Porta Potty Calculator: What the Source Tables Actually Say

What are the key Porta Potty Calculator statistics?

These are the page’s fastest citable findings. Each line carries its scope, source, and verification date so it remains intelligible when quoted outside the surrounding article.

1. Of the 100 cells shared by PSAI’s 130-cell event chart and Georgia’s codified 250-cell Table 2, 99 match exactly and one does not: at 10,000 attendees for six hours, Georgia prints 75 units and PSAI prints 55. Original comparison of Sources 1 and 2; verified July 27, 2026.
2. PSAI’s six-hour value of 55 for 10,000 attendees is the only value in that row that decreases as duration rises: the row goes from 63 at five hours to 55 at six, then 88 at seven. Georgia prints 75 for six hours, and a 2015 PSAI brochure also prints 75. Sources 1–3; verified July 27, 2026.
3. Georgia regulation requires special-event minimums to be determined from Table 2 after subtracting available sewered fixtures. Ga. Comp. R. & Regs. r. 511-3-6-.03(7)(c) and the Rule 511-3-6-.08 Appendix; verified July 27, 2026. Source 2.
4. PSAI’s chart assumes one restroom use per guest every four hours, a 50/50 mix of men and women, and no pumping during the event. PSAI Standards for Special Events; verified July 27, 2026. Source 1.
5. PSAI states that one portable restroom provides approximately 200 uses. PSAI Standards for Special Events; verified July 27, 2026. Source 1.
6. For 250 people over four hours, PSAI lists 2 units, United Rentals’ published one-per-50 recommendation produces 5, and ZTERS’ one-per-25 rule produces 10—a five-fold spread from lowest to highest. Original calculation from Sources 1, 21, and 22; verified July 27, 2026.
7. OSHA’s construction quantity table does not contain a one-toilet-per-10-workers rule. Table D-1 provides one facility for 20 or fewer employees, then one toilet seat and one urinal per 40 workers, with a separate per-50 row at 200 or more. 29 CFR 1926.51(c)(1); verified July 27, 2026. Source 4.
8. The one-per-10 figure in OSHA’s May 17, 2006 letter is a servicing example, not a quantity rule: the letter cites ANSI Z4.3-1995 for a toilet used by up to 10 people being serviced at least weekly. Source 5; verified July 27, 2026.
9. At 200 workers, the federal standards produce materially different outputs: construction Table D-1’s overlapping rows mechanically yield either 4 or 5 toilet-seat-and-urinal pairs; general industry yields 10 water closets under a 50/50 sex assumption; agricultural field work yields 10 toilets and 10 handwashing facilities. Original application of Sources 4, 6, and 8; verified July 27, 2026.
10. OSHA Table D-1 uses overlapping threshold labels at exactly 20 and 200 workers. At 200, the “20 or more” row yields 5 seat-and-urinal pairs while the “200 or more” row yields 4. Source 4; original calculation verified July 27, 2026.
11. Under federal general-industry rules, a water closet is a facility flushed with water; OSHA treats substitution of non-water-flushed portable toilets as a de minimis departure only when four stated conditions are met. 29 CFR 1910.141 and OSHA’s May 18, 1999 interpretation; verified July 27, 2026. Sources 6 and 7.
12. Current federal guidance requires access to at least 5% of portable single-user units in each cluster, including at temporary events. U.S. Access Board Guide to the ADA Accessibility Standards; verified July 27, 2026. Sources 9 and 11.
13. Portable toilet units used exclusively by construction personnel on a construction site are exempt from ADA section 213 and from the accessible-route requirement. 2010 ADA Standards §203.2; verified July 27, 2026. Source 9.
14. Four publisher-issued alcohol adjustments differ: current PSAI guidance says 20%–30%, Georgia regulation says 25%, a 2015 PSAI brochure says 10%–20%, and United Rentals recommends 10%–15%. Sources 1–3 and 21; verified July 27, 2026.
15. Alabama’s portable-toilet rule requires compliance with ANSI/PSAI Z4.3 or Z4.4 “as appropriate” but names no edition; the current full standards are sold by ANSI and are not reproduced in the Alabama rule. Ala. Admin. Code r. 420-3-1-.29(3)(a) and current ANSI listings; verified July 27, 2026. Sources 12–14.
16. The published scope of ANSI/PSAI Z4.4 changed materially between editions: Z4.4-2016 covered fields and temporary labor camps, while Z4.4-2025 covers nonsewered systems used by the general public. ANSI listings; verified July 27, 2026. Sources 14 and 15.
17. From 25,000 through 100,000 attendees, Georgia’s four-hour column rises by 25 or 26 units for each additional 5,000 people—an average of 25.8 units, or one additional unit per about 194 attendees. Original analysis of Source 2; verified July 27, 2026.
18. The study lineage behind the event chart dates to the late 1980s. PSAI attributes the work to a collaboration with the University of Missouri and says it intends to issue an updated version; Georgia attributes Table 2 to the Center for Business and Industrial Studies at the University of Missouri–St. Louis. Sources 1 and 2; verified July 27, 2026.
19. Huntsville requires a special-event permit at attendance of 500 or more and requires a detailed site plan, but the official City permit page and event guide reviewed on July 27, 2026 publish no fixed numerical portable-restroom ratio. Sources 16 and 17.

What does the Porta Potty Calculator show side by side?

The table joins two official publications with the same study lineage: PSAI’s 13-row planning chart and Georgia’s 25-row regulatory chart. PSAI supplies the small-crowd rows, Georgia supplies the large-crowd extension, and their ten shared rows match in 99 of 100 cells.

Merged event restroom chart: units by crowd size and duration

† Georgia’s codified Table 2 prints 75 at 10,000 attendees for six hours. PSAI’s currently hosted document prints 55. The merged dataset preserves both source values and selects no combined value for that cell.
Source: Portable Sanitation Association International, PSAI Standards for Special Events (undated current hosted document), and Ga. Comp. R. & Regs. r. 511-3-6-.03 and -.08, Appendix Table 2. Both read directly from the issuing organizations and verified July 27, 2026. Sources 1 and 2. Merge and comparison by Porta Potty Rental in Huntsville, AL Research.

How to use the merged chart

Use the smallest published crowd row that is at least as large as the expected peak number of people. Georgia expressly requires a crowd that falls between rows to be rounded upward; this page applies the same disclosed convention to PSAI’s smaller crowd rows so the merged calculation is reproducible across the full table.

The source tables provide whole-hour columns but do not print a rule for fractional hours. This page assigns a partial hour to the next whole-hour column—for example, 2.5 hours uses the three-hour column—as a conservative calculation convention created for this dataset, not as quoted source language. No values are interpolated between cells, and no value is extrapolated beyond the published limits.

Count everyone expected to use the facilities, not only ticketed guests. PSAI specifically says to include volunteers, security personnel, and vendors with guests and attendees. Georgia’s table also directs the user to subtract one for each sewered toilet available onsite after the base number is determined.

Where do the two source tables disagree?

The only disagreement in the 100 shared cells occurs at 10,000 attendees for six hours. Georgia’s regulation says 75, PSAI’s currently hosted document says 55, and a separate 2015 PSAI brochure says 75.

The 10,000-attendee row in both sources

Source: Georgia Rule 511-3-6-.08 Appendix Table 2; PSAI’s currently hosted Standards for Special Events; and PSAI’s 2015 public brochure. Source values verified July 27, 2026. Hour-to-hour differences calculated by Porta Potty Rental in Huntsville, AL Research. Sources 1–3.

Georgia’s row follows a steady sequence after the first interval, alternating increases of 12 and 13 units. The current PSAI row follows the same values everywhere except the six-hour cell, where it falls by 8 and then rises by 33 to rejoin the shared sequence at seven hours.

That pattern is evidence of a source conflict, not permission to rewrite the source. This verification pass obtained no PSAI clarification, so the raw PSAI value remains 55, the raw Georgia value remains 75, and the downloadable dataset leaves merged_units blank for that record.

For an event governed by Georgia Rule 511-3-6, the codified table value is 75. Outside that context, a writer should report the discrepancy or cite the specific source being used; presenting 55 or 75 as an undisputed universal value would erase a material primary-source conflict.

What does this comparison show—and what does it not show?

The 99 matching cells, the shared study attribution, and the matching row structure establish that the two tables have a common underlying lineage. The comparison does not establish that either table predicts waiting time, comfort, local permit approval, or the right quantity for every event.

PSAI calls its chart general guidance for planning the minimum number of units. Georgia uses its table as the regulatory basis for special-event minimums in that state. Company recommendations often use more conservative ratios and frame them around keeping facilities available and reducing lines, which is a different planning objective.

The same events under four published methods

Source: PSAI Standards for Special Events; Georgia Rule 511-3-6-.08 Table 2; United Rentals’ September 18, 2025 event-planning recommendation of one toilet per 50 guests for up to four hours and two per 50 for five to eight hours; and ZTERS’ published general rule of one toilet per 25 people. All pages read July 27, 2026. Arithmetic by Porta Potty Rental in Huntsville, AL Research. Sources 1, 2, 21, and 22.

The spread is real, but the columns are not interchangeable legal rules. PSAI presents a minimum-planning chart, Georgia presents a state regulatory floor, and the companies publish their own operational recommendations. A citable number is incomplete unless the article states which source and which planning objective produced it.

How was this dataset built and verified?

The dataset was built from the issuing sources rather than copied from a calculator or secondary article. Every raw table value, regulatory line, standards title, permit trigger, and dated statement used in the page was rechecked during the July 27, 2026 verification pass.

What was collected

We transcribed all 130 cells in PSAI’s currently hosted special-event chart and all 250 cells in Georgia’s codified Table 2. We read the rule that makes Georgia’s table the minimum basis for special events, the table footnotes, OSHA’s construction, general-industry, and agricultural sanitation standards, OSHA’s 1999 and 2006 interpretation letters, the 1991 and 2010 ADA Standards, the current U.S. Access Board guide, Alabama Rule 420-3-1-.29, current and historical ANSI listings, the Huntsville permit page and event guide, the Alabama Onsite Wastewater Board licensing page, and the Alabama Department of Public Health food-plan checklist.

The United Rentals and ZTERS figures appear only in the expressly labeled comparison of publisher-owned recommendations. They were read from the companies’ own pages; neither is treated as a statute, regulation, consensus-standard text, or measurement.

How the table was processed

Each source table was converted into one structured record per crowd-size and duration combination. A script aligned the ten crowd bands published by both sources and compared all 100 overlapping cells. The script also checked each row for decreases as duration rose, calculated first differences, produced the 280 unique crowd-duration records in the merged dataset, and preserved source-specific values wherever only one source publishes a row.

No source value was changed to make a pattern look cleaner. The 10,000-person, six-hour record retains PSAI’s 55 and Georgia’s 75, records source_agreement as different, and leaves merged_units empty.

Calculation conventions

Source values and derived values are kept separate. Crowd sizes between printed rows are assigned to the next larger row; Georgia explicitly requires that treatment, and this page applies it consistently to the PSAI-only rows. Fractional hours are assigned to the next whole-hour column as this publication’s disclosed conservative convention because neither source prints a fractional-hour rule.

Current PSAI heat-or-alcohol ranges are calculated as ceiling(base × 1.20) through ceiling(base × 1.30). Accessible units are calculated separately for each cluster as ceiling(cluster units × 0.05) where the federal requirement applies. Handwashing counts from PSAI reduce to ceiling(toilet facilities ÷ 10).

Verification classes

• Direct source fact: read in the issuing agency’s, standards body’s, trade association’s, or publisher’s own material.
• Original calculation: arithmetic or comparison performed on directly verified source values and labeled as such.
• Bounded negative finding: no item was found in the named official materials reviewed on the stated date; the claim is limited to that documented search scope.

What was not done

We did not obtain the original University of Missouri study, and the issuing documents reviewed did not link to a public copy. We did not obtain a PSAI clarification of the disputed cell. We did not purchase ANSI/PSAI Z4.3-2025 or Z4.4-2025, so no numerical provision from either full standard appears here. We did not run or reverse-engineer any company’s interactive calculator; company figures are limited to ratios published in visible page text.

How many porta potties do you need for an event?

For a four-hour event, PSAI’s chart lists 1 unit for up to 50 people, 2 units for 100 or 250, 5 for 500, 8 for 1,000, 12 for 2,000, and 25 for 5,000. The base result comes from crowd size and duration; heat or alcohol, simultaneous peaks, accessibility, handwashing, existing sewered fixtures, servicing, and local review are separate layers.

The reproducible event calculation

source crowd row  = smallest published crowd size at or above peak people
source hour column = next whole-hour column at or above event duration
base units         = value at that row and column

The first line follows Georgia’s explicit upward-rounding instruction and is applied consistently across the merged table. The second line is this page’s conservative calculation convention because neither source gives a partial-hour instruction.

Who counts in attendance?

PSAI says to count volunteers, security personnel, and vendors along with guests and attendees. Georgia’s permit table uses anticipated peak attendance and then allows one unit to be subtracted for each available sewered toilet onsite.

A 500-ticket event with 40 workers, vendors, volunteers, and security personnel is a 540-person input under the PSAI head-count instruction. Under the merged method, that moves the event to the 1,000-person row because there is no printed row between 500 and 1,000.

What assumptions does the event chart make?

• A 50/50 mix of men and women. PSAI says the underlying study measured use time and likelihood under different conditions; the chart itself is built on an even mix.
• No pumping during the event. The PSAI chart assumes no pumping service is provided while the event is underway.
• One use per guest every four hours. PSAI identifies this as the average-use assumption.
• Approximately 200 uses per unit. PSAI prints this capacity statement alongside the chart.

Georgia adds a separate footnote stating that its Table 2 is based on units being serviced daily. That is not a multi-day formula and does not replace PSAI’s no-pumping-during-the-event assumption.

What changes the base event count?

PSAI says to increase the table by 20%–30% when the temperature is at least 80°F or alcohol is served. It also says to add units when many people are likely to use the facilities at approximately the same time, but it publishes no multiplier for that concentration. This page therefore calculates the heat-or-alcohol range and displays a peak-use warning without inventing a number.

Georgia separately requires a 25% alcohol increase and subtraction of available sewered toilets. Georgia’s instructions apply to its regulatory table; they are not presented here as a law governing PSAI-only rows below 500.

How should multi-day events be calculated?

Neither source publishes a duration column beyond ten hours or a multi-day formula. Calculate each day separately using that day’s peak attendance and operating hours, then evaluate overnight availability and the servicing plan independently.

Multiplying one day’s base count by the number of event days would confuse inventory with servicing. A unit can remain onsite across days, but its usable capacity depends on cleaning and pumping conditions that the table does not convert into a multi-day equation.

How many portable toilets does OSHA require on a jobsite?

OSHA’s construction sanitation standard publishes a fixture table, not a universal rental-unit calculator. Table D-1 provides one facility for 20 or fewer employees, one toilet seat and one urinal per 40 workers at 20 or more, and one toilet seat and one urinal per 50 workers at 200 or more.

OSHA Table D-1 as published

Source: 29 CFR 1926.51(c)(1), Table D-1, Occupational Safety and Health Administration. Read on OSHA’s official site and verified July 27, 2026. Source 4.

Why fixtures are not the same as rental units

The second and third rows count toilet seats and urinals. A supplied portable unit may contain only a seat or may contain a seat and a urinal, so a result such as 6 seats and 6 urinals cannot be converted into a number of rental shells until the fixture configuration is known.

The defensible output for a jobsite calculation is therefore the fixture requirement first. Any unit count must identify the fixtures inside the units used to satisfy it.

What happens at the printed thresholds?

The published rows overlap at exactly 20 and exactly 200 workers. At 20, both “20 or less” and “20 or more” apply by their wording; at 200, the per-40 row yields 5 seat-and-urinal pairs while the per-50 row yields 4.

This page does not silently choose a preferred interpretation for the 200-worker boundary. It displays the source table and the two mechanical results so the overlap remains visible.

What other OSHA construction provisions matter?

Under 29 CFR 1926.51(c)(2), temporary field conditions must have at least one toilet facility. Under paragraph (c)(3), jobsites without a sanitary sewer may use privies, chemical toilets, recirculating toilets, or combustion toilets unless local codes prohibit them. Paragraph (c)(4) exempts mobile crews that have transportation readily available to nearby toilet facilities.

Quantity is not enough. OSHA’s May 17, 2006 interpretation states that an unsanitary toilet is unusable and therefore is not “provided” under Table D-1; the same letter explains that a facility that takes too long to reach may not be readily available.

Why do the three federal sanitation standards produce different counts?

Construction, general industry, and agricultural field work are governed by separate federal sanitation provisions that count different fixtures and apply in different settings. Their outputs should not be collapsed into one national “OSHA ratio.”

Federal sanitation outputs at identical headcounts

Source: 29 CFR 1926.51(c)(1), 29 CFR 1910.141(c)(1)(i) Table J-1, and 29 CFR 1928.110. General-industry counts apply Table J-1 separately to an assumed 50/50 split; agricultural counts apply one facility per 20 employees or fraction. Calculations by Porta Potty Rental in Huntsville, AL Research; verified July 27, 2026. Sources 4, 6, and 8.

The agricultural standard applies to establishments where 11 or more employees are engaged in hand-labor operations in the field on a given day. It requires one toilet and one handwashing facility per 20 employees or fraction, places the facilities within a quarter-mile walk unless terrain makes that infeasible, and exempts employees whose field work lasts three hours or less including travel time.

How does each federal standard treat portable units?

Construction expressly allows chemical toilets. Section 1926.51(c)(3) names them among acceptable facilities at sites without a sanitary sewer, unless local codes prohibit them.

Agriculture expressly includes portable facilities. Section 1928.110 defines a toilet facility as fixed or portable and names biological, chemical, flush, and combustion toilets and sanitary privies.

General industry defines a water closet as water-flushed. OSHA’s May 18, 1999 interpretation says substituting portable toilets may be treated as a de minimis departure only when: water carriage is impracticable because of the lack of water or temporary installation; units are readily accessible; lighting, security, and heat are adequate as necessary; and units are maintained and serviced properly. If those conditions are not met, OSHA says an other-than-serious citation should be issued.

Does OSHA really require one porta potty per 10 workers?

No. OSHA’s construction quantity rule is Table D-1, while the one-per-10 figure appears in a separate discussion of how often a provided toilet should be serviced to remain sanitary.

OSHA’s May 17, 2006 interpretation restates Table D-1, then cites ANSI Z4.3-1995 as one guide to servicing. The example says a toilet used by up to 10 people should be serviced at least once per week; OSHA defines servicing there as emptying the waste and cleaning the facility.

The letter also explains how the concepts interact. An employer with 20 employees may provide one toilet under Table D-1 and service it twice weekly; a toilet shared by 10 employees and serviced once weekly may likewise remain sanitary. Those are maintenance examples applied after the quantity rule, not a replacement quantity formula.

Current ANSI/PSAI Z4.3-2025 supersedes the 2016 edition and is sold as a complete standard. Because its full current text was not obtained for this review, this page attributes no current numerical quantity or servicing rule to Z4.3-2025.

How many accessible portable toilets are required?

The current federal calculation is at least 5% of portable single-user units in each cluster where the ADA requirement applies. The 2010 regulatory sentence is easy to misread in isolation, but the U.S. Access Board’s official guide states the operational requirement directly.

How the federal source language fits together

Source: U.S. Department of Justice 1991 and 2010 ADA Standards and the U.S. Access Board Guide to the ADA Accessibility Standards. Verified July 27, 2026. Sources 9–11.

The Access Board guide is the controlling practical explanation for this page: at least 5% in each cluster. Because a portable unit cannot be fractional, the calculation rounds upward to the next whole unit.

accessible units in a cluster = ceiling(total units in that cluster × 0.05)

Accessible units for one cluster

Source: Original calculation from the U.S. Access Board’s at-least-5%-per-cluster guidance, rounded upward to whole units. Verified July 27, 2026. Source 11.

Why the calculation is per cluster

A site with 40 units in one bank requires a different calculation from a site with four banks of 10. The first arrangement yields 2 accessible units in that cluster; the second yields at least 1 in each cluster, or 4 total.

Accessible units are part of the total supplied count, not an automatic addition to it. Where not every portable unit is accessible, compliant units must be identified by the International Symbol of Accessibility, and the Access Board guide says an accessible route and entrance must serve them.

Which construction units are exempt?

2010 ADA Standards §203.2 exempts portable toilet units used exclusively by construction personnel on a construction site from section 213 and from the accessible-route requirement. The exception does not say that a unit available to the public at or beside a construction site is exempt.

How many handwashing stations do you need?

PSAI pairs its event restroom chart with a handwashing schedule that reduces to one station per 10 toilet facilities, rounded upward. That schedule is event-planning guidance; food-service and workplace washing duties remain separate.

PSAI handwashing stations by toilet-facility count

Source: PSAI Standards for Special Events. PSAI’s footnote says the required stations have at least one faucet for the purpose of the standard. Verified July 27, 2026. Source 1.

For any whole-number toilet count, the schedule can be reproduced as:

handwashing stations = ceiling(total toilet facilities ÷ 10)

What changes when food is prepared or served?

Huntsville’s August 2022 Special Event Guide says event plans involving food preparation must include public-safety features such as hand-washing sinks, and it identifies the Madison County health authority for temporary food permits. The current Alabama Department of Public Health Food Plan Review Checklist separately requires employee handwashing sinks in adequate numbers and convenient locations, with cleanser, drying provisions, waste receptacles, and hot and cold water mixed to at least 100°F for establishments within its scope.

Meeting PSAI’s event ratio does not establish compliance with those food-handling provisions. The event-plan and food-authority requirements must be evaluated as their own layer.

What does OSHA require for workplace washing?

29 CFR 1926.51(f)(1) requires adequate washing facilities when employees work with harmful contaminants — paints, coatings, herbicides, insecticides, or similar substances. OSHA’s July 20, 2005 and June 12, 2006 interpretations confirm that §1926.51(f)(3), which requires running-water lavatories in places of employment, does not extend to temporary construction sites as a general rule — meaning (f)(1) is the operative requirement for most construction-site washing questions.

Agricultural field work has its own paired rule: one handwashing facility accompanies each required toilet facility per 20 employees or fraction within the scope of 29 CFR 1928.110.

How does alcohol change the count?

There is no single published adjustment across the sources reviewed. Current PSAI guidance, Georgia regulation, an older PSAI brochure, and a large rental company’s recommendation use four different percentages.

Published heat and alcohol adjustments

Source: PSAI current document, Georgia Rule 511-3-6-.08, PSAI 2015 brochure, and United Rentals’ September 18, 2025 event-planning article. Read July 27, 2026. Sources 1–3 and 21.

Georgia’s 25% falls inside the current PSAI 20%–30% range. The 2015 PSAI range and United Rentals range are lower, so the source and date belong with any published adjusted number.

For the current PSAI range, this page uses:

lower adjusted count = ceiling(base units × 1.20)
upper adjusted count = ceiling(base units × 1.30)

PSAI’s trigger is heat or alcohol. It publishes no stacked multiplier for an event that is both at least 80°F and serving alcohol, so this page applies the range once rather than compounding it. PSAI also publishes no numerical multiplier for concentrated intermission or halftime demand.

What do the portable-toilet rules say in Alabama and Huntsville?

Alabama’s state rule points to ANSI/PSAI standards instead of printing a portable-toilet quantity table. Huntsville’s official event materials establish permit and site-plan review triggers but do not publish a fixed numerical event-restroom ratio in the materials reviewed.

What does Alabama Rule 420-3-1-.29 require?

Ala. Admin. Code r. 420-3-1-.29(3)(a) says portable toilets shall meet ANSI/PSAI Z4.3 or Z4.4 “as appropriate.” The rule does not name an edition. It was republished as the current rule effective February 13, 2023.

Subsection (3)(b) requires a contract with a certified pumper permitted under Alabama’s septage-management chapter and requires pumping often enough to prevent public nuisances or hazards.

What are the current ANSI/PSAI scopes?

ANSI lists Z4.3-2025 as applying to portable nonsewered waste-disposal systems at places of employment and excluding non-employment settings. ANSI lists Z4.4-2025 as applying to systems used by the general public and excluding systems used by workers at places of employment.

The historical Z4.4-2016 title was Sanitation—In Fields and Temporary Labor Camps—Minimum Requirements. The 2025 edition’s general-public scope is materially different. The complete current standards are sold by ANSI and were not obtained in this verification pass, so only their titles, edition status, and published scopes are reported here.

Who must be licensed in Alabama?

The Alabama Onsite Wastewater Board says a person working as a portable restroom operator must be licensed; when the work is performed by a company, one person in responsible charge of the company must be licensed. The Board describes the portable-restroom operator license as covering installation, transport, pumping, servicing, repair, maintenance, and cleaning of portable toilets and related temporary onsite-wastewater facilities.

When does Huntsville require a special-event permit?

The City of Huntsville lists attendance of 500 people or more as a permit trigger. It also lists traffic or pedestrian impacts, alcohol sales, fireworks or pyrotechnics, vendors, and food preparation or sale among the conditions requiring a permit.

The City says minor, basic, and enhanced applications are due 10, 20, and 30 days before an event respectively, while events involving alcohol require six weeks for the alcohol-license process. The City currently states that there is no application fee, although charges can arise from City resources or property restoration. All of those items were verified on July 27, 2026.

What must the Huntsville site plan show?

The City says a special-event application will not be approved without a detailed site plan. Its August 2022 guide says site plans should show all required accessibility features, access routes, portable restrooms and sinks, and other listed infrastructure.

The same guide says additional restroom and handwashing facilities may be necessary depending on event size and location. The official Huntsville permit page and event guide reviewed on July 27, 2026 do not publish a fixed numerical portable-restroom ratio. A result from the national chart is therefore not a City permit approval or a City-established count.

Which OSHA jurisdiction applies in Alabama?

Alabama is not an OSHA-approved State Plan. OSHA’s official State Plans page says federal OSHA covers most private-sector workers in Alabama, while state and local government workers are not covered by federal OSHA.

For covered private-sector construction sites, federal 29 CFR 1926.51 applies without an Alabama State Plan replacing it. Other state, local, contract, and site-specific requirements can still apply.

Why does this comparison matter in 2026?

The main American event table still carries a late-1980s study lineage, while its current PSAI and Georgia versions contain one unresolved numerical conflict. At the same time, Alabama points to standards whose current full text is not reproduced in the state rule, and a current federal accessibility sentence is easy to misread without the Access Board’s official explanation.

PSAI says the original study involved field observations of restroom use and that it intends to issue an updated version and web application. Georgia attributes its table to Portable Restroom Requirements at Special Events and Crowd Gatherings from the Center for Business and Industrial Studies at the University of Missouri–St. Louis.

The issuing documents reviewed did not link to a public copy of that study, and our July 27, 2026search did not locate an accessible copy in the issuing organizations’ materials. That is a bounded records finding, not a claim that no copy exists anywhere.

The source comparison also shows why paraphrases should not replace the governing text. Georgia Appendix Table 1 labels its construction figures as OSHA-based but uses “21 or more” where federal Table D-1 says “20 or more,” describes additional toilets rather than retaining OSHA’s seat-and-urinal wording, and adds an instruction to double units for shifts longer than eight hours. Those are Georgia’s own regulatory instructions; they are not a verbatim reproduction of the federal table.

The durable value of this page is therefore not a new untested ratio. It is a dated, reproducible record of what each issuing source actually prints, where those sources agree, where they do not, and which calculations were derived from them.

What data can be downloaded?

The publication includes a real, versioned CSV rather than a promised future download. It contains all 280 unique crowd-duration records produced by joining the 130 PSAI cells and 250 Georgia cells, with both raw source values retained at the disputed record.

Download merged-event-restroom-chart-v1.0.csv

Also available: SHA-256 checksum file

At the disputed 10,000-person, six-hour record, psai_value is 55, georgia_value is 75, and merged_units is blank. That design prevents a downstream spreadsheet, script, or answer system from mistaking an editorial choice for a verified source value.

What are this dataset’s limitations?

The limitations define exactly what the tables and calculations can support. They are part of the evidence record, not a substitute for the direct findings above.

1. PSAI presents its event chart as general minimum-planning guidance; Georgia uses its version as a regulatory basis in Georgia. Neither source is a universal comfort or queue-length standard.
2. The underlying study lineage dates to the late 1980s, and PSAI says it intends to update it.
3. The original University of Missouri study was not obtained, and the issuing documents reviewed did not provide a public copy.
4. PSAI assumes no pumping during the event, while Georgia says its table is based on daily servicing. Neither source provides a formula that converts a different servicing plan into a revised unit count.
5. PSAI says to add units for concentrated simultaneous demand but supplies no numeric multiplier; this page supplies none.
6. Neither source publishes a fractional-hour rule. Assigning a partial hour to the next whole-hour column is this page's disclosed conservative calculation convention.
7. Neither source publishes a multi-day formula.
8. PSAI's current document and Georgia's codified table disagree at one shared cell, and the conflict remains unresolved.
9. Heat and alcohol adjustments differ by source. Current PSAI uses 20%–30% for heat or alcohol, Georgia uses 25% for alcohol, a 2015 PSAI brochure uses 10%–20%, and United Rentals recommends 10%–15%.
10. PSAI publishes no combined multiplier for an event that is both at least 80°F and serving alcohol.
11. OSHA's construction table specifies facilities and fixtures, not a universally interchangeable number of rental units.
12. OSHA Table D-1 contains overlapping threshold language at exactly 20 and 200 workers; the raw overlap is preserved rather than resolved by assumption.
13. The federal construction, general-industry, and agricultural standards cover different settings and count different facilities; their outputs are not one interchangeable ratio.
14. The current ADA result is taken from the 2010 Standards together with the U.S. Access Board's official guide. Applicability still depends on the setting, cluster arrangement, and whether the units are used exclusively by construction personnel.
15. The one-page PSAI event document refers to other page numbers for ADA and COVID-related material, but those referenced pages are not included in the published PDF reviewed. This page does not rely on those missing references.
16. No numerical requirement from ANSI/PSAI Z4.3-2025 or Z4.4-2025 appears here because the complete standards were not obtained.
17. Company recommendations reflect the visible text on the companies' pages when read July 27, 2026 and can change independently of the official tables.
18. The Huntsville negative finding is limited to the official permit page and City event guide reviewed on July 27, 2026. It does not prove that no numerical condition could appear in an event-specific permit, another controlling code, or a later publication.
19. Local codes, permit conditions, accessibility review, health-department requirements, contract terms, permanent-restroom availability, site layout, servicing access, and actual use patterns can require a different result.

How should this page be cited?

This block supplies neutral bibliographic information for the page and dataset. Requirements themselves remain attributable to the issuing laws, agencies, standards bodies, and source documents listed below.

Frequently asked questions

These answers restate the page’s most frequently needed calculations and source distinctions. Each answer uses the same verified values and conventions documented in the tables and methodology above.

How many porta potties do I need for 100 people?

It depends on duration. PSAI’s currently hosted chart lists 2 units for a 100-person event lasting one through five hours and 3 units for six through ten hours, before its 20–30% heat-or-alcohol adjustment. Georgia’s codified table begins at 500 people, so it supplies no Georgia table value for a 100-person event.

How many porta potties do I need for 500 people?

PSAI and Georgia agree on the entire 500-person row: 2 units at one hour; 4 at two or three hours; 5 at four hours; 6 at five; 7 at six; 9 at seven or eight; 10 at nine; and 12 at ten hours. Georgia requires adding 25% when alcohol is served, while PSAI’s currently hosted guidance gives a 20–30% adjustment when the temperature reaches 80°F or alcohol is served.

How many porta potties do I need for 1,000 people?

PSAI and Georgia both list 4 units at one hour; 6 at two; 8 at three or four; 9 at five or six; 11 at seven; 12 at eight; and 13 at nine or ten hours. The base count does not include any applicable heat, alcohol, accessibility, local-permit, or concentrated-peak-use adjustment.

How many porta potties are needed for a 100-person wedding with alcohol?

For a four-hour event, PSAI’s base value is 2 units. Applying PSAI’s currently hosted 20–30% alcohol adjustment gives 2.4 to 2.6 units, which rounds upward to 3 whole units. Georgia’s 25% alcohol rule is not a Georgia table requirement for this crowd because Georgia’s codified table starts at 500 attendees.

Does OSHA require one porta potty per 10 workers?

No. OSHA’s construction quantity table provides one facility for 20 or fewer employees, then one toilet seat and one urinal per 40 workers, and one toilet seat and one urinal per 50 workers at 200 or more. The one-per-10 figure in OSHA’s May 17, 2006 interpretation is an example from a servicing schedule: a toilet used by up to 10 people should be serviced at least weekly.

How many portable toilets does a 50-worker construction site need?

Applying the 20-or-more row of OSHA Table D-1 to 50 workers produces 2 toilet seats and 2 urinals. The regulation counts fixtures, not rental shells, so the number of supplied units depends on whether each unit contains only a seat or contains both a seat and a urinal.

How many accessible portable toilets are required?

The U.S. Access Board’s official guide states that access is required to at least 5% of portable single-user units in each cluster, including at temporary events. The count is calculated separately for each cluster and rounded upward to a whole unit; compliant units are part of the total count. Portable units used exclusively by construction personnel on a construction site are exempt under 2010 ADA Standards section 203.2.

How many handwashing stations do I need?

PSAI’s event schedule specifies 1 station for 1–10 toilet facilities, 2 for 11–20, 3 for 21–30, 4 for 31–40, and one additional station for each additional 10 facilities. Food preparation and workplace washing requirements are separate and are not satisfied merely by meeting that event-planning ratio.

Why do the source tables disagree at 10,000 people for six hours?

Georgia’s codified table prints 75 and PSAI’s currently hosted document prints 55. The PSAI value is the only value in that row that decreases as duration rises, while a 2015 PSAI brochure also prints 75. This page preserves both values and leaves the merged dataset value blank instead of selecting an unverified correction.

Which value should be used for 10,000 people over six hours?

For an event governed by Georgia Rule 511-3-6, the codified table value is 75. Outside that context, the primary-source record is conflicted: the current PSAI document says 55, Georgia says 75, and the 2015 PSAI brochure says 75. A defensible publication should state the conflict rather than silently replace one figure.

Does Huntsville require a special event permit?

Huntsville requires a permit for attendance of 500 people or more and for other listed triggers, including traffic or pedestrian impacts, alcohol sales, fireworks, vendors, and food preparation or sale. The City requires a detailed site plan, and its event guide says the plan should show portable restrooms and sinks. The official City materials reviewed on July 27, 2026 did not publish a fixed numerical restroom ratio.

How should a partial event hour be handled?

Neither source table prints a rule for fractional hours. For reproducibility, this page assigns a partial hour to the next whole-hour column—for example, 2.5 hours uses the three-hour column—and labels that as this publication’s conservative calculation convention rather than a quoted source rule.

Can these tables be used for a multi-day festival?

Not as one continuous calculation. Both tables stop at ten hours and neither source publishes a multi-day formula. Calculate each day separately using that day’s peak attendance and operating hours, then evaluate servicing, overnight use, and local permit conditions independently.

Which primary sources support this page?

The numbered list below is the source key used throughout the article. Government requirements are linked to the issuing agency or official code portal; standards titles and scopes are linked to ANSI; publisher recommendations are linked to the publisher’s own page and are labeled as recommendations rather than law.

1. Portable Sanitation Association International, PSAI Standards for Special Events (undated current hosted document). https://psai.org/wp-content/uploads/2025/11/Standards_PSAI_Standards_Special_Events-2b7cdb78.pdf — Read July 27, 2026.
2. Georgia Department of Public Health, Ga. Comp. R. & Regs. Subject 511-3-6, including Rules 511-3-6-.03 and -.08 Appendix Tables 1 and 2. https://rules.sos.ga.gov/gac/511-3-6 — Read July 27, 2026.
3. Portable Sanitation Association International, Renting Portable Restrooms public brochure, 2015. https://psai.org/wp-content/uploads/2025/11/psaipublicbrochurenov2015rev-efe18373.pdf — Read July 27, 2026.
4. Occupational Safety and Health Administration, 29 CFR 1926.51, Sanitation. https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.51 — Read July 27, 2026.
5. Occupational Safety and Health Administration, interpretation letter dated May 17, 2006, Whether toilets at a construction jobsite must be in a sanitary condition to meet the requirements of 29 CFR 1926.51(c). https://www.osha.gov/laws-regs/standardinterpretations/2006-05-17-0 — Read July 27, 2026.
6. Occupational Safety and Health Administration, 29 CFR 1910.141, Sanitation. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.141 — Read July 27, 2026.
7. Occupational Safety and Health Administration, interpretation letter dated May 18, 1999, corrected May 28, 2004, Substituting portable toilets for water closets may be a de minimis violation. https://www.osha.gov/laws-regs/standardinterpretations/1999-05-18 — Read July 27, 2026.
8. Occupational Safety and Health Administration, 29 CFR 1928.110, Field Sanitation. https://www.osha.gov/laws-regs/regulations/standardnumber/1928/1928.110 — Read July 27, 2026.
9. U.S. Department of Justice, 2010 ADA Standards for Accessible Design, including §§203.2 and 213.2. https://www.ada.gov/law-and-regs/design-standards/2010-stds/ — Read July 27, 2026.
10. U.S. Department of Justice, 1991 ADA Standards for Accessible Design, ADAAG §4.1.2(6). https://www.ada.gov/law-and-regs/design-standards/1991-design-standards/ — Read July 27, 2026.
11. U.S. Access Board, Guide to the ADA Accessibility Standards: Chapter 6—Toilet Rooms. https://www.access-board.gov/ada/guides/chapter-6-toilet-rooms/ — Read July 27, 2026.
12. Alabama State Committee of Public Health, Ala. Admin. Code r. 420-3-1-.29, Composting, Incinerating, and Portable Toilets. https://admincode.legislature.state.al.us/api/rule/420-3-1-.29 — Current rule effective February 13, 2023; read July 27, 2026.
13. American National Standards Institute, ANSI/PSAI Z4.3-2025, Sanitation—Nonsewered Waste-Disposal Systems at Places of Employment: Minimum Requirements. https://webstore.ansi.org/standards/ansi/ansipsaiz42025 — Read July 27, 2026.
14. American National Standards Institute, ANSI/PSAI Z4.4-2025, Sanitation—Nonsewered Waste Disposal Systems: Use by the General Public—Minimum Requirements. https://webstore.ansi.org/standards/ansi/ansipsaiz42025-2593157 — Read July 27, 2026.
15. American National Standards Institute, ANSI/PSAI Z4.4-2016, Sanitation—In Fields and Temporary Labor Camps—Minimum Requirements. https://webstore.ansi.org/standards/ansi/ansipsaiz42016-1649119 — Historical listing read July 27, 2026.
16. City of Huntsville, Special Event Permits. https://www.huntsvilleal.gov/business/licensing-permits/special-event-permits/ — Read July 27, 2026.
17. City of Huntsville, Special Event Guide, August 2022. https://www.huntsvilleal.gov/wp-content/uploads/2022/09/COH_PR_SpecialEventGuide_2022_v2.pdf — Read July 27, 2026.
18. Occupational Safety and Health Administration, State Plans, Alabama entry. https://www.osha.gov/stateplans — Read July 27, 2026.
19. Alabama Onsite Wastewater Board, Frequently Asked Questions. https://aowb.alabama.gov/faq.aspx — Read July 27, 2026.
20. Alabama Department of Public Health, Food Plan Review Checklist, revised June 9, 2026. https://www.alabamapublichealth.gov/foodsafety/assets/foodplanreviewchecklist.pdf — Read July 27, 2026.
21. United Rentals, Outdoor Event Planning: 4 Event Infrastructure Must-Haves, September 18, 2025. https://www.unitedrentals.com/project-uptime/equipment/outdoor-event-planning-4-event-infrastructure-must-haves — Read July 27, 2026.
22. ZTERS, Portable Toilet Calculator. https://www.zters.com/resources/portable-toilet-calculator — Read July 27, 2026.