TBS/CDC 13 (6546) P 3 
© TBS – 2020                                                                                                                                                 First Edition  
  
 
 
 
 
 
 
DRAFT  TANZANIA STANDARD 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Shellac varnish — Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU  OF STANDARDS 
 
 
 
 
. 
 
 
 
 
 
 
 
 
  
 
TBS/CDC 13 (6546) P 3 
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 Foreword 
This Draft Tanzania Standard was prepared by the Technical Co mmittee on Paints Varnishes  and related Products 
under supervision of Chemicals Divisional Standards Committee  and it is in accordance with the procedures of the 
Tanzania  Bureau of Standards.  
 
During the preparation of this standard  reference was made to the followin g standards : 
Kenya  Standard KS 2516: 2014 Shellac varnish — Specification  published by Kenya Bureau of Standards : 
ASTM  D360 – 12 (Reapproved 2019) Standard Specification for Shellac Varnishes  published by ASTM International.  
For the purpose of deciding whether a particular requirement of this standard is complied with, the final value observed 
or calculated expressing the result(s) of a test or analysis shall, be rounded off in accordance with  TZS 4  Rounding off 
numerical values . The number of significant places retained in the rounded off value should be the same as that of the 
specified value in this standard.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
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 TBS/CDC 13 (6546) P 3 
 
 
 
Shellac varnish — Specification  
 
 
 
1. Scope  
This Draft Tanzania Standard specifies requirements , methods of sampling and test ing for Shellac varnish used for 
protection and decoration of wooden surfaces.  
 
 
2. Normative references  
The f ollowing normative references are indispensable for the application of this standard. For dated references, only the 
edition cited applies. For undated references, the latest edition of the normative references (including amendments) 
applies  
TZS 525/ ISO 1513, Paints and varnishes - Examination and preparation of samples for testing   
TZS 1896 -1/ ISO 9117 -1, Paints and varnishes — Drying tests — Part 1: Determination of through -dry state and through -
dry time  
ISO 4618 , Paints and varnishes — Terms and definitions  
TZS 1887/ ISO 1516 , Determination of flash/no flash — Closed cup equilibrium method  
TZS 1893/ ISO 1514, Paints and varnishes – Standard panels for testing  
TZS 1892/ ISO 1518 Paints and varnishes - Scratch test  
FTZS 1896 -1:2016/ ISO 9117 -1 Paints  and varnishes - Drying tests - Part 1: Determination of through -dry state and 
through -dry time.  
TZS 1890:2016/ ISO 15528 Paints, varnishes and raw materials for paints and varnishes — Sampling  
TZS 1894/IS0 6503 Paints and Varnishes – Determination of total lead – Flame atomic absorption spectrometric method  
TZS 4 Rounding off numerical values  
TZS 604:2015/ ISO 2813 Paints and varnishes - Determination of gloss value at 20 degrees, 60 degrees and 85 
degrees  
 
3. Terms and definitions  
For the purposes of this standard, the terms and definitions given in ISO 4618 -1 and the following shall apply:  
3.1. batch  
a) when the material is supplied in single containers  with specific identification , a final blend of the material in one 
large vessel from which smaller containers are filled for distribution and marketing or  
b) when the material is supplied in dual containers  with specific identification , a final blend of the base component 
in one vessel and of the curing agents in another vessel, from which separate containers of base component and 
curing agents are filled for distribution and marketing . 
3.2. cut 
the number of kil ograms of dry lac resin (containing only that amount of moisture acceptable for proper cutting with the 
solvent to ensure satisfactory varnish) that were added 3.8 L of specified solvent in manufacturing the varnish  
DRAFT TANZANIA STANDARD   
 
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4. Requirements  
 
4.1. General requirements  
4.1.1.   Description  
 
4.1.2.  The material shall be clear  and, free from undissolved matter .  
4.1.3.  Composition  
The material shall be based on resins, drying oils, denatured alcohol, driers and thinners in suitable proportions.  
4.1.4.  Odour  
The odour of the varnish shall be characteristic of the normal ingredients of this material and shall not be unduly 
unpleasant . 
4.1.5.  Grade and Types  
There shall be two grades;  A and B of orange shellac varnish and two grades regular and refined of bleached lac . 
Each type and grade may be furnished in very light, light, medium, heavy, very heavy, or extra heavy body as specified  
in Table 2   
4.1.6.  Finish   
The dry shellac varnish shall show a smooth and gloss surface.  
4.2. Specific requirements  
4.2.1 Shellac varnish regardless of grade or type shall conform to the specific requirements stipulated in Table 1 below  
Table 1 – Specific requirements for Shellac varnish  
S/No:  Parameter  Requirement  Test method  
1.  Specular Gloss  at 60°, min. 85 %.  TZS 604   
2.  Drying time, (hard drying), max 1 h TZS 1896 -1 
3.  Acid value, max.   15.0 Annex A  
4.  Non-volatile  content, % m/m , min.  28.0 Annex B  
5.  Flash point, min 40 °C  TZS 1887  
6.  Total Lead content, max.  90 ppm  TZS 1894  
 
4.2.1.  4.2.2 Body and Cut  
The body and cut of the respective types and grades shall be based on percent of non volatile matter and shall conform 
to the minimum requirements  stipulated in Table 2 below : 
 
 
 
 
 
 
  
 
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Table 2 — The table of body and cut of respective types and grades based on percentage non -     volatile matter content    
     
    
     Non-volatile matter content, %, min.   
         SL No.  
 Orange grades,  
A and B  Bleached,  
regular and refined    
    
  i.  Very light body,1.4/kg cut varnish  28.5 28.0      
  ii.  Light body,1.8/kg cut varnish  35.0 34.5 
  iii.  Medium body,  2.0/kg cut varnish  37.5 37.0 
  iv.  Heavy body,  2.3/kg cut varnish  40.0 39.5 
  v.  Very heavy  body,  2.7/kg cut varnish  44 43.5 
  vi.  Extra heavy body, 2.7/kg cut varnish  51.0 50.5 
 
4.2.2.  Scratch hardness  
When tested in accordance TZS 1892 , no such scratches shall produce a bare metal.  
 
4.2.3.  Storage stability  
The shellac varnish, as supplied shall be free of any skin, dry sediment s and coarse particles and shall show no 
evidence of l ivering or curding or other signs of container instability . When examined visually , shellac varnish shall be 
in such a condition that manual stirring readily produces a smooth uniform mixture of good bru shing consistency.  
4.2.4.  Rosin and rosin derivatives  
When tested in accordance with Annex C, rosin and rosin derivatives shall not be present.  
4.2.5.   Resistance to acids  
When tested in accordance with Annex D, the film shall not show any signs of disintegration and not more than 40 % 
loss of gloss from the original as determined by a gloss meter at an angle of 60° specular reflection.  
4.2.6.  Resistance to alkali  
When tested in accordance with Annex E, the film shall not show any signs of disintegration and not more than 40 % 
loss of gloss from the original as determined by a gloss meter at an angle of 450 seculars reflections.  
4.2.7.  Resistance to boiling water  
When test ed in accordance with Annex F, the film shall not show any signs of deterioration or any whitening, dulling 
or other visible defects when compared with the film of the control panel.  
4.2.8.  Skinning   
When tested in accordance with Annex G, the shellac varnish shall not show any sign of skinning after 48 h.  
5. Packaging  
The varnish shall be packaged in a suitable container that prevents it from deterioration during storage, 
transportation and handling.  
6. Labelling  
6.1 The labelling shall be either in English  or Kiswahili or in combination as agreed between the manufacturer and/or 
the supplier. Any other language is optional.  
6.2 The varnish shall be packaged in containers that are legibly and in delibly marked with the following information:   
 
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 a) the name of the product shall appear as "Shellac varnish;  
b) name and address of the manufacturer;  
c) the type  and grade ; 
d) net content;  
e) date of manufacture;  
f) batch number;  
g) best before date; and  
h) instructions for storage, use, disposal and safety precautions.  
 
7. Sampling  
Sampling shall be done in accordance with TZS 1890 . 
8. Quality of reagents  
Unless otherwise specified, analytical grade reagents and distilled water or de -ionized water of equivalent purity shall 
be used in all tests.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
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 Annex A   
(normative)  
Determination of the acid value  
 
A.1 Apparatus  
Flask long necked , 250 mL by 300 mL.  
A.2 Reagents  
A.2.1  Standard potassium hydroxide solution , 0.1 N.  
A.2.2 Solvent mixture   
Consists of equal parts of ethanol (95 %) and benzene. Neutralize the mixture with ethanolic potassium hydroxide 
solution (0.1 N) in the presence of phenolphthalein as indicator.  
A.2.3  Phenolphthalein indicator solution  
0.1 g of phenolphth alein in 100 mL of 60 % rectified spirit  
A.3 Procedure   
A.3.1  Add indicator solution to the required amount of solvent mixture in ratio of 2 mL to 125 mL and neutralize  with 
alkali to a faint but permanent ink colour  
A.3.2  Weigh 5 g to 10 g of the well mixed liquid sample accurately into the flask.  
A.3.3  Add 125 mL of the neutralized solvent mixture to the contents of the flask and dissolve sample  completely, 
warm if necessary.  
A.3.4  Titrate this against standard potassium hydroxide to the appearance of light permanent pink colour of  the same 
intensity as that of the neutralized solvent before the latter was added to the sample. The colour shall persist for 30 
s. 
A.4 Calculation   
Calculate the acid value as follows:  
Acid value (as mg of KOH/g sample) = 56.1x V N 
W 
where,  
V = volume in mL of standard potassium hydroxide solution;  
N = normality of the standard potassium hydroxide solution; and  
W = weight in g of the material taken.  
 
 
 
 
  
 
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Annex B  
(normative)  
Determination of Non-volatile matter.  
 
B.1 Apparatus  
B.1.1  Stoppered bottle  or weighing pipette  
B.1.2  Flat-bottomed metal dish  (friction -top can plug ) 
B.1.3  Oven (maintained at 105 °C to 110  °C) 
A.2 Procedure  
Place a portion of the thoroughly mixed sample in a stoppered bottle or weighing pipette.  Weigh the container and 
sample ; Transfer 1.25 g (± 0.25 ) of the sample to a weighed flat -bottomed metal dish about 8 cm in diameter (a friction -
top can plug). Weigh the container again  and by difference calculate the exact weight of the portion transferred to the 
weighed dish  (m0). Heat the dish and its contents in an oven maintained at 105 ° C to 110° C. for 3 h, cool, and weigh  
(m1). From the weight of the residue left in the dish and the weight of the sample taken , calculate the percentage of 
non-volatile  residue  
A.3 Calculation  
 
Non-volatile content, %  = 𝑚1
𝑚0 ×100 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
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Annex C  
(normative)  
 
Qualitative detection of rosin - Lieberman -storch test  
 
 
C.1 Apparatus  
C.1.1 Test tube , 2.5 cm by 15 cm.  
 
C.1.2 Filter funnel,  75 mm in diameter.  
C.1.3 Porcelain spot plate.  
C.2 Reagents  
C.2.1 Acetic anhydride.  
C.2.2 Bromine reagent , dissolve 1 part by volume of bromine in 4 parts by volume of carbon tetrachloride (CCl 4)  
C.2.3 Phenol reagent,  dissolve 1 part by volume of phenol in 2 parts by volume of carbon tetrachloride (CCl 4).  
C.2.4 Sulfuric acid reagent,  add 35.7 mL of concentrated sulfuric (H 2SO 4) slowly 34.7 mL of water and cool to  room 
temperature. Store in glass stoppered bottle  
C.3 Procedure  
Place  0.1 to 0.2 g of the sample in a test tube and add 15 mL of acetic anhydride Heat gently until the specimen is 
dissolved or dispersed.  Cool and filter with an ash less rapid filter paper, into a clean test tube  
Place a few drops and of the clear solution in a depression of the spot plate and add one drop of sulphuric acid 
reagent so that the acid will mix slowly with the filtrate  
C.4 Report  
If rosin is present, a fugitive violet colour develops immediately. A pink or brown coloration shall be igno red. A 
control specimen containing rosin shall be run simultaneously.  
 
 
 
 
 
 
 
 
 
 
 
  
 
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 Annex D  
 
(normative)  
 
Test for resistance to acids  
 
D.1 Apparatus  
D.1.1 Glass panels . 
D.1.2 Gloss meter . 
 
D.2 Reagents  
Sulfuric acid reagent, 2 % (w/v) solution of sulphuric acid (sp gr 1.84).  
D.3 Procedure  
Apply a single coat of the varnish by brush to a wet film thickness of 60 to 65 µm and allow to air dry at 25 ± 2 °C and 
50 ± 5 % relative humidity for 48 h  
D.3.2 Protect the edges of the panel by applying a coat of wax immerse  
D.3.3 The panels in a 2 % solution of sulphuric acid for 24 h at room temperature  
D.4 Report  
Film shall not show any signs of disintegration and not more than 40 % loss of gloss from the original as determined 
by a gloss meter at an angle of 45° specular reflections . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
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 Annex E 
 
(normative)  
 
Test for resistance to alkali  
 
E.1 Apparatus  
E.1.1 Glass panels . 
E.1.2 Gloss meter . 
E.2 Reagents  
E.2.1 Sulfuric acid reagent,  2 % (w/v) solution of sulphuric acid (sp gr 1.84).  
E.2.2 Laundry soap,  1 % (w/v) solution of laundry soap  
E.2.3 Sodium carbonate (Na 2CO 3), 2 % (w/v) sodium carbonate.  
E.3 Procedure  
Put to  air dry at 25 ± 2 °C and 50 ± 5% relative humidity for 48 h. Apply a single coat of the varnish to the panel by 
brush to a wet film thickness of 60 to 65 µm and allow to dry.  
Protect the edges of the panel by applying a coat of wax  
Immerse the panel prepared 1 % solution of laundry for 30 min at temperature of 25 ± 2°C. Remove the panel, wash 
in running water, dry for an hour and examine the film and subject to test. Immerse the panel in the solution of sodium 
carbonate, analytical g rade for 30 min at temperature of 25 ± 2°C 
Remove, wash in running water and dry for 1 h, examine the film  
 
 
 
 
 
 
 
 
 
 
 
 
 
       
 
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 Annex F  
(normative)  
 
Test for resistance to boiling water  
 
F.1 Apparatus  
F.1.1 Glass panels . 
F.1.2 Gloss meter . 
F.2 Reagents  
Boiling distilled water.  
F.3 Procedure  
Apply a single coat of the varnish to the panel by brush to a wet film thickness of 60 to 65 µm and allow to air dry at 
air dry at 25 ± 2 °C and 50 ± 5% relative humidity for 48 h. Keep one panel as a control  panel.  
Protect the edges of the panel by applying a coat of wax  
Immerse one of the panel in boiling distilled water for 15 min  
Remove the panel from water and examine the film after 2 h  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
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 Annex G  
(normative)  
 
Resistance to skinning  
 
 
G.1 Apparatus  
G.1.1 Container, 500 mL tin with a tight -fitting lid.  
G.1.2 Spatula.  
G.2 Procedure  
Fill the tin to three -quarters of its capacity, with the well mixed sample. Put the lid on securely, invert the tin for a few 
seconds and then allow it to stand undisturbed in the normal upright position for 48 h.  
 
Open the tin and use the spatula to examine the sample for skinning 
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