FOR COMMENTS ONLY FINAL  DRAFT UGANDA 
STANDARD  
  FDUS EAS 766-2 
Second  Edition  
2013-mm-dd 
 
 Reference number  
FDUS EAS 766-2: 2013 
© UNBS 201 3 
  
Antibacterial toilet soap — Specification — Part 2: Liqu id 
 FOR COMMENTS ONLYFDUS EAS 766-2: 2013  
ii                © UNBS 2013 - All rights reserved 
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2013 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala 
Uganda 
Tel: 256 41 505 995 
Fax: 256 41 286 123 
E-mail: unbs@infocom.co.ug  
Web: www.unbs.go.ug  
 FOR COMMENTS ONLYFDUS EAS 766-2: 2013  
© UNBS  2013 - All rights reserved                iii National foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Tourism, Trade and 
Industry established under Cap 327 , of the Laws of Uganda. UNBS is mandated to co-ordinate the elaboration 
of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agreements of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council. 
This Final Draft Uganda Standard, FDUS EAS 766-2 : 2013 , Antibacterial toilet soap — Specification — Part 2 : 
Liquid , is identical with  and has been reproduced from an East African  Standard , EAS 766-2: 2013 , 
Antibacterial toilet soap — Specification — Part 2: Liqui d, and is being proposed for adoption as a Uganda 
Standard.  
 
This standard cancels and replaces US EAS 766:2011 which has been technically revised. 
Wherever the words, “ East African Standard" appear, they should be replaced by "Uganda Standard." 
 
  FOR COMMENTS ONLY EAS 766-2 : 2013 
ICS 71.100.40 
© EAC 2013                                                                                                                              First Edition 2013  
 
EAST AFRICAN STANDARD 
Antibacterial toilet soap — Specification ― Part 2: Liquid  
EAST AFRICAN COMMUNITY FOR COMMENTS ONLYFOR COMMENTS ONLYEAS 766-2 : 2013  
ii © EAC  2013  – All rights reserved  
 Copyright notice 
This EAC document is copyright-protected by EAC. While the reproduction of this document by 
participants in the EAC standards development process is permitted without prior permission from EAC, 
neither this document nor any extract from it may be reproduced, stored or transmitted in any form for 
any other purpose without prior written permission from EAC. 
Requests for permission to reproduce this document for the purpose of selling it should be addressed 
as shown below or to EAC’s member body in the country of the requester:  
© East African Community 2013  — All rights reserved 
East African Community  
P.O.Box 1096 
Arusha 
Tanzania 
Tel: 255 27 2504253/8 
Fax: 255 27 2504481/2504255 
E-mail: eac@eachq.org 
       Web: www.eac-quality.net 
Reproduction for sales purposes may be subject to royalty payments or a licensing agreement. 
Violators may be persecuted FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  iii 
 Contents Page 
Foreword ............................................................................................................................................................  iv 
1 Scope  ................................ ................................ ................................ ................................ ...................... 1 
2 Normative references  ................................ ................................ ............................................................  1 
3 Terms and definitions  ................................ ................................ ...........................................................  1 
4 Requirements  ................................................................ ................................ ................................ ......... 2 
4.1 General requiremen ts ................................ ................................ ...........................................................  2 
4.2 Specific quality requirements  ................................ ................................ ................................ .............. 2 
6 Packaging and marking  ................................ ................................ ................................ ........................ 2 
6.1 Packaging  ................................ ................................ ................................ ................................ ............... 2 
6.2 Marking  ................................ ................................ ................................ ................................ ................... 2 
7 Sampling  ................................ ................................ ................................ ................................ ................ 3 
8 Criteria for con formity ................................ ................................ ...........................................................  3 
Annex A (normative)  Permitted antibacterial agents ..................................................................................... 4  
Annex B (normative)  Determination of Trichlorocarbanilide (TCC) and TricIosan (TCN) in soaps 
by HPLC .................................................................................................................................................. 5  
B.1 Principle  ................................ ................................ ................................ ................................ ................. 5 
B.2 Normal phase HPLC  ................................ ................................ ..............................................................  5 
B.2.1  Reagents  ................................ ................................ ................................ ................................ ................ 5 
B.2.2  Apparatus  ................................ ................................ ................................ ................................ ............... 5 
B.2.3  Procedure  ................................ ................................ ................................ ................................ ............... 6 
B.2.4  Calculation  ................................................................ ................................ ................................ ............. 6 
B.3 Reverse phase  ................................................................ ................................ ................................ ....... 7 
B.3.1  Reagents  ................................ ................................ ................................ ................................ ................ 7 
B.3.2 Apparatus  ................................ ................................ ................................ ................................ ............... 7 
B.3.3  Procedure  ................................ ................................ ................................ ................................ ............... 7 
B.3.4  Calculations  ................................................................ ................................ ................................ ........... 8 
Annex C (normative)  Determination of chloroaniline .................................................................................... 9  
C.1 Principle  ................................ ................................ ................................ ................................ ................. 9 
C.2 Safety precautions  ................................ ................................ ................................................................  9 
C.3 Reagents  ................................ ................................ ................................ ................................ ................ 9 
C.4 Apparatus  ................................ ................................ ................................ ................................ ............. 10 
C.5 Procedure  ................................ ................................ ................................ ................................ ............. 10 
C.6 Determination of chloroanilines  ................................ ................................ ................................ ........ 11 
C.7 Calculations  ................................................................ ................................ ................................ ......... 11 
Annex D (normative)  Sampling ...................................................................................................................... 13 
D.1 Procedure  ................................ ................................ ................................ ................................ ............. 13 
D.2 Preparation of test samples  ................................ ................................ ................................ ............... 13 
D.2.1  Composite sample  ................................ ................................................................ ...............................  13 
D.2.2  Samples for testing  ................................ ................................ .............................................................  13 
 FOR COMMENTS ONLYEAS 766-2 : 2013  
iv © EAC  2013  – All rights reserved  
 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 that through 
harmonized standardization, trade barriers that are encountered when goods and services are exchanged 
within the Community will be removed.  
In order to achieve this objective, the Community established an East African Standards Committee mandated 
to develop and issue East African Standards.   
The Committee is composed of representatives of the National Standards Bodies in Partner States, together 
with the representatives from the private sectors and consumer organizations. Draft East African Standards 
are circulated to stakeholders through the National Standards Bodies in the Partner States. The comments 
received are discussed and incorporated before finalization of standards, in accordance with the procedures 
of the Community. 
East African Standards 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 standard s 
they are implementing .  
EAS 766-2 was prepared by Technical Committee EAS/TC 0 74, Surface active agents .EAS 766 consists of 
the following parts, under the general title Antibacterial toilet soap — Specification —: 
Part 1: Solid.  
Part 2: Liquid.  
 FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  v 
 Introduction 
Human skin provides a favourable environment for the existence and multiplication of a variety of microbes. 
The conventional toilet soap washes away the germs but does not kill them. The function of an antibacterial or 
antiseptic toilet soap is not only to clean the skin, but also to reduce drastically the bacterial count on the skin. 
This prevents skin infections and perspiration odour caused by the decomposition of perspiration by bacteria. 
Antibacterial toilet soap is a toilet soap that has antibacterial agents incorporated into it.  It not only cleans the 
skin, but also reduces drastically the bacterial count on the skin.  This prevents skin infections and 
perspiration odour caused by the decomposition of sweat by bacteria. The antibacterial toilet soap is specially 
effective against staphylococcus  and similar bacteria which have the habit of residing in the under layers of 
the skin. The antibacterial soaps have to be used regularly to be effective. 
In this revision, hexachlorophene has not been permitted to be used as antibacterial agent. The 
Trichlorocarbanilide (TCC) on heating decomposes to chloroanalines which are harmful to skin hence the limit 
and method for determination of chloroanaline is included. Use of other antibacterial agents not included in 
Annex A will be considered when need arises as long as their safety is assured. 
 
 FOR COMMENTS ONLYFOR COMMENTS ONLYEAST AFRICAN STANDARD  EAS 766-2: 2013  
 
© EAC 2013  – All rights reserved  1 
 Antibacterial toilet soap — Specification ― Part 2: Liquid  
1 Scope 
This East African Standard specifies the requirements, and methods of sampling and test for liquid 
antibacterial toilet soap. It includes antibacterial (bacteriostatic) and antifungal (fungal static). 
This standard does not cover synthetic hand wash liquid detergents, shampoo and products for specific 
purposes such as those for industrial and surgical uses. 
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. 
EAS 127, Synthetic laundry detergents for household use — Specification   
EAS 377-1 , Cosmetics and cosmetics products — Part 1: List of substances prohibited in cosmetic products  
EAS 377-2 , Cosmetics and cosmetics products — Part 2: List of substances which cosmetic products must 
not contain except subject to restrictions laid down  
EAS 377-3 , Cosmetics and cosmetics products — Part 3: List of colourants allowed in cosmetic products 
EAS 377-4 , Cosmetics and cosmetics products — Part 4: List of preservatives allowed in cosmetic products 
EAS 377-5 , Cosmetics and cosmetics products — Part 5: Use of UV filters in cosmetic products  
EAS 794 Determination of the microbial inhibition of cosmetic soap bars and liquid hand and body washes — 
Test method  
ISO 456, Surface active agents — Analysis of soaps — Determination of free caustic alkali 
ISO 685, Analysis of soap — Determination of alkali content and total fatty matter content 
ISO 673, Analysis of soap — Determination of matter insoluble in ethanol  
ISO 862, Surface active agents — Vocabulary  
3 Terms and definitions 
For the purposes of this standard  the terms and definitions given in  ISO 862 apply. FOR COMMENTS ONLYEAS 766-2 : 2013  
2 © EAC  2013  – All rights reserved  
 4 Requirements 
4.1 General requirements 
4.1.1 The antibacterial soap shall consist of essentially of an aqueous solution of potassium soaps, sodium 
soaps or both, made from oils, fatty acids or their mixture. It shall be a homogeneous, clear, translucent or 
opaque liquid with good lathering and cleaning properties. It may contain permissible synthetic detergents. 
4.1.2 The liquid antibacterial soap shall quickly form a satisfactory lather while in use.  
4.1.3 The liquid antibacterial soap shall remain as homogeneous stable product and shall show no sign of 
separation or sedimentation when kept at 5 °C for 24 h. 
4.1.4 The liquid antibacterial soap shall contain permitted antibacterial agent in accordance with Annex A.   
4.1.5 The liquid antibacterial soap shall pass the antibacterial activity test when determined by the method 
given in EAS 794. 
4.1.6 All the substances used in the liquid antibacterial soap shall comply with the requirements of all parts 
of EAS 377. 
4.1.7 Liquid antibacterial toilet soap shall pass the test for dermatological safety.   
4.2 Specifi c quality requirements 
Liquid antibacterial toilet soap shall also comply with the specific quality requirements specified in Table 1. 
Table 1 — Specific quality requirements for liquid antibacterial toilet soap 
SI No.  Characteristic  Requirement  Test m etho d  
i.  Total fatty matter, % by mass,  min 15.0 ISO 685  
ii.  Free caustic alkali, (K 2O), % by mass, max.  0.03 ISO 456  
iii.  Synthetic detergents, % by mass, max.  2.0 EAS 127  
iv.  Matter insoluble in alcohol, % by mass,  max 5 ISO 673  
v.  Antibacterial agent TricIosan (TCN ) and 
Trichlorocarbanilide (TCC), % by mass,  max 1 either singly or in combination  Annex B  
vi.  Chloroaniline content, ppm, max  10 Annex C  
vii.  Phosphate  absent  EAS 127  
NOTE  Trichlorocarbanilide (TCC) is not heat stable and decom poses into chloro anilines on pro longed heating above 
60 °C. If TCC is used in soap, the manufacturer should take care that such soap is not subjected to temperature above 
60°C during the entire manufacturing process or during storage.  
 
6 Pack aging and marking 
6.1 Pack aging 
The antibacterial soap shall be packed in protective containers that will not allow for damage of the product or 
its contamination. 
6.2 Marking 
Each container shall be marked legibly and indelibly with the following particulars: FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  3 
 a) name of the product as “antibacterial toilet soap” ;  
b) manufacturer’s name and physical address ;  
NOTE The name, physical address of the distributor/supplier and trade mark may be added as required. 
c) net content; 
d) batch number or lot number ;  
e) date of manufacture and best before date ;  
f) Total Fatty Matter content (TFM); 
g) country of origin; 
h) the antibacterial agent used and its level; and 
i) list of ingredients in descending order of quantity 
7 Sampling 
Sampling shall be done in accordance to Annex D. 
8 Criteria for conformity 
The lot shall be deemed to comply with the requirements of this standard if, after inspection and testing, the 
requirements of Clause 4 and 5 are satisfied.  FOR COMMENTS ONLYEAS 766-2 : 2013  
4 © EAC  2013  – All rights reserved  
 Annex A 
(normative) 
 
Permitted antibacterial agents 
The following is the list of antibacterial agents used generally in antibacterial soap:  
a) Triclosan (TCN); 
b) Trichlorocarbanilide (TCC); 
c) Zinc oxide;  
d) Chloro xylenols; 
e) Plant extracts; 
f) Any other internationally accepted antibacterial agent. FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  5 
 Annex B 
(normative) 
 
Determination of Trichlorocarbanilide (TCC ) and TricIosan (TCN) in 
soaps by HPLC 
B.1 Principle 
TCC and TCN are antibacterial agents, which are separated from other components in soap by normal phase 
or reverse phase liquid chromatography, detected spectrophotometrically and quantified by comparison with 
standard TCC and TCN. The method can estimate as low as 1 ppm of the above compounds: 
Procedures for both normal and reverse HPLC has been described and provide the option to use either 
method whichever is available to the users. Both methods are comparable. 
B.2 Normal phase HPLC 
B.2.1 Reagents 
B.2.1.1 Iso-octane , HPLC grade 
B.2.1.2 Iso-propanol (2-propanol) , HPLC grade 
B.2.1.3 Hexane , HPLC grade 
B.2.1.4 Standard TCC , 99 % pure 
B.2.1.5 Standard TCN , 99 % pure 
B.2.2 Apparatus 
B.2.2.1 High Performance Liquid Chromatograph consisting of a pump, a sample injector of fixed 
volume with UV detector having variable wavelengths and a recorder 
B.2.2.2 Standard volumetric flasks  
B.2.2.3 Pipettes 
B.2.2.4 Magnetic stirrer 
B.2.2.5 Millipore filter apparatus  with 0.5 micron filter  
B.2.2.6 Column , comprising:  
a) Silica column , stainless steel 25 cm x 0.46 cm packed with Normal phase-silica 5 micron 
(Lichrosorb Si -60) ; or 
b) Cyano column , stainless steel 25 cm x 0.40 cm packed with (Lichrospher 100) cyano 5 
micron 
NOTE Either, of the above columns can be used depending on the availability. FOR COMMENTS ONLYEAS 766-2 : 2013  
6 © EAC  2013  – All rights reserved  
 B.2.2.7 Mobile phase: 
a) for silica column, transfer 20 mL of iso-propanol into a 500-mL volumetric flask and make up to mark 
with iso-octane and mix well. Assemble millipore filter apparatus and filter the solvent system prior to 
use; and 
b) for cyano column, transfer 50 mL of HPLC grade iso-propanol (2-propanol) into a 500-mL volumetric 
flask, fill up to the mark with hexane and mix well. Assemble millipore filter apparatus and filter the 
solvent system prior to use. 
B.2.2.8  HPLC conditions  which include the following: 
a) Detector wavelength flow rate: 280 nm; 
b) Flow rate:     0.5 ml/min; 
c) Injection volume:    20 µl; 
d) Retention time; 
e) Silica column: 
 TCN - 7.5 min ; and   
 TCC - 19.2 min; 
f) Cyano column: 
 TCN - 4.0 min; and  
 TCC - 7.5 min. 
B.2.3 Procedure 
B.2.3.1 Standard preparation (see note under B.3.4) 
Weigh accurately 25 mg of triclosan (TCN) and 25 mg of TCC into a 100-mL volumetric flask and make up to 
volume with the mobile phase and mix well. Pipette 1.0 mL of this solution in a 50 mL volumetric flask and 
dilute with mobile phase. Final concentration of TCC and TCN is 250 µg/50 mL (5.0 ppm). 
B.2.3.2 Sample preparation 
Weigh accurately 1 g of homogenized sample into a 100-mL standard flask, and dilute to the mark with mobile 
phase. Pipette 10 mL of the supernatant liquid to a 50-mL volumetric flask, dilute with mobile phase, to the 
mark, and filter through 0.45 m filter. 
B.2.3.3 Chromatography 
Equilibrate the column, maintained at a temperature of 30 °C, with the mobile phase with a flow rate of 0.5 mL 
/min for iso-octane - iso-propanol mobile phase and 1.0 mL/min for Hexane - iso-propanol mobile phase for 30 
min. Set the wavelength at 280 nm. Inject 20 µL of standard solution and then sample solutions. 
Measure area of the peaks of respective retention time for standard and sample. 
B.2.4 Calculation 
TCN shall be expressed as follows: FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  7 
 
100x
sample of  ion Concentratx TCN standard of AreaTCN standard of ion Concentratx TCN for sample of Areamassby  percent TCN,  
100x
sample of  ion Concentratx TCC standard of AreaTCC standard of ion Concentratx TCC for sample of Areamassby  percent TCC, 
 
B.3 Reverse phase 
B.3.1 Reagents 
B.3.1.1 Methanol, HPLC grade 
B.3.1.2 Sodium Dihydrogen Phosphate Monohydrate , chemical grade  
B.3.1.3 Standard TCC 
B.3.1.4 Standard TCN (TCS) 
B.3.2 Apparatus 
B.3.2.1 Column 
B.3.2.1.1 Octyldimethylsilyl (C- DB) 
B.3.2.1.2 Supercosil LC-8- DB, 15 cm x 4.6 mm. 5 micron 
B.3.2.2 Mobile phase 
MeOH/0.01 M Phosphate buffer 62:38 v/v 
0.01 M Phosphate buffer: Dissolve 1.38 g sodium dihydrogen phosphate monohydrate in 1 000 mL of distilled 
water. Prepare to pH 3.0 by 10 % phosphate solutions. 
B.3.3 Procedure 
B.3.3.1 Standard preparation (see Note under B.3.4) 
B.3.3.1.1 Weigh accurately about 90 mg of TCN. Dissolve in methanol and make up to 1 000 mL volumetric 
flask with methanol. 
B.3.3.1.2 Weigh about 110 mg of TCC, dissolve well with methanol, and make up the volume to 1 000 mL. 
B.3.3.1.3 Accurately pipette 10 mL of the solution prepared in B.3.3.1.1 into the volumetric flask containing 
TCC (B.3.3.1.2). And make up to the volume with methanol. Then accurately pipette 5 ml of the solution into a 
50-mL volumetric flask. Make up to the volume with methanol. Filter this standard solution through 0.45 µm 
filter. 
B.3.3.2 Sample preparation 
Weigh accurately about 1.0 g of product, dissolve in methanol and make up to 100 mL in a volumetric flask 
with methanol. Filter this sample solution through 0.45 m filter. FOR COMMENTS ONLYEAS 766-2 : 2013  
8 © EAC  2013  – All rights reserved  
 B.3.3.3 HPLC conditions 
The HPLC conditions include the following: 
a) Detector wavelength: 280 nm; 
b) Column temperature: 35 ºC; 
c) Flow rate:    1.0 mL/min; and 
d) Injection volume:  10 µL. 
Prepare the standard solution and the sample solution at the same time. Inject the standard solution three 
times and calculate the average of each ingredients peak count. Inject 10 µg the sample solution and 
determine each ingredients percentage by the calculation shown. 
B.3.4 Calculations 
The TCN and TCC shall be expressed as follows: 
TCN, percent by mass = 
 
 100 t sr s

MAFA M  
TCC, percent by mass =  
 
 100 t sr s

MAFA M  
where 
Ar is the peak area of the test sample; 
As is the averaged peak area of the standard;  
F is the purity, expressed as percent, of the standard; 
Ms is the mass, in grams, of the standard; and 
Mt is the mass, in grams, of the test sample. 
NOTE Both TCC and TCN are photosensitive, hence standards should be freshly prepared. FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  9 
 Annex C 
(normative) 
 
Determination of chloroaniline 
C.1 Principle 
The chloroanilines are extracted from soap with dimethyl sulfoxide and diazotized with nitrous acid. The 
reaction products are then coupled with N-1-(naphthyl) ethylenediamine hydrochloride to produce coloured 
compounds which are estimated spectrophotometrically. 
C.2 Safety precautions 
Dimethyl sulfoxide (DMSO) is readily absorbed into the skin. Inhalation or skin penetration must be avoided. 
DMSO should never be pi petted using mouth. Always use pipette bulb. The standard chloroanilines and N-1-
(naphthyl)-ethylenediamine hydrochloride shall not be allowed to come into contact with the skin. If they 
should, then wash the contaminated parts thoroughly with soap and water. 
A supply of diluted sodium hypochlorite should be at hand at all times to deal with accidental spillages of 
chloroaniline solution. Spillage on laboratory surface should be treated immediately with the sodium 
hypochlorite solution, followed by water. 
C.3 Reagents 
C.3.1 Dimethyl Sulphoxide (DMSO) , AR grade 
C.3.2 Hydrochloric acid , concentrated (specific gravity, 1.18) 
C.3.3 Sodium nitrite , 0.4 % w/v  analytical grade, freshly prepared (aqueous) 
C.3.4 Ammonium sulphamate , 2 % w/v  solution freshly prepared (aqueous) 
C.3.5 N-1-(naphthyl) ethylene , 0.1 % w/v  solution diamine hydrochloride freshly prepared (aqueous) 
C.3.6 n-Butanol , AR grade 
C.3.7 Sand , acid purified 40 - 100 micron mesh 
C.3.8 Solvent mixture comprising:  
 DMSO   5 volumes 
 n-Butanol   2 volumes 
 Distilled water  2 volumes 
 Hydrochloric acid 1 volume 
Mix n -butanol, water and HCI. Cool the mixture and add DMSO. 
C.3.9 4-Chloroaniline and 3, 4-Dichloroaniline, AR grade FOR COMMENTS ONLYEAS 766-2 : 2013  
10 © EAC  2013  – All rights reserved  
 C.4 Apparatus 
C.4.1 Spectrophotometer,  suitable for use at 554 nm 
C.4.2 Cuvettes, glass (matched pair) 10 mm 
C.4.3 Water bath,  thermostatically controlled at 25 °C 
C.4.4 Stopwatch 
C.4.5 Standard laboratory glassware  
C.4.6 Filter Paper,  Whatman No. 541 
C.5 Procedure 
C.5.1  Dissolve 0.349 8 g of 3,4-dichloroaniline and 0.2753 g of 4-chloroaniline in solvent mixture (see  C.3.8) 
in a 250 mL amber volumetric flask. 
Dilute to mark with solvent mixture. [1 mL is 2.5 mg mixed chloroanilines (stock solution)]. 
C.5.2 Dilute this stock solution with solvent mixture as given below: 
a) take 5 mL of stock solution and dilute it to 250 mL with solvent mixture (1 mL = 50 µg mixed 
chloroanilines); and 
b) take 5 mL of the above solution [see  (a)] and further dilute to 250 mL with solvent mixture. [1 mL = 1 
µg mixed chloroanilines]. 
Use this solution for preparation of calibration curve. 
Transfer using a burette 0, 1 mL, 2 mL, 5 mL, 10 mL, 20 mL, 40 mL into 50 mL amber volumetric flasks. 
C.5.3 From a burette, add sufficient solvent mixture to make total volume to 40-mL in each flask. The flasks 
are incubated in a water bath at 25 °C for 20 min: After exactly 20 min, add 2-mL of reagent (see  C.3.3) into 
each flask and return them to the water bath for exactly 10 min (measure with a stop watch). 
Then add 2 mL of reagent (see  C.3.4) into each flask and return them to the water bath for exactly 10 min. 
Swirl the flask occasionally. 
Then add 2 mL of reagent (see  C.3.5) into each flask and remove them from the water bath. Dilute to volume 
with distilled water, mix and allow to stand for 30 min. Measure absorbance at 554 nm against the blank 
solution as prepared in C.5.4. 
C.5.4 In preparing the blank solution, take 40 mL of solvent mixture in a 50 mL amber volumetric flask. 
Incubate the flask in a water bath at 25 °C for 20 min. After exactly 20 min, add 2 mL of reagent (see C.3.3 ) 
into the flask and return it to the water bath for exactly 10 min. Then add 2 mL of reagent (see C.3.4) into the 
flask and return it to the water bath for exactly 10 min (swirl the flask occasionally). Then add 2 mL of reagent 
(see C.3.5 ) into the flask and remove it from the water bath. Dilute to volume with distilled water, mix and 
allow to stand for 30 min. Use this blank solution for preparation of calibration curve only. 
C.5.5 Prepare a graph by plotting weight ( g) of chloroanilines contained in each 50 mL-flask against 
absorbance. The linear calibration will pass through the origin/or determine the average absorbance ( AA) of 1 
g of mixed chloroanilines by dividing sum of absorbances of all different aliquots of the standard by sum of 
g of chloroanilines in all different aliquots of standard. FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  11 
 C.6 Determination of chloroanilines 
C.6.1  Weigh to the nearest mg 3.0 g - 15 g of finely grated soap and add 10.0 g - 15.0 g of acid purified 
sand. Transfer quantitatively the sample and the sand into a mortar and grind the mixture thoroughly with a 
pestle to give a homogenous mass. Transfer the mass to a previously weighed 250-mL flat bottom flask 
quantitatively and reweigh. Add DMSO (100 mL), stopper firmly and attach the flask to an automatic shaker. 
Shake for 1 h. Filter the DMSO extract through Whatman No. 541 into a 250 mL amber volumetric flask. Wash 
the flask and filter paper with small aliquots of DMSO. Allow the filtrate to drain completely, dilute to volume 
with DMSO and mix. Transfer 20 mL DMSO extract into a 50-mL amber volumetric flask. Add 20 mL of 
solvent mixture. The flask is incubated in a water bath at 25 °C for 20 min. After exactly 20 min, add 2 mL of 
reagent (see  C.3.3 ) into the flask and return it to the water bath for exactly 10 min (measure with a stop 
watch). Then add 2 mL of reagent (see  C.3.4) into the flask and return it to the water bath for exactly 10 min 
(swirl the flask occasionally). Then add 2 mL of reagent (see  C.3.5) into the flask and remove it from the water 
bath. Dilute to volume with distilled water, mix and allow to stand for 30 min. Read the absorbance at 554 nm 
against blank (prepared as below). 
C.6.2 Prepare the blank solution by mixing 20 mL of DMSO extract of sample and 20 mL of solvent mixture 
in a 50 mL amber volumetric flask. Incubate the flask in a water bath at 25 °C for 20 min.  
After exactly 20 min, add 2 mL of distilled water into the flask and return it to the water bath for exactly 10 min. 
Then add 2 mL of reagent (see  C.3.4) into the flask and return it to the water bath for exactly 10 min (swirl the 
flask occasionally). Then add 2 mL of reagent (see  C.3.5) into the flask and remove it from the water bath. 
Dilute to volume with distilled water, mix and allow to stand for 30 min. Use this solution as a blank for reading 
sample only. 
C.6.3 Deduce the amount of chloroanilines (µg) from the calibration graph curve. 
NOTE The determination should be completed in one day. 
C.7 Calculations 
Determine the amount of mixed chloroanilines in the aliquot of test solution from the calibration graph. 
Chloroaniline content (in ppm) = 

MMMMM
23 1
20250  
where 
M is the mass, in grams, of soap; 
M1 is the mass, in grams, of sand; 
M2 is the mass, in grams, of soap and sand transferred to the flask ; and  
M3 is the mass, in micrograms, of mixed chloroanilines found from calibration graph/or it can be 
calculated as given below: 
M3 = 
(AA) ines chloroanil mixed g  1 of absorbance Averagesample the of Mass
μ  
where 
AA = 
g in ines chloroanil standard of ion concentrat of Sumstandards the of OD the of Sum
μ  
 
 FOR COMMENTS ONLYEAS 766-2 : 2013  
12 © EAC  2013  – All rights reserved  
 Weight of soap actually used, in g  = 
12
MMMM
  
 
 FOR COMMENTS ONLYEAS 766-2 : 2013  
© EAC 2013  – All rights reserved  13 
 Annex D 
(normative) 
 
Sampling  
D.1 Procedure  
D.1.1 In a single consignment, all packages (cartons) containing toilet soap cakes drawn from the same 
batch of production shall constitute a lot. For ascertaining the conformity of the lot to the requirements of this 
standard, tests shall be carried out on each lot separately. The number of packages to be selected for drawing 
the sample shall be in accordance with Table D.1 .  
Table D.1 — Scale of sampling 
Number of packages (cartons) in 
the lot  
N Number of packages (cartons) to be 
selected  
n Number  of samples  
4 to 15  3 3 
16 to 40  4 4 
41 to 65  5 2 
66 to 110  7 2 
111 and above  10 1 
 
D.1.2 The packages shall be selected at random, using tables of random numbers. If these are not 
available, the following procedure shall be applied:  
Starting from any package, count all the packages in one order as 1, 2, 3.... N, selecting every k th package, 
where k is the integral part of N  n.  
D.1.3 From each package thus selected, draw at random an equal number of cakes so as to obtain a total 
mass of at least 2 kg.  
D.2 Preparation of test samples 
D.2.1 Composite sample  
Weigh each cake separately (including any material that may have adhered to the wrapper), and calculate the 
average mass. Cut each of the remaining cakes into eight parts by means of three cuts at right angles to each 
other through the middle. Grate finely the whole of two diagonally opposite eighths of each specimen. Mix the 
gratings and place in a clean, dry, airtight glass container.  
D.2.2 Samples for testing 
Immediately after preparation of composite sample (D.2.1), take at one time all test samples required for the 
tests in 4.2. Weigh out the test sample required for determination of free alkali or acid content, and use it 
immediately.  
 FOR COMMENTS ONLYEAS 766-2: 2013    
 
© EAC 2013  – All rights reserved