TBS/CDC 7 ( 5809) P3 
 
©TBS 2020  - All rights reserved        Second Edition  
 
  
 
 
 
 
 
 
 
DRAFT TA NZANIA STANDARD 
 
 
 
 
 
 
 
 
 
Hydrochloric acid — Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU  OF STANDARDS  
 
 
 
 
  
 
 
 
 
 
 
 
 
 TBS/CDC 7 ( 5809) P3 
2 
  
Foreword 
This Draft  Tanzania Standard was prepared by the Technical Committee on  Industrial and laboratory 
chemicals under supervision of Chemicals Divisional Standards Committee and it is in accordance with 
the procedures of the Tanzania Bureau of Standards.  
This second edition cancels and replaces the first edition, TZS 505: 1995  Specification for hydrochloric 
acid which technically revised by deleting pure grade and remaining with two grades i.e. technical and 
analytical grades.  
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.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 TBS/CDC 7 ( 5809) P3 
3 
  
 
 
 
 TBS/CDC 7 ( 5809) P3 
 
 
 
 
Hydrochloric acid  — Specification   
 
 
1. Scope  
This Draft Tanzania Standard specifies requirements and methods of test and sampling of 
hydrochloric acid.   
2. Normative references  
The following normative references are indispensable for the application of this standard. For dated 
references, only the edition citied applies. For undated references, the latest edition of the normative 
references (including amendments) applies  
TZS 4 Rounding off numerical values  
TZS 59/ISO: 3696 Water for analytical laboratory use – Specification and test method  
 
3. Terms and definitions  
 
<<<<<<<<Not applicable>>>>>>>>  
 
 
4. Requirements  
 
4.1. General requirements  
 
4.1.1  Grades  
There shall be two grades of hydrochloric acid, namely ; technical  grade and analytical /reagent  grade .  
4.1.2  Description  
4.1.2.1 Technical grade -The material shall be clear, yellow coloured liquid free from dirt and other 
visible impurities.  
4.1.2.2 Analytical reagent grade - The material shall be clear, colourless liquid,  
free from dirt and other visible impurities.  
 
4.2. Specific requirements  
Hydrochloric acid shall also comply with the following specific requirements given in Table 1, when 
tested according to the methods pres cribed in the Annex A. 
 
 
 
 
 
DRAFT TANZANIA STANDARD  TBS/CDC 7 ( 5809) P3 
4 
 Table 1 – Specific requirements for Hydrochloric acid  
SN Characteristic  Requirements  
Test 
method  Technical Grade  Analytical/Reagent 
Grade  
i.  Specific gravity at 300 K (26.85 °C, 
min 1.145  1.155  A.2 
ii.  Hydrochloric  acid (HCI) percent 
by mass, min. 30.0 32.0 A.3 
iii.  Residue on ignition, percent by 
mass, max.  0.1 0.0005 (5 ppm)  A.4 
iv.  Sulphates (as H 2SO 4), percent by 
mass, max.  0.1 0.0003 (3 ppm)  A.5 
v.  Iron (Fe), percent by mass, max. 0.005  0.0001  (1 ppm)  A.6 
vi.  Free chlorine and bromine (as Cl), 
percent mass, max.  0.02 0.0002  (2 ppm)  A.7 
vii.  Heavy metals (as Pb), percent by 
mass, max.  0.001 (10 ppm)  0.0002  (2 ppm)  A.8 
viii.  Sulphites (as SO 2), percent by mass, 
max.  0.05             0.0003  (3 ppm)  A.9 
 
5. Packing and labelling  
5.1 Packing  
Hydrochloric acid shall be packed in a suitable container that prevents it from deterioration of its 
quality during storage, transportation and handling.  
5.2 Labelling  
Each container shall legibly and indelibly label with the information  below  either in English or Kiswahili 
or in combination as agreed between the manufacturer and/or the supplier. Any other additional 
language is optional.  
a) Name and grade of the material;  
b) Name  and address of the manufacturer ;  
c) Trade mark, if any;  
d) Lot or batch number;  
e) Net content ; 
f) Date of manufacture ;  
g) Shall prominently display the words  ‘CORROSSIVE, HANDLE WITH CARE’.  
h) Pictogram s warning signs showing respective hazardous  
 
5.2.2 Manufacturer is required to provide the material safety data sheet for the Hydrochloric acid.  
5.2.3  In case of analytical reagent grade, the actual analysis of the hydrochloric acid  with respect to 
required characteristics shall also appear on the label.  
5.2.4 The packages shall be labelled with visible pictorial markings in red colour indicating  hazards 
associated with hydrochloric acid such as  corrosiveness.  
6. Sampling  
The method of drawing representative test samples of the material and the criteria for conformity s hall 
be as prescribed in Annex B. 
 
 TBS/CDC 7 ( 5809) P3 
5 
 Annex A 
(Normative)  
Analysis of hydrochloric acid  
A. 1 Quality of reagents  
Unless specified otherwise, analytical chemical reagents and distilled water shall be used in the test 
procedures.  
A.2 Determination of specific gravity  
A. 2.1 Apparatus   
Squibb specific gravity bottle. The specific gravity bottle is of 100 mL capacity, having a ground -in 
graduated capillary tube and glass stopper.  
A.2.2 Procedure  - Clean and thoroughly dry the specif ic gravity bottle and weigh it. Fill it up to the mark 
with freshly boiled and cooled water which has been maintained at a temperature of 300 ± 1 K, and 
weigh. Remove the water, dry the bottle again and fill it with the material maintained at the same 
temp erature. Weigh the bottle again.  
A.2.3 Calculation  
A.2.3.1  Specify the temperature of testing.  
A.2.3.2  Calculate as follows:  
Specific gravity at 300/300 K  (26.85/26.85 °C) = C−A
B−A 
Where  
A = weight in g of the empty specific gravity bottle,  
B = weight in g of the spe cific gravity bottle with water and   
C= weight in g of the specific gravity bottle with the material, specific gravity bottle, and  
A.3 Determination of hydrochloric acid  
A.3.1 Reagents   
A.3.1.1  Standard sodium hydroxide solution  - 1 M  
A.3.1.2  Methyl orange indicator solution  - dissolve 0.05 g or methyl orange in 100 mL of water.  
A.3.2 Procedure  - Weigh about 3 g of the material to the nearest milligram in a weighed stoppered 
weighing bottle containing about 10 mL of wat er. Transfer the contents completely into a clean, dry 
250 mL flask and dilute it with about 100 mL of water. Titrate against standard sodium hydroxide 
solution, using methyl orange as indictor.  
A.3.3 Calculation  
Hydrochloric acid (HCI) percent by weight  = 3.65  V
W  
 TBS/CDC 7 ( 5809) P3 
6 
 Where,  
\/= volume in mL of standard sodium hydroxide solution used, and  
W= weight in g of the material taken for the test.  
A.4 Determination of residue on ignition  
A.4.1 Procedure  - Transfer about 25 g of the material, accurately weighed to 0.01 g into a weighed 
porcelain dish. Evaporate to dryness on a sand -bath in a fume cupboard. Transfer the dish to a muffle 
furnace and raise the temperature till it reaches 973 K to 1 023 K. Cool in a desiccator and weigh.  
A.4.2 Calculation  
Residue on ignition, percent by weight  = 100 W1
W2 
where  
W1 = weight in g of the residue, and  
W2 = weight in g of t he material taken for the test.  
 
A.5 Test for sulphates  
A.5.1 For technical grade  
A.5.1.1  Reagent  
A.5.1.1.1  Sodium chloride  
A.5.1.1.2  Barium chloride solution  – approximately 10 percent (w/v).  
A.5.1.2  Procedure  – Weigh, to the nearest 0.01 g, 10 g of the material into porcelain dish, add 0.5 of 
sodium chloride and evaporate to dryness. Moisten the residue with 1.000 g of the material, add 200 
mL of boiling water and filter if necessary. Bring the contents to boi l over a low flame and, add slowly 
and with stirring, 5 mL of hot barium chloride solution. Boil the contents for two minutes and allow the 
precipitate to settle for four hours. Filter the supernatant liquid through a tared sintered glass crucible 
(G No.4)  or a tared Gooch crucible and transfer the precipitate carefully into the crucible. Wash 
thoroughly with hot water till free from chlorides. Heat the crucible at 105° to 110°C to constant weight.  
A.5.1.3 Calculation  
Sulphates (as H 2SO 4), percent by weight =  42.02 W
11 
Where 
W = weight in g of the precipitate  
A.5.2 For analytical reagent grade  
A.5.2.1 Reagents  
A.5.2.1.1 Sodium chloride  
A.5.2.1.2 Hydrochloric acid  – approximately 1 M, sulphate -free. TBS/CDC 7 ( 5809) P3 
7 
 A.5.2.1.3 Barium chloride solution  – same as in B. 5.1.1.2.  
A.5.2.1.4 Standard sulphate solution  – Dissolve 0.178 g of potassium sulphate in water and make up 
the volume to 100 mL. Dilute 100 mL of the solution in a graduated flask to 1000 mL. One millilitre of 
the diluted solution contain s 0.01 mg of sulphate (as H 2SO 4). 
A.5.2.2 Procedure  – To 20.00 g of the material add 20 mg of sodium chloride and evaporate to dryness. 
Take up the residue with 5 mL of water and 0.5 mL of hydrochloric acid. Filter, wash with water to 
make up to 10 mL and add 1 mL of barium chloride solution. Carry out a c ontrol test in the same 
manner using 6 mL of standard sulphate solution in place of the material. Stir the two solutions and 
compare the turbidity produced.  
The requirement prescribed in table 1 shall be taken as not having been exceeded if the turbidity 
produced with the material is not greater than that produced in the control test.  
 
A.6 Test for Iron  
A.6.1 Apparatus  
Nessler tubes  – 50 mL capacity.  
A.6.2 Reagents  
A.6.2.1  Ammonium persulphate  
A.6.2.2  Butanolic  potassium thiocyanate solution – Dissolve 10 g of potassium thiocyante in 10 mL of 
water. Add sufficient n -butanol to make up to 100 mL and shake vigorously until the solution is clear.  
A.6.2.3  Standard iron solution – Dissolve 0.702 g of iron  (II) ammoni um sulphate        
(FeSO 4.(NH 4)2SO 4.6H2O) in about 50 mL of water containing about 10 mL of dilute sulphuric acid (10 
percent v/v) and dilute to 1000 mL. Immediately before use, dilute 50 mL of the solution to 1 000 mL. 
One millilitre  of the dilute solution contains 0.005 mg of iron (as Fe).  
A.6.3 Procedure  
A.6.3.1  For technical grade – Dilute 1.000 g of the material to  100 mL with water. Transfer 10 mL of 
this solution to a Nessler tube, add about 30 mg of ammon ium persulphate and 15 mL of butanolic 
potassium thiocyanate solution. Shake vigorously  for about 30 seconds and allow the layers to 
separate. Carry out a control test in anot her Nessler tube usi ng the same reagents and in the same 
total volume, with 4 mL of standar d iron solution in place of the material.  
A.6.3.2  For analytical reagent grades – Weigh 50.0 g of the material and evaporate it to 10 mL. Dilute 
it to 30 mL; add about 30 mg of am monium persulphate and 15 mL of butanolic potassium thiocyanate 
solution. Carry out the test as  prescribed under B.6.3.1 using 10 mL of standard iron solution in the 
control test.  
A.6.3.3 The requirement prescribed in table 1 shall be taken as not having b een exceeded if the 
intensity of colour produced with the material is not greater  than that produced in the respective control 
test. 
 
 TBS/CDC 7 ( 5809) P3 
8 
 A.7 Test for free chlorine and bromine  
A.7.1 Reagents  
A.7.1.1  Potassium iodide solution – 2 percent (w/v).  
A.7.1.2  Starch indicator solution – see annex C for its preparation  
A.7.1.3  Standard sodium thiosulphate solution – 0.01 M, freshly standardized.  
A.7.2 Procedure – Take 5. 00 g of the material for technical gra de 25.0 g of the material analy tical 
reagent grade, in a 100 mL gas-washing bottle and dilute to 50 mL with water. Connect this bottle to 
another gas -washing bottle conta ining 10 mL of potassium iodide solution diluted with 50  mL of water 
and containing 5 mL of starch solution. Aspirate a current  of air through the first bottle for 15 minutes 
and then transfer the contents of the second bubbler into a conical flask. Titrate the solution against 
standard sodium thiosulphate solution till the blue colour disa ppears.  
The relevant requirement prescribed in table 1 shall be taken as not having been exceeded if the 
volume of standard sodium thiosulphate solution required for the titration does not exceed:  
a) 2.8 mL in the case of technical grade,  
b) 0.15 mL in the case of analytical reagent grade.  
A.8 Test for lead  
A.8.1 Apparatus  
Nessler tubes  – 50 mL capacity.  
A.8.2 Reagents  
A.8.2.1  Ammonium hydroxide  – approximately 6 M.  
A.8.2.2  Acetic acid  – 33 percent (w/w.  
A.8.2.3  Sodium sulphide  solution – Dissolve 10 g sodium sul phide in sufficient quantity of water to 
produce 100 mL of solution. Filter and preserve in a dark bottle.  
A.8.2.4  Standard lead solution – Dissolve 1.60 g of lead ni trate, in water, add 1 mL of concentrated 
nitric acid and dilute to 1  000 mL. Pipette out 10 mL of this solution and dilute again to 1  000 mL. 1 mL 
of the  diluted solution contains 0.01 mg of lead (as Pb). This solution should be freshly prepared.  
A.8.3 Procedure  
A.8.3.1  For analytical reagent grade – Transfer 20 g of the material into a beaker and dilute to 25 mL 
with water. Neutralize with ammonium hydroxide. Acidify with 1 mL of acetic acid and transfer 
quantitatively to a Nessler tube. Add 10 drops of sodium sulphide solution and dilute the conten ts to 
mark. Carry out a control test in another Nessler tube using 4 mL of standard lead solution in place of 
the material. Compare the intensity of colour produced in the two tubes.  
A.8.3.2 The requirements prescribed in table 1 shall be taken as not having been exceeded if the 
intensity of colour produced with the material is not greater than that produced in the control test.  
 TBS/CDC 7 ( 5809) P3 
9 
 A.9 Determination of sulphi tes  
A.9.1 Reagents   
A.9.1.1  Standard iodine solution  - 0.05 M, freshly standardized.  
A.9.1.2  Standard sodium thiosulphate solution  - 0.1 M, freshly standardized.  
A.9.2 Procedure  - introduce successively into a 500 mL glass-stoppered conical flask 100 mL of freshly 
boiled water and 10 mL of standard iodine solution. Add while cooling about 50 g of  the material 
weighed to ± 0.01 g. Stopper the flask, mix and afte r 2 minutes, titrate the excess iodine with standard 
sodium thiosulphate solution, adding 5 mL of starch so lution towards the end of the titration.  
A.9.3 Calculation  
Sulphites (as SO 2), percent by weight =  0.3203  (10−V)
W 
Where 
V = volume in mL of standard sodium thiosulphate solution used in the  titration, and  
W = weight in g of the material taken for the test. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 TBS/CDC 7 ( 5809) P3 
10 
 Annex B 
(Normative)  
Sampling of hydrochloric acid and conformity criteria  
B.1 General requirements of sampling:  
In drawing, preparing and storing test samples, the followings precautions and directions shall be 
observed:  
B.1.1 Samples shall not be taken in an exposed place.  
B.1.2 The sampling instrument shall be clean and dry when used.  
B.1.3 Precautions shall be taken to protect the samples the material being sampled, the sampling 
instrument and the containers for the samples from adventitious contamination.  
B.1.4 To draw a representative sample, the contents of each container selected for sampling shall be 
mixed thoroughly be rolling, shaking or stirring by suitable means and with necessary caution.  
B.1.5 The samples shall be placed in suitable clean, dry and air -tight glass containers.  
B.1.6 Each sample container shall be sealed air -tight after filling and shall be marked with full details 
of sampling, the date of sampling and the year of manufacture of the material.  
B.2 Scale  of sampling  
B.2.1 Lot – All containers in a single consignment of the material drawn from a single batch of 
manufacture shall constitute a lot. If a consignment is declared to consist of different batches of 
manufacture, the batches shall be marked separa tely, and the groups of each batch shall constitute 
separate lots.  
B.2.2 Samples shall be tested from each lot separately for judging the conformity of the material to the 
requirements of the specification. For this purpose, five containers shall be select ed at random from 
each lot.  
NOTE – If the number of containers in the lot is eight or less, the number of containers to be selected 
and the criteria for conformity of the lot to the specification requirements shall be as agreed to between 
the purchaser and  the vendor.  
 
B.2.3 The containers shall be selected at random and to ensure randomness of selection, the following 
procedure is recommended for use:  
Starting from any container in the lot, count them as 1, 2 …….up to r and so on,  
where r is the integral part of N/5 (N bein g the number of containers in the lot). Every r th container thus 
counted shall be withdrawn to constitute a sample till the required number of five containers is obtained.  
B.3 Preparation of test samples  
B.3.1 Sampling tube  – The sampling tube shall be mad e of glass and shall be 20 mm to 40 mm in 
diameter and 350 mm to 750 mm in length . The upper and lower ends are conical and reach 6 to 12 
diameters at the narrow ends. Handling is facilitated by two rings at the upper end.  TBS/CDC 7 ( 5809) P3 
11 
 For drawing sample, the apparatus is first closed at the top with the thumb or a stopper and lowered 
till a desired depth is reached. It is then opened for a short time to admit the material and finally closed 
and withdrawn.  
Note: For small containers, the size of the sampling tu be may be altered suitably.  
B.3.2 From each of the containers selected according to A.2.3, a small representative portion of the 
material, about 200 mL shall be taken out with the help of the sampling tube after thoroughly stirring 
the acid with the help o f a glass rod.  
B.3.3 Out of these portions, a small but equal quantity of the material shall be taken out and thoroughly 
mixed to form a composite sample not less than 600 mL. The composite sample shall be divided into 
three equal parts, one for the purcha ser, one for the vendor and the third to be used as a referee 
sample.  
B.3.4 The remaining portion of the material from each container shall be divided into three equal parts, 
each forming an individual sample. One set of individual samples representing the  five containers 
sampled shall be marked for the purchaser, another for the vendor and the third to be used as a referee 
sample.  
B.3.5 All the individual and composite samples shall be transferred to separate bottles. These bottles 
shall be sealed and labe led with full identification particulars.  
B.3.6 The referee samples consisting of composite sample and a set of five individual samples shall 
bear the seals of the purchaser and the vendor. They shall be kept at a place agreed to between the 
purchaser and the vendor, to be used in the case of a dispute between the two.  
B.4 Number of tests  
B.4.1 Tests for the determination of specific gravity and hydrochloric acid shall be performed on each 
of the five individual samples.  
B.4.2 Tests for the determination of  all other characteristics listed in table 1 shall be performed on the 
composite sample only.  
B.5 Criteria for conformity  
B.5.1 For individual samples – From each set of five test results for specific gravity and hydrochloric 
acid percentage by mass, the m ean ( x̄) and range (R) ( x̄) – 0.6 R) as calculated from the relevant test 
results is greater than or equal to the minimum value specified in columns 3, 4 and 5 of table 1 
(depending of the grade of hydrochloric acid under consideration).  
B.5.2 For composit e sample  – From declaring the conformity of the lot to the requirements of all other 
characteristics tested on the composite sample, the test result for each of the characteristics shall 
satisfy the relevant requirement specified in table 1.  
 
 
 
 
 TBS/CDC 7 ( 5809) P3 
12 
 Annex C  
(Normative)  
Preparation of Starch Solution  
 
C. 1 Introduction  
This procedure contains two recipes for preparing starch solution —the traditional method and the 
spray starch method. With the traditional method, soluble starch is added to boiling water. The spray 
starch method simply requires spraying spray starch into a container of water.  
C.2 Materials  
C.2.1 Traditional Method  
Soluble starch, 1 g  
Water, distilled or deionized, 100 mL Water, 100 mL  
Balance mL 
Beaker, 250 -mL mL 
Graduated cylinder, 100 -mL Stirring rod  
Hot plate  
C.2.2 Spray Starch Method  
Spray starc h (the type used for ironing)  
Water, 100 mL 
Beaker, 250 -mL  
Graduated cylinder, 100 -mL 
Stirring rod  
Note: Safety Precautions  
This activity requires the use of hazardous components and/or has the potential for hazardous reactions. Avoid 
spraying starch onto the floor as this may cause the floor to become slippery. Avoid spraying starch in the direction 
of anyone’s face or eyes. W ear chemical splash goggles, chemical -resistant gloves, and a chemical -resistant 
apron. Please review current Material Safety Data Sheets for additional safety, handling, and disposal information.  
C.3 Procedure  
C.3.1 Traditional Method for preparing 100 mL of a 1% starch solution.  
1. Place 100 mL of distilled or deionized water in a 250 -mL beaker and bring to boiling on a hot plate.  
2. Make a smooth paste with 1 g of soluble starch and a small volume (several milliliters or so) of 
distilled or deionized water.  TBS/CDC 7 ( 5809) P3 
13 
 3. Once the water is boiling, carefully remove the beaker containing the boiling water from the hot 
plate. Pour the starch pa ste into the boiling water and stir until all of the starch is dissolved. The 
resulting solution may be somewhat cloudy.  
4. Allow the starch solution to cool to room temperature before use. Note: This is especially important 
if the starch solu tion is to be used in a kinetics experiment where temperature is a factor.  
C.3.2 Spray Starch Method for preparing 100 mL of a starch solution.  
1. Pour 100 mL of distilled or deionized water into a 250 -mL beaker.  
2. Generously spray the spray starch into the water . Spray until the solution appears slightly blue in 
colour  (at least 10 sec ).  
3. Stir the solution to mix and allow the foam to settle. This may take up to 10 minutes.