DRAFT  TANZANIA STANDARD  
 
 
 
 
GDC 4 (107 6) DTZS Polyethylene tereph thalate (PET) bottles  for packaging 
liquid s products  -Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
 
 
 
© TBS 2022  — all rights reserved                                   1st Edition  
 
 EXECUTIVE SUMMARY OF  GDC 4 (107 6) DTZS POLYETHYLENE 
TEREPHTHALATE (PET) BOTTLES FOR PACKAGING LIQUIDS PRODUCTS -
SPECIFICATION  
This draft Tanzania standard specifies requirements, method of sampling and test for 
bottles made from Polyethylene Terephthalate (PET) intended for the packaging of 
liquids.  
This standard does not cover PET bottles for packing pharmaceutical products.  
It is anticipated that this draft Tanzania  Standard will be made COMPULSORY  in its 
application.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
 
 
NATIONAL FOREWORD S 
 
0.1 The Tanzania Bureau of Standards is the statutory national standards body for 
Tanzania, established under the Act.No.3 of 1975, amended by Act.No.2 of 2009.  
 
This draft Tanzania Standard has been adopted by Packaging Technical committee, 
under the supervision of the General Techniques Standards Divisional Committee 
(GTDC) and it is in accordance with the procedures of the Bureau.  
 
Polyethylen e Terephthalate popularly known as PET bottles are popular for packaging 
of different liquids including foodstuffs. Their glass like clarity, lightness and better 
barrier properties for moisture and air permeation and excellent organoleptic property 
make them popular for food packing industry. PET can be used in pure form without 
any additive. Due to this, there is no organoleptic quality of food packed in PET bottles. 
However, to ensure the compatibility and suitability of PET bottles for th eir shelf life a 
compatibility test has been included for this standard. Hence due these reasons and 
increasing use of PET containers for packaging of liquid foodstuff and other products 
in our country has led to the formulation of this standards.  
 
In form ulating this standard, considerable information was derived from the following 
documents:  
 
IS 2798 Methods of test for plastic containers  
IS 13123 Polyethylene Terephthalate (PET) Bottles for Packing of Liquid 
Pesticides  
IS 12887  Polyethylene Terephthalate  (PET) Bottles for Packaging of Edible 
Oils  
Acknowledgement is hereby made for the assistance derived from this source.  
0.2 Terminology and conventions  
 
Some terminology and certain conventions are not identical with those used as 
Tanzania Standard; attention is drawn to the following:  
 
The comma has been used as decimal marker for metric dimensions. In Tanzania, its 
current practice to use a full point on the baseline as decimal marker.  
 
Whenever the words “International Standard” appear, r eferring to this draft Tanzania 
Standard, they should read as “Tanzania Standard” . 
 
  
 1. Scope  
This d raft Tanzania standard specifies requirements, method of sampling and te st for bottles  made from 
Polyethylene Terephthalate (PET) intended for the packaging of liquids . 
This standard does not cover PET bottles for packing pharmaceutical products.  
2. Normative reference  
The following documents are referred to in the text in such a way that some or all of their content 
constitutes requirements 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.  
ASTM D 2463 , Standard Test Method for Drop Impact Resistance of Blow -Molded Thermoplastic 
Containers  
ISO 2859 -1 Sampling procedures for inspection by attributes — Part 1: Sampling schemes 
indexed by acceptance quality limit (AQL) for lot -by-lot inspection  
EN 1186 -3 Materials and articles in contact with foodstuffs - Plastics - Part 3: Test methods for 
overall migration into aqueous food simulants by total immersion  
 
3. Terms and definitions  
 
For the purpose of this document, the following terms and definitions shall apply . 
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— IEC Electropedia: available at http://www.electropedia.org/  
— ISO Online browsing platform: available at http://www.iso.org/obp  
 
3.1 brimful c apacity  
volume of liquid held by the container when filled to the point of overflowing while standing 
on a level with all closures removed  
3.2 closure  
device used to seal off the opening of the container for product containment and providing a barrier 
to external contaminants  
 
3.3 bottle  
flat-bottomed container, made from  Polyethylene Terephthalate (PET)  
  
3.4 blow moulding  
 method of forming hollow objects by inflating a parison into a mould with compressed gas  
  
3.5 thermal stability  
ability to withstand long time exposure to elevated temperature  
 
3.6 polyethylene terephthalate  
PET 
polymer made by the polycondensation of ethylene glycol and terephthalic acid or dimethyl 
terephthalate  
 
3.7 stack load  
maximum weight applied to the top of a bottle when stacked   
 4. Requirements  
 
4.1.  General Requirements  
 
 4.1.1  The packaging covered by the provisions of this specification must be packed in appropriate 
packaging, which safeguard the hygienic, nutritional, technological, and organoleptic qualities of the 
product.  
4.1.2  The bottles , including packaging material, shall be made of substances that are safe and suitable 
for their intended use. They should not impart any toxic substance or undesirable odor or flavor to the 
product.  
 
4.2 Raw material  
 
4.2.1  The bottles shall be  made by blow moulding process from polyethylene terephthalate (PET) 
material.  
 
4.2.2  The materials must be free of Phthalates (such as Butyl Benzyl Phthalate, Dibutyl Phthalate, 
Diethyl Hexyl Phthalate, Diisodecyl phthalate, di -n-octyl phthalate), Polyvinyl chloride (PVC), 
Polyvinylidene chloride (PVdC ), and be manufactured with materials whic h do not contain  bisphenol A  
(BPA) as an intended component of the plastic formulation . 
 
4.3 Closure and sealing system  
 
4.3.1 The product must be prop erly sealed with no leakages.  
 
4.3.2 The closure system must have a visible tamper evident system showing that t he product has not 
been opened.  
 
4.3.3  The closure must resist with no cracking  or permanent buckling  and when applie d to the same 
top load as the container.   
 
4.3.4  The product must be re -closable whilst remaining leakage proof . 
 
4.2.  Specific Requirements  
 
4.2.1  The product shall meet the requirements given in Table 1, when tested in accordance with the 
test methods specified therein.  
 
Table 1 — Specific requirements for  PET bottles  
 
S/No   
Parameter  Purpose   
Test 
method  For packing 
drinking 
water  For packing 
edible oil  For packing 
Carbonated 
soft drinks  For 
packing  
alcoholic  
or liquors  For packing 
liquid 
pesticides  
1.  Stack load  shall not show any cracks or permanent  buckling  Annex A  
2.  Drop impact  Not showing any sign of cracking  ASTM D 
2463  
3.  Closure 
leakage test  Shall not show any leakage, loss of tightness, backing off or popping  Annex B  
4.  Wall 
thickness 
minimum, 
mm  
0.25 0.2 (middle 
of side 
panels) and  
0.2  
0.2  
0.25  
Annex C   
 0.1mm on 
the corners  
5.  Leakage test  Shall not show a ny sign of rupture or leakage from the bottle  Annex D  
6.  Thermal 
stability  NA NA Shall not creep  NA Annex E  
 
4.2.2  Ink adhesion test         
The printed bottles , when tested by the method described in Annex F, shall show no sign of printed ink 
or paint removal.   
4.2.3  Handling system  
The product must have a system to ease its handling - If required (see table  2 below), the handle should 
be fit for an adult man hand size with n o sharp edges.  
Table 2  — Handling system  
Volume  Handling system  
1L TO 2L  No specific handling system  
required  
2.5 TO 4L  At least a grabbing feature  
> 5L Handle required  
 
4.2.3 Compatibility test  
The suitability of PET bottles for packing of liquid articles shall be ascertained by subjecting them to 
compatibility test by the method prescribed in Annex G.  
4.2.4 Capacity  
4.2.4.1 Nominal capacity  
The bottle shall be of the following capacities:1500,1000,500,750,375,250,180 and 60 ml or any other 
capacity as agreed to between the purchaser and the supplier  
 4.2.4.2 Brimful Capacity  
The brimful capacities shall be as agreed to between the purchaser a nd the supplier. The tolerance on 
agreed capacities shall be as follows:  
Table 3 -Bottle brimful capacity tolerance  
Nominal capacity, ml  Tolerance, ml  
1500  ±51 
1000  ±10 
750 ±7 
500 ±5 
375 ±4  
 250 ±4 
180 ±3 
60 ±3 
 
 
 
4.2.5 Overall migration  
The overall migration of constituents of  PET bottle shall be 10 mg/dm²  when tested with accordance 
with the EN 1186 -3. 
Note: This requirement is applicable to PET bottles intended for food packing only.  
4.2.6 Storage stability test   
IS 14537  
5. Marking and Labeling  
5.1 Marking and Labeling  
Each PET bottle  shall be marked, emboss ed, or labelled with the following information:  
a) Manufacturer's name,  identification mark, initials or trade -mark.  
b) Nominal capacity of the container in ml or litres.  
c) Batch No. and year of manufacture.  
d) Recycling symbol   
e) Plastic identification code  or name . 
f) For PET containers for packing pesticides the following sign shall be embossed on the side of 
the container to safeguard the reuse of these empty container s for storing foodstuffs, 
pharmaceutical and drinking water.  
 
The sign shall be suitably supplemented with a line “DANGEROUS FOR HUMAN”  
6 Sampling  
6.1 Sample of bottles shall be drawn and the criteria for conformity determined as described in Annex 
H. 
 
 
 
 ANNEX A  
(Clause 4.2.1)  
STACK LOAD TEST  
 
A.1 Principle  
 
A force is applied  to the top face of the package equivalent in magnitude t o the total weight of identical 
packages stacked on t op to a minimum stack height of 3 m. The duration is 24 h.  
 
A.2 Sample Siz e 
 
Four bottles  shall be used for each single test.  
 
A.3 Procedure  
 
Fill the bottle  with water at ambient temperature up to nominal capacity a nd close with the usual closure 
to the nominal torque (i f the liquid to be packed is of high density, it shoul d be used as the test medium).  
 
Arrange the bottle in a block at 2 x 2 on a rigid, level, flat surface. Appl y a top load evenly distributed 
on a flat plate placed  on the unsupported containers.   
 
The to tal superimposed load along with the load of the flat surface for different siz es of containers shall  
be as specified below according to the usage of bottle . 
 
Table 3 details of stack load for bottle for packing alcoholic liquors  
 
Nominal capacity, ml  Top load for 4 bottles, N  
60 80 
180 160 
250 240 
375 240 
500 320 
750 400 
1000  400 
 
Table 4 details of stack load for bottle for packing edible oil  
Bottle capacity  Top load for 4 bottles ,N  
1kg 400 
2kg 600 
 
Table 5 details of stack load for bottle for packing  drinking water  and Carbonated drinks  
 Nominal capacity , L Top load for 4 bottles ,N  
1 60 
1.5 90 
2 120  
 2.5 150 
3 210 
4 270 
5 300 
 
Table 6 details of stack load for bottle for packing  liquid pesticides  
Bottle capacity ,ml  Top load for 4 bottles ,N  
100 400 
250 400 
500 350 
1000  350 
3000  480 
5000  800 
 
 
Examine the containers  after 24 h of test period. The containers shall not show any cracks or permanent  
buckling likely to reduc e their strength, cause leakage or reduction in effectivenes s of the closure or 
cause instability in stacks.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ANNEX B  
(normative)  
(Clause 4.2 .1) 
CLOSURE LEAKAGE  TEST  
B.0 Principle  
  
 B.0.1 The method helps to determine the ability of a closure to prevent leakage.  
B.1 Apparatus  
A vibrating table  
B.2 Procedure  
 
B.2.1 Fill the bottle  up to nominal capacity with coloured  water or the m aterial to be packed at ambient 
temperature, and close t ight with the closure.  
B.2.2 Mount the bottle upside down rigidly on the vibrating table and subject to vibrations for 1 hour at 
a peak acceleration of 1g.  
B.3 At the end of the test period, the closure shall show no indication of leakage, loss of tightness, 
backing off or popping.  
 
 
 
 
 
 
 
 
 
 
 
Annex C  
(normative)  
(Clause 4.2 .1) 
MEASUREMENT OF CONTAINER WALL THICKNESS  
C.1 Apparatus  
A suitable instrument, e.g. micrometer, vernier caliper, non -contact instrument, etc. having a  
measurement accuracy of 0,02 mm.  
C.2 Procedure  
Cut the container body horizontally into three equal sections, top, middle, and bottom. Measure the wall  
thickness at four places, 90° apart and offset from the parting line, in each section. Take average of 
four readings and report as wall thickness at top, middl e, and bottom.  
C.2.1 Micrometer method  
Measure the wall thickness with a micrometer or screw gauge fitted with ball point tip.  
C.2.2 Dial caliper gauge method  
Measure the wall thickness with the help of dial caliper fitted with spherical anvils. Care shall  be taken  
to avoid movement of the container during measurement as this can affect the reading obtained.   
 C.2.3 Non -contact instrument method  
Measure the wall thickness according to the manufacturer’s instructions.  
C.3 Results  
The wall thickness is recorded  as the mean of the four readings each for top, middle, and bottom 
sections.  
 
 
 
 
 
 
 
Annex D  
(normative)  
(Clause 4.2.1)  
LEAKAGE TEST  
D.1 Apparatus  
D.1.1 Compressed air supply  
A source of compressed air and a pressure line with pressure regulator and indicator to provide uniform  
air pressure can be used for this test.  
D.1.2 Reservoir  
A reservoir suitable to hold enough water so that the test container can be fully or partly immersed in it  
as required. In case of large containers, the reservoir might no t be necessary, and could be functionally  
substituted by the use of a soap solution.  
D.2 Procedure  
The leakage test shall be performed with the compressed air main tained at 35 KPa (0. 35 bar). Connect  
the airline to the test container by tightly fitting the  plunger with rubber plug in the mouth of the  container. 
The test container shall be immersed in water while an internal air pressure is applied. The  test 
container shall be kept under water in such a way as not to distort the test result.  
Increase the air  pressure until the predetermined pressure is obtained. Observe the container for any  
leakage by the bubbles of air escaping through the water. For large containers, detect the leakage by  
applying soap solution at various areas on the container. The formation of bubbles is an indication of  
leakage at those specific areas on the container.  
Other acceptable techniques involve the use of pressure decay instrumentation. These can be single  
determination (manual) units or automated in -line units for detect ion of container leakage during  
production. With this technique, the container under test is injected with air to some specified  
overpressure, and the pressure is monitored for a specified period of time. If the pressure does not  
decay below a specified li mit value at the end of the designated time period, the container under test is  
considered to be leak -free. Specific guidance should be obtained from the instrument supplier.  
D.3 Results   
 Any sign of rupture or leakage from the container other than from the  closure shall be deemed to  
indicate failure. Container shall be retested if the leakage is detected from the closure, after necessary  
corrections have been made to correct the leakage. Localized bulging shall not be considered as rupture  
or leakage.  
 
 
 
Annex E  
(normative)  
(Clause 4.2.1)  
THERMAL STABILITY  
E.1 Purpose  
CO 2 gas in carbonated beverages exerts a pressure on the container walls. As temperature  increases, 
pressure increases, causing the bottle to expand and creep (permanently deform under the  influence 
of an applied stress). Excessive creep will cause the beverage fill level to drop, which will  negatively 
affect package appearance and affect how the bottle fits into a carrier shell, sits on a shelf,  or fits into a 
vending machine. The purpose o f this test is to measure a bottle’s resistance to creep.  
E.2 Application  
For CSD and NCB Cold -fill Pressurized bottles.  
E.3 Test equipment  
F.3.1 Equipment or chemicals to carbonate bottle to 4.20 +/ - 0.05 GV of CO 2 
E.3.2 An oven or temperature controlled room set to 38°C +/ -1°C (100°F +/ - 2°F) at any %  RH 
E.3.3 Equipment to measure carbonation level.  
E.3.4 Measurement tools: Pi tape, height gauge, calipers, etc.  
E.4 Procedure  
E.4.1 Verify calibration of equipment.  
E.4.2 Mark and then measure the required bottle dimensions on empty bottles.  
E.4.3 Mark the target fill level height on each bottle.  
E.4.4 Fill samples with carbonated water or product to a level of:  
CSD: 4.2 ± 0.1 volumes  
NCB Cold Fill Pressurized: 2.72 bar (40 ± 5psi)  
E.4.5. Wait approximately 1 hour after the bottles have been carbonated and check and record the 
carbonation level on 3 extra samples. Then place the remaining 12 bottles in the 38°C (100°F) condition.  
E.4.6. Leave the bottles in the 38°C (100°F) condition for 24 hours.  
E.4.7. Remove the bottles from the 38°C (100°F) condition and measure the required bottle dimensions.  
a) Measure the bottles “hot” which is 2 -4 hours after the bottles have been removed.   
 b) Measure the fill point drop from the original mark.  
c) Check the bottles for final carbonation level  
d) Note any visual abnormalities  
 
Annex F  
(normative)  
(Clause 4.2.2)  
INK ADHESION TEST FOR PRINTED CONTAINERS  
F.1 Procedure  
Apply two strips of 25 mm wide transparent pressure sensitive tape or cellophane tape to the printed  
area of container; one piece down the height and the other round the circumference of the container. 
Press the tape firmly on to the container and leave it for 15 s. Remove the tape by p ulling slowly at 
about 1 cm/s pulling rate from one end at 90° to the container surface.  
F.2 Results  
There shall be no removal of the print from surface of the container and the print shall be legible to the 
naked eye after the test.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
 
Annex G  
(normative)  
(Clause 4.2 .3) 
TEST FOR COMPATIBILITY  
G.1 General  
This method is for determination of compatibility of plastics containers for an intended purpose.  
G.2 Principle  
Piece of plastics material with which the container is made are treated at an elevated temperature with 
the liquid which the container is inten ded to transport. Any changes in organoleptic characteristics, 
weight, odour or flavour, size, shape and colour that occur in the test specimens are noted. For dry 
products, the tests may be carried out only on the containers filled with the product as in G.4.2. 
G.3 Test Specimens  
G.3.1 Material  
Three tes t pieces of approximately 15cm x 15cm  size shall be cut from any convenient part of the 
container. Each test piece shall be cleaned, wiped and dried. It shall be measured for length, width and 
thickness to the nearest 0.05 mm and weighed to the nearest milligram.  
G.3.2 Container  
Six samples of specific bottle  intended for packing of particular product shall be tested in accordance 
with the test procedure given at G .4.2. 
G.4 Procedure  
G.4.1 Testing of Materia l 
The liquid -which is intended to be filled in the bottle  shall be introduced into a glass vessel and  test 
pieces completely immersed, avoiding unnecessary contact with the other pieces or the walls  of the 
glass vessel. Where the density of plastics mater ial is less than that of the liquid, small weights, inert  to 
the liquid, may be used to prevent the test pieces from either floating or curling. The test shall be carried 
out continuously over 28 days at a temperature of 50 ± 2°C. The liquid and the test p ieces shall be 
thoroughly agitated every 24 h.  
After the required test period has elapsed, the. Test pieces shall be removed from the liquid, suitably  
cleaned, drie d, weighed and measured as in G .3.1 
G.4.2 Testing of  Container  
In order to assess the compatibility of the container, the container shall be filled with the product to 
nominal capacity, sealed and capped in the manner intended and kept at a temperature of 50 ± 2°C for 
a period of 28  days. At the end of this period the containers shall be ex amined for the following:  
a) Visible  cracks, if any;  
b) Change in colour;  
c) Change in weight; and  
d) Change in shape.  
G.5 Test Result and Interpretation   
 Any change in weight, dimensions or alterations in other characteristics (such as colour, blooming, etc.) 
or any other deterioration in quality of the product shall be used by manufacturer and purchaser in 
reaching agreement as to the stability of the plas tics material for its intended purpose.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 Annex H  
(normative)  
(clause 6)  
SAMPLING  
H.1 Scale of sampling  
H.1.1 lot  
In any consignment all the bottles of the same material, nominal capacity and drawn from a single 
batch of manufacture shall be grouped together to constitute a lot.  
H.1.2 Scale of sampling  
For ascertaining the conformity of the lot to the requirements of this standard, test shall be carried out 
for each lot separately.  The sampling criteria shall be in accordance with ISO 2859 -1 and as given in  
Table 7 . 
For drop impact resistance, Closure  leakage,  Leakage  and stack load tests, one set of sample 
containers as given in the test methods  shall be drawn from the lot and these shall be subjected to the 
respective tests.  
 
The sample shall pass the tests for the lot in respect of drop impact resista nce and stack load 
requirements.  
Ink adhesion testing is applicable only to printed containers.  
 
Compatibility testing to confirm  conformance to the requirements of the application shall be conducted 
when changes are made in  the raw materials used to produ ce containers (e.g. material composition, 
formulation, and functional  additive master batch, etc.)  
 
Table 7  -Scale of Sampling and Permissible Number of Defectives  
S/No.  
 Lot size  Sample size  Permissible number of 
defects  
1.  501-1200  32 1 
2.  1201 -3200  50 2 
3.  3201 - 10000  80 3 
4.  10001 -35000  125 5 
5.  35001 -150000  200 7 
6.  Over 150000  300 10 
 
H.1.3 The bottles shall be selected at random from a lot.