Draft version  
 
 
 
 
 
 
 
 
 
 
The Voluntary Water Efficiency Labelling  
Scheme on Water Closet s 
May 2018 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
48/F., Immigration Tower,  
7 Gloucester Road, Wanchai, Hong Kong  
Homepage: http://www.wsd.gov.hk  Draft version  
 
Page 1 of 22 
 
 CONTENTS  
Section  Title  Page  
 
1. Purpose  3 
2. Background  3 
3. Definitions  4 
4. Scope  5 
5. Testing Methodology and Standard  6 
6. Water Efficiency Grading  9 
7. Water Efficiency Label  10 
8. Testing  Laboratories and Certification Bodies  11 
9. Application for Registration  12 
10. Legal Provisions  17 
11. Compliance Monitoring and Inspection  17 
12. Complaints and Appeals  21 
13. Maintenance of Scheme  22 
 
  Draft version  
 
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Annexes  
1 Testing Guidelines for Water Closet s 
2 Reporting Requirements for Water Closets  
3 Water Efficiency Label  
4 Proforma Letter of Application  
5 Information/Material to be submitted to the Water Supplies 
Department  
6 Flow Chart for Registration  
7 List of International Standards  accepted by the Water Supplies  
Department as equivalent testing and acceptance criteria for the 
purpose of registration of water closets under Water Efficiency 
Labelling Scheme  
 
  Draft version  
 
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 1.    Purpose  
 
This docum ent serves  to give  a detailed description on the voluntary  Water 
Efficiency Labelling Scheme (WELS) on Water Closet s. 
 
2.    Background  
 
2.1. The Water Supplies Department of the Government of the Hong Kong 
Special Administrative Region has adopted the voluntary WELS as one of 
the water conservation initiatives.  The WELS cover s common types of 
plumbing fixtures and  water -consuming appliances.  Registered p roducts 
under  the WELS will carry  a water efficiency label which  serves to inform 
consumers of the products ’ water  consumption level and efficiency rating.  
Cons umers should then be able to  take these factors into account in making 
their purchasing decision.  
 
2.2. In other places , the WELS is in different stages of development and  
implemented in several forms. For instance , it is compulsory in Australia to 
provide water efficiency labels for certain kinds of plumbing  fixtures and 
appliances before they can be put on sale in the market.  In some other  
places  such as the United Kingdom , the WELS is implemented on a 
voluntary basis so as to allow a lead  time for the market to transform 
towards more water efficient products.  The implementation of WELS in 
Hong Kong currently adopts a mixed * approach . The WELS  aims  to: 
 
(a) provide consumers with information on the levels of water  
consumption and efficiency ratings of plumbing fixtures and 
water -consuming appliances;  
(b) facilitate consumers to select water efficient plumbing fixtures and 
water -consuming appliances;  
(c) promote public awareness on water conservation and efficiency issues; 
and 
(d) achieve water savings.  
 
* Mandatory use of some designated water efficient products in new plumbing works and 
 voluntary labelling in the retail market.  
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 2.3. The voluntary WELS in Hong Kong has been  implemented in phases for  
five groups of plumbing fixtures and water -consuming appliances.  They 
are showers for  bathing , water taps , washing machines , urinal equipment  
and flow controllers , launched in September 2009 , September 2010 , March 
2011 , March 2012  and August 2014 respectively .  The next group of 
products for implementation of the WELS is water closet s. 
 
 
3.    Definitions  
 
Unless otherwise specified, the following definitions (in alphabetical order) 
shall apply throughout this document:  
 
Department  means  the Water Supplies Department  of the Government 
of the Hong Kong Special Administrative Region . 
 
Director  means the Director of Water Supplies.  
 
Government  means the Government of the Hong Kong Special 
Administrative Region . 
 
HKAS  means  the Hong Kong Accreditation Service.  
HOKLAS  means Hong Kong Laboratory Accreditation Scheme.  
Inspecting 
Officer  means the officer authorized by the Director to carry out 
the inspection as described in Section 11 of this document.  
 
ISO means the Interna tional Organization for Standardization.  
 
Label  means the water efficiency label (both full version and 
simplified version) as described in Section 7 of this 
document.  
 
MRA  means a mutual recognition arrangement.  Draft version  
 
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 Participant  means  a manufacturer, an importer or other related party 
of the water closet registered in the Scheme . 
Recognized  
Laboratory  means a laboratory which  complies with the requirements 
for testing laboratory as stated in Section 8.  
 
Scheme  means  the Voluntary Water Efficiency Labelling Scheme 
on Water Closets.  
 
Water 
Authority  
 means the Director of Water Supplies.  
Water Closets  means  flushing cisterns, bowl -shaped appliances for 
reception and flushing away of human solid and liquid 
excrement, or any combination of aforementioned 
flushing cisterns and bowl -shaped appliances.  
 
 
4.    Scope  
 
4.1. The Scheme will apply to the water closet s manufacturers, importers, or  
other related parties participating in the Scheme.  
 
4.2. The Scheme registra tion will commence from (date to be advised)  and 
expire  on 31 December 2020, when re -registration may be  necessary.   
 
4.3. A review exercise w ill be conducted in early -2020 to facilitate the 
consideration of whether any modification  of the Scheme is required by 
late-2020.  If the review exercise conclude s that Scheme modification  is 
not required, the valid ity period of  standing  registrations will be extended 
automatically and those who have joined the WELS on water closets  are 
not required to make any re -submission.  On the other hand,  if the review 
exercise conclude s that Scheme modification is required, new applications 
after 31 December  2020 shall  meet the modified  Scheme requirements for 
registration and for those who have joined the WELS on water closets , they 
shall provide  relevant information  to the Department  for re -registration 
during a transitional period  to be announce d. 
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 4.4. The Scheme only covers new water closet s imported to or manufactured  in 
Hong Kong but does not cover second -hand water closet products, water 
closet products already in  existing use, under trans -shipment or 
manufactured for export, etc.  
 
4.5. The Scheme is operated as a ‘Grading T ype’ labelling system.  Under th e 
Scheme, participating water closet s shall have  met the statutory 
requirements and performance requirements specified in the Scheme , and 
will be rated to different grades  according to their water flush volumes . 
 
4.6. The provisions of this Scheme shall apply to the following types of  water 
closet s: 
(a) toilet suite (one -piece water closet pan) ; 
(b) water closet pan only ; 
(c) water closet cistern only ; and  
(d) a combination of a water closet pan and cistern (close -coupled suite) . 
 
5.    Testing Methodology  and Standard  
 
Statutory Requirement  
5.1. The flushing valve of water closet , if applicable,  shall be tested in 
accordance with the relevant requirements as specified in the Waterworks 
Regulati ons (Cap . 102A)  and comply with the standards specified for the 
flushing  valve of water closet by the Water Authority.  Uponcompletion of 
the test(s) and compliance with the standards , the approval for the flushing 
valve of water closet shall also be obtained from the Wat er Authority prior 
to the WELS application.  The WELS registration record will expire on the 
expiry date of the General Acceptance of the flushing valves of the 
corresponding wate r closets .  
 
Water Flush Volume  
5.2. The water flush volume shall be determined in accordance with Section I of 
Annex 1 , with reference to the testing conditions and requirements 
specified in the B S EN  997:2012+A1:2015  – WC pans and WC suites with 
integral trap  or other equivalent international standards accepted  by the 
Department .  The water efficiencies  of the water closet s will be rated to 
different grades according to the water flush volume  test results , subject to Draft version  
 
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 the compliance with other performance requirements mentioned in Section 
5.3 below.  
 
Other Performance Requirements  
 
5.3. The water closet s shall also be tested in accordance with Sections II to V of 
Annex 1 , with reference to the testing conditions and requirements 
specified in th e BS EN 997:2012+A1:2015 – WC pans and WC suites with 
integral trap or other equivalent international standards accepted  by the 
Department,  for conformity with all the performance requirements as 
shown in Table 1  and/or Table 2 .  A list of internation al standard s 
comparable  to BS EN  997:2012+A1:2015 and accepted by the Department 
as equivalent testing and acceptance criteria  for the purpose of registration 
of water closets under WELS is provided in Annex 7. 
 
Table 1: Performance Requirements for All Types of Water Closets  (for 
Dual Flush only)  
 
Performance Property  Performance Requirements  
Flush Volume - Reduced 
Flush (for dual flush only)  The measured discharge volume of the 
reduced flush shall not exceed two -thirds 
of the full -flush volume  
 
  Draft version  
 
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 Table 2: Performance Requirements for T oilet Suite, Water Closet Pan only 
(to be tested with a Flushing Cistern) and Combination of a Water Closet 
Pan and Cistern  
 
Performance Property  Performance Requirements  
Solid Discharge for 
Maximum Flush  For the first six flush cycles, or for a 
minimum of eight out of ten flush cycles, 
each of the four test specimens shall be 
completely evacuated from the water 
closet  bowl and pan's outlet.  
 
The recorded after -flush volume in each 
flush cycle shall be no l ess than 40% of 
the full -flush volume.  
Paper Discharge for Reduced 
Flush Volume (for Dual 
Flush only)  For the first six flush cycles, or for a 
minimum of eight out of ten flush cycles, 
all six sheets of toilet paper shall be 
flushed out of the water close t pan and 
outlet.  
Liquid Contaminant Dye 
Retention  For the first five flush cycles, or for a 
minimum of nine out of ten flush cycles 
at full -flush volume, the contaminate 
level shall be not more than  1%. 
 
For the first five flush cycles, or for a 
minimum of nine out of ten flush cycles 
at reduced -flush volume, when provided, 
the contaminate level shall be not more 
than 6%. 
Wash of Bowl  The arithmetic average of any unflushed 
area below the rim and above the surface 
of the trap shall be no greater than 50 cm2 
after five flushing operations  
 
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 Quality Requirement  
5.4. The water closet s shall be manufactured under a design (if applicable) and 
production system operating according to a recognized international quality 
system (such as ISO 9001  or equivalent ). 
 
6.    Water Efficiency Grading  
 
Water Efficiency Grading  
6.1. For a product of toilet suite or combination of a water closet pan and cistern, 
the water efficiency of the product will be rated to different grades 
according to the water flush volume of the water closet  cistern as shown in 
Table 3 provided that the accompanied water closet pan shall also fulfil l all 
performance requirements as specified in Section 5.3.  Grade 1 is the most 
water efficient whereas Grade 4 is the least water efficient.  
 
6.2. For water closet pan alone, it will be  rated to different grades  according to 
their minimum water flush volume s required to fulfill performance 
requirements in Section 5.3 . For water closet cistern alone, it will be  rated 
to different grades according to their  water  flush volumes  as shown in 
Table 3 . 
 
Table 3:  Conversion of Water Consumption to Water Efficiency Grades for  
Water Closet s  
Water flush volume 
for full flush:  
fF (litre s/flush ) Water flush volume 
for reduced -flush:  
fR (litre s/flush ) Water  
Efficiency  
Grade  Symbolic Presentation on  the 
Water Efficiency Label  
4.5 ≤ fF ≤ 4.8 3.0 ≤ fR ≤ 3.2 Grade 1  1 water droplet  
4.8 < fF ≤ 6.5 3.0 ≤ fR ≤ 3.5 Grade 2 2 water droplet s   
4.5 ≤ fF ≤ 6.5 Not specified  Grade 3 3 water droplet s    
6.5 < fF ≤ 15 Not specified  Grade 4 4 water droplet s     
Draft version  
 
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6.3. If a water closet  has an integral basin or a basin directly connected to it, and 
the water from that basin is used to flush the toilet, the water saving merit 
will be shown on the Label for public information and description of the 
merited function will be shown in  the registration certificate.   
 
6.4. If the water closet  cannot fulfil l the performance requirements specified in 
Sections 5.3, application for registration under the Scheme will be rejected . 
 
 
7.    Water Efficiency Label  
 
Label Versions and  Affixation  
7.1. The Label should be self-adhesive or pre-printed onto the packing .  There 
are two versions of the Label – full and simplified versions.   It is a  
compulsory requirement  for the participant to a ffix or print the Label (s) to 
his/her  registered water closet  or its packi ng at a prominent location.  The 
participant should also ensure that the registered water closet  shall be 
displayed for sale with the full version Label(s) in order to enhance the 
awareness of installing the water efficient plumbing fixtures . The simplified 
version Label is designed to facilitate the participant to affix it to the water 
closet  in cas e the full version Label is too large to do so.  However, the 
affixation of the simplified version Label to the water closet is optional . 
 
Colour Scheme and Dimensions  
7.2. The Label should be printed on white -coloured self -adhesive sheet mate rial 
(for self -adhesive type) in accordance with the figures and dimensions as 
shown in Anne x 3.  It should be printed in English and Chinese in 
accordance with the colour codes specified in Annex 3.  The soft co py of 
the Label will be provided to the successful applicants for WELS after the 
approval of the respective application.  
 
Paper Quality  
7.3. The paper used for the Label should be du rable and possess good wear and  
tear characteristics.  It should be affixed  tightly  on the water closet  or its  
packing.  
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 Information on the Label  
7.4. The information that appears on the Label shall accord with the Label 
format as indicated in A nnex 3 and shall tal ly wit h the information listed on 
the registration certificate issued by the Department.  
 
 
8.    Testing Laboratories and Certification Bodies  
 
8.1. The Department will accept the results and certificates of testing specified 
in Sections 5.2 and 5.3 issued by the testing laboratories as specified in 
either Sections 8.2, 8.3 or 8.4.  
 
8.2. The laboratory is accredited by the Hong Kong Accreditation Service 
(HKAS) under the Hong Kong Laboratory Accreditation Scheme 
(HOKLAS) or by other accreditation bodies with which HKAS has 
concluded mutual recognition agreement s# for carrying out tests sti pulated 
in Sections 5.2 and 5.3  of this document ; and the results are issued in a test 
report or certificate bearing the accreditation symbol . 
 
8.3. On or before 31 December 202 0, a laboratory with HOKLAS accreditation 
(or is accredited by a scheme with which HKAS has concluded a mutual 
recognition agreement#) for laboratory testing of water consuming 
appliances other than the tests stipulated in the Scheme , and the laboratory 
can demonstrate their capability of carrying out tests on water closets in 
accordance with Annex  1. 
 
 
 
# HKAS has concluded mutual recognition arrangements with overseas accreditation bodies for 
testing laboratory accreditation. The list of mutual recognition arrangement partne rs may 
change from ti me to time  and the up‐to‐date list is available from the HKAS website  of 
http://www.itc.gov.hk/en/quality/hkas/doc/common/mramla/MRA_HOKLAS_en_ch.pdf . 
Partners of these arrangements recognise the accreditations granted by one another as equivalent. 
An up‐to‐date APLAC MRA list is available from http://www.aplac.org/aplac_mra.ht ml. An up‐
to‐date ILAC MRA is available from https://ilac.org/signatory_print.php . 
 
  Draft version  
 
Page 12 of 22 
 
 8.4. An in-house  laboratory fulfills the criteria listed below:  
 
(a) Self-declaration by manufacturer  or importer or other related parties 
that the operations of their in-house laboratory follow the requirements 
of ISO/IEC 17025; and 
(b) The manufacturer or importer or other related parties is currently 
operating according to a recogni sed international quality system (such 
as ISO 9001  or equivalent ); and 
(c) The manufacturer’s or importer’s or related parties’ in-house 
laboratory has been successful in carrying out tests on water 
consumption appliances and where these tests have been evaluated  and 
certified by internationally recognized third party certification 
organisations ; and 
(d) The in -house laboratory can demonstrate their capability of carrying 
out tests on water closets in accordance with Annex 1.  
 
 
9.    Application for Registration  
 
Application Procedures  
9.1 All manufacturers, im porters and other related parties in the water closets  
trade  are welcome  to partic ipate in the Scheme.   For known manufacturers 
and importers, invitation lette rs will be issued to  them.  However, any 
manufacturers, importers and other related parties in  the water closet s trade 
may submit applications for registration no  matter whether they are invited 
or not.  
 
9.2 The application for registration can be submitted by means of an 
application  letter  (a proforma letter)  by post, facsimile or electronic mail to 
the Department:  
 
Address:  Water Supplies Department  
47/F, Immigration Tower  
7 Gloucester Road, Wanchai, Hong Kong  
Fax number:  2824 0578  
Email:  wsdinfo@wsd.gov.hk  
 Draft version  
 
Page 13 of 22 
 
 In order to ensure effective implementation of the Scheme, the participant 
must commit to full compliance with the obligations set out in the Scheme.  
A copy of t he proforma letter of application which details the obligations  is 
given at Annex 4 and at the De partment ’s website 
(http://www.wsd.gov.hk/en/wels/index.html ).  The application can be 
made in either English or Chinese . 
 
Information/Documents/Materials to be Submitted for Application  
9.3 The information/material to be submitted with the application are listed in 
Annex 5 and recapped  as follows:  
 
(a) Information of the company, i.e. name, address, telephone number, fax  
number, e -mail address, website address, contact person,  and sale 
distribution network (names and addresses of the distributor(s) ), etc.; 
(b) Information of the water closet  being applied for registration in the  
Scheme, i.e. brand name, model no. and/or name, catalogue  (if 
available), at least  three photos ( showing the front , side  and bottom  
views of the water closet ) and country of origin;  
(c) Proposed commencement date to affix the Label to water closet  (Year 
_____, Month _____);  
(d) Documentary proof that the design (if any) and production system for 
the water closet  is operating according to a recogni sed international 
quality system (such as ISO 9001  or equivalent ).  The submission of 
product drawings extracted from the product manual or design manual, 
and international quality system certificate on the manufacturer can be 
considered as documentary proof of recognition of the quality system.  
Failure to renew the recog nised international quality system may 
render the model registration null and void ; and 
(e) Detailed test report in accordance with the reporting requirements is 
specified in Annex 2.  The test report shall be issued by a recogni sed 
laboratory complying with t he requirements in Section 8.  The 
required information requested in Sections I, II, III, IV & V  of 
Annex  1 of the Scheme document have to be provided in a single 
section of the test report ;  
(f) Documentary proof that the testing laboratory appointed by the 
participant has satisfied the requirement of Section 8.  The submission 
of certificate of accreditation, self -declaration statement that the Draft version  
 
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 operation of the testing laboratory meets the requirements of ISO/IEC 
17025 can be considered as do cumentary proof; and  
(g) For the case of water closet of same design but with the variation in 
colour and finishing, the applicant should consult with the testing 
laboratory and confirm in writing that such variation will not affect the 
water flush volume and other performance requirements specified in 
Section 5.3 and 5.4.  
 
9.4 Company ’s chop should be stamped on all the front covers/pages of the 
documents submitted .  All photocopy test reports submitted to the 
Department shall be certified as true copy.  The participant is also required 
to provide the original copy of the test reports  if requested by the 
Department . 
 
Acceptance/Rejection of Application  
9.5 On receipt of the application, the Department will assess  whether the water 
closet  meets the requirements based on the submitted information and will  
rate the water closet  with a water efficiency grade according to the  water 
closet ’s water flush volume . 
 
9.6 Upon the request of the Department , the applicant  is required to provide 
additional  supporting information/material within the time prescribed by 
the Department .  Failure to comply may render rejection of the 
application.  
 
9.7 If the application is accepted, the participant will be notified of the result  
within 17 working days  upon the receipt of all necessary information  
requested.  A registration certificate listing the information to be displayed  
on the Label will be issued to the participant by the Department.  Soft copies 
of WELS labels will be transmitted by the WSD to suc cessful applicants for 
WELS  after the approval of the respective application.  The participan t will 
then be allowed to affix  or print the Label to the ‘registered’  water closet  or 
its packing.  The participant should ensure that the  Label is correctly 
printed and affixed to the water closet  or its packing in  accordance with 
Section 7.  
 
  Draft version  
 
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 9.8 If the application is rejected, a notification letter with reason(s) of rejection  
will also be given to the applicant  within 17 working days  upon receipt of  
all necessary information requested.  
 
9.9 The flow chart for registration is shown in Annex 6. 
 
Participant’s Obligations  
9.10 In order to ensure effective implementation of the Scheme, the participant  
must understand and be committed to full compl iance with the obligations 
set out in the Scheme.  The participant is obliged to:  
 
(a) submit application, the information/material required in Section 9. 3 
and the test results which follow the reporting requirements set out in 
Annex 2; 
(b) at his/her own costs, produce the Label and affix  or print the Label 
either  to the water closet  or its packing at a prominent location in  
accordance with Section 7;  
(c) ensure that the registered water closet  shall be displayed for sale  with 
the full version Label (s); 
(d) fully inform other related parties (such as sales agents, retailers, etc.) 
in the participant’s sale distribution network once the water closet  is 
registered under this Scheme and notify them that the Department may  
request to enter their premises to carry out the annu al/ad-hoc 
inspections as stated in Section 11;  
(e) allow annual /ad-hoc inspection to be conducted by Inspecting Officers  
authorized by the Director on the registered water closet  at his/her  
premises;  
(f) allow the tested and performance data of the registered wate r closet  to 
be uploaded to the Department’s website for public  information;  
(g) upon the request of the Department, a reference sample for each water 
closet to be participated in the Scheme shall be submitted by the 
participant at his/her own cost;  
(h) conduct  re-test(s) at his/her own costs at a recognized laboratory if  
non-compliance is found on the registered water closet .  The result  of 
re-test(s) shall reach the Department within the time specified by the  
Department;  
(i) provide additional supporting informati on/material upon request of the Draft version  
 
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 Department within the time prescribed. Failure to comply may render 
rejection of the application;  
(j) notify  the Department by means of a notification letter (in either 
English or Chinese with the company’s chop stamped on all submitted 
documents) by post, facsimile or electronic mail of any changes of the 
company information (e.g. company name).  The notificati on should 
be made not less than 14 working days before the change.  Failure to 
comply may render the model registration null and void.  Changes of 
water closet  information (e.g. brand name, model no.) will be 
considered as major changes that require new ap plications for 
registration in the Scheme . The participant shall return the former 
registration certificate to the Department  soon after the termination of 
previous registration ; and 
(k) remove within three months all Labels from the water closet and/or  its 
packing  if it has been de -registered.  The participant shall return the 
registration certificate to the Department soon after the termination of 
registration under the Scheme.  
 
9.11 The details of water closet s registered under the Scheme will be kept in  a 
regis ter maintained by the Department.  The registration records will be  
regularly uploaded to the Department’s website for public information.  
 
Termination  
9.12 Under circumstances of poor performance such as:  
 
(a) the participant failing to fulfil l the obligations set out in the Scheme; 
or 
(b) the water closet  failing to perform in accordance with rated water  
efficiency grade and/or the performance requirements of the Scheme  
and the participant not being able to rectify the non -compliance within  
the tim e frame  specified by the Department; or  
(c) where the Director is of the opinion that registration of a water closet  
is contrary to the public interest . 
 
The Department may de -register a water closet  from the Scheme with  
immediate effect by giving the participant notice in writing.  Once a water 
closet  is de -registered, it is not allowed to affix a Label to it.  The Draft version  
 
Page 17 of 22 
 
 participant shall remove all Labels from the de -registered water closet  
and/or  its packing  within three mont hs from the notice.  The participant 
shall return the registration certificate to the Department soon after the 
termination of  registration under  the S cheme.  
 
9.13 Participant who decides to discontinue participating in the Scheme or to  
withdraw any registered water closet  from the Scheme shall give at  least 
three months’ advance notice to the Department.  The participant shall 
return the registration certificate to the Department soon after the 
termination of registration under the Scheme.  
 
 
10.    Legal Provisions  
 
10.1 Without prejudice to any remedy a purchaser may have against the party  
under the Laws of Hong Kong, a culpable party may be subject to the 
following  sanctions . 
 
10.2 This Scheme is a voluntary scheme.  However, a participant who abuses 
the Scheme by giving false  information on the Label may constitute an 
offence  under the Trade Descriptions Ordinance (Cap. 362). 
 
10.3 Unauthorized use of the Label (s) may constitute an offence under the 
Copyright  Ordinance (Cap. 528 ). 
 
 
11.    Compliance Monitoring and Inspection  
 
Purpose  
11.1 To uphold credibility of the Scheme and to maintain continuous confidence 
of the consumers, compliance check on the Labels on those water closet s 
registered in the Scheme is necessary.  In addition, to avoid the  
unsatisfactory situation that unauthorized Labe ls are used on non -registered  
water closet s, the Department may also carry out suitable form o f 
inspection on those water closet s which have not been registered under  the 
Scheme.  
 Draft version  
 
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 Scope  
11.2 The scope of inspection includes, but not limited to, sample checking and 
testing for the following items:  
 
(a) whether the Label is  affixed /printed  to registered water closet s or their 
packing  as required  in Section 7; 
(b) whether the Label being displayed is of correct format in accordance  
with Section 7; 
(c) whether the water efficiency grade rated by the Department based on  
the data submitted by the participant is in line with the grade rated 
from  the results of testing conducted by the Department;  
(d) whether the data shown on the Label tally with the information listed 
on the re gistration certificate; and  
(e) whether unregistered water closet s display unauthorized Labels.  
 
11.3 The participants will be requested to tak e immediate remedial action and  
report the follo w-up action taken if non -compliance is found on their  
registered water clo sets such as incorrect information shown on the  Label.  
 
11.4 The Department may appoint a recogni sed laboratory to conduct  annual 
testing on the registered water closet s in accordance with the  requirements 
specified in Sections I, II, III, IV and V  of Annex 1 .  For a registered  
water closet  which is found to fall within either one of the  following cases , 
the Department may request the participant to conduct  separate test at 
his/her own cost on the registered water closet s, in accordance with the 
testing methodol ogy as stated in Annex 1  in a recogni sed laboratory agreed 
by the Department.  
 
(a) The water closet  is found not meeting the performance requirements 
specified in Section 5. 3; or 
(b) The water closet  is found not meeting the water efficiency grade rated 
based on the data previously submitted by the participant in the 
application ; or 
(c) The measured water  flush volume  of water closet  is found different to  
the registered water flush volume  by more/less tha n 20%.  
 
The re -test should be carried out on at least three further samples of the  Draft version  
 
Page 19 of 22 
 
 water closet .   
 
For case 11.4(a) above, the performance test results of the three water 
closet s should meet the requirements specified in Section 5. 3.  If the test 
results fail to meet such requirements, the Department may either require 
the participant to withdraw his/her registration or de -register the water 
closet  rated from the Scheme. The participant shall return the registration 
certificate to the D epartment soon after the termination of registration under  
the Scheme.  
 
For case s 11.4(b) above, the water efficiency grading rated from the 
average water flush volume  of the three water closet  samples should be the 
same as the grading on the Label. Otherwise, the Department will require 
the participant to take appropriate remedial action including re -registering 
in th e Scheme by replacing a Label  with correct grading and water flush 
volume  for the registered water closet . The participant shall return the 
former registration certificate to the Department  soon after the termination 
of previous registration . 
 
For case  11.4(c) above, the water flush volume of the water closet samples 
shall be determined in accordance with Annex 1 and rated to the 
corresponding water efficiency grades as shown in Table 3. If the measured 
water flush volume of water closet is found different to the regis tered water 
flush volume by more/ less than 20% , the Department may either require 
the participant to withdraw his/ her registration  or de-register the water 
closet from the Scheme.  The participant shall return the registration 
certificate to the Department soon after the termination of registration under  
the Scheme.  
 
11.5 If non -compliance is confirmed and no remedial action is taken by the  
participant within the time prescribed by the De partment, the Department  
may order it be de -registered from the Scheme.  The participant shall 
return the registration certificate to the Department soon after the 
termination of registration under the Scheme. Once a water closet  is 
de-registered, it is not allowed to affix  or print  a Label to it  or its packing .  
The participant shall  remove all Labels from the de -registered water closet  
and its packing  within three months from the notice. Failure to remove the Draft version  
 
Page 20 of 22 
 
 Labels from the  de-registered water closet  may contravene the relevant 
ordinances as  mentioned in Section 10 above.  
 
Inspecting Officers  
11.6 The Director will authorize Inspecting Officers to carry out water closet  
compliance monitoring and inspection.   The officers will carry proper  
identification card s which will be produced during their inspection. 
However,  the officers will not inform the participants in advance of their 
inspection.  
 
11.7 It is the participants ’ obligation to allow the Inspecting Officers to gain 
access  to their premises to carry out the inspection.  Failure to comply may 
render the model registration null and void.  
 
 
Mode of Inspection  
 
11.8 Annual  inspections will be carried out on registered water closet s under the  
Scheme. Based on the record of the registration, annual inspection 
programmes  will be developed.  Inspection will also be  conducted on the 
non-registered water closet s with unauthorized Labels.  
 
11.9 In addition to the annual  inspections, the Inspecting Officers will carry out  
ad-hoc inspections in response to complaints.  The items to be inspected in  
such a case will depend upon the nature of complaints and may include the  
items as stated in Section 11.2.  
 
11.10  Inspections will normally be carried out at the retail outlets and water closet  
showrooms.  Where necessary, inspection will also be  done at  warehouses.  
 
11.11  The inspection results will be properly recorded for future analysis as well 
as on evaluation of the effectiveness of the Scheme.   
 
 
  Draft version  
 
Page 21 of 22 
 
 12.    Complaint s and Appeals  
 
12.1 The Department will be responsible for dealing with complaints from  
participants and other parties against matters related to the Scheme.  
 
Complaints Handling Procedure  
12.2 The Department shall ensure that complaints are properly recorded and  
handled without undue delay.  
 
12.3 The Department shall carry out investigation on complaints and reply to 
them  within a reasonable time. For complaints that require site inspection 
and laboratory test, the complainant shall be notified through an interim 
reply.  
 
12.4 The Department shall inform the complainant of the result or decision made  
on the complaint.  
 
Appeal Procedure  
12.5 A participant may appeal against the decision or action taken by the  
Department in writing to the Director stating the reason for the appeal.  
 
12.6 The Director may decide to suspend the decision or action taken by the  
Department from the day on which the appeal is made until such appeal is  
disposed of, withdrawn or abandoned unless such suspension would, in the  
opinion of the Director, be contrary to public interest.  
 
12.7 The Director may, by notice to the appellant, requir e the appellant to attend 
meeting(s) with him or his representatives and provide documents and give 
evidence relevant to the appeal.  
 
12.8 The Director shall notify the appellant of his decision and reasons for it.  
The decision will be final.  
 
 
  Draft version  
 
Page 22 of 22 
 
 13.    Maintenance of  Scheme  
 
13.1 To ensure that the Scheme can continue to operate effectively and 
efficiently,  the Scheme will be maintained as follows:  
 
(a) Continuous updating of the Register  of water closet s registered in the  
Scheme as follows:  
 
(i) registered water closet s with details such as registration  numbers 
in the Scheme, dates of registration, flush volume  data,  
performance data, makes, models and other related information;  
and; 
 
(ii) manufacturers, importers or other related parties of the  registered 
water closet s with details such as addresses,  telephone numbers, 
e-mail addresses, etc.  
 
(b) Periodic review of the testing methodologies, procedures for 
registration application and compliance  monitoring etc.  
 
(c) Continuous evaluation of the effectiveness of the Scheme and  
assessment of the changes , if any,  are necessary . Annex 1  
 
 
                                                                                    
Page 1 of 6 
  
 
 
Testing Guidelines for Water Closets  
 
 
 
Condensed Testing Requirements with reference to the BS EN  
997:2012+A1:2015  Standard  
 
 
 
- Note - 
 
 
This Annex is a guideline to facilitate the  participant to grasp the context of water 
efficiency testing requ irements  and it should be read in conjunction with the reporting 
requirements in Annex 2. This Annex  makes reference to some of the chapters of the 
captioned standard and focuses on flush volume – full flush and r educed flush (for 
dual flush only) , solid discharge for maximum flush, paper discharge for reduced 
flush volume (for dual flush only) , liquid contaminant dye retention  and w ash of bowl. 
The participant should be able to obtain from the text a good appreciation of the 
testing requirements. On the other hand, the captioned standard is much more 
comprehensive and detailed and contains exact definitions. Due to condensed size, 
this Annex cannot replace the captioned standard nor is there  any intention to do so. 
In case of doubt, the captioned standard should always be consulted.  
Section I of this Annex describes the methodology for determination of flush volume . 
The performance tests for water closets  are elaborated in Section s II, III, IV and V .  
Permission to reproduce extracts from British Standards is granted by BSI. British 
Standards can be obtained in PDF or hard copy formats from the BSI online shop: 
www.bsigroup.com  / Shop or by contacting B SI Customer Services for hardcopies 
only: Tel: +44 (0)20 8996 9001, Email: cservices@bsigroup.com.  
 
  Annex 1  
 
 
                                                                                    
Page 2 of 6 
 Section I  Methodology for Determination of the Flush Volume of 
Water Closets  
 
A1. Scope  
 
This section sets out the method for determining the flush volume of a water closet.  
 
A2.  Principle  
 
The test is to determine the flush volume of water closets by o perat ing the flushing 
device and collect ing the water in the measuring vessel.  
 
A3 Testing Apparatus  
 
Please refer to Clause 6.17.3.1  in BS EN 997:2012+A1:2015 . 
 
A4 Procedure  
 
Please refer to Clause 6.17.3.2  in BS EN 997:2012+A1:2015 . 
 
A5 Expression of Results  
 
Please refer to  Clause 6. 5.2 in BS EN 997:2012+A1:2015  on the ratio of reduced 
flush  volume against full flush volume  and record compliance or any failure . 
 
 
 
 
 Annex 1  
 
 
                                                                                    
Page 3 of 6 
 Section I I  Solid Discharge and After -flush Volume for Maximum 
Flush Volume test for Water Closets  
 
B1 Scope  
 
This section sets out the method for performing solid discharge and after-flush 
volume for maximum flush volume test for water closets . 
 
B2 Principle  
 
The tests are to determine the performance requirements for water closets  with respect 
to solid discharge and after-flush volume for maximum flush volume .  
 
B3 Testing Apparatus  
 
Please refer to Clause 6.17.7.1  in BS EN 997:2012+A1:2015 . 
 
B4 Procedure  
 
Please refer to Clause 6.17.7.2  in BS EN 997:2012+A1:2015 . 
 
B5 Expression of Results  
 
Please refer to  Clause 6.9 in BS EN 997:2012+A1:2015  to record compliance or any 
failure . 
 
 Annex 1  
 
 
 
Page 4 of 6 
 
 Section I II  Liquid Contaminant Dye Retention test for Water 
Closets  
 
C1 Scope  
 
This section sets out the method for performing liquid contaminant dye retention test  
for water closets . 
 
C2 Principle  
 
The tests are to determine the performance requirements for water closets  with respect 
to liquid contaminant dye retention .  
 
C3 Testing Apparatus  
 
Please refer to Clause 6.17.9.1  in BS EN 997:2012+A1:2015 . 
 
C4 Procedure  
 
Please refer to Clause 6.17.9.2  in BS EN 997:2012+A1:2015 . 
 
C5 Expression of Results  
 
Please refer to Clause 6.11 in BS EN 997:2012+A1:2015  to record compliance or 
any failure . 
 
  Annex 1  
 
 
 
Page 5 of 6 
 
 Section I V  Wash of Bowl  test for Water Closets  
 
D1 Scope  
 
This section sets out the method for performing wash of bowl test for water closets . 
 
D2 Principle  
 
The tests are to determine the performance requirements for water closets  with respect 
to wash of bowl .  
 
D3 Testing Apparatus  
 
Please refer to Clause 6.17.10.1  in BS EN 997:2012+A1:2015 . 
 
D4 Procedure  
 
Please refer to Clause 6.17.10.2  in BS EN 997:2012+A1:2015 . 
 
D5 Expression of Results  
 
Please refer to Clause 6.12 in BS EN 997:2012+A1:2015  to record compliance or 
any failure . 
 
  Annex 1  
 
 
 
Page 6 of 6 
 
 Section V  Paper Discharge for Reduced Flush Volume  for Water 
Closets  (for Dual Flush only)  
 
E1 Scope  
 
This section sets out the method for performing paper discharge for reduced flush 
volume  test for water closets  (for dual flush only) . 
 
E2 Principle  
 
The tests are to determine the performance requirements for water closets  (for dual 
flush only) with respect to  paper discharge for reduced flush volume .  
 
E3 Testing Apparatus  
 
Please refer to Clause 6.17.8.1  in BS EN 997:2012+A1:2015 . 
 
E4 Procedure  
 
Please refer to Clause 6.17.8.2  in BS EN 997:2012+A1:2015 . 
 
E5 Expression of Results  
 
Please refer to Clause 6.10  in BS EN 997:2012+A1:2015  to record compliance or 
any failure . 
 
 Annex 2 
 
 
 
 
 Reporting Requirements  for Water Closets  
 
 
The testing report shall  contain the following information:  
 
(a) Manufacturer, country of origin, brand name, model name, model number  of 
water closet pan, water closet cistern and flushing device  (if these are applicable) 
of water closet s; 
(b) At least t hree photos clearly showing the front, side and bottom views of water 
closets;  
(c) The full flush volume, calculated as the mean of the average of five f ull flush 
volume obtained in paragraph A4 of Annex 1 in 1 decimal place;  
(d) If dual flush setting is available, the reduced flush volume, calculated as the mean 
of the average of five reduced flush volume obtained in paragraph A4 of Annex 1 
in 1 decimal place ; 
(e) Record compliance  or any failure to comply with the ratio of reduced -flush 
volume against full -flush volume according to  paragraph A5 of Annex 1; 
(f) Record  compliance  or any failure to comply with the solid d ischarge and 
after-flush volume for maximum -flush  volume test according to  paragraph B5 of 
Annex 1; 
(g) Record compliance or any failure to comply with the liquid contaminant dye 
retention test according to paragraph C5 in Annex 1;  
(h) Record compliance or any failure to comply with the wash of bowl test according 
to paragraph D5 in Annex 1; and  
(i) Record compliance or any failure to comply with the paper discharge for reduced 
flush volume (for dual flush only) according to  paragraph E5 in Annex 1 . Annex 3  
 
Water Efficiency Label  
 
  
Full Version Grade 1 WELS Label  Simplified  Version Grade 1 WELS Label  
  
 
Full Version Grade 2 WELS Label  Simplified  Version Grade 2 WELS Label  
  
 
Full Version Grade 3 WELS Label  Simplified  Version Grade 3 WELS Label  
  
 
Full Version Grade 4 WELS Label  Simplified  Version Grade 4 WELS Label  
 
Annex 4  
 
                                                                                        
1 
 Proforma Letter of Application  
Our ref.  
 
Tel.  
Fax.  
 
Date  
 
Water Supplies Department  
47/F, Immigration Tower  
7 Gloucester Road, Wanchai  
Hong Kong  
 
Dear Sir/Madam,  
 
Application for Registration in the Voluntary Water Efficiency Labelling 
Scheme on Water Closet s 
 
Our company is the (manufacturer / importer / other related parties (please specify)*)  
of___________________(brand name, model number and/or name of water closet ) in 
Hong Kong. We would like to apply for registration of the water closet  in the above 
Scheme.  
 
We understand fully our obligations as stated in the Scheme document and will 
comply with all relevant requirements, in particular those specified below:  
 
(a) submit application, the information/material required in Section 9. 3 of the 
Scheme document and the test report in accordance with the reporting 
requireme nts specified in Annex 2;  
(b) at our own costs, produce the Label (s) and affix/print the Label (s) either to 
the water closet  or its packing at a prominent location in accordance with 
Section 7;  
(c) ensure that the registered water closet  shall be displayed for s ale with the 
full version Label (s);  
(d) fully inform other related parties (such as sales agents, retailers, etc.) in the 
participant’s sale distribution network once the water closet  is registered 
under this Scheme and notify them that the Water Supplies  Department 
(Department) may request to enter their premises to carry out the Annex 4  
 
                                                                                        
2 
 annual /ad-hoc inspections as stated in Section 11 of the Scheme document;  
(e) allow annual /ad-hoc inspection to be conducted by Inspecting Officers 
authorized by the Director of Water Supplies on the registered water closet  
at our premises;  
(f) allow the tested and performance data of the registered water closet  to be 
uploaded to the Department’s website for public information;  
(g) upon the request of the Department, a reference sample for each water 
closet to be participated in the Scheme shall be submitted by us at our cost; 
(h) conduct re -test(s) at our own costs at a recognized laboratory if 
non-compl iance is found on the registered water closet . The result of 
re-test(s) shall reach the Department within the time specified by the 
Department;  
(i) provide additional supporting information/ material upon request of the 
Department within the time prescribed. Failure to comply may render 
rejection of the application ;  
(j) notify  the Department by means of a notification letter (in either English or 
Chinese with the company’s chop stamped on all submitted documents) by 
post, facsimile or electronic mail of any changes of the company 
information (e.g. company name).  The notificatio n should be made not 
less than 14 working days before the change.  Failure to comply may 
render the model registration null and void.  Changes of water closet  
information (e.g. brand name, model no.) will be considered as major 
changes that require new app lications for registration in the Scheme . The 
participant shall return the former registration certificate to the Department 
soon after the termination of previous registration ; and  
(k) remove within three months all Labels from the water closet and/or  its 
packing if it has been de -registered. The participant shall return the 
registration certificate to the Department soon after the termination of 
registration under the Scheme.  
 
  Annex 4  
 
                                                                                        
3 
 The detailed information of the water closet  which we apply for registration is shown 
in the attached documents (see Annex 5 for the list of information to be submitted) for 
your processing . 
 
Yours faithfully,  
 
 
 
 
(Manufacturer/Importer/Agent's Name and Company Chop)  
 
Date  
_____________  
* delete as appropriate  Annex 5  
 
                                                                                        
1 
 Information/Material to be Submitted  
to the Water Supplies Department  
 
 
1. Information of the company, i.e. name, address, telephone number, fax 
number, e -mail address, website address, and contact person, and sale 
distribution network (names and addresses of the distributor (s)), etc.; 
2. Information of the water closet  being applied for registration in the 
Scheme, i.e. brand name, model no. and/or name, catalogue  (if 
available), at least  three photos clearly showing the front , side  and 
bottom  views of the water closet s and co untry of origin . 
3. Proposed commencement date to affix the Label (s) to water closet  
(Year _____, Month _____) . 
4. Documentary proof that the design (if any) and production s ystem for 
the water closet  is operating according to a recognised  international 
quality system (such as ISO 9001  or equivalent ). The submission of 
product drawings extracted from the product manual or design manual, 
and international quality system certificate on the manufacturer can be 
considered as documentary proof of recognition of the quality system. 
Failure to renew the recogn ised international quality system may 
render the model registration null and void ;  
5. Detailed test report in accordance with the reporting re quirements  is 
specified in Annex 2. The test report shall be issued by a recognised  
laboratory complying with the re quirements in Section 8. The required 
information  requested in Sections I, II, III, IV & V  of Annex 1  of the 
Scheme document have to be provided in a single section of the test 
report ; 
6. Documentary proof that the testing laboratory appointed by the 
participant has satisfied the requirement of Section 8.  The submission 
of certificate of accreditation, self -declaration statement that the 
operation of the testing laboratory meets the requirements of ISO/IEC 
17025 can be considered as do cumentary proof; and  
7. For the case of water closet of same design but with the variation in 
colour and finishing, the applicant should consult with the testing 
laboratory and confirm in writing that such variation will not affect the 
water flush volume and other performance requirements specified in 
Section 5.3 and 5.4 . 
 Annex 5  
 
                                                                                        
2 
  
Note:  Com pany’s chop should be stamped on all the front covers/pages of the 
documents submitted . All photocopy  test reports submitted to the Water 
Supplies Department  (WSD)  should be certified as true copy. The participant 
is also required to provide the original copy of the test reports if requested 
by WSD . Annex 6  
 
                                                                                        
1 
 Flow Chart for Registration  
 
 
 
 Commencement of 
Scheme  
Manufacturers , importers, 
other related parties  to 
submit application &  
supporting information 
for their water closet  
products  
(see Annexes 4 and 5)  
WSD to p rocess  
application  
Application 
accepted ? 
WSD  to issue notification 
letter  notif ying the result  
WSD to keep 
record  in the 
Register  yes no WSD to issue notification 
letter with reason(s) of 
rejection  Annex  7  
 
                                                                                        
1 List of International Standards  accepted by the Water Supplies 
Department as equivalent testing and acceptance criteria for the 
purpose of registration of water closets under Water Efficiency 
Labelling Scheme  
 
Note:  
This is a non -exhaustive list of international standards  comparable  to 
BS EN 997:2012+A1:2015 and accepted  by the Water Supplies 
Department  as equivalent testing and acceptance criteria  for the 
purpose of registration of water closets under Water Efficiency 
Labelling Scheme . 
 
1. BS EN 997:2003  
 
 Advisory Notes for the Purchase of Water Closets  with WELS Labels  
 
(1) One of the aims of the Scheme is to provide consumers with information on the 
levels of water consumption and efficiency ratings of plumbing fixtures and 
water -consuming appliances . The Labels  do not imply that water closets comply 
with any statutory , product quality and functional requirements .  
 
(2) Consumers are advised to follow the manufacturer’s  or importer’s instructions if 
a WELS registered water closet pan and a WELS registered water closet cistern  
are purchased separately.  
 
(3) Consumers are recommended  to match the Water Efficiency Grading of a WELS 
registered water closet pan with the grade of a WELS registered water closet 
cistern . For example, Grade 2  water closet cisterns pans matching with Grade 2 
water closet cisterns.