DEAS 186 -2: 2020 
ICS 71.100.40  
© EA C 2020                                                                                                                        Second  Edition 2020  
 
  DRAFT EAST AFRICAN STANDARD  
 Bathing  soap — Specification ― Part 2: Liquid   
EAST AFRICAN COMMUNITY  DEAS 186 -2: 2020 
ii © EAC  2020 – All rights reserved  
 Copyright notice  
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Reproduction for sales purposes may be subject to royalty payments or a licensing agreement.  Violators 
may be persecuted  DEAS -2: 2020 
© EAC 2020 – All rights reserved  iii 
 Contents  Page 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Requirements  ................................ ................................ ................................ ................................  2 
4.1 General requirements  ................................ ................................ ................................ ..................  2 
4.2 Specific requirements  ................................ ................................ ................................ ..................  2 
6 Packaging and labelling ................................ ................................ ................................ ...............  3 
6.1 Packaging  ................................ ................................ ................................ ................................ ...... 3 
6.2 labelling  ................................ ................................ ................................ ................................ .........  3 
7 Sampli ng ................................ ................................ ................................ ................................ ....... 3 
8 Criteria for conformity ................................ ................................ ................................ ..................  3 
Annex A (normative)  Permitted antibacterial agents  ................................ ................................ ............  4 
Anne x 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)  Determination of pH  ................................ ................................ ...........................  12 
D.1 General  ................................ ................................ ................................ ................................ ........  12 
D.2 Apparatus  ................................ ................................ ................................ ................................ .... 12 
D.3 Reagents  ................................ ................................ ................................ ................................ ..... 12 
D.4 Procedure  ................................ ................................ ................................ ................................ .... 12 
Annex E (normative)  Sampling  ................................ ................................ ................................ .............  13 
E.1 Procedure  ................................ ................................ ................................ ................................ .... 13 
E.2 Preparation of test samples  ................................ ................................ ................................ ...... 13 
E.2.1  Composite sample  ................................ ................................ ................................ ......................  13 
E.2.2  Samples for testing  ................................ ................................ ................................ ....................  13 
 DEAS 186 -2: 2020 
iv © EAC  2020 – 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 harmonize d 
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 Standard s (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 ar e 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 stakeholders through the Natio nal Standards Bodies in the Partner 
States. The comments received are discussed and incorporated before finalization of standards, in accordance 
with the Principles 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 committee responsible  for this document is Technical Committee EASC/TC 074, Surface active agents  
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 edition cancels and replaces the first edition (EAS 766 -2:2013), which has been technically revised  
and numbered as EAS 186 -2. 
EAS 186 consists of the following parts, under the general title Bathing  soap — Specification : 
- Part 1: Solid.   
- Part 2: Liquid.  
 DEAS -2: 2020 
© EAC 2020 – 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 ant ibacterial 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 o f sweat by bacteria. The antibacterial toilet soap is especially  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 includ ed. Use of other antibacterial agents not included in 
Annex A will be considered when need arises as long as their safety is assured.  
 
 DRAFT  EAST AFRICAN STANDARD                                                               DEAS 186-2: 2020  
 
© EAC 2020 – All rights reserved  1 
  Bathing  soap — Specification ― Part 2: Liquid   
 
1 Scope   
 
This Draft East African Standard specifies requirements, sampling and test methods for liquid bathing  soap. It 
does not apply to hand wash liquid detergents, shampoo and products for specific purposes such as those for 
industrial and surgical uses.  
 
2 Norma tive 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 subst ances 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 pre servatives 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 4 56, 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  
ISO 2271 Surface active agents  — Detergents  — Determination of anionic -active matter by manual or 
mechanical direct two -phase titration procedure   
3 Terms and d efinitions  
For the purposes of this standard  the terms and definitions given in  ISO 862 apply.   
2 © EAC  2020 – All rights reserved  
 4 Requirements  
4.1 General requirements  
4.1.1 The liquid bathing soap shall consist of essentially of an aqueous solution of potassium soaps, sodium 
soaps or both, made from oils, fatty acids or their mixt ure. 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 bathing  soap shall remain as homogeneous stable product and shall show no sign of 
separation or sedimentation when kept at 5  °C for 24  h. 
4.1.3 The liquid antibacterial bathing  soap shall contain permitted antibacterial agent in accordance with  
Annex A.   
4.1.4 All the substances used  in the liquid  bathing  soap shall comply with the requir ements of all parts of EAS 
377. 
4.1.5 Liquid  bathing  soap shall pass the test for dermatological safety.   
4.2 Specific  requirements  
Liquid  bathing  soap  shall also comply with the specific quality  requireme nts specified in Table 1.  
Table 1 — Specific  requirement s for liquid bathing  soap  
SI No.  Characteristic  Requirement  Test m ethod   
liquid bathing soap  Antibacteria
l liquid 
bathing 
soap  
i.  Total fatty matter, % by mass,  min 15.0 15.0 ISO 685  
ii.  Free caustic alkali, (K 2O), % by mass, max.  0.03 0.03 ISO 456  
iii.  Synthetic detergents, % by mass, max.  2.0 2.0  
ISO 2271  
iv.  Matter insoluble in  ethanol , % by mass,  max 5.0   
 5.0 ISO 673  
v.  Antibacterial agent TricIosan (TC N) and 
Trichlorocarbanilide (TCC), % by mass,  max n/a 1.0  
either singly 
or in 
combination  Annex B  
vi.  Chloroaniline content, ppm, max  n/a 10.0 Annex C  
vii.  Phosphate  absent  absent  EAS 127  
viii.  Antibacterial activity  n/a To pass test  EAS 794  
ix.  pH at  27 ± 2°C  7.5 – 9.5 7.5 – 9.5 Annex D  
NOTE  Trichlorocarbanilide (TCC) is not heat stable and decom poses into chloro anilines on prolonged 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.  
  
© EAC 2020 – All rights reserved  3 
 6 Pack aging and labelling  
6.1 Pack aging 
The bathing soap shall be packed in protective containers that will not allow for damage of the product or  its 
contamination.  
6.2 labelling  
a) Each container  shall be legibly and indelibly labelled either in English, Kiswahili or French or 
combination or any other language as agreed between the  manufacturer and supplier with the following 
information  name of the product as “ liquid bathing  soap or antibacterial liquid bathing 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) country of origin;  
g) the antibacterial agent used (for antibacterial bathing  soap ); and 
h) list of ingr edients in descending order of quantity  
7 Sampling  
Sampling shall be done in accordance to Annex E 
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 Cl ause 4 and 5 are satisfied.   
4 © EAC  2020 – 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 extr acts; 
f) Any other internationally accepted antibacterial agent .  
© EAC 2020 – 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 component s 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 vari able wavelengths and a rec order  
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.  
B.2.2.7  Mobile phase :  
6 © EAC  2020 – All rights reserved  
 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 50 0-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 triclos an (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 m ark, 
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:   
© EAC 2020 – 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  Appar atus 
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 t he 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 produ ct, dissolve in methanol and make up to 100 mL in a volumetric flask with 
methanol. Filter this sample solution through 0.45 m filter.  
B.3.3.3  HPLC conditions  
The HPLC conditions include the following:  
a) Detector wavelength : 280 nm ;  
8 © EAC  2020 – All rights reserved  
 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 so lution 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 photosen sitive, hence standards should be freshly prepared.   
© EAC 2020 – 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 couple d 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 th oroughly with soap and water.  
A supply of diluted sodium hypochlorite should be at hand at all times to deal with accidental spillages of 
chlor oaniline 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 volum es 
 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   
10 © EAC  2020 – 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  Stop watch  
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 b elow:  
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 thi s 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 fla sks 
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 fl ask 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. Meas ure absorbance at 554 nm against the blank solution 
as prepared in C.5.4.  
C.5.4 In preparing the blank solution, take 40 m L 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 m L 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 reage nt (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 c hloroanilines 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 sta ndard by sum of g 
of chloroanilines in all different aliquots of standard.   
© EAC 2020 – 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 samp le 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 b ath 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 fro m 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 mix ture 
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. Us e 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  
 
Weight of soap actually used, in g  = 
12
MMMM
   
12 © EAC  2020 – All rights reserved  
 Annex D  
(normative)  
 
Determination of pH  
D.1 General  
pH determination should be made in an acid free atmosphere .  
D.2 Apparatus  
D.2.1  Any standard pH meter , equipped with a low sodium error glass electrode. The instrument shall be 
calibrated and standardized with standard buffer solutions (see D.3.2) before use.  
D.2.2  Volumetric flask , 1000 -mL capacity  
D.2.3  Beakers , 1000 -mL 
D.3 Reagents  
D.3.1  Distilled water shall be boiled thoroughl y or purged with carbon dioxide -free air to remove carbon dioxide 
and shall b e protected with soda lime or soda asbestos while cooling and in storage. The pH of this water shall 
be protected with soda lime or soda asbestos while cooling and in storage. The pH of this water shall be between 
6.2 and 7.2 at 27 °C. The residue on evapo ration when heated at 105 °C for one hour shall not exceed 0.5 m L 
per litre.  
D.3.2  Standard buffer solutions with the pH range of 9 to 11 at 27 °C for calibrating the pH meter.  
D.4 Procedure  
Weigh to the nearest milligram approximately 10  g of the ma terial and transfer to a 1 -L volumetric flask. Partially 
fill the flask with distilled water and agitate until the sample is completely dissolved. Adjust the temperature of 
the solution and the distilled water to 27 °C ± 2 °C and fill to the calibration mark wi th distilled water, stopper the 
flask mix thoroughly and allow the solution to stand at a temperature of 27  °C ± 2 °C for two hours prior to 
measuring the pH. Measure the pH of the solution at 27  °C ± 2 °C using a glass electrode.  
  
© EAC 2020 – All rights reserved  13 
 Annex E 
(normative)  
 
Sampling  
E.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 E.1.  
Table E.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 
 
E.1.2 The packages shall be selected at random, using tables of random numbers. If these are not available, 
the following procedure shall be appli ed:  
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.  
E.1.3 From each package thus selected, draw at random an equal number of cakes so as to obtain a to tal 
mass of at least 2 kg.  
E.2 Preparation of test samples  
E.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 co ntainer.  
E.2.2 Samples for testing  
Immediately after preparation of composite sample ( E.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 i t 
immediately.   EAS 766-2: 2013    
 
© EAC 2013  – All rights reserved