TBS/CDC -2(5795) P3 
© TBS 201 9 All right reserved                First Edition 201 9 
  
  
DRAFT TANZANIA STANDARD  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TBS/CDC -2(5795) P3- Household laundry detergent bars – Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
  
 
 TBS/CDC -2(5413) P 2 
 
© TBS 2019 All right reserved                 First Edition 2019  
 Foreword  
 
This Draft Tanzania Standard was developed by the Soap and Detergents Technical Committee under 
supervision of the Chemicals Divisional Standards Committee and it is in accordance with the procedures of 
the Bureau.  
In the preparation of this Draft Tanzania Standard assistance was drawn from IS 8180:1992 (Reaffirme d 2016) 
household laundry detergent bars  - Specification ; published by the Bureau of Indian Standards.  
In reporting the results of analysis of a test if the final value is to be rounded off, it shall be done in accordance 
with TZS 4 Rounding off numerical values  
 
  TBS/CDC -2(5795) P2 
2 
   TBS/CDC -2(5795 ) P3 
 
Household laundry detergent bars – Specification  
1 Scope  
This Draft Tanzania Standard specifies requirements, sampling and test methods for  household laundry 
detergent bars .  
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.  
TZS 638 -1/EAS 377 -1 Cosmetics and cosmetic products — Part 1: List of substances prohibited in cosmetic 
products  
TZS 1780/EAS 814 Determination of biodegradability of surfactants  — Test method  
TZS 1392(Part 2)/ISO 672, Analysis of soap — Determination of moisture and volatile matter content  
TZS 1392(Part 3)/ISO 673, Analysis of soap — Determination of ethanol insoluble matter  
TZS 610/ISO 2870 Surface active agents — Detergents — Determination of  anionic -active matter hydrolysable 
and non -hydrolysable under acid conditions  
FTZS 676 -1/ISO 2871 -1Surface active agents — Detergents – Determination of cationic -active matter content 
— Part 1:  High -molecular -mass cationic -active matter.  
FTZS 676-2/ISO 2871 -2Surface active agents — Detergents — Determination of cationic -active matter content 
— Part2: Cationic – active matter of low molecular mass (between 200 and 500)  
TZS 1396 -3/ISO 673, Soaps — Determination of content of ethanol -insoluble matt er 
ISO 862, Surface active agents — Vocabulary  
TZS 625/ISO 4313 Washing powders - Determination of total phosphorus (V) Oxide content - Quinoline 
phosphomolybdate gravimetric method  
FTZS 646 /ISO 4316 Surface active agents - Determination of pH of aqueous s olutions - Potentiometric method  
3 Terms and definitions  
For the purposes of this standard, the terms and definitions given in ISO862 shall apply.  
DRAFT TANZANIA  STANDARD  TBS/CDC -2(5413) P 2 
 
© TBS 2019 All right reserved                 First Edition 2019  
 4 Requirements  
4.1 General requirements  
4.1.1  Laundry detergent bar shall be free from visible dirt and other foreign matter.  
4.1.2  Laundry detergent bar shall be of firm texture and possess good lathering and cleaning properties.  
4.1.3  Laundry detergent bar shall be free from objectionable odour. It shall not leave objectionable odour on 
clothes after washi ng and thoroughly rinsing with water.  
4.1.4 When coloured laundry detergent bar is used in washing any safe white fabric, it shall not leave any 
visible stains on the fabrics after washing and thorough rinsing with water when tested in accordance with 
Anne x A. 
4.1.5  When immersed in distilled water for one hour at 25 C – 30 C, laundry detergent bar  shall not 
disintegrate, and when dried at room temperature for 25 h thereafter, it shall not crumble, crack or break.  
4.1.6 All the ingredients used in the product  shall comply with the requirements of all parts of TZS 638  
4.2 Specific quality requirements  
Laundry detergent bar shall also comply with the specific quality requirements given in Table 1, when tested in 
accordance  with the method prescribed therein.  
Table 1 — Specific quality requirements for laundry detergent bar  
S/No  Characteristic  Requirement  Method of test  
i)  Moisture and volatile matter content at 105 °C, % by 
mass, max.  30 TZS 1392 -2 
ii)  Active ingredient, % by mass, min.   20 TZS 610  
TZS 676 -1 
TZS 676 -2 
iii)  Matter insoluble in alcohol, % by mass, max.  90 TZS 1392 -3 
iv)  Phosphate (expressed as sodium tripoly -phosphate), 
% by mass of matter insoluble in alcohol, max.  15 TZS 625  
v)  pH of 1 % solution (m/v), at 25 °C ± 2 °C  9 - 11 TZS 646  
vi)  Non-detergent organic matter, % by mass, max.  1.0 Annex E 
vii)  Matter insoluble in water*, % by mass, max.  5.0 Annex C  
viii)  Available O 2 as sodium perborate, %, max  10 Annex D  
ix)  Biodegradability test  To pass the test  TZS 1780  
* For the case of non -phosphate -based  laundry detergents, MIW shall be 15 % by mass, max.  TBS/CDC -2(5795) P2 
4 
  
5 Packaging and labelling  
5.1 Packaging  
Laundry detergent  bar shall be packed in clean and dry containers made of a material, which does not affect 
the product and which protects the product from exces sive loss of moisture and shall be free from 
contamination.  
5.2 Labelling  
Each bathing bar pack shall be  legibly and indelibly labelled either in Englis h or Kiswahili or combination or any 
other language as agreed between the manufacture r and supplier  with the following information : 
a) name of the product as  ‘laundry detergent bar ’; 
b) manufacturer’s name and physical address;  
c) country of origin ; 
d) recognized trade m ark (if any);  
e) net content ; 
f) batch number or code number;  
g) date of manufacture and best before date;  and 
6 Sampling  
Sampling shall be  done in accordance with Annex B . 
7 Criteria for conformity  
The lot shall be deemed to comply with the requirements of this st andard if, after inspection and testing, the 
requirements of Clause 4 and Clause 5 are satisfied.  
 TBS/CDC -2(5413) P 2 
 
© TBS 2019 All right reserved                 First Edition 2019  
 Annex A  
(normative)  
 
Determination of staining test of laundry  detergent  bar 
A.1 Method 1: Undissolved powder (5.0 % product concentration)  
A.1.1  Principle  
Test pieces of cloth of defined area are rubbed with soap and then dipped in water overnight then scrubbed 
and rinsed in running water.  
A.1.2  Materials  
Pieces of white cott on, nylon and Crimpling  C cloth  
A.1.3  Procedure  
A.1.3.1  Rub evenly about 10 g of soap over a 15 cm x 7.5 cm test swatch placed on a china plate.  
A.1.3.2  Pour gently 50 -mL of hot water (approximately 55 °C) into the plate so that the test swatch is 
covered and left overnight (16 h).  
A.1.3.3  Hand rub the swatch 10 times and then rinse each of the three test swatches are rinsed twice in 
about two litres of water and then dried in the drier.  
NOTE  The staining test is conducted in triplicate for all cloth types.  
A.2 Method 2: Pre -dissolved soap (2.5 % product conce ntration)  
A.2.1  Principle  
The method involves subjecting fabrics to prolonged soaking in a highly concentrated soap solution.  
A.2.2  Materials  
Pieces of white cotton, nylon and Crimpling  C cloth of dimension 15 cm x 7.5 cm  
A.2.3  Procedure  
A.2.3.1  Weight 1 0 g of soap in a honey jar and then add 200 mL of hot water at a temperature of 
approximately 60 °C, shake until when the soap is thoroughly dissolved.  
A.2.3.2  Place a test swatch A 15 cm x 7.5 cm in the soap solution (A.2.3.1)  and allow standing  overnigh t.  
A.2.3.3  Transfer the test swatch in a bowl containing one litre of water and then agitate vigorously by hand 
for 10 s.  
A.2.3.4  Rinse the test swatches in 5 L of water by hand. The times should be fixed for all washes, and 
then dry swatches.  
NOTE  The s taining test should be conducted in triplicate for all cloth types.  TBS/CDC -2(5795) P2 
6 
 Annex B  
(normative)  
 
Sampling  of laundry detergent bar  
B.1 Procedure  
B.1.1 In a single consignment, all packages (cartons) containing laundry detergent bars  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 B.1.  
Table B.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 
 
B.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 package , whe re 
k is the integral part of Nn.  
B.1.3 From each package thus selected, draw at random an equal number of bars so as to obtain a total 
mass of at least 2 kg.  
B.2 Preparation of test samples  
B.2.1 Composite sample  
Weigh each cake separately (including an y 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 ei ghths of each specimen. Mix the 
gratings and place in a clean, dry, airtight glass container.  
B.2.2 Samples for testing  
Immediately after preparation of composite sample ( B.2.1), take at one time all test samples required for the 
tests in 4.2. Weigh out t he test sample required for determination of free alkali or acid content, and use it 
immediately.  TBS/CDC -2(5413) P 2 
 
© TBS 2019 All right reserved                 First Edition 2019  
 Annex C 
(normative)  
 
Determination of matter insoluble in water  
C.1 Procedure  
C.1.1  Starting with a fresh portion of the material, weigh accurately about 5 g of the material into a beaker, and 
digest with 50 mL of ethyl alcohol by heating on a steam bath for about 2 min. Stir and break up any hard lump 
with a glass rod flattened at one en d. Allow the solid matter to settle and decant the hot alcoholic solution 
through a sintered glass filter funnel fitted to a Buchner flask, to which suction is applied. Repeat the alcoholic 
digestion in a similar manner with five further consecutive 30 -mL portions of boiling ethyl alcohol. Filter each 
extract in turn through the same sintered glass  funnel and, finally, wash the residue several times with hot ethyl 
alcohol to remove all the alcohol solubles. Dry the sintered glass funnel with the residue in an air -oven at a 
temperature of 105 °C ± 2 °C until a constant mass is obtained.  
C.1.2 Even after digestion with five 30 -mL portions of boiling ethyl alcohol, the alcohol insoluble portion may 
sometimes be found to be sticky. In that case, treat it further  with more boiling ethyl alcohol until it is free from 
active matter and the alcohol insoluble portion is no longer sticky.  Do not dry or weigh the matter insoluble in 
alcohol. After filtering and washing the residue thoroughly with hot ethyl alcohol, chan ge the receiver, extract 
the residue with successive portions of distilled water at about 60 °C, and wash the residue several times to 
remove all the water solubles. Dry the sintered glass funnel with the residue in an air -oven at a temperature of 
105 °C ±  2 °C until a constant mass is obtained . 
C.2 Calculation  
The m atter insoluble in water  is expressed as follows:  
Matter insoluble in water, % by mass =  100 
mm1  
where  
m1 is the mass , in grams,  of matter insoluble in water; and  
m is mass , in grams,  of material taken for the test.  TBS/CDC -2(5795) P2 
8 
 Annex D 
(normative)  
 
Test method for perborate  
D.1 Method  
Weigh  1.5 g to2g of sample, dissolve in wat er and make up to exactly 250 mL . Take an aliquot of 25 mL 
for titration and add 20 mL  of 0.1M sulphuric acid. Titrate immediately with standard 0.1N potassium 
permanganate until a faint pink colour persists.  
D.2 Calculation  
The available oxygen shall be expressed as follows:  
% available  oxygen = 
Wa N x0.8       
Where; 
a is the titre;  
Nis the normality of potassium permanganate ; 
Wis the weight of material in aliquot . 
NOTE: When fresh contains approximately 95% corresponding to 9.9% available oxygen.  TBS/CDC -2(5413) P 2 
 
© TBS 2019 All right reserved                 First Edition 2019  
 Annex E  
(normative)  
 
Determination of non -detergent organic matter  
E.1 General  
The term non -detergent organic matter includes hydrocarbons, fatty alcohols and perfumes. Using petroleum 
ether and under the conditions prescribed, non -detergent organic matter only is  extracted leaving any 
alkylolamide present in the material.  
E.2 Apparatus  
E.2.1 Evaporating basin  
E.2.2 Separating funnels, 1 000 mL capacity  
E.2.3 Wide mouthed flat -bottomed flask, 200 mL capacity  
E.2.4 Buchner flask, 500-mL capacity  fitted with a sintered glass filter funnel (porosity 4)  
E.3 Reagents  
E.3.1 Ethyl alcohol, 50 %, 7 0 %, 90 % and 96% (by volume)  
E.3.2 Petroleum ether,  boiling range 40 °C to 60 °C non -volatile residue at 80 °C maximum 0.001%  
E.3.3 Acetone,  non-volatile residue at 80 °C maximum 0.001 %  
E.4 Procedure  
E.4.1 Weigh accurately about 5 g of the material in a  150 mL squat beaker. Extract with 50 mL of hot 90 
% ethanol by heating on the steam bath for about 2 min stirring and breaking up any hard lumps with a glass 
rod flattened at the end.  
Allow the solid matter to settle and decant the hot aIcoholic solution through a sintered glass filter funnel 
(porosity 4) fitted to a 500 -mL Buchner flask to which suction is applied. Repeat the extraction in a similar 
manner with five further consecutive 30 -mL quantities of boiling 90 % ethanol. Pass each extract in turn through 
the filter into the flask.  
E.4.2 Transfer quan titatively all the combined filtrat e from the Buchner flask to a 1 L separating funnel 
and rin se the flask four times with 40 mL quantities of distilled water, transferring each wash in turn to the 
separating funnel. Add 100 mL of petroleum ether, swirl ge ntly to ensure adequate mixing and allow the two 
phases to separate. Run off the aqueous alcoholic layer into a second separating funnel, and extract with 75 
mL of petroleum ether. Repeat the extraction of the aqueous alcoholic phase in the third separatin g funnel with 
a further 75 mL of petroleum ether. Combine the three ether extracts in the first separating funnel. Rinse each 
of the two empty funnels with a few millilitres petroleum ether and add the rinsing to the combined ether 
extracts.  
E.4.3 Wash the  combined ethe r extracts and rinsing (see E .4.2) with four successive 50 -mL portions of 
70 % ethyl alcohol, shaking and removing the alcoholic phase each time. Transfer the ether layer in stages to 
a tared flask and evaporate off the solvent. Add 10 mL of acetone and evaporate off the solvent. Rotate the 
flask on a steam bath during the operation. Cool the flask to about 60 °C to 65 °C, gently blow out the last 
traces of solvent with a current of dry air, cool in a desiccators  and weigh.  TBS/CDC -2(5795) P2 
10 
 E.5 Calculation  
The n on- detergent organic matter  is expressed as follows:  
Non- detergent organic matter, %, by mass  
where  
m1 is the mass , in grams,  of the non -detergent organic matter in the flask; and  
m is the mass , in grams,  of the material taken for the test. 
 
mm1100=