TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20  
DRAFT TANZANIA STANDARD  
 
 
 
Polyethylene Terephthalate (Pet) Bottles for Packaging of Edible 
Oils - Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
  
                                  TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20 0.   Foreword  
Polyethylene terephthalate popularly known as PET Containers are getting popular f or packaging of 
food and edible oil, their glass like clarity, lightness and better barrier properties for moisture and  air 
permeation make them popular for food packaging industry . PET can be used in pure form with out 
any additive . This standard provides requirements on  the constitution of polyethylene terephthalat e 
plastics  used for the packing of edible oil  
In reporting the result of a test or analysis made in accordance with this standard , if the final values 
observed or calcu lated, is to be rounded of f it shall be done in accordance with TZS 4 Rounding off 
nume rical values .  
In the preparation of this standard assistance has been derived from:  IS 12887 :1989 polyethylene 
terephthalate (PET) bottles for packaging edible oils -specifications published by B ureau of Indian 
Standards (BIS)  
1. Scope  
This standard presc ribes the requirements , methods of sampling and testing for the polyethylene 
terephthalate (PET) bottles for pack aging of  edible oils . 
2. Normative references  
The following standard , in whole or  in part, are normatively referenced in this do cument and are  
indispensable for its application. For dated references, only the edition cited applies. For undated 
references, the latest edition of the referenced document (including any amendments) applies  
AFDC2(231) P1: Specification for plastic materials for food c ontact applications part 3: pigments and   
   colorants  
AFDC 2 (230) P 3: Specification for plastic materials for food contact applications part 2: Polyethylene   
   (PE)  
AFDC 2(229) P1: Determin ation of overall migration of constituents of plas tics materi als and articles 
  intended to come in contact with foodstuffs - Method of analysis   
AFDC2 (227) P 2: Guide on suitability of plastics for food packaging   
AFDC 2 ( 228) P1: Code for evaluation of  the effect of packaging and storage on the sensor y qualities  
of    foods  and beverages  
TZS 4: Rounding off numerical values  
TZS 816: Packaging - glossary of terms in plastics and flexible packaging  
TZS 928: Plastics -Films and Sheeting -Determination of T hickness by Mechanical Scanning  
TZS 1876 : Plastics vocabulary  
 TZS 2247 Prerequisite Programme on Food Safety -Part 4: Food Packaging Manufacturing                                   TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20 3. Terms and definitions  
 for the purpose of this standard  the definitions prescribed  in TZS 816 and TZS 1876 and the 
following shall apply.  
3.1 Polyethylene Terephthalate  (PET )  
the basic material produced by the catalytic condensation at high temperature and reduce d pressure 
of dime thyl terephthalate ( DMT ) terephthalic acid (PTA) and if required , relatively s mall amount s of 
dimethyl isophthala te (DMI) isophthalic acid (IPA)  with monoe thylene  glycol.  
 3.2 Polybutylene Tereph thalate (PBT)  
the basic material produced by the catalytic conden sation at high temperature and reduced pressure 
of DMT/PTA (and, if required, relatively small amounts of DMI/IPA) with 1,4 butanediol.  
 4. Requirements  
4.1 materials    
the bottles shall be made by blow moulding process from polyethylene terephthalate mat erials 
conforming to the requirement laid down  in 4.1.1 to 4.1.5  
4.1.1 Basic Raw Materials  
the following basic raw materials may be used  
i) Mono ethylene glycol (MEG)  
ii) 1, 4 Butanediol  
iii) Dimethyl terephthalate (DMT)  
iv) Dimethyl isophthalate (DMI)  
v) Terephthalic aci d (TPA)  
vi) Isophthalic acid (IPA)  
4.1.1.1  the polymer shall e xist at least 50 percent of units derived from TPA.  
4.1.1.2 t o the thermoplastic polyesters made from the above raw m aterials polyethylene up to 5 per - 
cent used conforming to AFDC2( 230) P 3, may a lso be added.  
 4.1.2 residual catalyst  
Table 1: maximum l imits for the residual cataly sts  
Residual catalyst  Maximum limits (mg/kg or ppm)  Test methods  
Antimony  350  
 
AFDC2 (229) P1  Gallium  20 
Germanium  100                                  TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20  4.1.3 Crystallization  accelerators  
Table 2: maximum limits for the crystallization accele rators   
 4.1.4 Auxili ary items for Working  
the fo llowing auxiliary items may be present with limits prescribed against each:  
Table 3: maximum limits for the auxiliary items in percentage  
 Auxiliary items  Maximum limits (percent)  Test methods  
Calcium stearate and zinc stearate together  0.5  
 
 
AFDC2( 229) P 1 Synthetic paraffin  0.25 
Iso-butyl stearate  0.2 
Even numbered, saturated, aliphatic primary 
alcohols of the chain length C 12 to C 20  0.5 
Low molecular polyolefins  0.5 
 silicon oi l  0.3 
Penta -erythrite -ester of saturated even 
numbered aliphatic  mono  carbonic acids of 
the chain length C 14 to C 32  1.0 
 4.1.5 Pigments and Colourant  
the pigments and co lourants shall be as specified in AFDC  2 (231) P1  
4.2 cap  
The bottles shall be provided with a cap  and if required  with a n insert plug, the materia l for cap and 
plug shall be food grade  HDPE injection moulding grade according to the relevant standards or  any 
other suitable materials as agreed to between the purchaser  and the su pplier .     
4.3 wad  
The wad, if required, shall  be of cork board  or pulp -board or any other suitable material compatible 
with the contents and suitable for food contact applications  
 
 
 Cobalt  125 
Lithium  130 
Mangane se  80 
Zinc  80 
Titanium  120 
Crystallization Accelerators  Maximum limits (percent)  Test methods  
Talc, free of asbestos  0.25 AFDC2( 229) P 1 
Sodium benzoate  0.25                                  TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20 5. Capacity   
5.1 brimful capacity  
The brimful capacity of bottles when meas ured by method given in annex A shall exceed the nominal 
capacity by a minimum of 2 percent . 
6. Mass  
mass of the bottles shall be as agreed between the purchaser and supplier with  a tolerance of ±5 
percent  
 7. Shape and Design  
7.1 the shape and design sh all be as agreed between  the purchaser and th e supplier.  
7.2 Wall Thickness  
the minimum wall thickness of the bottle  shall be 0.25mm  when determined according to TZS 928 or 
any other relevant method . 
8. Workmanship and finish  
8.1 the bottle and closures s hall be manufactured according to the good manufacturing pr actices 
(GMP) and shall be free from any burnt, oxidized or un -homogenized particles. The bottles shall be 
clear and transparent and free of any scratches.  
9. Tests  
9.1 closure leakage test  
The b ottle filled with water at ambient tem perature and closed t ightly with the cap when subjected to 
vibration on the vibration table as detailed in annex A, shall not show any leakage through the closure 
after one hour of testing.  
9.2 drop impact test  
the bo ttle and the cap when subjected to the  drop test as given i n Annex B, shall not show any sign of 
cracking. Slight deshaping of the body shall not render the bottle unacceptable in the test.  
9.3 Stacking test  
9.3.1 the bottles shall not show any leakage, cracks, or permanent buckling when sub jected to test as 
described in 9.3.2 .  
9.3.2  arrange  four bottles, filled with water at ambient temperature to their nominal capacity and 
closed with their caps to the normal torque on a flat level surface in a block o f 2 x 2 without any other 
support. App ly a top load evenly distributed on a flat level surface placed on the unsupported bottles 
and examine after 24  hours .  
                                  TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20 9.4 storage test  
this shall be a type test. The storage test shall be carried out both at 38 ±1°C  and 90 ±2 percent  RH 
(relative humidity ) (acce lerate d con dition) and 27±1°C and 65±2 perce nt RH (Relative humidity)  
(standards conditions) . the change in free fatty acids (as percentage of oleic acid), moisture content, 
peroxide value as milliequivalent of  oxygen per kilo fat (wherever applicable) and rancidity as  per 
AFDC 2 (228) P 1, of the content shall be noted at the end of 60 and 180  days when tested under 
accelerated and standards conditions respectively.  Bottles shall be accepted if edible oil  does  not 
show rancidity or increase in the value of the moisture  contents , free fatty acids and peroxide value 
above the permissible limits specified in the relevant Tanzania standards on edible oils at the end of 
60 days and 180  days under accelerated and stan dards conditions respectively.  
10. Packing, Marking and La beling  
10.1 Packing  
The material should be suitably packed with suitable liner (food grade) in a container as agreed 
between the purchaser and the supplier , in a manner so as to ensure that the it ems do not become 
contaminated during storage.  
10.2 Markin g and Labeli ng   
Each package shall be marked legibly and indelibly with the following  :  
a) Name and type of  the mater ial 
b) Manufacturing date material  
c) Country of origin   
d) Name of the manufacturer and/ or trade mark, if any.  
e) The packages shall carry the symbol  for food grade (Fig. 1) or the word “for food grade” on it  
                                                                        
  
11. Sampling   
11.1 Sample of bottles shall be drawn and the cr iteria for conformity determined as described in 
Annex C.  
 
 
 
                                  TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20 Annex A  
Closure Leakage Test  
A-0. General  
A-0.1 the method helps to determine the a bility of a closure (on a c ontainer) to prevent leakage due to 
transformational vibration  
A-1 apparatus  
A-1.1 a vibrating table conforming to a relevant standard   
A-2 Procedure  
A-2.1 Fill the bottles to its nominal capacity with the product or water and c lose it with the usual 
closure in the manner in which it is intended to be used.  
A-2.2 Mount the bottle upsid e down rigidly on the vibrating table and subject to vibrati on for 1hour at a 
peak acceleration of 1g  
A-2.3 at the end of the test period, the clos ure shall show no indicatio n of leakage, loss of tightness, 
backing -off or popping  
A-3 precautions  
A-3.1 befo re the test is carried out, it should be ensured that the in ner plag, if provided, and cap are 
fully tightened  
 
 
 
 
 
 
 
 
 
 
                                  TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20 Annex B  
Drop Impact T est 
B-1 Apparatus  
B-1.1 the ap paratus shall consist of a vertical scale marked in 15mm increments from 1m to 4m fixed 
above a rigid flat base of steel or smooth concrete as  a dropping surface.  
B-2 procedure  
B-2.1 the bottles shall be filled to their nomin al capacity with water at ambi ent conditions and closed 
tightly with the cap. each bottle shall be drop ped freel y from a height of 1.2 m in the following 
sequence:  
a) Vertical position, so that the bottom strikes the impact surface flat; and  
b) Horizontal positi on, so that the bottle strikes  the impact surface horizontally with its side flat.  
B-2.2 bottles shall not show any leakage of water through cracks or closures. Slight dent ing shall not 
be taken as failure of the bottle in the test.  
 
 
 
 
 
 
 
 
 
 
 
 
 
                                  TBS/AFDC 2(69 ) P3 
                                           ICS 67:250  
  
 
   ©TBS 20 20 Annex C 
Sampling  
C-1 Scale of Sampling   
C-1.1 Lot  
In any consignment all the bottles of the same material, nominal capa city and drawn from a single 
batch of manufacture shall be g rouped together to constitute a lot.  
C-1.2 Scale of Sampling  
For ascertaining th e conformity of the lot to the  requirements of this standard, test shall be carried out 
for each lot separately. Th e number of bottles to be sampled from a lot shall be in acc ordance with 
table 1.   
Table 1 scale of sampling and acceptance of number  
Lot si ze For visual examination  
 For clo sure leakage test  
 
Sample size  Acceptance   
Number  Sample 
size  Acceptance   
Number  
Up to 500  13 1 5 0 
501-1000  20 2 8 0 
1001 -3000  32 3 13 0 
3001 -5000  50 5 20 1 
5001 and above  80 7 32 2 
                                                                                                                                                                                 
C-1.3 the bottles shall be selected at random from the lot according to the relevant Tanzania standard  
C-2 Criteria for Conformity     
C-2.1 visual examination  
The sample bottle selected as per column 2 of table 1 shall  be examined for workmanship and finish 
(8.1). any bottle failing in one or more of the requirements shall be termed as defective. The lot shall 
be accepted under this head i s the number of defective bottles in sample does not exceed the 
acceptance number given in column 3 of table 1