DKS 1941 – 1: 2017 
            
DRAFT KENYA STANDARD 
 
 
 
 
 
 
 
   
Scouring compounds for utensil cleaning— 
Specification      
Part 1: Dishwashing paste  
 
 
 
 
 
  
 
 
  
 
 
 
  
 
 
 
  
JULY 2017 
 
 
 
© KEBS 2017        Second Edition 2017 
 
 
  DKS 1941 – 1: 2017  
© ECK 2017 — All rights reserved  ii  
TECHNICAL COMMITTEE REPRESENTATION 
 
The following organizations were represented on the Technical Committee: 
 
PZ Cussons  Unilever Kenya 
Colgate-Palmolive
 
Orbit Chemicals 
Kenya Industrial Research and Development Institute 
Government Chemist’s Department 
University of Nairobi 
Consumer Information Network Pwani Oil Refineries 
Diversey East & Central Africa 
BIDCO Africa Ltd. Reckitt Benckiser  
MEP Chemicals 
Kenya Bureau of Standards — Secretariat  
 
 
  
 
 
 
 
REVISION OF KENYA STANDARDS 
 
In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed. Suggestions 
for improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards, 
are welcome. 
 
 
 
  
 
 
© Kenya Bureau of Standards, 2017 
  
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 12 of 2001  of the Laws of Kenya, copyrig ht 
subsists in all Kenya Standards and except as provided under Section 26 of this Act, no Kenya Standard produced by Kenya Bureau  of 
Standards may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in w riting 
from the Managing Director. 
 
  
 
  
 
 
                                       DKS 1941 – 1: 2017 
© KEBS 2017 — All rights reserved  iii 
  
 
Scouring compounds for utensil cleaning—
Specification
   
Part 1: Dishwashing paste  
 
 
 
  
 
 
 
KENYA BUREAU OF STANDARDS (KEBS) 
 
Head Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254 020) 605490, 602350, Fax: (+254 020) 604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org   
 
Coast Region    Lake Region         Rift Valley Region  
P.O. Box 99376, Mombasa-80100  P.O. Box 2949, Kisumu-40100       P.O. Box 2138, Nakuru-20150 
Tel.: (+254 041) 229563, 230939/40               Tel.: (+254 057) 23549, 22396       Tel.: (+254 051) 210553, 210555 
Fax: (+254 041) 229448   Fax: (+254 057) 21814  
 
 
 
 DKS 1941 – 1: 2017  
© ECK 2017 — All rights reserved  iv  
Foreword 
 
This Kenya Standard was developed by the Technical Committee on Surface Active Agents under the 
guideline of the Standards Project Committee, and is in accordance with the procedures of the Kenya Bureau 
of Standards. 
 
Dishwashing bars are used to remove grease from dishes, pots, pans, glasses and cutlery.  Surfactants and 
builders are the major components of dishwashing bars. Other ingredients (builders) are added to provide a 
variety of functions, such as increasing cleaning performance for specific soils/surfaces, ensuring product 
stability and supplying a uni que identity to a product. 
 
Surfactants (surface active agents) are organic chemic als that change the properties of water. By lowering 
the surface tension of water, surfactants enable the cleaning solution to wet a surface so that soil can be 
readily loosened and removed. Surfactants also emulsify oily soils.  Builders enhance and maintain the 
cleaning efficiency of the surfactant. The primary function of builders is to reduce water hardness. Complex 
phosphates and sodium citrate are common builders. Builders can also maintain alkalinity, which assists 
cleaning, especially of acid soils; help keep removed soil and emulsify oily and greasy soils. 
 
During the preparation of this standard, reference was made to the following documents:  
 
KS 1941-1: Dishwashing paste – Specification 
IS 6047: Scouring products for utensil cleaning- Specification  
Acknowledgement is hereby made for assistance derived from these sources. 
 
 
 
 
  
 
 
 
 
  
 
  
 
 
 
  
 
 
 
  
 
 
               
     KENYA STANDARD                           DKS 1941 – 1: 2017 
KEBS 2017 — All rights reserved  1 
Scouring compounds for utensil cleaning  — Specification 
Part 1: Dishwashing paste  
 
1 Scope 
This Kenya Standard prescribes the requirements and methods of test for dishwashing paste.  
This standard does not cover antibacterial dishwashing paste and dishwashing bar. 
 
2  Normative references  
 
This Kenya Standard incorporates by dated and undated reference, provisions from other publications.  
These normative references are cited at the appropriate place in the text and the publications are listed  
hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply  
to this Kenya Standard only when incorporated in it by amendment or revision. For undated references the  
latest edition of the publication referred to applies. 
 
KS ISO 456, Surface active agents — Analysis of soaps — Determination of free caustic alkali  
KS ISO 685, Analysis of soap — Determination of alkali content and total fatty matter content  
KS ISO 4315, Surface active agents -- Determination of alkalinity -- Titrimetric method 
KS ISO 2870,  Surface active agents — Detergents — Determi nation of anionic-active matter hydrolysable 
and non-hydrolysable under acid conditions  
KS ISO 2871-1, Surface active agents — Detergents — Determination of cationic-active matter content — 
Part 1: High-molecular-mass cationic-active matter  
KS ISO 2871-2, Surface active agents — Detergents — Determination of cationic-active matter content — 
Part 2: Cationic-active matter of low molecular mass (between 200 and 500) KS ISO 672, Soaps — Determination of moisture and volatile matter content — Oven method 
KS ISO 4317, Surface-active agents and detergents — Determination of water content — Karl Fischer 
methods  
KS EAS 814,  Determination of biodegradability of surfactants — Test method  
 
3 R equirements  
 
3.1 General 
 
3.1.1 The paste shall be water-based and shall consist essentially of an abrasive together with a  
surfactant, and may contain alkaline salts.  3.1.2 The paste shall be smooth, and shall be uniformly mixed. It shall not be irritating to the normal skin, and  
it shall not contain ingredients in quantities that are toxic to human beings. 
 3.1.3 When the paste is stored or transported under normal conditions in its original package, no cracking of 
the material shall occur. 
 3.2 Biodegradability   
The active ingredient used shall pass the biod egradability test as given in KS EAS 814. 
 
3.3 Odour  
 
The dishwashing paste, both as received and when dissolved in hot water, shall not have objectionable odour.  
 
 
3.5 DETAILED REQUIREMENTS .  
 
In addition to the above requirements, the dishwashing paste shall also comply with the relevant requirements   
© KEBS 2017 — All rights reserved  2given in Table 1. 
 
Table 1: Detailed requirements 
 
 
 
  
 
  
 
  
 
  
 
   
 
  
 
4. Packaging and Marking 
 
4.1 Packing   
 4.1.1  The dishwashing paste shall be so packed as to prevent  drying out and contamination of the 
product. 
 
4.1.2  It shall be packed in containers that are strong enough to withstand normal usage and 
transportation.  
 
4.2 Marking  
 
Each package and bulk package shall bear in prominent, legible, and indelible marking the following 
information,  
 
i) Name of the product i.e. dishwashing paste  
ii) manufacturer’s name and physical address 
 
NOTE   The name, physical address of the distributor/supplier and trade mark may be added as required 
 
iii) Nominal weight of the product at the time of packaging. 
 
iv) List of ingredients 
 
v) Instructions for use 
 
vi) Date of manufacture  
 
vii) Best before date 
 
viii) In the case of bulk packages, the number of packets.  
 
ix) Country of origin  
 Sl. No Characteristic Requ irement Method of test  
1)  Free alkali content* (as sodium 
hydroxide) % (m/m), max.  0.1 KS ISO 456 
2)  Total alkalinity* (as sodium 
hydroxide) % (m/m), max.  14 KS ISO 685 
KS ISO 4315 
3)  Active (reserve) alkalinity in mL, max.  20 Annex A 
4)  Active detergent*, % (m/m), min. 12 KS ISO 2870 
KS ISO 2871-1 
KS ISO 2871 -2 
5)  Water insoluble matter content*, % 
(m/m), max 55 Annex B 
6)  Moisture and volatile matter 
content*,at  105 ºC % (m/m), max 35 KS ISO 672 
KS ISO 4317 
7)  Fineness of water insoluble matter 
retained on a 250- µm aperture sieve 
% (m/m), max.   
0.1 Annex C 
8)  Lather volume, in mL, min 70 Annex D 
*On the dishwashing paste as received  
© KEBS 2017 — All rights reserved  3 
Annex A 
(normative) 
Determination of active (Reserve alkalinity) 
 
A.1 Principal 
 
Reserve alkalinity is expressed as amount of 0.1 N hydr ochloric acid in ml required for 50ml of 1 percent 
solution of product sample to lower its pH to 8.0.  
A.2 Apparatus 
 
A.2.1 pH meter  A.2.2 Beaker , 250-ml and 100-ml capacity. 
 
A.2.3 Magnetic stirrer 
 
A.2.4 Burette 
 
A.3 Reagents 
 
Hydrochloric acid, 0.1 N. 
 
A.4 Procedure 
 Weigh accurately 1.0 g of sample in a 250-ml beaker. Add 100 ml of distilled water and dissolve the sample. 
Filter through Whatman filter paper No. 42 and collect t he filtrate. Pipette out 50 ml of filtrate in a 100 ml 
beaker. Place the beaker on a magnetic stirrer and mix thoroughly. Note down the pH of the solution using 
pH meter. With the electrode of pH meter dipping in solution and keeping the pH meter on, add drop by drop 
of 0.1 N hydrochloric acid from a burette till the pH of the solution drops to 8.0. While adding hydrochloric 
acid stir the solution continuously. Note the amount of hydrochloric acid required to bring down the pH of solution 8.0 which is a measure of the reserve alkalinity of the test sample. 
 
NOTE : Average of 2 replicate measurements will give reserve alkalinity expressed as amount in ml of 0.1 N hydrochloric acid.  
© KEBS 2017 — All rights reserved  4Annex B 
(normative) 
 
Determination of Water insoluble matter content of Dishwashing paste   
 
B.1 Procedure  
 
B.1.1 Starting with a fresh portion of the material, weigh accurately about 5 g of the material into a 
beaker, and digest with 50 ml of ethyl alcohol by heating on a steam bath for about 2 min. Stir and 
break up any hard lump with a glass rod flattened at one end. Allow the solid matter to settle and decant the hot alcoholic solution through a sintered glass filter funnel fitted to a Buchner flask, 
to which suction is applied. Repeat the alcoholic digestion in a similar manner with five further 
consecutive 30-ml portions of boiling ethyl alcohol. Filter each extract in turn through the same 
sintered glass funnel and, finally, wash the residue several times with hot ethyl alcohol to remove all the alcohol solubles. Dry the sintered glass funnel with the residue in an air-oven at a 
temperature of 105 °C ± 2 °C until a constant mass is obtained. 
 
B.1.2 Even after digestion with five 30-ml portions of boiling ethyl alcohol, the alcohol insoluble portion 
may sometimes be found to be sticky. In that case, treat it further with more boiling ethyl alcohol 
until it is free from active matter and the alcohol insoluble portion is no longer sticky. Do not dry or weigh the matter insoluble in alcohol. After filtering and washing the residue thoroughly with hot 
ethyl alcohol, change the receiver, extract the residue with successive portions of distilled water at 
about 60 °C, and wash the residue several times to remove all the water solubles. Dry the sintered glass funnel with the residue in an air-oven at a temperature of 105 °C ± 2 °C until a constant mass 
is obtained. 
 
B.2 Calculation 
 
The matter insoluble in water is expressed as follows:  
 
Matter insoluble in water, % by mass = 100 m1
 
m 
 
where  
 
m1     is the mass, in grams, of matter insoluble in water; and  
 
m    is mass, in grams, of material taken for the test. 
 
  
© KEBS 2017 — All rights reserved  5 
Annex C 
(normative) 
 
Fineness of water insoluble matter dishwashing paste (Metric units ) 
 
C.1 Apparatus 
 C.1.1 Sieve  A nest of standard sieve of diameter 200 mm, and another of nominal aperture size 250 µm. 
 
C.1.2 Oven  A dying oven capable of being maintained at 105 ± 5 
oC. 
 
C.2. Procedure 
 
C.2.1 Weigh out 50.0 g of the test sample into a beaker and add 200 ml of water.  Heat on a water bath, 
with frequent stirring, until all the soluble salts are dissolved. 
 C.2.2 Assemble the nest of sieves in the correct order with the 250 µm aperture sieve at the top and the 
200 µm aperture at the bottom.  Pour the mixture on to the top sieve and transfer the residue quantitatively to 
this sieve by washing the beaker several times with water. 
 
C.2.3 Using a fine stream of tap water, wash the insoluble matter through the sieves.  Continue this 
washing until the amount of any residue on the top sieve appears to remain constant.  
C.2.4 If there is any residue on the top sieve, remove the sieve, stand it in a basin, and continue washing 
the material on it for a further 2 min.  Transfer any furt her material that passes this sieve to the bottom sieve.  
Repeat the washing of the top sieve and the transfer of ma terial until no further material passes through after 
2 min.  C.2.5 Repeat this procedure on the bottom sieve but discard any material that passes through. 
 
C.2.6 Dry each sieve and its contents in the oven at 105 ± 5 
oC.  Allow them to cool and, using a camel-
hair brush, transfer the contents of each sieve quantitatively to separate tarred, glass dishes and determine the masses of the residues. 
 
C.3  Calculation 
 
Water insoluble matter retained on any particular sieve, % (m/m) of the total water insoluble  
 
matter = 
CBA
10000 
 
Where  A = mass of the insoluble matter on the sieve, g 
B = mass of the test sample used, g 
C = water insoluble matter present in the test sample, % (from Annex B) 
 
  
© KEBS 2017 — All rights reserved  6 
Annex D  
(normative) 
 
Test for lather volume 
D.1 General 
Strict attention shall be paid to all details of the procedure in order to ensure concordant results. Particular 
care should be taken to invert the cylinder exactly as described. 
D.2 Outline of the method 
A suspension of the material in standard hard water is taken in a graduated cylinder and given 12 inversions 
under prescribed conditions. The volume of the foam formed is observed after keeping the cylinder for 5 min. 
D.3 Reagents 
D.3.1  Calcium chloride CaCl 2.2H 2O, AR 
D.3.2  Magnesium sulphate MgSO 4.7H 2O, AR 
D.3.3  Distilled water  
D.4 Apparatus 
D.4.1  Graduated cylinder  — Glass stoppered with graduation from 0 ml - 250 ml, with 2-ml divisions. 
Overall height about 35 cm and the height of the graduated portion about 20 cm. 
D.4.2  100-ml glass beaker  
D.4.3  Thermometer  of range 0 ºC – 110  ºC 
D.5 Preparation of standard hard water 
Dissolve 0.220 g of calcium chloride dehydrate and 0.24 6 g of magnesium sulphate heptahydrate in distilled 
water. Dilute to 5 l with distilled water. 
 
NOTE This standard hard water has a hardness of approximately 50 mg/kg calculated as calcium 
carbonate. 
D.6 Sample preparation 
Cut away the outer edges of bathing bar using a knife. 
Using a stand up type of grater, grate up to 10 g – 15 g of the bathing bar into small chips. 
D.7 Procedure   
D.7.1 Weigh 1 g of the grated chips accurately in a 100-ml glass beaker. Add 10 ml of the standard hard 
water. Cover the beaker with a watch glass and allow to stand for 30 min. The operation is carried out to 
disperse the antibacterial bathing bar. D.7.2 Stir the contents of the beaker with a glass rod and transfer the slurry to a 250-ml graduated cylinder 
ensuring that not more than 2 ml foam is produced. Repeat the transfer of the residue left in the beaker with 
further portions of 20 ml of standard hard water ensuring that all the matter in the beaker is transferred to the 
cylinder.  
© KEBS 2017 — All rights reserved  7D.7.3 Adjust the contents in the cylinder to 100 ml by adding sufficient standard hard water. Bring the 
contents of the cylinder to 30 ºC. Stir the contents of the cylinder with a glass rod or thermometer to ensure a 
uniform suspension. 
D.7.4 As soon as the temperature of the contents of the cylinder reach 30 ºC, stopper the cylinder and give 
it 12 complete inversions, each inversion comprising movements in a vertical plane, upside down and vice 
versa. After the 12 inversions, let the cylinder stand for 5 min. Take the following readings as shown in Figure A.1: 
1. a) foam plus water ( V
1 ml). 
2. b) water only ( V2ml). 
 
Figure A.1 — Measurement of foam 
D.8 Calculation 
Lather volume = V1 - V2 
 
Where  
V
1  = Volume, in millilitres of foam + water; 
V2   = Volume, in millilitres of water only.