AFRICAN 
STANDARD  DARS  
1455  
First Edition 2018  
 
 Reference No. ARS 1455: 2018 (E) 
ICS 71.100.40  
 
 
© ARSO 2018  
  
 
 
 
 
 
 
 
 
 
Bathing bars — Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 DARS 1455: 2018  
ii © ARSO 2018 — All rights reserved   
Table of contents  
 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ .....................  1 
3 Definitions  ................................ ................................ ................................ ................................ ....... 1 
4 Requirements  ................................ ................................ ................................ ................................ . 2 
4.1 Physical requirements  ................................ ................................ ................................ ...........  2 
4.2 Description  ................................ ................................ ................................ .............................  2 
4.3 Performance and safety requirements  ................................ ................................ ..................  2 
4.4 Ingredients  ................................ ................................ ................................ .............................  2 
5 Packaging and marking  ................................ ................................ ................................ ..................  3 
5.1 Packaging  ................................ ................................ ................................ ..............................  3 
5.2 Marking  ................................ ................................ ................................ ................................ .. 3 
6 Sampling  ................................ ................................ ................................ ................................ .........  4 
6.1 Scale of sampling  ................................ ................................ ................................ ..................  4 
7 Test methods  ................................ ................................ ................................ ................................ .. 4 
7.1 Preparation for test samples  ................................ ................................ ................................ .. 4 
7.2 Criteria for conformity  ................................ ................................ ................................ ............  4 
Annex A (normati ve)  Permitted structuring and processing aids  ................................ ...........................  5 
Annex B (normative)  Test for lather volume  ................................ ................................ ..........................  6 
Annex C (normative)  Evaluation o f the mushing properties of a bathing bar  ................................ ........  9 
Annex D (normative)  Determination of grittiness in a bathing bar  ................................ .......................  11 
Annex E (normat ive)  Identification of rosin content of fatty matter in soaps  ................................ ........  12 
Annex F (normative)  Determination of rosin content of fatty matter in soaps  ................................ ...... 13 
Bibliography  ................................ ................................ ................................ ................................ ..........  16 
 DARS 1455: 2018  
© ARSO 2018 — All rights reserved  iii  
Foreword  
 
The African Organization for Standardization (ARS O) is an African intergovernmental organization 
established by the United Nations Economic Commission for Africa (UNECA) and the  Organization of 
African Unity (AU)  in 1977 . One of the fundamental mandates of ARSO is to develop and harmoniz e 
African Standards (ARS) for the purpose of enhancing Africa’s internal trading capacity, increase 
Africa’s product and service competitiveness globally and uplift the welfare of African communities.  
The work of preparing African  Standards is normally carried out through ARSO  technical committees. 
Each Member State  interested in a subject for which a technical committee has been established has 
the right to be represented on that committee. International organizations, Regional Economic 
Communities (RECs), governmental and non -governmental  organizations , in liaison with ARSO , also 
take part in the work.  
 
ARSO  Standards are drafted in accordance wi th the rules given in the ISO/IEC Directives, Part 2.  
 
The main task of technical committees is to prepare ARSO  Standards. Draft ARSO  Standards 
adopted by the technical committees are circulated to the member bodies for voting. Publication as an 
ARSO  Standard requires approval by at least 75 % of the member bodies casting a vote.  
 
Attention is drawn to the possibility that some of the elements of this document may be the subject of 
patent rights. ARSO  shall not be held responsible for identifying any or al l such patent rights.  
 
This African Standard was prepared by the ARSO Technical Harmonization Committee Number 5 on 
Chemistry and Chemical Engineering (ARSO/THC 05) . 
 
 
 
 
 
© African Organisation for Standardisation  2018 — All rights reserved* 
 
ARSO Central Secretariat  
International House 3rd Floor  
P. O. Box 57363 — 00200 City Square  
NAIROBI, KENYA  
 
Tel. +254 -20-2224561, +254 -20-3311641, +254 -20-3311608  
 
E-mail: arso@arso -oran.org  
Web: www.arso -oran.org  
                                                 
* 2018 ARSO — All rights of exploitation reserved worldwide for African Member States’ NSBs. 
 DARS 1455: 2018  
iv © ARSO 2018 — All rights reserved   
 
Copyright notice  
 
This ARSO document is copyright -protected by ARSO. While the reproduction of this document 
by participants in the ARSO standards development process is permitted without prior 
permission from ARSO, 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 ARSO.  
 
Requests for permission to reproduce this document for the purpose of selling it should be 
addressed as shown below or to ARSO’s member body in the country of the requester:  
 
 
© African Organisation for Standardisation 2018 — All rights reserved  
 
ARSO Central Secretariat  
International House 3rd Floor  
P.O. Box 57363 — 00200 C ity Square  
NAIROBI, KENYA  
 
Tel: +254 -20-2224561, +254 -20-3311641, +254 -20-3311608  
 
 
E-mail: arso@arso -oran.org  
Web: www.arso -oran.org  
 
Reproduc tion for sales purposes may be subject to royalty payments or a licensing agreement. 
Violators may be p rosecuted.  
 
 
 DARS 1455: 2018  
© ARSO 2018 — All rights reserved  v  
Introduction  
 
The current African S tandard on toilet soaps is based on composition. The major concern is that the 
present compositional standards based primarily on the total fatty matter (TFM) do not necessarily 
correspond to the performance of toilet soaps. The performance of soaps depends on the type of fatty 
matter present rather than the total fatty matter in soap. For example, the so lubility of soap depends on 
the characteristics of fatty acids such as chain length, level of unsaturation and on type of cation. Further 
the use of acceptable non -soap surfactants would result in the substitution of oils and fats, which are 
scarce resourc es. 
 
This standard therefore reflects the trends in the latest technological developments while ensuring the 
performance and safety of the product to the consumer. This will in particular facilitate use of acceptable 
non-soapy surfactants and structuring a ids, some of which are locally available. These will often 
substitute oils and fats, most of which are imported and expensive, and hence their use can help to boost 
the country's economy.  
 
The important in -use criteria for bathing bars are safety, cleaning  and economy. With regard to safety it is 
important to guard against the removal of the beneficial skin lipids by the product and over -cleaning 
resulting in defatting of the skin. This is ensured in the present standard by allowing only surfactants that 
have a history of safe use in personal washing products. A list of the proposed surfactants is contained in 
Annex A. Other surface -active agents may be added to the list at a future revision if there is adequate 
evidence of their safety.  
 
The lather requirem ent is intended to ensure the presence of adequate level of surfactants in the bathing 
bar for cleaning. The test is designed to take into account dissolution of the bar and subsequent lather 
generation. The mush test covers the aspect of economy. Limits a re prescribed for caustic alkali and 
alkalinity of alcohol insolubles to restrict the use of alkaline ingredients.  
 
 DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  1  
Bathing bars — Specification  
 
 
1 Scope  
 
This African Standard prescribes the requirements and methods of test for bathing bars.  The st andard 
applies to bathing bars supplied in the form of cakes and produced from vegetable or animal oils or 
fats, fatty acids, or from a blend of all or part of these materials, with or without the addition of rosins 
or non -soapy /synthetic  surfactants.  
 
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 amendme nts) applies.  
 
CD-ARS 1462 :2018, Powder detergents — Biodegradability  
 
ISO 4315 , Surface active agents — Determination of alkalinity — Titrimetric method  
 
ISO 456, Surface active agents — Analysis of soaps — Determination of free caustic alkali  
 
ISO 457, Soaps — Determination of chloride content — Titrimetric method  
 
ISO 672 , Soaps — Determination of moisture and volatile matter content — Oven method  
 
ISO 673, Soaps — Determination of content of ethanol -insoluble matter  
 
ISO 684, Analysis of soaps — Determi nation of total free alkali  
 
ISO 685, Analysis of soaps — Determination of total alkali content and total fatty matter content  
 
ISO 862, Surface active agents — Vocabulary  
 
ISO 4314 , Surface active agents — Determination of free alkalinity or free acidity — Titrimetric 
method  
 
ISO 4315 , Surface active agents — Determination of alkalinity — Titrimetric method  
 
ISO 4316 , Surface active agents — Determination of pH of aqueous solutions — Potentiometric 
method  
 
ISO 6839 , Anionic surface active agents — Determin ation of solubility in water  
 
Regulation (E C) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 
on Cosmetic Products  
 
3 Definitions  
 
For the purpose of this standard the definitions given in ISO 862  and the following shall appl y. 
 
3.1 
bathing bars  
the bathing bar shall be a product containing soap of fatty acids and synthetic surface active agents 
listed in 4.4.1 as active ingredients and which could be used for bathing purposes in soft and hard 
water  
 AFRICAN STANDARD  DARS 1455: 2018  
2 © ARSO 2018 — All rights reserved  4 Requirements  
 
4.1 Physic al requirements  
 
4.1.1  Bathing bars shall be in the form of bars. The colour of the cake or bar shall generally be 
uniform, but uniformity of colour shall not be obligatory in the case of genuinely mottled products.  
 
The product shall not be injurious to health if used in a manner and purpose meant for their use or 
under reasonably foreseen conditions.  
 
4.1.2  Odour   
 
The bar shall not have a n unpleasant odour.  
 
4.2 Description  
 
4.2.1  The bathing bar shall be firm and shall contain adequate quantity of one or mor e surface -
active agents listed in 4.4.1 and may contain components indicated in 4.4.2.  
 
4.2.2   They are for personal washing purposes, and primarily contain saponified fatty matter, 
structurants, preservatives and moisture. They may also contain suitable q uantities of colouring 
matter, perfume, opacifiers and optical brightening agents.  
 
4.3 Performance and safety requirements  
 
Bathing bars shall also comply with the requirements given in Table 1 when tested against the 
methods described.  
 
Table 1 — Perfo rmance and safety requirements  
 
SL. No  Characteristic  Requirement  Test method  
1. Lather, mL, minimum.  200 Annex B  
2. Mush (loss in mass due mushing on a 
wet surface) (g/30cm2, maximum).  10 Annex C  
3. Freedom from grittiness  To pass the test  Annex D  
4. Total alkalinity (as NaOH) % by 
mass, maximum.  1.0 ISO 4315  
5. Free caustic alkali (as NaOH), % by 
mass, maximum.  0.3 ISO 456  
 
4.4 Ingredients  
 
4.4.1  The bathing bar shall have one or more of the following surfactants ;  
 
a) There is no restriction on the  use of soap of fatty acids, fatty acid ester sulphonates, fatty 
alkalonamide, fatty alcohol ethoxylates, sarcosinates, taurides, fatty isothionates, alpha olefin 
sulphonates, alcohol sulphates and amphoterics such as betaines and fatty alcohol ethoxy 
sulphate, linear alkyl benzene sulphonates (LAS) and akyl poly glycosides (APG) and fatty 
alcohol sulphosuccinate and fatty alkanol amido sulphosuccinate.  
 
b) Rosins, as % of total fatty matter, shall not exceed 2 %.  
 
c) The synthetic surface active agents sha ll pass the biodegradability test as given in CD-ARS 
1462:201 8. 
 DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  3 4.4.2  In addition to the surfactants and perfume, the bathing bar may contain other ingredients such 
as electrolytes, bar structuring and processing aids, colouring matter, permitted antioxidants, 
preservatives, permissible germicides, super fatting agents, humectants and such additional 
substances as are declared on the label.  
 
4.4.3  All other ingredients except moisture shall be declared on the label.  
 
For guidance, a list of bar structuring and p rocessing aids is given in Annex A. All these materials 
shall be non -injurious to skin in use with the bathing bar.  
 
4.4.4  The bathing bar shall not contain any material s prohibited by regulations such as Regulation 
(EC) No 1223 . 
 
5 Packaging and  labelling  
 
5.1 Packaging  
 
Each bar may be unwrapped or may be wrapped. Unwrapped or wrapped bars may be packed in 
suitable boxes, packages or cartons to avoid contamination or damage during transportation.  
 
5.2 Labelling  
 
5.2.1  Wrapped bars  
 
Each bathing bar shall  be marked legibly and indelibly with the following particulars:  
 
a) the words ‘Bathing Bar’;  
 
b) the name and address of the manufacturer and trade mark if any;  
 
c) nominal weight of each bar or cake at the time of packaging;  
 
d) number of bars or cakes contained in the package;  
 
e) batch number or code number;  
 
f) all ingredients except moisture;  
 
g) date of manufacture and best before date;  
 
h) country of origin.  
 
5.2.2  Unwrapped bathing bars  
 
Each unwrapped bathing bar shall be marked legibly and indel ibly with the following particulars:  
 
a) name of product  
 
b) weight of the bar  
 
5.2.3  Cartons/Boxes/ Other packages  
 
a) the name and address of the manufacturer and trade mark if any;  
 
b) batch number or code number;  
 
 
 
 
 DARS 1455: 2018  
4 © ARSO 2018 — All rights reserved  6 Sampling  
 
6.1 Scale of sampling  
 
The consignment of bathing bar cakes to be sampled shall be divided into lots, each lot containing 
about 20 cakes from the same source and of the same declared weight and brand.  
 
From each lot, a sample of 9 cakes shall be drawn at random. The cakes of so ap thus chosen shall 
be kept, until tested, in a clean closed container, marked so as to identify the lot from which they have 
been chosen.   
 
The cakes shall be tested separately for each of the tests mentioned in Table 1.  
 
This scale of sampling will en sure that there are a further 9 samples remaining with which to repeat 
any of  the tests that give results not conforming to the criteria for conformity, or in the event of a 
dispute over the results.  
 
7 Test methods  
 
7.1 Preparation for test samples  
 
The c akes of a given type (brand) of bathing bar shall be packed into a clean airtight container until 
tested.  
 
The requirements given in Table1 shall be tested according to Annexes B to D. Testing should 
commence as soon as possible after sampling.  
 
7.2 Criter ia for conformity  
 
Criteria for conformity to tests are included in the Annexes B  to D describing the individual test 
methodologies.  
 DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  5  
Annex A 
(normative)  
 
Permitted structuring and processing aids  
 
 
Following is the list of structuring and processing aid s used generally in bathing bars.  
 
A.1 Starch and derivatives  
A.2 Cellulose and derivatives  
A.3 Propylene glycol  
A.4 Sorbitol  
A.5 Glycerol  
A.6 Dextrin  
A.7 Kaolin  
A.8 Talc 
A.9 Bentonite  
A.10  Calcite  
A.11  Sodium lactate  
A.12  Soda ash  
A.13  Vegetable/animal oi l fatty acids and salts  
A.14  Phosphates  
A.15  Sodium chloride  
A.16  Sodium sulphate  
A.17  Dolomite  
A.18  Fatty alcohol  
A.19  Rosin and rosin salts  
A.20  Fatty acid ethanolamide  
A.21  Diethylene glycol monostearate  
A.22  Paraffin  
A.23  Polyoxyethylene glycol  
A.24  Glycerol monostearates  
A.25  Silicates  
A.26  Any other internationally accepted builder cleared by the relevant authorities  
 DARS 1455: 2018  
6 © ARSO 2018 — All rights reserved   
Annex B 
(normative)  
 
Test for lather volume  
 
 
B.1 Principle  
 
The speed of a domestic kitchen blender is adjusted so that when operate d for 60 seconds it will 
deliver 600 ± 100 mL of lather (foam) from a 1 % solution of sodium lauryl sulphate in 300 ppm 
calcium hardness water at 25 ºC.  
 
Soap samples are grated to a uniform noodle of about 2 -3 mm diameter (domestic cheese grater). 
Five g rams of the noodles are mixed in the domestic blender for 60 seconds with 100 mL of 300ppm 
calcium hardness water at 25  ºC. 
 
The volume of the lather generated from the soap is normalised to a volume of 600 mL delivered from 
the sodium lauryl sulphate solu tion tested in the same blender at the same speed.  
 
B.2 Equipment/reagents  
 
A variable speed kitchen blender with a container/ jar of at least 1000 mL capacity.  
 
B.2.1  Kitchen cheese grater  
 
B.2.2  1000 mL measuring cylinder  
 
B.2.3  100 mL measuring cylinder  
 
B.2.4  Thermometer 0 – 100 ºC 
 
B.2.5  Water containing 300ppm calcium hardness  
 
To make 2 litres of a 300 ppm hard water dissolve 1.66 g of analytical grade anhydrous calcium 
chloride in demineralised water and make to 2 litres.  
 
1 % SLS solution in water  containing 300 ppm calcium water hardness.  
 
Dissolve 20g of analytical grade sodium lauryl sulphate (SLS) in water and make to 2 litres with the 
300 ppm calcium hardness water.  
 
Note especially that this SLS solution should be prepared fresh every day.  
 
B.3 Sample preparation  
 
B.3.1  The requirement is for duplicate lather measurements from three bars of each product, and 
for six replicate lather measurements from the freshly made solution of sodium lauryl sulphate.  
 
B.3.2  A sample of the bathing bar is g rated to give at least 20 grams of 2 – 3 mm diameter noodles.   
 
Cut-off the end third of the bar before grating the freshly exposed face of the remaining two thirds. 
This will limit the proportion of over dried surface soap that is converted into noodles.  
 
Immediately place the grated noodles onto a coarse sieve e.g. aperture 850 microns or similar and 
shake gently to allow any fine and over dried soap to pass through.  
 
Small diameter noodles can lose water very quickly and the gratings should be transferr ed very 
quickly from the sieve into a labelled container that can be closed to prevent such water loss.  DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  7  
Duplicate lather determinations on an individual sample of a bathing bar will only require 2 x 5 g 
samples of the noodles. However, it is always wise t o take at least 20 grams to allow for any repeat 
tests.  
 
B.4 Procedure for lather determination  
 
NOTE  All tests are to be performed with solutions and equipment at 25 ± 2 0C. 
 
B.4.1  Lather volume from standard sodium lauryl sulphate (SLS) solution  
 
B.4.1.1  Pour 100 mL of 1 % SLS solution into the blender, cover the blender jar.  
 
B.4.1.2  Run the blender for exactly 60 seconds.  
 
B.4.1.3  Invert the blender jar over the 1000 mL measuring cylinder and allow to drain. If necessary a 
long plastic spatula or ruler can be used to scoop the residual foam from the jar into the cylinder.  
 
B.4.1.4  If necessary level the top of the foam with the long plastic spatula or ruler and measure the 
lather (foam) volume (S).  
 
NOTE  The total volume of material in the cylinder is t aken as the lather volume. There is no allowance for any liquid that 
may separate from the actual foam.  
 
B.4.1.5  Measure the temperature of the foam in the measuring cylinder.  
 
B.4.1.6  If the lather volume is not 600 ± 100 mL adjust the blender speed and r epeat the test until a 
volume in this range is achieved.  
 
B.4.2  Lather volume from a bathing bar sample  
 
B.4.2.1  Prepare 20g of 2 – 3mm diameter noodles from each sample to be tested, as described in 
Section B.3.  
 
B.4.2.2   Quickly weigh 5 ± 0.05 g of the grated sample.  
 
B.4.2.3  Add the sample to the blender jar which should contain 100 mL of water with 300 ppm Ca 
water hardness.  
 
B.4.2.4  Run the blender for exactly 60 seconds.  
 
B.4.2.5  Invert the blender over the 1000 mL measuring cylinder and allow to d rain.  If necessary a 
long plastic spatula or ruler can be used to scoop the residual foam from the jar into the cylinder.  
 
B.4.2.6  If necessary level the top of the foam with the long plastic spatula or ruler and measure the 
lather (foam) volume (*X)  
 
NOT E The total volume of material in the cylinder is taken as the lather volume. There is no allowance for any liquid that 
may separate from the actual foam.  
 
B.4.2.7  Measure the temperature of the foam in the measuring cylinder. The target temperature is 25 
± 2 °C. See 4.4.  
 
B.4.3  Calculation  
 
The normali zed value (X) of lather for the soap sample will be calculated as follows:  
 
X  =  
SmlX600*  
 DARS 1455: 2018  
8 © ARSO 2018 — All rights reserved   
B.4.4  Criteria for conformity  
 
The test for lather will give six test results for a given product, o btained from duplicate determinations 
of the parameter from three samples of the product.  
 
The mean and the range of the corresponding test result shall be calculated as:  
 
results of number Theresults test of sum The  )x( Mean
 
 
Range (R)  =  The difference between the highest and the lo west value obtained for the test results.  
 
The sampled lot of products shall be declared as conforming to requirements for this standard if the 
expression 
x  - 0.6R is greater than or equal to the minimum value in Table 1.  
 
B.4.5  Notes  for guidance  
 
B.4.5.1  The kitchen blender  
 
The requirement is for a kitchen food blender operated at a speed, which will deliver a lather volume 
of 600 ± 100 mL from a standard solution of sodium lauryl sulphate. Commercial blenders may have 
adequate inte gral speed controls. Any blender may be operated through an external electronic speed 
controller or a variable output transformer. Normally the  lowest speed  will be required from blenders 
having integral speed control.  
 
B.4.5.2  Preparing the noodles  
 
The h ole size in the grater should be 2 – 3 mm diameter, but is not critical. The size of holes in a 
grater can be checked quickly by using a magnifier with a built -in measurement scale, or very simply 
by inserting the shafts of twist drills into the holes.  
 
A cheese grater with a rotary drum action may be used.  
 
Older soaps may create some dust/ broken noodles during the grating operation. This fine material 
will have been removed by sieving the noodles immediately after preparation.  
 
Prepared noodles can be k ept is a wide top, screw cap, jar or a sealed plastic bag. A sealed plastic 
bag is less efficient at retaining moisture but is adequate for 1 day. Ideally the samples should be kept 
in a refrigerator until it is re -equilibrated back to room temperature for  about 1 hour before testing.   
  
B.4.5.3  Temperature control  
 
All tests should be carried out at 25 ±2 °C and all apparatus and solutions should be at this 
temperature.   
 
The temperature of the foam is measured in the measuring cylinder, immediately afte r the foam 
volume measurement.  
 
It is not always easy to achieve this level of temperature control. To achieve a foam temperature in 
the specified range it may be necessary to start with the 300 ppm hard water supply adjusted to a 
slightly higher or sligh tly lower temperature than ambient.  
 DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  9  
Annex C 
(normative)  
 
Evaluation of the mushing properties of a bathing bar  
 
 
 
C.1 Principle  
 
A test piece of defined size is cut from the sample bar to remove harder outer layers. The test piece is 
preconditioned by g iving 18 x 180 degree twists under running water at 25 °C or in a bowl of water at 
25 °C. The bar is left for six hours on a piece of fabric that has been wetted  and drained of excess 
water. During the six hours the soap/ cloth are covered to prevent dryin g. At the end of the test period 
mush is removed from the test piece face in contact with the cloth. Weight loss from the test piece is 
expressed as mush per 30 cm2 of original surface area in contact with the cloth.  
 
C.2 Equipment  
 
C.2.1  For sample prepar ation  
 
— Coarse kitchen cheese grater  
— Sharp thin blade knife or carpenters plane  
— Callipers or ruler to ensure the sample dimensions  
 
C.2.1  Other equipment/ materials for the test  
 
Plastic or non -corrodible trays which are suitable sized for the test pi ece. Plastic soap dishes 7 x 11 x 
2 cm are quite suitable.  
 
Cotton cloth pieces cut and folded to fit as a triple layer inside the trays. Normal, flat weave, cotton 
sheeting as used for bed sheets will be quite suitable.  
 
C.3 Bar preparation  
 
C.3.1  Three ( 3) individual bars of a type should be tested. A test piece is cut from each bar. The test 
piece should if possible have a working face (to be applied to the fabric) of 6 ±1 cm x 4 ±1 cm.  
 
All bars in a set must be cut to have the same face size.  If the s mallest of the range of bars to be 
tested at a given time is too small to allow a working face within these limits, then all bars should be 
cut to the maximum size possible from the smallest bar.  
 
The longest axis of the test piece (6 ±1 cm) should be from  a direction parallel to the longest axis of 
the original bar sample.  
 
The working face should be a fresh surface from the interior of the bar sample. The face opposite the 
working face should be identified by making a small hole with a sharp object. This enables the 
working face to be identified after the preconditioning step.  
 
C.3.2  To cut the bar it is convenient to first trim it to the approximate size using a coarse kitchen 
cheese grater and then to make the final adjustments to a smooth surface with a  sharp thin -bladed 
knife or carpenters plane. If a plane is used, it is better to move the bar over the plane blade.  
 
C.4 Test procedure  
 
For each test piece  
 DARS 1455: 2018  
10 © ARSO 2018 — All rights reserved  C.4.1  The tray plus triple thickness of cloth is filled with demineralised water. The tray is the n held 
vertically to drain the water from the cloth. The vertical position is maintained until water ceases to run 
from the dish in a continuous stream i.e. starts to drip.  
 
C.4.2  The area of the working face of the test piece is measured (A).  
 
C.4.3  The working face of the bar is placed onto the damp fabric and then the tray plus soap are 
covered e.g. with a sealed plastic bag, to prevent water loss.  
 
C.4.4  The covered test piece and holder are maintained at 25 °C for 6 hours.  
 
C.4.5  The mushed soap test piece is removed from the tray and is weighed (W1).  
 
C.4.6  Mush is removed from the working face of the soap test piece by scraping with the edge of a 
blunt sided spatula or plastic ruler.  
 
C.4.7  The test piece is reweighed (W2) and the amount of mush remo ved is calculated as in C.5. 
The mush is expressed as grams per 30cm2 of original test piece surface area.  
 
NOTE  The procedure for weighing the bar and removing the mush will take some minutes. During that time the remaining soaps 
will continue to form mus h. While this time is not critical for a set of three test pieces from a given product, if more than one product is 
under test it is advised to stagger the start of the test for the second product. This will give adequate time to complete wo rk on the 
first set before the 6 -hour storage time of the subsequent set is completed.  
 
C.5 Calculation  
 
 Weight of mush (grams)   = W = W1 – W2 
 
 Surface area of bar (cm2) = A = (width x breadth)  
 
 Mush  = 
AW30  grams per 30 cm2 
 
C.6 Criteria for confor mity 
 
The test is done with three (3) separate samples of each product type, and the mean value from three 
samples is quoted  
X. The range of values (R) is quoted as the difference between the highest and 
lowest values obtained for a g iven product type.  
 
The sample lot of products shall be declared as conforming to the requirements for this standard if 
)6.0 ( R X
 is less than the maximum value given in Table 1.  DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  11  
Annex D 
(normative)  
 
Determination of grittiness in a bathin g bar  
 
 
 
D.1 Procedure  
 
Either  
 
Hold the soap tablet under a smooth stream of running water at a temperature of 30 °C and gently rub 
the two sides of the bar on the palm of one hand for one minute each side.  
 
or 
 
Immerse the soap in a bowl containing 5 lit res of water at 30 °C and gently rub two opposite bar faces 
with the palm of one hand for 30 seconds (15 seconds per bar face). Remove the bar from the water 
and continue to gently rub the two opposite bar faces for a further 30 seconds (15 seconds per fac e). 
 
Allow the used bar to dry in the open for 4 hours and examine the surface.   
 
A set of 3 samples will be tested for each product.  
 
NOTE 1   Hands will become hydrated and insensitive with prolonged immersion in water. Testers should wait 15 minutes 
between testing every 3 sets of products (9 grit tests).  
 
NOTE 2   If using a bowl rather than running water use fresh water after testing every set of 3 samples.  
 
D.2 Criteria for conformity  
 
The performance criteria are:  
 
During manipulation under running w ater the washing bar will not have a visibly rough surface and will 
feel smooth to the touch.  
 
No gritty particles will be observed on the surface of the dried bar 4 hours after the washing test.  DARS 1455: 2018  
12 © ARSO 2018 — All rights reserved   
Annex E 
(normative)  
 
Identification of  rosin content of fa tty mat ter in soaps  
 
 
 
E.1 Scope  
 
This Annex  specifies the Halphen -Grimaldi and Liebermann -Storch method for the identification of 
rosin in fatty matter.  
 
E.2 Reagents  
 
NOTE  Use only analytical grade reagents and distilled water.  
 
E.2.1 Acetic anhydride.  
 
E.2.2 Sulphuric acid, density 1 .53 g/mL. Cautiously add 97 mL of sulphuric acid (density  1.84 
g/mL) to 100 mL of water.  
 
E.2.3 Solution A. Dissolve 10 g of phenol in 27 mL of chloroform.  
 
E.2.4 Solution B. Dissolve 10 mL of bromine in 40 mL of chloroform.  
 
E.3 Procedure  
 
E.3.1 Halphen -Grimaldi method  
 
E.3.1.1 Place one or two drops of the fatty matter, reserved from the determination of fatty matter  
(ISO 685 ), in a porcelain basin and add approximately 2 mL of the solution A to dissolve it. Wet  the 
walls of  the basin by tilting and turning it and let it stand for a few seconds so that the walls of  the 
basin are covered with a very thin film of the solution.  
 
E.3.1.2 Hold the neck of the flask containing the solution B in such a position that the bromine  vapo ur 
diffuses into the porcelain dish and comes into contact with the walls. In the presence of  rosin a 
blueish -grey to purple colour develops immediately.  
 
E.3.1.3 Carry out a comparison test with a sample of fatty matter to which 2 % ( m/m) of rosin has  
been added.  
 
NOTE  Should the colour reaction in E.3.1.2 be masked by other colours, conduct a second qualitative test, using the 
Liebermann -Storch method.  
 
E.3.2 Liebermann -Storch method  
 
E.3.2.1 Place 1 g - 2 g of the fatty matter in a test tube, add 5 mL - 10 mL of the acetic anhydride,  and 
heat the mixture in a boiling water bath for approximately 3 min. Cool to room temperature and  pour 1 
mL - 2 mL of the solution into a white porcelain basin.  
 
E.3.2.2 Allow one or two drops of the sulphuric acid to run do wn the side of the basin. If rosin is  
present, a violet colour immediately develops where the acid is in contact with the solution. This  
colour then turns brown on standing.  
 
E.3.2.3 Carry out a comparison test with a sample of fatty matter to which 2 % ( m/m) of rosin has  
been added.  
 DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  13  
Annex F 
(normative)  
 
Determination of rosin content of fatty ma tter in soaps  
 
F.1 Scope  
 
This Annex  specifies a method for the determination of the rosin content of fatty matter in soaps.  
 
NOTE 1  Before proceeding with the q uantitative determination of rosin, first establish its presence by a qualitative test (see 
Annex E). 
 
NOTE 2  The following method is not accurate for rosin concentrations below a mass fraction of 5 %.  
 
F.2 Reagents  
 
NOTE  Use only analytical grade reagents  and distilled water.  
 
F.2.1 Diethyl ether  
 
Free from peroxides.  
 
F.2.2 Sodium chloride  
 
F.2.3 Sodium sulfate  
 
Anhydrous.  
 
F.2.4 Hydrochloric acid solution  
 
Dilute one volume of concentrated hydrochloric acid (density 1 .16 g/mL) with two volumes of  distill ed 
water.  
 
F.2.5 Sodium hydroxide solution  
 
10 % mass fraction aqueous solution.  
 
F.2.6 Naphthalene -2-sulfonic acid solution  
 
Dissolve 40 g of naphthalene -2-sulfonic acid in 1 L of absolute methanol.  
 
F.2.7 Sodium chloride solution, saturated  
 
Shake an exc ess of sodium chloride with water at ambient temperature until no more dissolves.  Keep 
the solution over solid sodium chloride.  
 
F.2.8 Sodium chloride solution, 10 %  
 
Dissolve 10 g of sodium chloride in 100 mL of water.  
 
F.2.9  Standard ethanolic potassium hydroxide solution, 0.2 N  
 
F.2.9.1 Preparation  
 
Purify 95 % (by volume fraction) ethanol by boiling 1 .5 L of it over 20 g of potassium hydroxide for  1 h 
under reflux. Distil, discarding the first 50 mL of the distillate and stopping the distillation when  
approximately 1 .3 L have been distilled. Dissolve 12 g of potassium hydroxide in 1 L of the purified  
ethanol, allow the solution to stand for approximately one week, and then decant the clear  
supernatant liquid from any potassium carbonate that has precipit ated.  DARS 1455: 2018  
14 © ARSO 2018 — All rights reserved   
F.2.9.2 Standardization  
 
Accurately weigh out approximately 1 g of potassium hydrogen phthalate (previously dried at  110 °C ± 
5 °C for 3 h) into a 250 mL Erlenmeyer flask. Add approximately 100 mL of carbon  dioxide -free 
distilled water and three dro ps to five drops of the phenolphthalein indicator, and swirl  gently until the 
solid has dissolved. Titrate the solution with the standard ethanolic potassium  hydroxide solution, until 
a permanent pink colour is formed.  
 
F.2.9.3 Calculation  
 
Normality of th e standard ethanolic potassium hydroxide solution ( N): 
 
B. AN8974
 
 
where  
 
A is the mass of the potassium hydrogen phthalate, in grams;  
 
B is the volume of the standard ethanolic potassium hydroxide solution used for the  
titration, in millilit res. 
 
F.2.10 Methyl orange indicator  
 
Dissolve 0 .2 g of methyl orange in 100 mL of carbon dioxide -free water.  
 
F.2.11 Phenolphthalein indicator  
 
Dissolve 0 .5 g of phenolphthalein in 100 mL of freshly boiled, 95 % (by volume fraction) ethanol.  
 
F.3 Procedur e 
 
F.3.1 Preparation of fatty matter  
 
F.3.1.1 Carbolic soaps  
 
F.3.1.1.1  Weigh out accurately into a 600 mL beaker such quantity of the test sample as contains  
approximately 40 g of fatty matter and dissolve it in approximately 400 mL of hot water, to which  40 
mL of the sodium hydroxide solution has been added.  
 
F.3.1.1.2  Salt out the soap by adding sufficient sodium chloride to the hot solution to saturate it (at  
ambient temperature) with sodium chloride. Filter the soap quantitatively, and allow it to drai n. 
 
F.3.1.1.3  Dissolve the drained soap in approximately 400 mL of hot water, and repeat the salting out  
and filtering procedure.  
 
F.3.1.1.4  Wash the soap thoroughly with the saturated sodium chloride solution, and proceed in  
accordance with F.3.1.2.2 to F.3.1.2.7.  
 
F.3.1.1.5 Reserve the combined filtrates and washings for the determination of carbolic acids.  
 
F.3.1.2 Other soaps  
 
F.3.1.2.1  Weigh accurately into a 600 mL beaker such quantity of the test sample as contains  
approximately 40 g of fatty matter.  
 
F.3.1.2.2  Dissolve the soap in approximately 400 mL of hot distilled water, cool the solution, and  
slowly add an excess of the hydrochloric acid solution. Cover the beaker with a watch -glass and  heat DARS 1455: 2018  
© ARSO 2018 — All rights reser ved  15 the contents until the fatty matter separates into a c lear layer, but do not allow the temperature  to 
exceed 60 °C.  
 
F.3.1.2.3  In the cases of liquid and gel soaps, acidify the soap as it is.  
 
F.3.1.2.4  Cool to approximately 25 °C and transfer the contents of the beaker to a separating funnel.  
Rinse the watch -glass and the beaker with portions of the diethyl ether totalling 100 mL and add  them 
to the separating funnel. Shake the mixture in the separating funnel vigorously for 1 min, and  let it 
stand until the two phases have separated.  
 
F.3.1.2.5  Draw off and discard the aqueous layer and wash the ether extract with 50 mL portions of  
the sodium chloride solution until the last washing is neutral to the methyl orange indicator.  
 
F.3.1.2.6  Filter the washed ether extract into a 250 mL beaker through a filter pape r containing  
approximately 5 g of anhydrous sodium sulfate, and wash the separating funnel and the filter with  
small portions of the diethyl ether.  
 
F.3.1.2.7  Evaporate the ether extract plus washings on a warm water bath. When the residue is just  
dry, hea t it rapidly to 130 °C and immediately place the beaker in a desiccator to cool.  
 
NOTE  F.3.1.2.2 to F.3.1.2.7 should be completed in the shortest possible period of time, so as to prevent oxidation of the 
fatty acids.  
 
F.3.2 Determination of rosin content  
 
F.3.2.1 Weigh accurately into a 150 mL flask with a ground -glass joint approximately 2 g of the  
prepared fatty matter ( F.3.1.2.7) and reserve the rest in the case of soap powders for the fatty matter  
titre determination.  
 
F.3.2.2 Add exactly 25 mL of the naphthalene -2-sulfonic acid solution to the flask and two or three  
glass beads, and boil under reflux for 30 min.  
 
F.3.2.3 Carry out a blank test at the same time, using exactly 25 mL of the naphthalene -2-sulfonic  
acid solution only.  
 
F.3.2.4 Cool the cont ents of both flasks (sample and blank) to ambient temperature, add 0 .5 mL of  
the phenolphthalein indicator to each flask, and immediately titrate to the end point with the  standard 
ethanolic potassium hydroxide solution.  
 
F.4 Calculation  
 
Rosin content of fatty matter, as a mass fraction percentage ( R): 
 
01634.C. N)BA(R 
 
 
where  
A is the volume of the standard ethanolic potassium hydroxide solution used for the 
titration  of the sample solution, in millilitres;  
 
B is the volume of the standard ethanoli c potassium hydroxide solution used for the 
titration  of the blank solution, in millilitres;  
 
N is the normality of the standard ethanolic potassium hydroxide solution;  
 
C is the mass of the fatty matter taken, in grams.  
 DARS 1455: 2018  
16 © ARSO 2018 — All rights reserved   
Bibliography  
 
 
Working Group to identify and acknowledge useful literature used in the preparation of this standard.  
 
IS 13498:1997, Bathing bar — Specification  
 
EU Cosmetics Directive 76/768/EEC  
 
New EU Cosmetic Products Regulation (EC) No 1223/2009  
 
REACH Regulation (EC) No 1907/2006  
 
 
 DARS 1455: 2018 
© ARSO 2018 — All rights reserved