WaterSense Specification for Tank-Type Toilets

Version 1.1 1 May 20, 2011

 

WaterSense® Specification for Tank-Type Toilets 

1.0 Scope and Objective 

This specification establishes the criteria for a tank-type high-efficiency toilet under the U.S. 

Environmental Protection Agency’s (EPA’s) WaterSense program. It is applicable to: 

Single flush, tank-type gravity toilets; 

Dual flush, tank-type gravity toilets;

Dual flush, tank-type flushometer tank (pressure-assist) toilets;

Tank-type, flushometer tank (pressure-assist) toilets; 

Tank-type electrohydraulic toilets; and

Any other tank-type technologies that meet these performance specifications. 

The specification is designed to ensure both sustainable, efficient water use and a high level of 

user satisfaction with flushing performance. 

2.0 Summary of Criteria

Toilets must meet criteria in three areas:

Effective flush volume shall not exceed 1.28 gallons1

Solid waste removal must be 350 grams

(4.8 liters), as specified in 

Section 3.0;

2

The toilet must conform to the adjustability and other supplementary 

requirements specified in Section 5.0.

or greater, as specified in Section 4.0; 

and

3.0 Water Efficiency Criteria

3.1 Single Flush Toilets – The effective flush volume shall not exceed 1.28 gallons 

(4.8 liters) when evaluated in accordance with the sampling plan contained in 10 

CFR 429.30. For single flush toilets the effective flush volume is the average 

flush volume when tested in accordance with ASME A112.19.2/CSA B45.1.

3

3.2 Dual Flush Toilets – The effective flush volume shall not exceed 1.28 gallons (4.8 

liters) when evaluated in accordance with the sampling plan contained in 10 CFR 

429.30. For dual flush toilets the effective flush volume is the composite, average 

 

1 The effective flush volume has been established as 1.28 gallons, which is a 20 percent reduction from the 1.6 gallons per flush 

standard that became mandatory pursuant to the 1992 EPAct. 

2 A qualified tank-type toilet must provide superior flushing performance while saving significant volumes of water. Based on data 

contained in the medical study Variability of colonic function in healthy subjects, 1978, J.B. Wyman, K.W. Heaton, A.P. Manning, 

and A.C.B. Wicks of the University Department of Medicine, Bristol Royal Infirmary, the greatest single ‘loading’ of the 20 study 

participants was approximately 450 grams, and the 99.5 percent confidence level of the men in the study equates to a loading of 

approximately 350 grams. 3 References to this and other ASME standards apply to the most current version of that standard.
WaterSense Specification for Tank-Type Toilets

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flush volume of two reduced flushes and one full flush. Flush volumes shall be 

tested in accordance with ASME A112.19.2/CSA B45.1 and ASME A112.19.14. 

4.0 Flush Performance Criteria

4.1 Toilet model performance is identified as either a Pass or Fail depending upon 

whether it can successfully and completely clear all test media from the fixture in 

a single flush in at least four of five attempts. Only toilet models that Pass qualify 

for EPA’s WaterSense label. Flush performance testing shall be conducted in 

accordance with the test protocol provided in Appendix A.

4.2 Test media consists of seven test specimens, 50 ± 4 grams each, consisting of 

soybean paste forming a ‘sausage’ approximately 4 ± 0.5 inch (100 ± 13 mm) in 

length and 1 ± 0.25 inch (25 ± 6 mm) in diameter and four loosely crumbled balls 

of toilet paper as defined in Appendix A.

4.3 The flush performance criteria apply to single flush toilets, and to the full flush 

option of dual flush toilets. No solid waste removal requirement applies to the 

reduced flush option on dual flush toilets. 

5.0 Supplementary Requirements for Flush Volume Adjustability 

5.1 All single flush toilets must conform to ASME A112.19.2/CSA B45.1 and all dual 

flush toilets must conform to ASME A112.19.14.

5.2 The criteria in this section apply to tank-type gravity toilets.

5.2.1 Must conform to ASME A112.19.5.

5.2.2 Fill Valve 

The fill valve shall be the pilot valve type only, or, alternatively, the fill 

valve shall meet the performance requirements of the fill valve test 

protocol in Appendix B. All fill valves must conform to ANSI/ASSE 1002.

5.2.3 Tank Capacity

5.2.3.1 Any barrier, bucket, dam, displacement device, or similar fixture 

used in a toilet tank to affect flush volume shall be tamperresistant and permanently affixed to the tank. Any device that 

can be tampered with or removed such that the toilet can be 

made to flush with greater than the maximum flush volumes 

specified in Section 5.2.3.2 shall be deemed noncompliant. 

5.2.3.2 The maximum volume of water that may be discharged by the 

toilet, when field adjustment of the tank trim is set at its 

maximum water use setting, shall not exceed the following 

amounts:

For single flush fixtures: 1.68 gallons (6.4 liters) per flush4

 

4 Value based on a maximum effective flush volume of 1.28 gallons (4.8 liters), with no more than 0.40 gallon (1.6 liter) increase with 

tank trim adjusted to maximum water use settings. 
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For dual flush fixtures: 1.40 gallons (5.3 liters) per flush5 in 

reduced flush mode and 2.00 gallons (7.6 liters) per flush6

The maximum volume of water discharged, using both 

original equipment tank trim and using aftermarket closure 

seals shall be tested according to the protocol in Appendix 

C.

in full flush mode. 

6.0 Product Marking

6.1 Toilet tank trim shall be marked in accordance with requirements in ASME 

A112.19.5. 

6.2 Toilet tanks shall not be packaged, marked, or provided with instructions 

directing the user to an alternative water-use setting that would override the rated

flush volume, as established by this specification. Any instruction related to the 

maintenance of the product shall direct the user on how to return the product to 

its rated flush volume. 

6.3 Toilet bowls may be marked in a manner that indicates compatibility with flush 

volumes below 1.6 gallons per flush. 

7.0 Effective Date

This specification is effective on May 20, 2011. 

8.0 Future Specification Revisions

EPA reserves the right to revise this specification should technological and/or market changes 

affect its usefulness to consumers, industry, or the environment. Revisions to the specification 

would be made following discussions with industry partners and other interested stakeholders.

9.0 Definitions

Definitions within ASME A112.19.2/CSA B45.1, ASME A112.19.5, and ASME A112.19.14 are 

included by reference. 

Electrohydraulic toilet: A toilet fixture of siphonic or washdown design that uses 

a motor, pump, and controller to assist flushing action.

Pressure-assist toilet: A flushometer tank toilet as defined in ASME 

A112.19.2/CSA B45.1.

Rated flush volume: The stated flush volume of the toilet, as certified.

 

5 Value based on the reduced flush requirement in ASME A112.19.14-2001. 6 Value based on the requirement in the Los Angeles Department of Water and Power Supplementary Purchase Specification, 

adopted in 2000 and as amended in 2005.
WaterSense Specification for Tank-Type Toilets

Version 1.1 A-1 May 20, 2011

Appendix A: Fixture Performance Testing Protocol

7

1.0 Scope of Testing

1.1 Toilet model performance is identified as either a Pass or a Fail depending upon 

whether the test fixture can successfully and completely clear all media (350 

grams) from the fixture in a single flush in at least four of five attempts.

1.2 Tests where toilet sample clogs, plugs, or fails to restore a minimum of a 2-inch 

(50 mm) trap seal following each flushing test will be deemed a failed test.

1.3 Test media is comprised of the following:

1.3.1 Seven (7) test specimens at 50 ± 4 grams per test specimen (“test 

specimen”) consisting of soybean paste forming a “sausage” 

approximately 4 ± 0.5 inch (100 ± 13 mm) in length and 1 ± 0.25 inch (25 

± 6 mm) in diameter. The total mass of test media used for each test shall 

be 350 ± 10 grams.

1.3.2 Four (4) loosely crumpled balls of toilet paper (“paper”).

2.0 Testing Protocol

2.1 Set-Up

2.1.1 Samples shall be assembled according to manufacturer’s written 

instructions as contained within the product packaging, and placed on test

rig, ensuring tank and bowl are level.

2.1.2 Tank water level shall be adjusted to the level specified by manufacturer 

in the manufacturer’s instructions (e.g., set to waterline) where applicable.

2.1.3 Static water supply pressure shall be set to 50 ± 3 PSIG.

2.1.4 Inlet water temperature shall be 65 to 80o

F (18 to 27 oC).

2.1.5 Flush sample a minimum of three times prior to commencement of 

testing.

2.1.6 Re-adjust tank water level to proper level if required.

2.2 Flush Volume Measurement

2.2.1 Measure and record flush volume of sample (sample set-up as outlined in 

Section 2.1). Repeat the test two additional times and record the results 

and the average of the three test replicates. A receiving vessel may be 

used, either calibrated in increments not exceeding 0.025 gallon (0.1 liter) 

or placed on a load cell with a readout in increments not exceeding 0.025

gallon (0.1 liter). Other methods capable of measuring volumes to within 

in 0.025 gallon (0.1 liter) shall be acceptable.

2.2.2 Samples with average flush volumes in excess of 0.10 gallon (0.4 liter) 

greater than their rated flush volume shall be deemed to fail testing 

requirements due to excessive flush volume.

8

 

7 Testing protocol based on Maximum Performance (MaP) Testing Protocol, Version 3, January 2006, by Bill Gauley, Veritec 

Consulting, Inc., and John Koeller, Koeller and Company.

8 For example, fixtures rated at 1.28 gallons per flush (the maximum flush volume) but flushing at greater than 1.38 gallons (5.2 liter) 

when adjusted to water line shall be deemed to have “failed” the requirements of this specification.
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2.2.3 Samples with average flush volumes less than 0.10 gallon (0.4 liter) 

greater than their rated flush volume shall be adjusted, if possible, to their 

rated flush volume prior to performance testing.

2.2.4 Samples with average flush volumes less than their rated flush volume

shall be tested at measured volume and this volume shall be recorded on 

test report.

2.3 Waste Extraction Test

2.3.1 Test specimens shall be formed such that they are roughly cylindrical in 

shape and uniform in diameter.

2.3.2 A test specimen drop guide shall be placed across the top of the bowl, 

with the centerline of a 2-inch (50 mm) diameter opening 6 inches (15 cm) 

in front of the center of the seat post holes, equidistant from each hole. 

Drop guide may be made of plastic or other rigid material, to be no more 

than 0.5 inch (12 mm) thick, and be of sufficient length to span top of 

toilet bowl.

2.3.3 Seven (7) test specimens (350 grams) shall be freely dropped in a vertical 

orientation through opening in drop guide into bowl.

2.3.4 Immediately remove drop guide and freely and randomly drop four balls 

of crumpled toilet paper over center of bowl sump.

2.3.5 Wait 10 ± 1 seconds.

2.3.6 Flush sample.

2.3.7 Record test as Pass or Fail (test is a Fail if any waste remains in the 

bowl or trap, or if minimum 2-inch (50 mm) trap seal has not been 

restored).

2.3.8 Flush sample to clean bowl and trapway and fully restore trap seal.

2.3.9 Repeat testing until toilet sample either (i) achieves four Pass grades or 

(ii) achieves two Fail grades.

2.3.10 Models must Pass at least four of five attempts to qualify for EPA’s

WaterSense Program.

3.0 Test Media Specifications

3.1 Soybean Paste Nominal Specifications

35.5 percent water, 33.8 percent soybean, 18.5 percent rice, and 12.2 percent 

salt, and having a density of 1.15 ± 0.10 gram/milliliter (i.e., density greater than 

that of water). 

3.2 Test Specimens

Each test specimen shall have a mass of 50 ± 4 grams. 

3.3 Toilet Paper Specifications

Each ball of paper is comprised of six sheets of single ply toilet paper conforming 

to ASME A112.19.14, section 3.2.5.1.2. 
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Version 1.1 B-1 May 20, 2011

Appendix B: Fill Valve Integrity Test Protocol9

1.0 Scope of Testing

This requirement shall apply to all fill valves that are not otherwise classified as pilot valves. 

Samples must conform to both Sections 2.0 and 3.0 of this appendix. 

2.0 Consistent Water Level

2.1 Purpose of Test – To determine whether or not the fill valve shuts off at a 

consistent water level in a toilet tank independent of any change in inlet water 

supply pressure.

2.2 Test Procedure

2.2.1 Install the fill valve in the toilet tank provided, install the tank on a leveled 

test stand, and adjust the water level per the manufacturer’s 

recommendation at an inlet water pressure of 20 ± 2 PSIG or at the 

manufacturer’s recommended minimum pressure as noted in the product 

literature and product packaging.

2.2.2 Flush the tank to verify and mark water level after completed refill.

2.2.3 Increase the inlet water pressure to 60 ± 2 PSIG.

2.2.4 Flush the tank.

2.2.5 Measure any difference in water level after completed refill.

2.2.6 Repeat steps 2.2.3 to 2.2.5 utilizing 80 ± 2 PSIG inlet water pressure. 

2.3 Performance Requirement – The fill valve shall shut off at the same water level ±

0.5 inch (± 12 mm) for all three inlet water pressures. In addition, water shall not 

enter the overflow tube or flow out of the tank at any of the three tested inlet 

pressures.

3.0 Shutoff Integrity With Increased Water Pressure

3.1 Purpose of Test – To determine whether or not the fill valve shuts off at a 

consistent water level in a toilet tank independent of changes in inlet water 

supply pressure.

3.2 Test Procedure

3.2.1 Install the fill valve in a toilet tank and adjust the water level per the 

manufacturer’s recommendation at an inlet water pressure of 20 ± 2 PSIG 

or at the manufacturer’s recommended minimum pressure as noted in the 

product literature and product packaging.

3.2.2 Flush the tank to verify and mark water level after completed refill.

3.2.3 Increase the inlet pressure to the fill valve from 20 (or recommended 

minimum pressure) to 60 PSIG, then to 80 PSIG at a rate of less than 10 

PSIG per second.

 

9 Testing protocol based on Appendix B to Los Angeles Department of Water and Power Supplementary Purchase Specification,

November 16, 2005 version.
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Version 1.1 B-2 May 20, 2011

3.3 Performance Requirement – The water level shall remain at the initial mark ± 0.5 

inch (± 12 mm). In addition, water shall not enter the overflow tube or flow out of 

the tank.
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Version 1.1 C-1 May 20, 2011

Appendix C: Tank Trim Adjustability Testing Protocol10

1.0 Scope of Testing

All tank-type gravity toilet fixtures must conform to the requirements of Section 2.0 of this 

appendix, which address the adjustability of original equipment tank trim and the resulting flush 

volume of the toilet fixture. All tank-type gravity toilet fixtures with flush seals must conform to 

the requirements in Section 3.0 of this appendix, which address the flush volume resulting from 

the replacement of original equipment seals with seals available in the aftermarket.

2.0 Tank-Type Gravity Toilets With Original Equipment

2.1 Purpose of Test – The objective of this tank trim adjustability test is to determine 

the upper limit to the volume of water that may be discharged by the field 

adjustment of tank trim components. The maximum volume of water that may be 

discharged by the toilet, when field adjustment of original equipment tank trim is 

set at its maximum water-use setting, shall not exceed the following amounts:

For single flush fixtures – 1.68 gallons (6.4 liters) per flush

For dual flush fixtures: 

Reduced flush (“short flush”) mode – 1.40 gallons (5.3 liters) per 

flush

 Full flush mode – 2.00 gallons (7.6 liters) per flush

The following test procedure shall be used to verify that the toilet sample meets 

these requirements.

2.2 Test procedure – Test shall be conducted per section 8.4 of ASME 

A112.19.2/CSA B45.1 with the following modifications:

2.2.1 The toilet shall be installed on a leveled test stand and all adjustable tank 

trim components (any field adjustment features in the tank that might 

increase the toilet flush volume) shall be adjusted to the maximum water 

use setting, while taking care not to damage or alter the parts. 

2.2.2 The water level in the tank shall be set to 0.25 ± 0.06 inch (6 ± 2 mm) 

below the top of the overflow tube. Where the tank utilizes an internal 

containment vessel and does not possess an overflow tube, the vessel 

shall be filled to a level 0.25 ± 0.06 inch (6 ± 2 mm) below the top rim of 

the vessel or to the manufacturer’s designated water line, whichever is 

higher.

2.2.3 The static pressure of the water supply shall be adjusted to 80 ± 2 PSIG. 

2.2.4 The toilet shall be flushed maintaining the activator in the flushing position 

for a period of one (1) second, the water being drained into a container. 

2.2.5 After the flush cycle is complete, the total flush volume shall be observed 

and recorded. 

2.2.6 This procedure shall be repeated until five (5) sets of data are obtained.

2.2.7 The static pressure of the water supply shall be adjusted to 20 ± 2 PSIG 

or at the manufacturer’s recommended minimum pressure as noted in the 

 

10 Testing protocol based on Los Angeles Department of Water and Power Supplementary Purchase Specification, 16 November 

2005 version, modified to reflect the deletion of certain trim durability and marking requirements incorporated into ASME A112 19.5.
WaterSense Specification for Tank-Type Toilets

Version 1.1 C-2 May 20, 2011

product literature and product packaging, and test procedure steps 2.2.4 

to 2.2.6 shall be repeated.

2.2.8 For dual-flush toilet fixtures, this test shall be conducted at both full flush 

and reduced flush modes.

2.3 Report – The five (5) individual flush volumes and the average of the five (5) runs 

shall be reported for each of the two static water supply pressures specified.

2.4 Performance Requirement – The average total flush volume for five (5) test runs 

for each of the two static water supply pressures shall not exceed the following:

For single-flush fixtures – 1.68 gallons (6.4 liters) per flush

For dual-flush fixtures: 

Reduced flush (“short flush”) mode – 1.40 gallons (5.3 liters) per 

flush

Full flush mode – 2.00 gallons (7.6 liters) per flush

The volume of water may be determined visually using a graduated container or 

by weight calculated as a unit to volume unit.

3.0 Tank-Type Gravity Toilets With Aftermarket Closure Seals

3.1 Purpose of Test – The objective of this tank trim adjustability and aftermarket 

seal test is to determine the upper limit to the volume of water that may be 

discharged when an off-the-shelf replacement flush valve seal/flapper is installed 

on the toilet. The maximum volume of water that may be discharged by the toilet, 

when the original equipment flush valve seal (flapper or other sealing device) is 

replaced with a standard (buoyant) seal available in home improvement centers 

and hardware stores, and the field adjustment of tank trim is set at its maximum 

water-use setting, shall not exceed the following amounts:

For single flush fixtures – 1.68 gallons (6.4 liters) per flush

For dual flush fixtures: 

Reduced flush (“short flush”) mode – 1.40 (5.3 liters) gallons per 

flush

 Full flush mode – 2.00 gallons (7.6 liters) per flush

The following test procedure shall be used to verify that the toilet sample meets 

these requirements.

3.2 Test procedure – Test shall be conducted per section 8.4 of ASME 

A112.19.2/CSA B45.1 with the following modification:

3.2.1 The toilet shall be installed on a leveled test stand and all adjustable tank 

trim components (any field adjustment features in the tank that might 

increase the toilet flush volume) shall be adjusted for maximum water 

use, while taking care not to damage or alter the parts. 

3.2.2 Remove the original equipment flush valve seal and replace it with a 

standard (buoyant) aftermarket seal/flapper for that toilet where possible. 

For any ongoing surveillance testing, the same model replacement flush 
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Version 1.1 C-3 May 20, 2011

valve seal shall be used as was used during the initial product testing and 

certification.11

3.2.2.1 Two-inch flush valves – In the case of a standard configuration 2-

inch flush valve, a non-adjustable Fluidmaster Bullseye Super 

flapper (part no. 501) or a Coast Foundry Ultra Blue flapper shall 

be used. 

 

3.2.2.2 Three-inch flush valves – In the case of a standard configuration 

3-inch flush valve, an adjustable Lavelle Korky model 3060 flapper 

shall be used. The flapper shall be adjusted in accordance with 

the flapper manufacturer’s instructions to provide the rated flush 

volume of the toilet. 

3.2.2.3 Non-standard flush valves – In the case of non-standard flush 

valves, one or more replacement seals available at hardware, 

plumbing supply, and building supply stores or from the 

manufacturer or other recognized source shall be used.

12

3.2.3 The water level in the tank shall be set to 0.25 ± 0.06 inch (6 ± 2 mm) 

below the top of the overflow tube. Where the tank utilizes an internal 

containment vessel and does not possess an overflow tube, the vessel 

shall be filled to a level 0.25 ± 0.06 inch (6 ± 2 mm) below the top rim of 

the vessel or to the manufacturer’s designated water line, whichever is 

higher.

3.2.4 The static pressure of the water supply shall be adjusted to 80 ± 2 PSIG.

3.2.5 The toilet shall be flushed maintaining the activator in the flushing position 

for a period of one (1) second maximum, the water being drained into a 

container. 

3.2.6 After the flush cycle is complete, the total flush volume shall be observed 

and recorded.

3.2.7 This procedure shall be repeated until five (5) sets of data are obtained.

3.2.8 The static pressure of the water supply shall be adjusted to 20 ± 2 PSIG 

or at the manufacturer’s recommended minimum pressure as noted in the 

product literature and product packaging, and test procedure steps 3.2.5 

to 3.2.7. shall be repeated.

3.2.9 For dual-flush toilet fixtures, this test shall be conducted at both flush 

modes (full flush and reduced flush).

3.3 Report – The five (5) individual flush volumes and the average of the five (5) runs 

shall be reported for each of the two static water supply pressures specified.

3.4 Performance Requirement – The average total flush volume for five (5) test runs 

for each of the two static water supply pressures shall not exceed the following:

For single-flush fixtures – 1.68 gallons (6.4 liters) per flush

For dual-flush fixtures: 

Reduced flush (“short flush”) mode – 1.40 gallons (5.3 liters) per 

flush

 

11 If during the ongoing surveillance testing the type of replacement flush valve seal used in the initial product testing is no longer 

available, then the manufacturer no longer has to comply with Section 3.0 of Appendix C.

12 In the case of a toilet fixture with a non-standard flush valve seal, the testing laboratory shall have discretion as to which 

aftermarket flapper or seal shall be used in the test.
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Version 1.1 C-4 May 20, 2011

Full flush mode – 2.00 gallons (7.6 liters) per flush

The volume of water may be determined visually using a graduated container or 

by weight calculated as a unit to volume unit.

m t- WaterSense 
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Version 1.1 D-1 May 20. 2011

Appendix D: Requirements for WaterSense Labeling

The following requirements must be met for products to be marked with the WaterSense label.

1.0 WaterSense Partnership

The manufacturer of the product must have a signed partnership agreement in place with EPA.

2.0 Conformity Assessment

Conformance to this specification must be certified by an EPA licensed certifying body 

accredited for this specification in accordance with the WaterSense Product Certification 

System. 

3.0 Clarifications

3.1 Adjustability

Toilet tanks with adjustable water-use settings that can be identified and activated by a 

user or plumbing professional to override the rated flush volume, as established by this 

specification, do not comply with the intent of this specification or the WaterSense 

program and do not qualify for use of the WaterSense label.

3.2 Tanks and Bowls Manufactured and Sold by Different Companies

WaterSense requires every combination tank and bowl to be tested and certified for 

conformance to this specification in order to ensure that the toilet as a whole provides 

the expected water efficiency and performance. Wall hung bowls and in-wall carrier 

systems manufactured and sold by different companies may earn the WaterSense label, 

provided that the combination unit is tested and certified. However, since these products 

may not necessarily be sold as a unit, WaterSense has established some additional 

certification requirements that these products must meet in order to earn the 

WaterSense label. Both manufacturers must agree to have their products tested and 

certified together in order for the tank and bowl combination to receive the WaterSense 

label.

Certification Listing

In order to control the use of the WaterSense label, EPA is requiring each manufacturer 

(e.g., the tank manufacturer and the bowl manufacturer) to obtain a certification listing 

with one of EPA’s licensed certifying bodies to show that the toilet, formed by the 

combination tank and bowl, was certified for conformance to the specification. The 

listings must identify both components along with the respective manufacturers’ names, 

brand names, model names, and model numbers by which the products are identified 

and sold. Separate listings will allow the licensed certifying body to directly authorize 

each manufacturer to use the WaterSense label on their tanks or bowls. Note that 

though a certification listing is required for each manufacturer, WaterSense is not 
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Version 1.1 D-2 May 20. 2011

requiring the combination toilet to be tested more than once. The licensed certifying 

body must ensure that the listing information is complete prior to issuing the certification 

and the WaterSense label to either manufacturer. 

As an alternative to separate listings, and at the discretion of the licensed certifying 

body, the manufacturer of one of the components (e.g., either the tank or bowl 

manufacturer) may become listed as an additional company under the certification listing 

of the manufacturer of the corresponding component (e.g., the bowl or tank). However, 

both components, along with the respective manufacturer’s names, brand names, model 

names, and model numbers by which the products are identified and sold, must be 

identified under both the certification file owner’s listing and the additional company’s 

listing. This will ensure that there is no confusion about which products were certified in 

combination to earn the WaterSense label.

3.3 Product Packaging Marking and Labeling

Though every combination tank and bowl must be tested and certified for conformance 

to this specification in order to ensure that the toilet as a whole provides the expected 

water efficiency and performance, in some cases the tank and bowl may be packaged 

individually and/or sold separately. To ensure that it is clear to the purchaser that a 

particular combination tank and bowl is labeled, EPA is providing clarification regarding 

how the packaging must be marked and how the WaterSense label must be used.

These marking and labeling requirements apply to tanks and bowls made by the same 

company and those made by different companies, as is the case for some wall-hung 

bowls and in-wall carrier systems.

Manufacturers must adhere to the following product packaging marking and labeling 

requirements for toilet tanks and bowls packaged and sold individually:

In all cases the toilet tank packaging must bear the WaterSense label. 

If the toilet bowl packaging is marked ONLY with the rated flush volume, as 

established by this specification, the toilet bowl packaging must bear the 

WaterSense label.

If the toilet bowl packaging is marked in a manner that indicates compatibility with 

flush volumes other than the rated flush volume, as established by this 

specification, the manufacturer may NOT use the WaterSense label on the toilet 

bowl packaging. 

Toilet bowl packaging must indicate all of the specific brand names, model 

names, and model numbers, as applicable, of the counterpart tanks it may be 

used with to form a WaterSense labeled tank- type toilet. For example, the toilet 

bowl packaging may say:

“This [insert description of bowl] is WaterSense labeled when used with 

[list brand names, model names, and model numbers, as applicable, of 

the tank(s) that the bowl may be used with to form a WaterSense labeled 

tank-type toilet].”

Product specification sheets or other product documentation for both the toilet 

tank and bowl must indicate all of the specific brand names, model names, and 

model numbers, as applicable, of the counterpart products (e.g., the bowl or 
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tank) that the product may be used with to form a WaterSense labeled tank-type 

toilet. 

Note that for toilet tanks and bowls packaged and sold together as a unit, the packaging 

must bear the WaterSense label.