DEAS 123 : 2021  
ICS 71.040.30  
© EAC 20 21                                                                                                               Second  Edition  2021   
 
 DRAFT EAST AFRICAN STANDARD  
Distilled water — Specification  
EAST AFRICAN COMMUNITY  
 
 
 
 
 
 
 
 
 DEAS 123: 2021  
ii © EAC 20 21 – All rights reserved  
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may be p rosecuted . DEAS 123 : 2021  
iii 
 Foreword  
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged th at through harmonized 
standardization, trade barriers that are encountered when goods and services are exchanged within the Community 
will be removed.  
The Community has established an East African Standards Committee (EASC) mandated to develop and issue 
East African Standards (EAS) and other deliverables. The Committee is composed of representatives of the 
National Standards Bodies in Partner States, together with the representatives from the public and private sector 
organizations in the community.  
East African Standards are developed through Technical Committees that are representative of key 
stakeholders including government, academia, consumer groups, private sector and other interested parties. 
Draft East African Standards are circulated to stakeholde rs through the National Standards Bodies in the Partner 
States. The comments received are discussed and incorporated before finalization of standards, i n accordance 
with the p rinciples and procedures for development of East African Standards.  
East African  Standards and other deliverables are subject to review, to keep pace with technological advances. 
Users of the East African Standards are therefore expected to ensure that they always have the latest versions 
of the standards they are implementing.  
The c ommittee responsible for this document is  Technical Committee EASC/TC 069 , Organic and Inorganic 
chemicals.  
Attention is drawn to the possibility that some of the elements of this document may be subject of patent rights. 
EAC shall not be held responsible for identifying any or all such patent rights.  
This second  editio n cancels and rep laces the first edition (EAS 123 :1999 ), which has been technically revised.  
 
 
 DEAS 123 :2021    
 
© EAC 20 21 – All rights reserved  
  
 Distilled water  — Specification  
1 Scope  
This Draft  East African Standard prescribes the requirements , sampling  and test methods for distilled water.  
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references , only the edition cited applies. For undated references, the latest edition of the referenced document 
(including any amendments) applies.  
ISO 3696 Water for lead acid batteries – Specification  
EAS 121, Water for lead -acid batteries — Specification ,  
3 Terms and definitions  
No terms and definitions are listed in this document. ISO and IEC maintain terminological databases for use in 
standardization at the following addresses: — ISO Online browsing platform: available at 
http://www.iso.org/obp  
4 Requirements  
4.1 General  requirements  
The distilled water  shall be the water purified by thermal distillation or any other suitable means, such  as ion 
exchange. It shall be clear, colourless, odourless and tasteless.  
 
4.2 Specific requirements  
The distilled water  shall comply with specific  requirements given in Table 1  when tested according to the 
methods  prescribed . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
2 
 Table - 1: Specific requirements for distilled water.  
 
S/No.  Characteristic  Requirements  Test method  
i)  Non-volatile residue at 105 °C,  
mg/kg max.  10 B.2 
ii)  pH 6.5 – 7.5 B.3 
iii)  Chlorides , mg/kg, max 1 B.4 
iv)  Sulfate , mg/kg, max . 2 B.5 
v)  Calcium, mg/kg, max 5 B.6 
vi)  Magnesium, mg/kg, max 1 B.7 
vii)  Heavy metals, mg/kg , max.  1 B.8 
viii)  Ammonia, mg/kg, max  1 B.9 
ix)  Carbon dioxide  To pass test  B.10 
x)  Oxidizable matter  To pass tes t B.11 
xi)  Iron, mg/kg, max.  1 B.7 
xii)  Specific conductivity μS/cm  at 27  °C, 
max.  0.2 ISO 3696   
 
5 Pack aging  
 
The distilled water shall be packed in securely closed suitable containers that will ensure the integrity of the 
product.  
 
6 Labelling  
Each package  shall be legibly and indelibly labelle d in English and/or any other official language (French,   
Kiswahili, etc) used in the importing East African Partner State with the following information:  
 
a) name  of the product as “ distilled water” ; 
b) manufacturer’s name and physical address ;  
c) net content  in litre s  
d) country of origin ; 
e) batch number or lot number.  
f) date of manufacture and best before date   
 
7 Sampling  
Sampling shall be done in accordance with Annex A. 
 
  
3 
 Annex A  
(Normative)  
Sampling of bulk supplies of water, distilled quality  
 
A.1 General requirements of sampling  
A.1.1 In drawing, preparing, storing and handling samples, the following precautions and directions  shall be 
observed.  
A.1.2 Samples shall not be taken in an exposed place.  
A.1.3 The sampling instrument shall be clean. Before use, these shall be washed several times with  the material 
to be sampled.  
A.1.4 Precautions shall be ta ken to protect the samples, the material being sampled, the sampling  instruments 
and the containers for samples from adventitious contamination.  
A.1.5 To draw a representative sample, the contents of each container selected for sampling shall  be mixed 
thoroughly as possible by suitable means.  
A.1.6 The samples shall be placed in clean airtight glass bottles or other suitable containers on  which the 
material has no action and which have previously been washed several times with the  material to be sampled.  
A.1.7 The sample containers shall be of such a size that they are filled by the sample leaving an  ullage of 10 
%. 
A.1.8 Each sample container shall be sealed airtight after filling, and marked with full details of  sampling, the 
date of sampling and the year of manufacture of the distilled water . 
 
A.2 Scale of sampling  
A.2.1 All containers in a single consignment of the distilled water  drawn from a single batch of  manufacture shall 
constitute a lot. If a consignment is declared or known to consist of different  batches of manufacture, the batches 
shall be marked separately and the groups of containers in each  batch constitute a separate lot.  
 
A.2.2 For ascertaining conformity of distilled water  in a lot to the requirement of this standard, samples  shall be 
tested for each lot separately. The number of containers to be selected at random from lots of  different sizes 
shall be in accordance with Table 2.  
 
Table 2 – Number of containers to be selected for sampling (See A.2.2)  
 
Lot size  
N 
 Number of containers  
to be selected  
n 
 
3 to 15   
 3 
16 to 40  
 4 
41 to 65   
 5 
66 to 110   
 7 
111 and above   
 9  
4 
  
A.3 Preparation of test samples  
A.3.1 From each of the containers select according to A.2.2 equal portions of the distilled water  shall be  taken 
out so that the total quantity collected from all the containers is about 18 L. This shall be the  composite sample.  
 
A.3.2 The composite sample shall be divided into three test samples not less than 2 L each. These  test samples 
shall be transferred immediately to thoroughly washed bottles which are sealed airtight  with glass stoppers and 
marked with the particulars of sampling as given in A.1.8. One test sample  shall be sent to the purchaser and 
one to the vendor. The third test sample bearing the seals of the  purchaser and the vendor shall constitute the 
referee sample, to be used in case of dispute.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
5 
 Annex B  
(Normative)  
Analysis of distilled water  
B.1 Quality of reagents  
 
Unless specified otherwise, analytical grade chemicals and distilled water complying to ISO 3696   
shall be used in tests.  
 
B.2 Determination of non -volatile residue at 105 °C ± 2 °C  
B.2.1 Procedure  
Evaporate to dryness 500 ml of the sample in a weigh ed container, adding the sample in instalments , if 
necessary.  
B.2.2 Calculation  
Non-volatile residue at 105 °C, mg/kg = 2 m  
where  
m mass in mg of the dried residue.  
 
B.3 Determination of pH  
B.3.1 Methods  
The determination shall be carried out either by the electrometric method or by the indicator method.  In case 
of dispute the electrometric method shall be adopted.  
B.3.2 Test temperature  
The determination shall be made at room temperature and the sample shall be collected and tested in  an 
atmosphere reas onably free from carbon dioxide.  
B.3.3 Electrometric method  
The determination shall be made by using a pH meter with glass electrode.  
 
B.3.3 Indicator method  
B.3.3.1 Reagents  
B.3.3.1.1 Bromocresol purple , pH range s 5.2 to 6 .8 and colour change yellow to bl ue violet.  
B.3.3.1.2 Bromothymol blue , pH range s 6.0 to 7. 6 and colour change yellow to blue.  
B.3.3.2 Procedure  
Take 10 ml of the sample in two hard glass test tubes and add 0,5 ml of the two indicators, one to each tube. 
Compare the colour produced with a series of buffer t ubes of known pH in the range 6. 0 to 7.0. Report as pH, 
the pH of the buffer solution, which gives the closest match with the colour, produced by the sample.  
B.3.4 Apparatus  
Standard calibrated glass discs may also be used  for determination of pH.  
B.4 Test for chloride  
B.4.1 Apparatus  
Nessler tubes , 100 ml capacity.  
B.4.2 Reagents   
6 
 B.4.2.1 Dilute nitric acid , approximately 5 M. 
B.4.2.2 Silver nitrate , approximately 0.5 M. 
B.4.2.3 Standard chloride solution. Dissolve 0.164 9 g of sodium chloride in water and make up  to 1 000 ml. 
One millilitre of this solution is equivalent to 0.1 mg of chloride (as Cl).  
B.4.3 Procedure  
Transfer 100 ml of the sample into a Nessler tube. Add 1 ml of dilute nitric acid and 1 ml of silver nitrate solution. 
Carry out a control test in another Nessler tube using 100 ml of water (which does not give any opalescence 
with dilute nitric acid and silver nitrate), 0.1 ml of standard chloride solution, one ml  of dilute nitric acid and 1 ml 
of silver nitrate solution. Mix both the solutions and observe after 3 min. The sample shall be taken to have 
passed the test if any opalescence produced in the test with the sample is not greater than that produced in the 
control test.  
 
B.5 Test for sulfate  
B.5.1 Apparatus  
Nessler tube , 100 ml capacity.  
B.5.2 Reagents  
B.5.2.1 Dilute hydrochloric acid, approximately 1 M. 
B.5.2.2 Barium chloride, approximately 0.5 M. 
B.5.3 Procedure  
Transfer by means of a pipette 100 ml of the sample into the Nessler tube. Add 1 ml of dilute hydrochloric acid 
and then 1 ml of barium chloride solution to it and mix well. The sample shall be taken to have passed the test 
if no turbidity is produced within 12 min.  
 
B.6 Test for calcium  
B.6.1 Apparatus  
Nessler tube, 100 ml capacity  
B.6.2 Reagent  
Ammonia oxalate solution , dissolve 3.5 g of ammonium oxalate in 100 ml of water.  
B.6.3 Procedure  
Transfer by means of a pipette 100 ml of the sample into the Nessler tube. Add 2 ml of ammo nium  
oxalate solution and mix well.  The sample shall be taken to have passed the test if no turbidity is produced 
within 5 min.  
 
B.7 Test for magnesium  
B.7.1 Reagents  
B.7.1.1 Titan yellow solution , dissolve 0.1 g of titan yellow (also known as clayton yellow or thiazole yellow) 
in 100 ml of water.  
B.7.1.2 Sodium hydroxide solution , approximately 5 M. 
Transfer 10 ml of the sample into it test tube and add 0.2 ml of titan yellow solution and 4 ml of  
sodium hydroxide solution.  
The distilled water  shall be taken to have passed the test if no red colour or precipitate is produced.  
  
7 
  
B.8 Test for heavy metals  
B.8.1 Apparatus  
Nessler tubes , 100 ml capacity.  
B.8.2 Reagents  
B.8.2.1 Dilute acetic acid, approximately 1 M 
B.8.2.2 Hydrogen sulfide solution , freshly made and saturated.  
B.8.3 Procedure  
Transfer 40 ml of the sample into one of the Nessler tubes. Add 1 ml of dilute acetic acid and 10 ml of hydrogen 
sulfide solution. Carry out a control test in another Nessler tube by taking 40 ml of sample and 1 ml of dilute 
acetic acid. Compare the colour of the solution in both the tubes after 10 min. The sample shall be taken to have 
passed the test if the intensity of colour, if produced, in the Nessler tube containing hydrogen sul fide solution is 
not deeper than that produced in the control test.  
 
B.9 Test for ammonia  
B.9.1 Apparatus  
Nessler tubes, 100 ml capacity.  
B.9.2 Reagents  
B.9.2.1 Nessler reagent  
Dissolve 10 g of potassium iodide in 10 ml of ammonia free water and add to it slowly, with stirring, saturated 
mercury (II) chloride solution until a slight permanent precipitate forms. Add 30 g of potassium hydroxide and 
when it has dissolved, add 1 ml more of mercury (II) chloride solution. Dilute to 200 ml with water (ammonia -
free). Allow to settle overnight, decant the clear solution and keep the solution in the bottle closed with a well -
fitting rubber stopper.  
B.9.2.2 Standard ammonia chloride solution  
Dissolve 3.15 g of ammonium chloride in sufficient water to produce 1000 ml. Dilute 10 ml of this solution with 
water to 1 000 ml.  
B.9.3 Procedure  
B.9.3.1 Transfer 10 ml of the sample into a Nessler tube and add five drops of Nessler reagent. Carry out a 
control test in the other Nessler tube using 2 ml of standard ammonium chloride solution, dilute to 100 ml and 
add 5 drops of Nessler reagent. Shake and compare the colour after 3 min. The sample shall be taken to have 
passed the test if the intensity of c olour produced with the sample is not greater than that produced in the control 
test. 
B.9.3.2 Alternatively, permanent standard glass colour disc may be used for the determination.  
 
B.10 Test for carbon dioxide  
B.10.1 Apparatus  
Nessler tube , 50 ml capacity . 
B.10.2 Reagents  
Calcium hydroxide solution , saturated  
B.10.3 Procedure  
Transfer 25 ml of the sample into the Nessler tube. Add 25 ml of calcium hydroxide solution and mix  well.  
8 
 The sample shall be considered to have passed the test if no turbidity of pre cipitate is produced within  5 min.  
 
 
B.11 Test for oxidizab le matter  
B.11.1 Reagents  
B.11.1.1 Dilute sulfuric acid , 1 M. 
B.11.1.2 Potassium permanganate solution , 0.002 M. 
B.11.2 Procedure  
Transfer 100 ml of the sample into a beaker. Add 10 ml of dilute sulfuric acid and 1 ml of potassium  
permanganate solution. Boil for 10 min.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
9 
 Bibliography  
EAS 123:2006,  Distilled water –Specification