash water at every construction site, and toilets within 200 feet of every worker.

The construction sanitation standard says, in full:

Toilets shall be provided for employees according to the following table:

Three things to read carefully in that table.

It is a minimum.

The rule does not say a crew of 20 should have one toilet. It says a crew of 20 may not have fewer than one.

It counts seats and urinals, not units.

From 20 workers up, the requirement is one seat and one urinal per 40. A portable toilet is one seat. Many standard units have a small urinal built in, some do not. OSHA has not said whether a built-in urinal counts as the separate urinal the table asks for.

The rows overlap on purpose.

"20 or less" and "20 or more" both include 20. That is how the regulation is written, and it means a crew of exactly 20 satisfies the rule with one toilet.

The same section makes portable toilets legal on a job site in the first place. Where there is no sewer connection, the rule allows "privies, chemical toilets, recirculating toilets, or combustion toilets" unless a local code prohibits them. A portable toilet is a chemical toilet.

The regulation says toilets must be "provided." Four OSHA letters of interpretation define the word, and they are where every "10 minutes" and "dirty toilets don't count" claim comes from.

Under 10 minutes.

In 2002 OSHA wrote that "toilets that take too long to get to are not 'available'," and that "in general, toilets would be considered 'nearby' if it would take less than 10 minutes to get to them." In 2005 it applied the same test to a crew on the tenth floor of a high-rise with toilets only at ground level: if the trip down takes longer than that, the ground-floor units do not count toward Table D-1.

Sanitary or it does not exist.

In 2006 OSHA wrote: "toilets that are unsanitary are unusable and therefore are not 'available.' Consequently, a toilet is not 'provided' under §1926.51(c)(1) if it is in an unsanitary condition." A site with two units where one is unusable is a site with one unit. The same letter adds that the rule "does not require toilet facilities to be in immaculate condition."

Mobile crews are the only exception.

The rule does not apply to "mobile crews having transportation readily available to nearby toilet facilities." OSHA defines a mobile crew as workers who "continually or frequently move from jobsite to jobsite on a daily or hourly basis," such as a power-line crew. A crew that reports to the same construction project for days or weeks is not a mobile crew, and OSHA said in 1993 that house-building crews do not qualify.

The federal table, Washington's table, and the general-industry table for permanent workplaces, side by side. Seats and urinals are listed the way the rule counts them; the "units" reading is the plain one for standard portable toilets that have both. Fractions round up, because a rule stated "per 40 workers" cannot be satisfied by part of a toilet.

Two notes on reading it.

The federal count is the floor, and OSHA's letters say the point of the table is "to assure that employees will not have to wait in long lines." A crew of 40 on one seat and one urinal meets the rule and still queues at 7 a.m. In Washington the count comes from Table B-1, which is stricter.

OSHA's construction rule does not say how shifts are counted. Its rule for permanent workplaces, 1910.141, counts "the maximum number of employees present at any one time on a regular shift," so a two-shift site with 30 workers per shift counts as 30, not 60. The units still get twice the use: industry guidance doubles the unit count for two 8-hour shifts, and the servicing section below covers the other way to handle it.

This is where the three jurisdictions split the widest.

Federal.

The construction standard requires "adequate washing facilities for employees engaged in the application of paints, coating, herbicides, or insecticides, or in other operations where contaminants may be harmful." For everyone else on a construction site, it requires nothing. In 2005 OSHA was asked whether "a couple of rags and a can of waterless hand cleaner" satisfies that rule for contaminant work; the answer was that washing facilities "would not be 'adequate' unless they included soap and potable water." Sanitizer does not substitute for washing where washing is required.

Oregon.

Oregon did not adopt the federal handwashing paragraph. Its own rule says handwashing facilities "shall be provided in work areas where the employees are exposed to hazardous materials which will have a deleterious effect on or be absorbed through the skin if the contamination is not removed." Same substance, broader words: any skin-harmful material, not just the four the federal rule names.

Washington.

Every construction site, whatever the work. "You must provide clean, tepid wash water, between 70 and 100 degrees Fahrenheit, at all construction sites," with individual hand towels and soap or hand cleaner "adequate to remove any paints, coatings, herbicides, insecticides or other contaminants." Gasoline and solvents may not be used for personal cleaning. On a Washington site, a handwashing station is not an upgrade.

Three different answers, and they are usually blended into one.

What the law says.

Federal OSHA sets no interval. It requires the toilet to be in sanitary condition, and a unit that is not sanitary does not count, per the 2006 letter above. Oregon's rule adds that toilets "shall be maintained in good repair and in a clean and sanitary condition." Washington requires service "on a regular schedule" that includes disinfecting the seat and urinal, pumping the waste, recharging the chemical, and restocking tissue and seat covers, and it requires the holding tank to be sized so it is never more than half full before the scheduled service. No jurisdiction says "weekly."

What the industry standard says.

ANSI Z4.3 is the portable sanitation industry's consensus standard. OSHA's 2006 letter cites it as "one way for an employer to meet its obligation": a toilet used by up to 10 people, serviced at least once a week. The letter's own example is that one toilet for 20 workers, serviced twice a week, "would likely be providing a toilet in a sanitary condition." The current edition is Z4.3-2025.

What that means in practice.

Weekly service is the baseline for a unit used by 10 or fewer people on a single shift. More users, a second shift, or hot weather mean more frequent service, not a bigger unit.

Oregon runs its own OSHA program, Oregon OSHA, and adopts 29 CFR 1926.51 by reference, so Table D-1 above is Oregon law. Oregon then adds to it under OAR 437-003-0020, and interprets it under Program Directive A-97. None of the national pages that rank for this search mention any of it.

Projects of $1,000,000 or more need flush toilets and wash basins.

At the site of every project with an estimated cost of $1,000,000 or more, the employer or owner of such place of employment shall provide flush toilet facilities in accordance with subparagraph (1) of 29 CFR 1926.51(c) and washing facilities which include wash basins, warm water and soap.

The count is still Table D-1; the type changes. Oregon OSHA's directive confirms that "self-contained flush toilets are acceptable," so a flush portable unit qualifies and no sewer connection is needed. Highway, electrical, water, sewer, and gas transmission projects are exempt. On an Oregon project over the threshold, standard chemical units alone do not satisfy the rule; RHC confirms the project estimate before quoting so the unit type matches it.

Three minutes, not ten.

Federal OSHA's letters say under 10 minutes. Oregon's compliance officers use Program Directive A-97: toilets must be "no further than a person can walk at a unhurried pace in three minutes," on a path "free of obstructions" that does not cross "extensive accumulations of mud, debris, or other obstacles." Up to five minutes is allowed only where a closer placement is impractical or the cost is out of proportion to the distance gained. On a construction site, chemical toilets "must be within the three-minute travel distance."

Under $1,000,000, a neighbor's restroom can count.

A project under the threshold may arrange to use a nearby business's toilets if the owner agrees, every worker knows about it, transport is available, the arrangement does not overload the neighbor, and the facilities are "within a 5-minute travel distance of the worksite." The employer is still responsible for those toilets meeting 1926.51(c).

Urinals can replace some toilets, to a limit.

Where the toilets will not be used by women, urinals may stand in for toilets, "except that the number of toilets in such cases shall not be reduced to less than 2/3 of the minimum specified."

Washington's Department of Labor & Industries wrote its own construction sanitation rule, WAC 296-155-140, instead of adopting the federal one. It was last amended effective July 1, 2025. Almost every line is stricter than federal.

Table B-1, toilets required:

A crew of 12 needs two units in Washington and one under the federal table. A crew of 45 needs four, against two seats and two urinals federally. The table applies to portable chemical toilets; flush toilets on a Washington site are counted under a separate general-industry chapter, WAC 296-800-230.

Distance is measured in feet.

Facilities must be "as close as practical to the highest concentration of employees," "within 200 feet horizontally of all employees," and on multistory structures "on every third floor."

Latches, and separate facilities at 20.

Every unit needs "internal latches to secure the units from inadvertent entry." Where there are 20 or more employees of both sexes, facilities must be provided for each sex.

Inspected every shift, in writing.

The employer must inspect the sanitation facilities "at the beginning of each shift," fix anything that fails, and "document and maintain such action at the site for at least 72 hours." The inspection covers tissue, seat covers, chemical, tank level, cleanliness, the lock, and the seat. A defective unit must be removed from service immediately.

The prime contractor is responsible.

"On multiemployer worksites, the prime contractor must ensure that the requirements of this section are met." Each employer still has to provide for its own people.

Warm wash water at every site.

Covered above: 70 to 100°F, soap, individual towels, at all construction sites.

Menstrual products, since July 2025.

Employers must provide workers who menstruate a bathroom at least the size of a standard chemical toilet with an internal latch, adequate time, and "an adequate and convenient supply of menstrual hygiene products at no cost to the workers," either stocked in the units or issued as kits. This applies to fixed and mobile crews.

Mobile crews.

Washington's exception uses a tighter definition of "nearby": "a sanitary facility that is within three minutes travel by the transportation provided."

If the site is a permanent place of employment rather than a construction project, a different standard applies: 29 CFR 1910.141, and its Table J-1. It is counted per sex, and it is the table behind the "1 toilet for 1 to 15 employees" figure that often gets mixed into construction answers.

Separate rooms for each sex are not required where a toilet room holds one person, locks from the inside, and has at least one water closet. Where women will not use the facilities, urinals may replace water closets down to two-thirds of the minimum. Oregon adopts this standard; Washington's equivalent is WAC 296-800-230.

Two reasons, and neither is a federal, Oregon, or Washington rule.

It is the first row of Table D-1, "20 or less: 1," read as if it continued in a straight line. It does not; the next row switches to seats and urinals per 40.

It is also California's actual rule. Cal/OSHA's construction order, Title 8 §1526, says "a minimum of one separate toilet facility shall be provided for each 20 employees or fraction thereof of each sex." National rental companies write for California and the figure travels. It is not the law in Oregon or Washington.

In Oregon, one per 20 sits above the federal floor. In Washington it is below the law from 11 workers up.