IS 16240 : 2023

Indian Standard

—
(

Reverse Osmosis Based Point of

Use Water Treatment System for
Drinking Purposes — Specification
( First Revision )

ICS 130.060.01

BIS 2023

B UREAU OF IN DIAN S TANDA RDS

- 110002
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI - 110002
www.bis.gov.in www.standardsbis.in

March 2023 Price Group 9

Water Purification Systems Sectional Committee, FAD 30

FOREWORD

This Indian Standard (First Revision) was adopted by the Bureau of Indian Standards, after the draft finalized by
the Water Purification Systems Sectional Committee had been approved by the Food and Agriculture Division
Council.
The quality of water available for human consumption has a bearing on health of the population/community. In
highly populated countries like India, the quality of drinking water has deteriorated due to contamination of soil
and water from agricultural run-offs and industrial effluents, and due to over exploitation of groundwater. Tapping
of groundwater for domestic use has also increased in urban and semi-urban areas to meet the growing demand
of water. Groundwater typically has higher concentrations of dissolved solids, namely minerals, and may contain
harmful contaminants like heavy metals and naturally occurring elements like fluoride or arsenic in excess.
Reverse Osmosis (RO) technology combined with sediment and carbon filters has proved to be an effective water
treatment method for removing various inorganic, organic, and microbiological contaminants from the water.
Realizing this fact, many manufacturers and assemblers in the organized and unorganized sectors have entered
the RO water treatment market. Taking cognizance of this trend, this Indian standard for RO-based water treatment
systems was formulated establishing minimum requirements for design and construction, performance, and testing
of materials that come in contact with treated water.
The standard was first published in 2015. This revision is undertaken to update the standard having regard to the
available technology and corresponding recovery efficiency and output water quality reliability. In this revision,
the following major changes have been incorporated:

a) In the terminology clause, new terms, ‘permeate’ and ‘reject water’ have been incorporated;
b) Requirement of recovery percentage has been increased from 20 percent to 40 percent in order to minimize
water wastage;
c) Requirements for chemical reduction of contaminates, copper and pesticides have been updated;
d) For TDS display, hand held TDS meter and IoT enabled display methods have been incorporated as
alternative options to inbuilt TDS display meter.
e) Methods of test for TDS, chemical, and microbiological reduction and recovery testing have been
elaborated to incorporate details of influent challenge water preparation;
f) Clauses on electrical safety and power supply have been updated; and
g) Hydrostatic testing has been revised, to differentiate between different zones of pressurization in the
complete RO system.

With the advancement of technology and based on availability of technical data on optimum recovery efficiency
from further research and study, the specified value of recovery efficiency of 40 percent would be reviewed by
the concerned technical committee of Bureau.
The composition of the committee responsible for formulation of the standard is listed in Annex G.

For the purpose of deciding whether a particular requirement of this standard is complied with, the final value,
observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with
IS 2 : 2022 ‘Rules for rounding off numerical values (second revision)’. The number of significant places retained
in the rounded-off value should be the same as that of the specified value in this standard.
 IS 16240 : 2023

Indian Standard
REVERSE OSMOSIS BASED POINT OF USE WATER
TREATMENT SYSTEM FOR DRINKING PURPOSES —
SPECIFICATION
( First Revision )

1 SCOPE IS No. Title

1.1 This standard covers reverse osmosis (RO)
based point-of-use (PoU) water treatment system IS 4905 : 2015 Random sampling and
with a product water capacity of up to 50 litre per randomization
hour, that reduces total dissolved solids (TDS); and
physical, chemical, and microbiological
IS 9845 : 1998 Determination of overall
contaminants from specified concentrations in the migration of constituents
feed water to the maximum allowable limits in the of plastics materials and
product water. articles intended to come
1.2 The standard does not cover requirements for in contact with foodstuffs
consumables, such as filters and treatment media. — Method of analysis
(second revision)
2 REFERENCES IS 10500 : Drinking water —
The standards listed below contain provisions, 2012 Specification (second
which, through reference in this text, constitute revision)
provisions of this standard. At the time of IS 15185 : Water quality —
publication, the editions indicated were valid. All 2016 Detection and
standards are subject to revision, and parties to enumeration of
agreements based on this standard are encouraged to Escherichia coli and
investigate the possibility of applying the most coliform bacteria —
recent editions of the standards listed below: Membrane filtration
method for water with
IS No.
low bacterial background
IS 302 (Part 1) : Safety of household and flora (first revision)
2008 similar electrical 3 TERMINOLOGY
appliances: Part 1
For the purpose of this standard, the following
General requirements
definitions shall apply.
(sixth revision)
IS 3025 Method of sampling and 3.1 Chemical Reduction — A reduction in the
test (physical and concentration of one or more specified organic or
chemical) for water and inorganic chemical contaminants by a system from
wastewater: feed water.
(Part 16) : 2023 Filterable residue (total 3.2 Contaminant — An undesirable physical,
dissolved solids) at 180 chemical, or microbiological substance or parameter
°C (second revision) in water that may have adverse effects on health or
(Part 34) : 1988 Nitrogen (first revision) aesthetics, or both.
(Part 37) : 2022 Arsenic (second revision) 3.3 Drinking Water — Water from any source
(Part 41) : 1992 Cadmium (first revision) which is intended for human consumption, both
(Part 42) : 1992 Copper (first revision) drinking and cooking purposes (see IS 10500).
(Part 47) : 1994 Lead (first revision) 3.4 Feed Water — Water entering the system,
(Part 48) : 1994 Mercury (first revision) which is to be treated by the system.
(Part 52) : 2003 Chromium(first revision) 3.5 Influent Challenge Water — The standard test
(Part 60/Sec 1) : Fluoride (second water with specified contaminants entering a system
2023 revision) for evaluation.

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IS 16240 : 2023

3.6 Permeate — The portion of feed water that has components:

been treated by passage through the RO membrane.
a) Sediment Filter — A filter required to
3.7 Point-of-Use (PoU) Drinking Water remove physical impurities in the form of
Treatment System — A plumbed-in or faucet- suspended solids like dust, dirt, silt and other
mounted system used to treat the feed water for fine particles from the feed water;
direct consumption or use, hereinafter referred to as
‘system’. b) Adsorption Media — Required for the
removal of chlorine and organic matter from
NOTE — PoU RO systems are not intended for distribution. water;
3.8 Production Rate — The volume of water
c) Reverse Osmosis Membrane Element —
produced by a system in litres per hour (lph).
Should be able to reduce TDS, comprising
3.9 Product Water — Water that has been treated of dissolved inorganic and organic
by the system. contaminants;
3.10 Recovery Rating — The ratio of product water d) Booster Pump — Should be able to provide
to feed water, expressed as a percentage. the required operating pressure based on the
3.11 Reject Water — The portion of the feed water RO membrane used;
that is not converted to product water. It is also e) Reject Water Control Mechanism —
called the concentrate, as the solutes (contaminants) Required to control the reject water flow,
are concentrated in the reject water stream. thereby controlling the recovery rating
3.12 Reverse Osmosis (RO) — A pressure-driven or/and pressure;
membrane separation technique to reduce the
f) Power Supply;
concentration of dissolved solutes such as minerals,
salts and organic species in water. Reverse osmosis g) Auto Shut-off Mechanism — Required to
uses an applied pressure to drive the transport of prevent overflow and dry running of the
water across a semi-permeable membrane from a pump; and
more concentrated solution (feed) to a more dilute
solution (permeate). h) TDS Display Meter — Required to display
NOTE — RO is often used in commercial and residential
the TDS value (mg/litre) of feed water and
water treatment. It is also one of the methods used for the product water within a tolerance of ± 10% of
desalination of brackish water and seawater. In RO-based TDS when tested as per IS 3025 part 16.
systems, typically, a spiral wound membrane element is
used along with pretreatment filters consisting of sediment NOTES
filters, activated carbon filters, etc.
1 If the system does not have an inbuilt/integrated TDS
3.13 RO Membrane — A semi-permeable barrier Display meter, the manufacturer shall provide hand held
that allows the preferential passage of water. TDS meter with digital display, as an accessory along with
Commonly used reverse osmosis (RO) membranes the system. IOT enabled TDS display method may also be
include cellulose triacetate and aromatic polyamide provided as an option.
2 The functioning of the TDS meter shall be ascertained
polymers, popularly known as TFC (thin film
periodically by the maintenance service provider and
composites). explicit instructions for calibration and maintenance of the
TDS meter shall be provided by the manufacturer in the
4 CONSTRUCTION user manual.

4.1 Inlet Port 4.3.2 The RO system may have the following
additional components (non-exhaustive list):
The system’s inlet port shall be so designed that it
can be suitably connected to the feed water source. a) Flushing Mechanism;
4.2 Method of Mounting b) Ultraviolet (UV) Disinfection Chamber/In
Tank Sanitization;
The system shall facilitate wall-mounting,
countertop placement, or under-the-sink installation, c) Ultrafiltration (UF) Membrane;
etc.
d) TDS Control Valve — A valve that splits
4.3 Main Components the feed flow into two streams, one passing
through the RO membrane and the second
4.3.1 The RO system shall have the following through an RO by-passing line. A blend of

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 IS 16240 : 2023

RO permeate flow and bypass flow yields 6.3 Performance

product water; and
6.3.1 TDS Reduction
) The following post-membrane
components/treatments may be 6.3.1.1 The system shall reduce the TDS level of
incorporated: feed water to less than or equal to 500 mg/litre in the
product water, as per the maximum desirable
1) Mineraliser/Taste Enhancer Media — concentration specified in IS 10500, when tested as
Required to improve the taste of RO treated per IS 3025 (Part 16).
water; and 6.3.1.2 The influent challenge water for TDS
reduction testing shall have minimum 1 500 mg/litre
2) Activated Carbon Media. of TDS or the maximum operating TDS level as
declared by the manufacturer, whichever is higher.
NOTE — For systems where mineraliser/taste enhancer
media is used, the manufacturer shall declare that the 6.3.1.3 The method of testing TDS reduction is given
mineraliser/taste enhancer media being used will not cause in Annex A.
any of the parameters in product water to exceed acceptable
limits specified in IS 10500. 6.3.2 Chemical Reduction

5 MATERIALS 6.3.2.1 The system shall meet the maximum allowable

product water levels as given in Table 1.
5.1 Materials in contact with water shall comply
with the overall migration limits of 60 mg/litre, Max 6.3.2.2 The method of testing chemical reduction is
for various plastic materials when tested by the given in Annex B.
method prescribed in IS 9845.
6.3.3 Microbiological Reduction
5.2 Materials of Construction
6.3.3.1 The manufacturer shall meet the
5.2.1 Those surfaces of the components of the RO requirements of Table 1 to deliver microbiologically
system, which are expected to get wetted by the flow safe drinking water. The method of testing
of water through the RO system, shall be made of microbiological (bacteriological and virological)
corrosion-resistant materials or shall have corrosion- reduction is as given in Annex C.
resistant treatment or coating of food-grade quality.
The manufacturer shall provide evidence of the 6.3.3.2 Optional requirements for microbiological
same. reduction

5.3 Membrane Preservatives 6.3.3.2.1 The requirements given in Table 2 shall be

optional requirements which shall be tested for the
5.3.1 The chemical preservatives used in the RO system as per Annex D by manufacturers
membrane shall be of food-grade quality and shall claiming their reduction. These requirements shall
be declared by the manufacturer in the user guide for be mandatorily tested in case, the system has a TDS
consumers. control mechanism employing RO-bypass blending.
5.3.2 The manufacturer shall also declare the 6.4 Percent Recovery of Product Water and
flushing requirement at the time of installation, in Hourly Production Rate
the user guide.
6.4.1 The minimum recovery rate shall be equal to
6 PERFORMANCE REQUIREMENTS or more than 40 percent.

6.1 General 6.4.2 Production rate shall not be less than 5 litre per
hour.
The RO system shall be so designed and constructed
that its intended purpose is accomplished when 6.4.3 The method for evaluating recovery rating and
installed and operated in accordance with the hourly production rate is as prescribed in Annex A.
manufacturer’s instructions.
6.4.4 The manufacture shall declare:
6.2 Reject Water Control Mechanism
a) Recovery rating;
6.2.1 A reject water control mechanism (flow
restrictor) shall be provided as an integral part of the b) Maximum operatable feed water TDS;
system to regulate the flow of reject water. The
d) Production rate, in lph; and
performance of the system (recovery rating)
depends on the specified reject water flow rate. e) Operating pressure range, in MPa or psi.

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 IS 16240 : 2023

Table 1 Chemicals and Microbiological Reduction

(Clauses 6.3.2.1, 6.3.3.1 and B-1.2)

Sl No. Contaminant Influent Challenge Maximum Allowable Method of Testing

Level Product Water Level
(1) (2) (3) (4) (5)
i) Arsenic (as As), mg/litre 0.10 ± 10 % 0.01 IS 3025 (Part 37)
ii) Cadmium (as Cd), mg/litre 0.03 ± 10 % 0.003 IS 3025 (Part 41)
iii) Chromium (as Cr), mg/litre 0.30 ± 10 % 0.05 IS 3025 (Part 52)
iv) Copper (as Cu), mg/litre 3.00 ± 10 % 1.0 IS 3025 (Part 42)
v) Fluoride (as F), mg/litre 8.00 ± 10 % 1.0 IS 3025 (Part 60)
vi) Lead (as Pb), mg/litre 0.15 ± 10 % 0.01 IS 3025 (Part 47)
vii) Mercury (as Hg), mg/litre 0.006 ± 10 % 0.001 IS 3025 (Part 48)
viii) Nitrate (as NO3), mg/litre 150.00 ± 10 % 45 IS 3025 (Part 34)
ix) Pesticides total µg/litre 0.3 of each pesticide 0.1 (of each pesticide) IS 10500
0.5 (total pesticides)
x) E. coli 1.0 × 107 cfu/100 ml to 99.9999 percent reduction IS 15185
8
1.0 × 10 cfu/100 ml (LRV 6)

xi) MS-2 Coliphage (Virus) 1.0 × 104 pfu/ ml to 99.99 percent reduction Annex B of IS 10500 or
5 the USEPA method in
1.0 × 10 pfu/ ml (LRV 4)
Manual of Method for
Virology Chapter 16, June
2001
NOTES

1 Method for testing chemical reduction is given in Annex B wherein the preparation of influent challenge water is also prescribed for the test. The
testing protocol given in Annex B is to be followed along with methods of test indicated in col (5) of Table 1 for specific contaminants.
2 Method for testing microbiological reduction (for E. coli and MS-2 Coliphage) is given in Annex C wherein the preparation of influent challenge
water is also prescribed for the test. The testing protocol given in Annex C is to be followed along with methods of test indicated in col (5) of Table 1
for specific contaminants
3 For the estimation of contaminants given at Sl No. (i) to (viii) approved and validated international test methods from
ISO/APHA/ASTM/AOAC/EPA/EN may also be followed.

Table 2 Optional Requirements for Microbiological Reduction

(Clause 6.3.3.2.1)

SI No. Contaminant Influent Challenge Minimum Percent Method of Testing, Ref to

Level Reduction Required
(1) (2) (3) (4) (5)

i) Cryptosporidium parvum > 5×103/100 ml 99.9 percent (LRV 3) Annex D

3
ii) Giardia lamblia > 5×10 /100 ml 99.9 percent (LRV 3) Annex D
NOTES
1 Claims for above microbiological reduction shall be made for the specific contaminants shown in this table. To qualify for a specific contaminant
reduction claim, the system shall reduce the level of the contaminant from the influent challenge to the specified limits.
2 LRV- Log reduction value.
3 Annex D prescribes two alternative methods for evaluating the reduction of specified protozoans. The method given in D-1 shall be the referee
method in case of dispute, and either of the methods D-1 or D-2 shall be the routine method of testing.

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 IS 16240 : 2023

6.5 Electrical Safety dissolved solids. The product water shall be tested
periodically by the maintenance service provider to
6.5.1 The system shall not have excessive leakage verify the system performance after replacement of
current when tested in accordance with 13 of consumables as specified by the manufacturer.
IS 302 (Part 1).
8.2 For all filtration components like sediment filter,
6.5.2 The system shall be able to withstand high activated carbon filter and RO membrane filter,
voltage test when tested in accordance with 13 of manufacturer shall declare the maximum possible
IS 302 (Part 1). life in terms of liters of water, which can be
6.5.3 The system shall have provision for earthing in processed through each filter. Factors affecting the
accordance with 27.5 of IS 302 (Part 1). All parts of performance of the filters shall be mentioned. All
metallic construction shall be permanently and this information shall be provided in the user
reliably connected to an earthing termination within manual.
the RO system and shall be free of rough or sharp 8.3 The manufacturer shall give explicit instructions
edges or other hazards that may cause injury to in the user manual and also on the product for
persons adjusting, servicing, or using the system. cleaning and disinfecting of the storage tank by
NOTE — Class II appliances and Class III appliances shall halogenated solutions (usually chlorine) or any other
have no provision of earthing. equivalent disinfection methods. The recommended
frequency shall also be mentioned in the user
6.6 Power supply manual. This would help in prevention and control
The system shall work on electrical supply upto and of biofilm formation in the storage tank.
including 250 V, 50 Hz for single phase & upto and 9 PACKING
including 440 V, 50 Hz for three phase supply.
The RO system shall be suitably packed in order to
6.7 Pressure Test (Hydrostatic Test) — Type Test avoid damage during transit and storage.
All the components of the RO system through which 10 MARKING
the water passes shall pass the hydrostatic test as
prescribed in Annex E. 10.1 The system shall be affixed with a conformance
label meeting the following requirements, namely:
6.8 Routine Pressure Test (Pneumatic Test)
a) The label shall be durable and all the
6.8.1 Minimum 5 percent of the units of RO system markings shall be legible and indelible; and
produced per batch shall be tested by a routine b) The label shall be affixed on a part necessary
pneumatic test. for normal operation of the product and not
normally requiring replacement during the
6.8.2 Full Device Leakage Testing life of the product.
Compressed air (at a pressure 0.2 MPa) is fed 10.2 The label shall be marked with the following
through the inlet point of the device keeping all the details:
outlets shut. After the pressure reaches the
maximum, the airline is isolated by a manual valve a) Name and address of the manufacturer or
and checked for a drop in pressure over a period of assembler of product, as the case may be;
3 min. If the pressure is sustained, then this is found b) Model name or code;
to be free from any leak. c) Production serial number;
d) Date of manufacture of product;
7 SAMPLING AND CRITERIA FOR e) Rated recovery efficiency and
CONFORMITY corresponding water reject generation;
f) Production rate in litres/h;
7.1 Take samples (test systems) as per the sampling g) Maximum operating TDS level;
plan given in Annex F. h) Supply voltage whether single or three-
phase, frequency, volts and wattage; and
7.2 Test as per the sequence given in Annex F.
j) Any other requirement as given under the
7.3 All tested systems should pass in all the Environment (Protection) Rules, 1986.
requirements. In case of any failure, discontinue
further testing. 10.3 The manufacturer shall explicitly state the
following caution on the label of the RO system:
8 MAINTENANCE OF THE PRODUCT
‘RO system is not recommended for arsenic level
8.1 RO system contains a replaceable treatment above 0.1 mg/litre, fluoride level above 8.0 mg/litre
component critical for effective reduction of total and iron level above 0.3 mg/litre’.

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IS 16240 : 2023

10.4 A user manual for the proper method of Standard Mark.

operation and use of the RO system shall be supplied
along with the RO system. It shall also include the 10.6.2 The use of the Standard Mark is governed by
specifications and life/replacement frequency of all the provisions of the Bureau of Indian Standards
the filters/consumables. Act, 2016 and the Rules and Regulations framed
thereunder. The details of conditions under which
10.5 The manufacturer shall provide a suitable the licence for the use of the Standard Mark may be
warranty for the RO system. granted to manufacturers or producers may be
obtained from the Bureau of Indian Standards.
10.6 BIS Certification Marking
10.6.1 The product may also be marked with the BIS

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 IS 16240 : 2023

ANNEX A
(Clauses 6.3.1.3 and 6.4.3)
EVALUATION OF TDS REDUCTION, RECOVERY RATING AND HOURLY PRODUCTION RATE

A-1 TDS REDUCTION TESTING may be evaluated along with TDS reduction testing.
A-1.1 TDS reduction testing may be done prior to, A-2.2 Recovery Rating
or with inorganic contaminants reduction testing
described in B-1. Connect the system to the TDS influent challenge
water feed (prepared as per A-1.2) at the maximum
A-1.2 To prepare the influent challenge water for recommended inlet pressure, and allow the system
TDS reduction testing, sodium chloride (NaCl) shall to operate until the flows of product and reject water
be added to chlorine-free deionized water (Turbidity have stabilized. (If a storage tank is present, operate
pH 7.5 ± 0.5, C µS/cm, with the storage tank’s dispensing tap open.) After
Temperature 25 °C), to achieve the required the stabilization of flows, collect product water and
challenge concentration (± 10 %). the corresponding volume of reject water for one
A-1.3 Method of Testing hour of system operation. The volume of product
and reject water collected shall be recorded in litres.
Two fresh systems shall be used for TDS reduction The recovery rating shall be calculated using the
testing. following formula:
Install and condition the new RO system as per the
manufacturer’s instructions. After flushing with tap Recovery rating (%) = × 100
, T 1 NTU, ( + )
pH 7.5 ± 0.5, Iron < 0.3 mg/l), connect the system to
where
the TDS influent challenge water feed at the
maximum recommended inlet pressure. Before the VPW = volume of product water generated in
initial sampling, allow at least 10 litres of product 1 h of operation (litres); and
water to filter and drain away with the storage VRjW = corresponding volume of reject water
tank’s dispensing tap open. Then close the storage generated (litres)
tank tap and allow the tank to fill until automatic cut-
off. Collect water samples in duplicate from the NOTE — If the system has a TDS control mechanism
influent challenge water tank and the product water employing RO-bypass blending, recovery rating shall be
determined with the TDS control valve in full-closed
storage tank and analyse for TDS as per
position.
IS 3025 (Part 16).
In case of direct flow models (where no storage tank A-2.3 After collecting the samples for recovery
is provided), allow 10 litres of product water to flow testing, allow the system to operate for 2 continuous
before collecting water samples and test as per hours and record the volume of product water
IS 3025 (Part 16). collected. Hourly production rate is calculated as
follows:
A-1.4 If the system has a TDS control mechanism
employing RO-bypass blending, TDS reduction Hourly production rate (litres/hour) = Volume of
testing will be done with the TDS control valve in water collected in litres/hour
full-open position (maximum flow in the bypass
line).
A-2 RECOVERY RATING AND HOURLY
PRODUCTION RATE
A-2.1 Recovery rating and hourly production rate

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IS 16240 : 2023

ANNEX B
(Clause 6.3.2.2 and Table 1)
EVALUATION OF CHEMICAL REDUCTION
B-1 INORGANIC CONTAMINANTS recommended inlet pressure and allow at least
10 litres of product water to filter and drain away
Inorganic contaminants reduction testing may be with the storage tank tap open. Then close the
done with or subsequent to TDS reduction testing storage tank tap and allow the storage tank to fill
described in Annex A. until automatic cut-off. Collect water samples in
B-1.1 Two test systems shall be evaluated. Prepare duplicates from the influent challenge water tank
100 litres of influent challenge water for inorganic and the product water storage tank and analyse for
contaminant reduction testing, as follows: the various chemical contaminants as per
applicable parts IS 3025 as indicated in Table 1.
Prepare TDS reduction test water as per A-1.2. In case of direct flow models (where no storage
The influent challenge levels specified in Table 1 tank is provided), allow 10 litres of product water
may be achieved by adding salts in the amounts to flow before collecting water samples and test
specified in Table 3. Using NaCl, adjust the final as per the applicable parts of IS 3025.
TDS of the influent challenge water to the
required TDS challenge level (1 500 mg/litre or B-2 PESTICIDES
the maximum TDS claimed by the manufacturer B-2.1 The influent challenge water for testing
± 10 percent). pesticide reduction shall be prepared by adding
NaCl to deionized water, adjusting TDS in the
B-1.2 Method of Testing 250 mg/litre to 300 mg/litre range. Adjust pH in the
The systems previously used for TDS reduction 7.5 ± 0.5 range by adding dilute HCl or NaOH
testing may be used for inorganic chemicals solution as required. To this add appropriate
reduction testing. After flushing with tap water amount of each pesticide solution (in methanol) to
yield 0.3 µg/litre concentration of each pesticide.
pH 7.5 ± 0.5, Iron < 0.3 mg/litre), connect the system
to influent challenge water feed at the maximum

Table 3 Composition of Inorganic Contaminants Influent Challenge Water

(Clause B-1.1)
Sl No. Contaminant Influent Challenge Compound Weight of Compound
Level in 100 litres Solution

(1) (2) (3) (4) (5)

i) Arsenic as As (V) 0.1 mg/litre Na2HAsO4.7H2O 41.7 mg
ii) Cadmium as Cd 0.03 mg/litre CdCl2 anhydrous 4.9 mg
or
6.3 mg
Cd(NO3)2 anhydrous
iii) Total Chromium as Cr 0.3 mg/litre CrCl3.6H2O 77 mg
(III) and Cr (VI) [0.15 mg/litre each of and
Cr(III) and Cr(VI)] 86 mg
Na2Cr2O7.2H2O
iv) Copper as Cu 3 mg/litre CuSO4.5H2O 1.18 g
v) Fluoride as F 8 mg/litre NaF 1.77 g
vi) Lead as Pb 0.15 mg/litre PbCl2 20.1 mg
or
24.0 mg
Pb(NO3)2
vii) Mercury as Hg 0.006 mg/litre HgCl2 0.81 mg
viii) Nitrate as NO 3 150 mg/litre NaNO3 20.6 g

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 IS 16240 : 2023

B-2.2 Method of Testing influent challenge water tank and the product
water storage tank and analyse for the various
To the system previously used for inorganic pesticides as per IS 10500.
chemicals reduction testing, connect influent
challenge water prepared in B-2.1, but without In case of direct flow models (where no storage tank
pesticides added, and flush until 10 litres product is provided), allow 10 litres of product water to flow
water is produced. Then connect the system to before collecting water samples and test as per
pesticides influent challenge water at the maximum IS 10500.
recommended inlet pressure and allow at least
10 litres of product water to filter and drain away B-3 If the system has a TDS control mechanism
with the storage tank tap open. Then close the employing RO-bypass blending, all chemical
storage tank tap and allow the product water to be reduction testing will be done with the TDS control
collected in the tank until automatic cut-off. valve in full-open position (maximum flow in the
Collect water samples in duplicate from the bypass line).

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IS 16240 : 2023

ANNEX C
(Clause 6.3.3.1 and Table 1)
EVALUATION OF MICROBIOLOGICAL REDUCTION

C-1 Two fresh systems shall be used for boiling, adjust to final pH, and autoclave at
microbiological reduction testing. Bacterial 120 °C and 15 psi for 20 min. Pour the
reduction testing shall be done followed by viral tempered media into sterile Petri dishes.
reduction testing in the same RO system as per the Store the agar plates at 5 °C, but allow to
sampling plan given in Annex F. come to room temperature before use;
c) Phage top Agar - 1% TSA, pH 7.3. Dissolve
C-2 GENERAL TEST WATER TSA by boiling, adjust to final pH, and
autoclave at 120 °C and 15 psi for 20 min.
A chlorine free general test water with the following Agar shall be stored at 5 °C. On the day of
characteristics shall be used: testing, liquefy the TSA and place in a 45 °C
a) pH – 7.5 ± 0.5; water bath. The MS-2 Coliphage top agar
b) Turbidity < 1 NTU; shall be maintained at 45 °C to prevent agar
c) TDS – 400 mg/litre to 500 mg/litre (adjust solidification;
using NaCl);
d) Iron < 0.3 mg/litre; and d) Sterile Tryptic Soy Broth Medium (TSB)
e) Temperature (25 ± 5) °C Dissolve TSA by boiling and adjust to final
pH. Dispense 8 ml aliquots of TSB into
A public tap water supply may be used. TDS may be 16 mm x 150 mm test tubes. Autoclave the
adjusted by addition of NaCl (to raise TDS) or by tubes at 120 °C at 15 psi for 20 min. Store
diluting with RO treated/deionized water (to lower the cooled broth at 5 °C;
TDS). pH may be adjusted using dilute HCl or e) Sterile Saline (0.85 percent);
NaOH solution.
f) Phosphate-buffered saline (PBS);
C-3 EQUIPMENT AND ACCESSORIES g) Ethylenediamine tetra acetic acid (EDTA);
and
a) Autoclave;
b) Incubator; h) Lysozyme.
c) Laminar air flow;
d) Vortex mixer; C-5 CHALLENGE ORGANISMS
e) Vacuum pump;
f) pH meter; C-5.1 Bacterial Challenge
g) UV-Vis spectrophotometer; Escherichia coli (ATCC # 10536 or MTCC 68).
h) Centrifuge;
j) Refrigerator; The level of bacteria in the challenge water should
k) Water bath; be approximately ~ 5 x 107/100 ml, as a 7 log10
m) Colony counter; concentration is required for determining 6 log10
n) Membrane filters of ; reduction. The quantity of bacteria in a sample is
p) Sterile polycarbonate membrane filters of expressed as colony forming units (cfu)/100 ml.
0.22 µ;
C-5.2 Viral Challenge
q) Sterile filtration apparatus;
r) Sterile syringes and forceps; MS-2 Coliphage (ATCC #15597-Bl)
s) Pipettes;
Escherichia coli (ATCC #15597) host strain for
t) Petri dishes;
MS-2
u) Test tubes 16 mm x 150 mm; and
v) Sterile centrifuge tubes. Coliphage presence in ground water is an indication
of faecal contamination. The quantity of Coliphage
C-4 REAGENTS AND MEDIA in a sample is expressed as plaque forming units
(pfu)/ml. The procedure of stock culture
a) Sterile Coliform Chromogenic Agar preparation, preparation of challenge water and
/Sterile MacConkey Agar Medium/M- quantification of MS-2 Coliphage plaques are given
Endo agar/ Eosin Methylene Blue agar; below.

b) Tryptic Soy Agar Medium (TSA) - The level of MS-2 Coliphage lysate in the viral
1.5 percent, pH 7.3. Dissolve TSA by challenge water should be about ~ 5 x 105 pfu/ml.

10
 IS 16240 : 2023

C-6 PREPARATION OF c) Prepare serial dilutions of MS-2 Coliphage

MICROBIOLOGICAL CHALLENGE WATER suspension in sterile PBS. Plate 10-5 to 10-12
dilutions (1 ml dilution per plate) in
C-6.1 Bacterial Influent Challenge Water
triplicate on 1.5% TSA plates. In a sterile
C-6.1.1 Bacterial Stock Culture Preparation tube, transfer 1 ml of diluted MS-2
Coliphage. Then quickly add 0.1 ml of E.
E. coli cultures in stationary growth phase shall be
coli host to ~ 5 ml of melted 1 percent TSA.
washed and suspended in phosphate-buffered saline Vortex to mix inoculum and media and pour
before challenge water preparation:
on the 1.5 percent TSA basal plates, with
a) E. coli is grown overnight on tryptic soy rocking to spread the inoculum evenly. After
agar (TSA) slants and checked using the 1 percent TSA layer has solidified, the
MacConkey’s agar or equivalent selective plates shall be inverted and incubated at
media (M-Endo agar, Eosin Methylene Blue 37 °C for 15 h to 18 h;
agar) for confirmation; d) Select the plates that show complete lysis of
b) The culture is then transferred to a TSB tube host bacterial cells by the MS-2 Coliphage.
for 15 h to 18 h and incubated at 37 °C; Flood the surface of each plate with 3 ml of
TSB, and remove the 1 percent TSA layer
c) The resultant suspension is subjected to gently using a cell scraper. Pour the contents
three cycles of centrifugation-resuspension into two sterile 50 ml centrifuge tubes and
in 0.85 percent sterile saline (Eppendorf make up the total volume to 40 ml with TSB.
3 000 x g for 4 min at room temperature). Add 0.2 g EDTA and 0.026 g lysozyme to
The bacterial pellet is washed and re each tube. Incubate at room temperature for
suspended in sterile saline (0.85 %) to get 2 h, mixing every 15 min;
OD between 0.8 to 1.0 = 600 nm. This
corresponds to a viable count of about e) After incubation, the tubes shall be
109 cfu/ml; and centrifuged at 9 280 x g for 5 min, or
2 320 x g for 20 min, at 20 °C. Collect the
d) Alternatively, the culture could be recovered resulting supernatant taking care to avoid the
from the overnight plate directly in sterile pellet. A sterile 47 mm filtration assembly
saline (taking care not to scrape out agar) with a 0.22 shall be
and the OD adjusted to 0.8 to 1.0 at aseptically constructed. Wash the filter with
= 600 nm. 10 ml of TSB broth just prior to the filtration
C-6.1.2 To prepare 100 litres challenge water, add to minimize MS-2 Coliphage adsorption to
appropriate quantities of the bacterial suspension in the filter. Filter the supernatant; and
the general test water described in C-2, for a final g) The MS-2 Coliphage suspension is to be
bacterial count between 107 ml to 108/100 ml. The titrated as in C-6.2.2. The concentration of
actual cell numbers are verified by the counts of MS-2 Coliphage should be 1010 to
colony forming units (cfu). 1012 pfu/ml.
C-6.2 Viral Influent Challenge Water
C-6.2.2 Enumeration of MS-2 Coliphage plaques
C-6.2.1 Viral Stock Culture Preparation
a) Thaw a cryogenically frozen E. coli ATCC
This section describes the propagation and
host strain and inoculate 0.1 ml of the stock
harvesting methods for stock suspensions of MS-2
suspension in one TSB tube. Incubate the
Coliphage for use as a challenge suspension. The
TSB tube at 37 °C for 15 h to 18 h;
stock preparation procedure may have to be repeated
multiple times to achieve the required volume of b) Liquefy 1 % TSA and temper in a 45 °C
MS-2 Coliphage challenge water. water bath. Prepare room temperature
1.5 percent TSA plates;
a) One day prior to preparation of MS-2
Coliphage stock, thaw a cryogenically c) Serial dilutions of MS-2 Coliphage
frozen E. coli host strain (ATCC #15597). suspension shall be made using sterile
Inoculate one TSB tube with 0.1 ml of the PBS. 10 -7 to 10-12 dilutions (1 ml dilution
stock suspension and incubate at 37 °C for per plate) shall be plated in triplicate on
15 h to 18 h; 1.5 % TSA plates. In a sterile tube, 1 ml of
diluted MS-2 Coliphage shall be
b) For preparing MS-2 Coliphage stock, liquefy transferred. Add 0.1 ml of E. coli cells
1percent TSA and temper the media in a quickly to ~ 5 ml of melted 1 % TSA. The
45 °C water bath. Prepare 1.5 percent TSA inoculum and media shall be vortexed and
plates, which should be at room temperature poured on TSA plates, with rocking plates to
prior to use; spread inoculum evenly. After the 1percent

11
IS 16240 : 2023

TSA layer has solidified, the plates shall be stored at (5 ± 3) °C. Analysis should be commenced
inverted and incubated at 37 °C for 15 h to on the same day as sample collection.
18 h; and
C-8.1.2 For enumeration, serial dilutions of the
d) After incubation, plates containing 20 to 200
influent and product water samples (100 to 10-5) shall
distinct plaque forming units (pfu) shall be
be made using sterile PBS.
enumerated using a Colony Counter. The
MS-2 Coliphage suspension titer shall be
C-8.1.3 Method of enumeration shall be as specified
calculated by multiplying the number of pfu
in col (5) of Table 1.
obtained by the inverse of the dilution factor.
The concentration of MS-2 Coliphage
C-8.1.4. The E. coli suspension titer shall be
should be 1010 to 1012 pfu/ml.
calculated by multiplying the number of cfu
obtained by the inverse of the dilution factor. Results
C-6.2.3 To prepare 100 litres challenge water, use
shall be expressed as the number of cfu/100 ml.
appropriate quantities of the viral suspension in the
general test water specified in section C-2, for a final
C-8.1.5 Use appropriate positive and negative
viral count between 104 to 105 pfu/ ml, verified by
controls to eliminate errors due to bacterial strain,
the counts of plaque forming units (pfu) in a colony
diluent or culture media.
counter.

C-7 METHOD OF CHALLENGING RO TEST C-8.2 Enumeration of MS2 Coliphage Plaques in

SYSTEMS AND SAMPLE COLLECTION Influent and Product Water Samples

C-7.1 Install and condition the new RO system as C-8.2.1 Virological water samples should be stored
per the manufacturer’s instructions. After flushing at (5 ± 3) °C. Analysis should be commenced on the
with general test water, connect the system to the same day as sample collection.
microbiological influent challenge water feed at the
maximum recommended inlet pressure and allow at C-8.2.2 Serial dilutions of the influent and
least 10 litres of product water to filter and drain product water samples (100 to 10-5) shall be made
using sterile PBS. 100 to 10 -5 dilutions shall be
away with the product water storage tank tap open.
plated in duplicate on 1.5 percent TSA plates. In
Then close the storage tank tap and allow the tank to a sterile tube, 1 ml of diluted MS-2 Coliphage
fill until automatic cut-off. In case of direct flow shall be transferred. Then quickly add 0.1 ml of E.
models (where no storage tank is provided), allow coli host to ~ 5 ml of melted 1 percent TSA. Vortex
10 litres of product water to flow before collecting the inoculum and media and pour on TSA base
samples. plates with rocking to spread the inoculum evenly.
After the 1 percent TSA layer has solidified, the
plates shall be inverted and incubated at 37 °C for
C-7.2 Collect 500 ml of water samples from the 15 h to 18 h.
influent challenge water tank and the product water
storage tank in duplicate and analyse for the C-8.2.3 After incubation, plates containing 20 to
200 distinct plaque forming units (pfu) shall be
microbiological contaminants as per methods
enumerated using a Colony Counter. The MS-2
specified in 5, Table 1. Coliphage suspension titer shall be calculated by
multiplying the number of pfu obtained by the
For direct flow models, collect product water
inverse of the dilution factor. Results shall be
samples from the outlet faucet. expressed as the number of pfu/ ml.

C-7.3 If the system has a TDS control mechanism C-8.3 Challenge Verification
employing RO-bypass blending, all microbiological
reduction testing will be done with the TDS control After the appropriate incubation period for MS-2
valve in full-open position (maximum flow in the Coliphage and E. coli, the colonies shall be counted
bypass line). on all of the density determination plates. The mean
number of microorganisms per ml for plates with 25
C-8 ANALYSIS OF WATER SAMPLES FOR to 250 colonies/plaques shall be calculated. This
MICROBIOLOGICAL REDUCTION shall verify that the challenge organism was present
TESTING in the challenge test water at the optimum
concentration before conducting the challenge
C-8.1 Enumeration of E. coli in Influent and reduction test.
Product Water Samples

C-8.1.1 Bacteriological water samples should be

12
 IS 16240 : 2023

C-9 DETERMINATION OF LOG10 C-10 SAFETY PRECAUTIONS AND

REDUCTION HAZARDS
The bacterial or viral log reduction is calculated as a) Steam sterilized samples and equipment
follows: shall be handled with protective gloves
Input Load = ____cfu/100 ml or when being removed from the autoclave;
pfu/ml b) Cryogenic culture vials shall be handled
Log10 (Input) = ____ with cryoprotective gloves; and
Output Load (mean) = ____cfu/100 ml or c) All microbiological samples and
pfu/ml contaminated test supplies shall be steam-
Log10 (Output) = ____ sterilized to 120 °C at 15 psi for a minimum
Log10 Reduction = Log10 (Input) – Log10 of 20 min prior to being discarded.
(Output)

( – )
Percentage reduction = X

100

13
IS 16240 : 2023

ANNEX D
(Clauses 6.3.3.2.1 and Table 2)
EVALUATION OF MICROBIOLOGICAL REDUCTION - SPECIFIED PROTOZOANS USING
INACTIVATED CYSTS AND MICROSPHERES

D-0 GENERAL f) Filtration assembly with vacuum pump; and

g) Fluorescent microscope.
Cryptosporidium and Giardia are often identified
during waterborne disease outbreaks. As they are D-1.2 Preparation of Challenge Water
less sensitive than most bacteria and viruses to
conventional drinking water treatment methods, Prepare 50 litres of challenge water per testing unit
they are ideal candidates for protozoa group containing 50 000 oocysts/litre (or 5 ×104/litres), as
representation. This method, based on size follows:
exclusion principle, prescribes the use of
irradiated cysts of Cryptosporidium parvum or a) Based on the initial count of the cysts (as
fluorescent polystyrene microspheres of similar given on the vial), prepare 100 ml to 150
physical dimensions [> 95 percent in the ml of a working stock suspension using
(3.0 ± 0.15) range] for the evaluation of 0.01 percent polysorbate 20 as diluent, to
removal of protozoans (Cryptosporidium, Giardia obtain the target number of 50 000
lamblia, Entamoeba histolytica) or their oocysts (the oocysts/litre in 50 litres challenge water.
resistant stage in the life cycle of waterborne Vials containing the cysts should be
protozoa that may be found in surface drinking washed thrice with 0.01 percent
water supplies and includes oocysts of polysorbate-20 followed by rinsing thrice
Cryptosporidium and Toxoplasma and cysts of with distilled water; and
Giardia and Entamoeba). The method given at D-1
b) Add the working stock of cysts to 50 litres
shall be the referee method in case of dispute and
of test water (C-2); mix well and aliquot a
either of the methods given at D-1 or D-2 may be
100 ml sample of challenge water for
used as the routine method of test.
analysis from the influent (feed water) tank.
D-1 REDUCTION OF INACTIVATED
D-1.2.1 Analysis of Challenge Water Samples
CRYPTOSPORIDIUM PARVUM OOCYSTS
a) Assemble the membrane holder with 25 mm
D-1.1 Requirements
membrane filter in the filtration assembly
and check that there is no leakage;
a) Commercially available suspension of
b) Filter 5 ml* of the challenge water sample
inactivated (by irradiation or formalin
and wash the membrane and holder with
treatment) Cryptosporidium parvum oocysts
1 ml of 0.01 percent polysorbate 20
containing a minimum of
followed by distilled water; and
400 000 oocysts/10 ml;
c) Proceed for staining as per the
b) Stock polysorbate-20 (0.1 percent solution)
manufacturer’s instructions in the staining
— Prepare a 0.1 percent stock solution of
kit.
polysorbate-20 (tween-20 or equivalent) by
dispersing 1 ml polysorbate-20 in 900 ml
D-1.2.2 Collection of Product Water Samples
deionized water and make up the volume to
1 000 ml;
a) After flushing the test unit with tap water
c) Working solution of polysorbate-20 (0.01 500 mg/litre 1 NTU,
percent solution) — Dilute the stock of
pH (7.5 ± 0.5), iron (< 0.3 mg/litre),
polysorbate 20 with deionized water in a
connect the system to the influent
1 : 10 ratio to get the working solution; challenge water feed at the maximum
d) Staining kit — Fluorescent antibody staining
recommended inlet pressure and allow at
kit containing: least 10 litres of product water to filter and
1) Stain; drain away with the product water storage
2) Wash buffer;
tank tap open. Then close the storage tank
3) Positive control; and
tap and allow the tank to fill until
4) Mounting medium. automatic cut-off. (In direct flow models
e) Membrane filters — 25 mm,
without storage tanks, allow 10 litres of
0.4

14
 IS 16240 : 2023

product water to flow out before collecting D-2 REDUCTION OF MICROSPHERES

samples.);
D-2.1 General
b) Collect 1 litre of product water samples in
triplicates from the delivery point of the For water purification systems that rely on physical
system, in sample dilution bottles containing filtration processes (for example, exclusion and
1 ml of 1 percent polysorbate-20; and adsorption-based technologies), testing for the
required log reduction of polystyrene microspheres
c) All the samples should be refrigerated until may be used to demonstrate the ability to remove
analysis. Cryptosporidium oocysts, if the use of inactivated
cysts is not feasible. The polystyrene microspheres
D-1.2.3 Product Water Sample Analysis shall have 95 percent of particles in the range of
(3.00 ± 0.15)
a) Assemble the membrane holder with 25 mm
membrane filter in the filtration assembly;
The RO systems tested should demonstrate a
b) Conduct a leak test to check that there is no minimum of 3 log10 reduction (99.9 percent
leakage from the assembly by filling the reduction).
assembly completely with distilled water
and wait for 10 min. Make sure that the D-2.2 Requirements
water does not come out from the filter;
a) 0.1 percent polysorbate 20;
c) In separate filter assemblies, filter 200 ml
each from the 3 product water samples b) Neutral charged fluoresbrite YG carboxy
through a 25 mm membrane filter by microspheres (3.0 ± 0.15)
applying vacuum (the sample size should be available as 5 ml vial containing minimum
such that the final slide will have 20-200 1 × 1011 spheres/ml), or equivalent;
cysts). Rinse the filtration assembly funnel c) Membr
with 0.01 percent polysorbate 20 followed
by distilled water; d) Filtration assembly with vacuum pump; and

d) Proceed with staining as per the kit protocol; e) Fluorescent microscope.

and
D-2.2.1 Influent Challenge Water Preparation
e) Observe and count the stained oocysts under
20/40x objective using a fluorescent a) Prepare 50 litres of spike water per device
microscope. containing 50 000 microspheres/litre
(or 5 × 104/litre);
D-1.3 Results and Computation
b) Based on microsphere counts/litre as
Record the number of oocysts on the slides of provided by the supplier, prepare a working
challenge and product water samples and convert stock of 100 ml to 150 ml using 0.01 percent
them into oocysts per liter of sample as follows: Polysorbate as diluent, for spiking 50 litres
a) Oocysts/litre of challenge water sample = of water to achieve a final number as
No. of cysts in 5 ml of sample × 200 50 000 microspheres/litre;
b) Oocysts/litre of product water sample =
Average no. of cysts counted in the three c) Add the working stock of microspheres to
200 ml samples × 5 50 litres of water; mix well and aliquot
100 ml sample of influent challenge water
D-1.3.1 Expression as log10 Value for analysis from the influent (feed water)
tank; and
Cysts log10 reduction = log10 (cysts/L of input
10 (cysts/L of output sample) d) All the samples should be refrigerated until
analysis.
The water purifier must demonstrate 3 log10
reduction in Cryptosporidium oocysts, which
corresponds to 99.9 percent reduction.

15
IS 16240 : 2023

D-2.2.2 Challenge Water Sample Analysis b) Conduct a leak test to check that there is no
leakage from the assembly by filling the
a) Assemble the membrane holder with 25 mm assembly completely with distilled water
membrane filter in the filtration assembly and wait for 10 min. Make sure that the
and check that there is no leakage; water does not come out from the filter;
c) In separate filter assemblies, filter 200 ml
b) Pass 10 ml of challenge water sample and each from the 3 output water samples
wash the membrane and holder with 1 ml of through a 25 mm membrane filter by
0.01 percent polysorbate 20 followed with applying vacuum. Rinse the filtration
distilled water; assembly funnel with 0.01 percent
polysorbate-20 followed by distilled water;
c) Add a drop of mounting medium on a clean
slide and keep the filter membrane on the d) Add a drop of mounting medium on a clean
slide and add cover slip; slide and keep the filter membrane on the
slide and add cover slip;
d) Slides should be stored in a covered
container (dry box, that is, in dark e) Slides should be stored in a covered
condition); container (dry box, that is, in dark
condition);
e) Slides should be observed microscopically
within 5 days of preparation, after which the f) Slides should be observed microscopically
fluorochrome dye begins to fade; and within 5 days of preparation; and
f) Observe the slide and count the spheres g) Observe and count the microspheres
under 20/40x objectives, using a fluorescent microscopically, as in D-2.2.2.
microscope.
D-2.3 Calculation
D-2.2.3 Product Water Sample Collection
D-2.3.1 Microspheres per litre of Samples
a) After flushing the test unit with tap water
litre
Record the microspheres on the slides of challenge
pH (7.5 ± 0.5), iron (< 0.3 mg/litre),
and product water samples and calculate their
connect the system to the influent
numbers per litre of samples as follows:
challenge water feed at the maximum
recommended inlet pressure and allow at
a) Microspheres/litre of challenge water
least 10 litres of product water to filter and
sample = No. of microspheres in 10 ml of
drain away with the product water storage
sample × 100; and
tank tap open. Then close the storage tank
tap and allow the tank to fill until
b) Microspheres/litre of product water sample
automatic cut-off. (In direct flow models
without storage tanks, allow 10 litres of = No. of microsphere in 200 ml (average of
product water to flow out before collecting 3 counts) of sample × 5.
samples.);
D-2.3.2 Expression as log10 Value
b) Collect 1 litre of product water samples in
triplicates from the delivery point of the Microsphere log10 reduction =
system, in sample dilution bottles containing
1 ml of 1 percent polysorbate-20; and log10 (Microspheres/litre of challenge water sample)
c) All the samples should be refrigerated until log10 (Microspheres/litre of product water sample)
analysis.
The RO system should demonstrate a minimum of
D-2.2.4 Product Water Sample Analysis 3 log10 reduction which corresponds to 99.9 percent
reduction.
a) Place the membrane in the filtration
assembly;

16
 IS 16240 : 2023

ANNEX E
(Clause 6.7)
HYDROSTATIC PRESSURE TEST

E-1 Hydrostatic pressure test of the completely hydrostatic testing of Zone 2, the pressurization
assembled RO system shall be conducted in 3 stages, shall be increased slowly at a constant rate to reach
with differentiation of zones for different the testing pressure in 5 min and held at that pressure
pressurization conditions (Refer Fig. 1 for Flow path for 15 min.
of wall-mounted/table top Reverse Osmosis System
and Fig. 2 for Flow path of under-counter Reverse There shall not be any leakage of water, water
Osmosis System). bubbles or a hissing sound, when the pressurization
of Zone 2 is held for 15 min. Release the pressure by
E-2 TESTING OF ZONE 1 opening the open/close valve and turn off the
pressurization pump.
The components of the RO system from the inlet
port up to the booster pump comprise the low- E-4 TESTING OF ZONE 3
pressure zone. This zone shall be subjected to
hydrostatic pressure at 1.5 times of the maximum Zone 3 covers the path of the water from the inlet of
input water pressure recommended by the any post-RO filter to the product water discharge
manufacturer. outlet.
For RO systems that are open to atmosphere
Before commencing the test, attach an open/close
(Fig. 1), Zone 3 is to be pressurized at a moderate
valve followed by a non-return valve (NRV) at a
pressure of 0.2 MPa (30 psi).
point before the end of the booster pump inlet.
Connect the system to a test water trough using a For RO systems that have a hydro-pneumatics
manual pressurization pump. (pressurized) storage tank for product water (Fig. 2),
Zone 3 is to be pressurized at 1.5 times the back
Initially, purge the system with available tap water pressure exerted by the tank.
(< 1 NTU turbidity), allowing at least 2 litres to
3 litres of permeate water to flow. Then close the The pressurization shall be increased slowly at a
open/close valve and slowly increase the pressure at constant rate to reach the testing pressure in 5 min
and held at that pressure for 15 min.
a constant rate to reach 1.5 times of maximum
recommended pressure in 5 min. Hold at this There shall not be any leakage of water, water
pressure for 15 min, and observe the components bubbles or hissing noise, when the pressurization of
and tubing at joints. Zone 3 is held for 15 min. Release the pressure by
opening the open/close valve and turn off the
There shall not be any leakage of water, water pressurization pump.
bubbles or hissing noise when the pressurization E-5 TESTING OF HYDROPNEUMATICS
is held for 15 min. Release the pressure by STORAGE TANK
opening the open/close valve and turn off the
pressurization pump. The testing requirement is 1.5 times the pressure of
the tank declared by the manufacturer.
E-3 TESTING OF ZONE 2
The pressurization has to be done by closing the
Zone 2 is the high-pressure zone, from the inlet of water faucet or tap emerging from the tank. The
the booster pump up to the permeate outlet of the RO pressurization shall be increased slowly at a
membrane and flow-restrictor or any other valve in constant rate to reach the testing pressure in 5 min
the reject water line. This zone shall be tested at a and held at that pressure for 15 min.
pressurization of at least 1.5 times of the pressure
exerted by the booster pump. There shall not be any leakage of water, water
bubbles or hissing noise, from the storage tank inlet
The testing laboratory shall initially measure the
transmembrane pressure when the booster pump is when pressurization is held for 15 min. Release the
pressure by opening the open/close valve and turn
switched on and accordingly calculate 1.5 times the
off the pressurization pump.
pressure. This shall be the testing pressure. For

17
IS 16240 : 2023

FIG. 1 WATER FLOW PATH OF WALL MOUNT/TABLE TOP REVERSE OSMOSIS SYSTEM

18
 IS 16240 : 2023

FIG. 2 WATER FLOW PATH OF UNDER COUNTER REVERSE OSMOSIS SYSTEM

19
IS 16240 : 2023

ANNEX F
(Clause 7)
SAMPLING PLAN FOR RO SYSTEM
F-1 Randomly select 4 sample units of Reverse recovery rating, chemical, and microbiological
Osmosis (RO) based Point-of-Use (PoU) water contaminants reduction, as per methods described in
treatment system from the same batch. All RO Annexes A, B and C respectively.
systems of the same capacity produced under similar
condition of manufacturing in a week shall F-4 Collect influent and product water samples for
constitute a batch. To ensure the randomness of analysis as per the sequence and frequency below.
selection, methods given in IS 4905 may be F-5 Allow at least 10 litres of product water after
followed. every sequence to wash out the previous set of
F-2 Use two units for microbiological reduction contaminants.
tests and two for chemical contaminants, TDS F-6 All water samples shall be collected in
reduction testing, recovery rating and hourly duplicates, although only one of which may be
production rate evaluation. subjected to analysis, with the other being retained
F-3 Conduct the testing for TDS reduction and for verification if required.

Parameters Day 1 Day 2 Day 3 Day 4 Day 5 No. of Units Tested

Sl No.
(1) (2) (3) (4) (5) (6) (7) (8)
i) TDS 2 (new)
ii) Recovery rating and hourly
2
production rate
iii) Inorganic contaminants 2
iv) Pesticides 2

v) Microbiological parameters
1) E. coli 2 (new)
2) MS2 Coliphage

20
 IS 16240 : 2023

ANNEX G
(Foreword)
COMMITTEE COMPOSITION
Water Purification Systems Sectional Committee, FAD 30

Organization Representative(s)

CSIR - National Environmental Engineering DR P. K. LABHASETWAR (Chairperson)

Research Institute, Nagpur

Bhabha Atomic Research Centre, Mumbai DR S. T. PANICKER

SHRI T. K. DEY (Alternate)

Bhavan's Research Center (Microbiology), DR SANDHYA SHRIVASTAVA

Mumbai
DR NISHITH DESAI (Alternate)
CSIR - Central Food Technological Research DR UMESH HEBBAR
Institute, Mysore
SHRI KESHAVA MURTHY. P (Alternate)

CSIR- Central Salt and Marine Chemicals DR V. K. SHAHI

Research Institute, Bhavnagar

CSIR - Institute of Minerals and Materials DR JAYANT KUMAR POTHAL

Technology, Bhubaneswar
SHRI DEBABRATA S INGH (Alternate)

CSIR - National Environmental Engineering DR NOOR AFSHAN KHAN

Research Institute, Nagpur
DR PRANAV NAGARNAIK (Alternate)
Christian Medical College, Vellore PROF VENKATA RAGHAVA MOHAN
DR DILIP ABRAHAM (Alternate)

Confederation of Indian Industry, New Delhi SHRI J. S. K. SRINIVASAN

MS MAMTA ARORA BUDHIRAJA (Alternate)

Consumer Education and Research Centre, MS ANINDITA MEHTA

Ahmedabad
MS KARUNA CHAUHAN (Alternate)

Consumer Electronics and Appliances SHRI SRINIVASAN MOTURI

Manufacturers Association, Noida
SHRI ADITYA ANIL (Alternate)
Department of Science and Technology, New DR RAJIV K. TAYAL
Mehrauli Road, New Delhi
DR NEELIMA ALAM (Alternate)
Development Alternatives, New Delhi DR K. VIJAYA LAKSHMI
MS NEHA AGGARWAL (Alternate)

Federation of Indian Chambers of Commerce and MS KIRTIKA ARORA

Industry, New Delhi

21
IS 16240 : 2023

Organization Representative(s)

Indian Institute of Technology Delhi, New Delhi PROF SHAIKH ZIAUDDIN AGAMMAD

Indian Institute of Technology Madras, Chennai PROF T. PRADEEP

DR LIGY PHILIP (Alternate)

Indian Plumbing Association, New Delhi SHRI MUKESH ASIJA

Indian Water Works Association, Mumbai DR M. S. SATYANARAYANA

SHRI ANIL KUMAR GUPTA (Alternate)
Ministry of Environment Forest and Climate DR SONU SINGH
Change, New Delhi
SHRI P. K. MISHRA (Alternate)
Ministry of Jal Shakti, New Delhi DR D. RAJASHEKHAR

National Chemical Laboratory, Pune DR ULHAS KHARUL

National Institute of Cholera and Enteric Diseases, DR SHANTA DUTTA

Kolkata
SHRI ASISH K. MUKHOPADHYAY (Alternate)
National Institute of Virology, Pune DR KAVITA LOLE
DR SHAILESH PAWAR (Alternate)
Safe Water Network, New Delhi SHRI RAVINDRA SEWAK
SHRIMATI POONAM SEWAK (Alternate I)
DR SHVETA MAHAJAN (Alternate II)
Water Quality India Association, Mumbai DR NEERAJ GUPTA
In Personal Capacity (Villa #69, Skanda Avani
DR T. N. V. V. RAO
Layout, Hadosiddapura, off Sarjapur Road,
Bangalore -560035)

In Personal Capacity (ICMR NIRTH Complex,

DR TAPAS CHAKMA
Jabalpur - 482003)

BIS Directorate General SHRIMATI SUNEETI TOTEJA, SCIENTIST ‘E’/DIRECTOR AND

HEAD (FOOD AND AGRICULTURE)[REPRESENTING
DIRECTOR GENERAL (Ex-officio)]

Member Secretary
SHRIMATI N ITASHA DOGER
SCIENTIST ‘D’/JOINT DIRECTOR
(FOOD AND AGRICULTURE), BIS

22
 IS 16240 : 2023

Panel for reviewing the Indian Standard on Reverse Osmosis Based Point of Use Water Treatment System for
Drinking Purposes, FAD 30/Panel 1

Organization Representative(s)
In Personal Capacity (Villa #69, Skanda Avani
DR T. N. V. V. RAO (Convenor)
Layout, Hadosiddapura, off Sarjapur Road,
Bangalore -560035)

CSIR-Central Salt and Marine Chemicals Research DR V. K. SHAHI

Institute, Bhavnagar

Safe Water Network, New Delhi DR SHVETA MAHAJAN

Water Quality India Association, Mumbai DR NEERAJ GUPTA

In Personal Capacity (534, 29th Main, 11th cross,
DR S. MURALIDHARA RAO
HSR layout 1 St sector, Bangalore 560102)

23
Bureau of Indian Standards

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