KENYA STANDARD  KS 2923 -1:2020  
ICS 55.080  
First  Edition  
  
 © KEBS 2020   
 Tarpaulins for post -harvest handling of 
agricultural Produce  — Specification     
Part 1: 
Woven High density Polyethylene  
  
  
 
 
KS 2923 -1:2020  
ii © KEBS 2020  – All rights reserved  
 TECHNICAL COMMITTEE REPRESENTATION  
The following organizations were represented on the Technical Committee:  
Technical University of Kenya.  
Government Chemist Department  
Kenya Agriculture and Livestock Research Organization (KALRO)  
Africa PVC Industries  
Nairobi University Department of Food Science  
Environment Institute of Kenya,  
Moi University Department of Industrial and Textile Engineering  
Tarpo Industries Ltd.,  
Agroz Ltd Arusha  
BUMA Holdings  
One Acre Fund  
Kenyatta University  
A Plus Industries Ltd  
Ministry of Agriculture  
National Cereals and Produce Board (NCPB)  
Redblum Industries Ltd  
Government Chemist  
National Public Health Laboratory  
Moi University — Department of industrial and Textile Engineering  
Kenya Bureau of Standards — Secretariat  
REVISION  OF KENYA STANDARDS  
In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed.  Suggestions for 
improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards, are 
welcome.  
© Kenya Bureau of Standards, 2020  
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 130 of 2001 of  the Laws of Kenya, copyright subsists 
in all Kenya Standards a nd except as provided under Section 25 of this Act, no Kenya Standard produced by Kenya Bureau of Standards 
may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing f rom the 
Managing Direct or.  KENYA STANDARD  KS 2923 -1:2020  
ICS 55.080  
First  Edition  
 
© KEBS 2020  – All rights reserved  iii 
  Tarpaulins for post -harvest handling of 
agricultural Produce    
Part 1: 
 Woven High density polyethylene  
Kenya Bureau of Standards, Popo Road, Off Mombasa Road,  
P.O. Box 54974 - 00200,  Nairobi, Kenya  
 +254 020 6948000, + 254 722202137, + 254 734600471  
 info@kebs.org  
 @KEBS_ke  
 kenya bureau of standards (kebs)  
  
KS 2923 -1:2020  
iv © KEBS 2020  – All rights reserved  
 Foreword  
This Kenya Standard was prepared by the TC 001 cereals and pulses, TC 66 Hard fibres and TC 053 Packaging  
Technical Committee under the guidance of the Standards Projects Committee, and it is in accordance with the 
procedures of the Kenya Bureau of Standard  
KS 2923  consists of the following parts,  under the general title; Tarpaulins for post -harvest handling of 
agricultural Produce    
 Part 1 : Woven High density woven polyethylene  
 Part 2:  Polyester fabric coated with Polyvinyl    chloride (PVC  
During the preparation of this standard, reference was made to the following document (s):  
KS 1434 Specification fo r Coated Tarpaulin Fabrics  
 
Acknowledgement is hereby made for the assistance derived from this (these) source (s)  
 KS 2923 -1: 2020  
© KEBS 2020  – All rights reserved  v 
  Introduction  
A tarpaulin  used for post-harvest handling of agricultural produce such as grains  is a large sheet of  flexible, 
water -resistant or  waterproof  material, often  cloth  such as  polyester  coated with  polyurethane ,  of plastics  such 
as polyethylene  and polyvinyl chloride (pvc)  
Development of this standard was necessitated by the need to protect farmers and users of tarpaulins mainly 
used as drying sheets for post -harvest handling of grains from substandard products and safety aspect in terms 
of heavy metal contamination used as printing inks and microbial contamination as a result of production and 
product handling. In most cases harvested agricultural produce have   high moisture content for safe storage, 
that may result in migration of pigments, organic pollutants from tarpauli ns during drying  
Tarpaulins are sold to food value chains in Kenya with users benefiting from lower post -harvest losses, maintain 
qualities of stored commodities and leading to Increased food security, income, nutrition and health.  
As the market for tarpa ulins expands, there is a risk of substandard products being imported or manufactured 
locally and hence undermine proper storage of dry food commodities and their derived product.  
 KS 2923 -1: 2020    
 
© KEBS 2020 – All rights reserved   
 Tarpaulins for post -harvest h andling of agricultural produce  
Part 1: 
Woven High density Polyethylene  
1 Scope  
 
This part of the Kenya Standard prescribes the requirements and test methods for tarpaulins made from woven 
high density polyethylene and are used for post -harvest handling of agricultural produce such as grains  
 
2 Normative references  
 
The following referenced documents 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 docum ent (including any amendments) applies . 
 
 
ISO 13934 -1:2013 Textiles -- Tensile properties of fabrics -- Part 1: Determination of maximum force and  
elongation at maximum force using the strip method  
 
KS ISO 105 B02 , Textiles — Tests for colour  fastness — Part B02: Colour fastness to artificial light: Xenon arc 
fading lamp test  
 
KS ISO 105 C10 Textiles — Tests for colour fastness — Part C10: Colour fastness to washing with soap or 
soap and soda  
 
KS ISO 105 X12  Textiles — Tests for colour  fastness — Part X12: Colour fastness to rubbing  
KS ISO 811 Textile fabrics -Determination of resistance to water penetration -Hydrostatic pressure 
test. 
KS ISO 2286 -1 Rubber - or plastics -coated fabrics - Determination of roll characteristics -Part 1: 
Methods for determination of length, width and net mass  
 
 KS ISO 1421:2016 Rubber - or plastics -coated fabrics - Determination of tensile strength and 
elongation at break   
KS ISO 4674 -1:2016 Rubber -or plastics -coated Fabrics -Determination of tear Resistance -Part 1 : 
Constant rate of tear methods.  
KS ISO 22958: 2005 Textiles - Water resistance - Rain tests: exposure to a horizontal water spray.   
ISO 24153 Random  sampling and randomization procedures  
 
 
3 Terms and definition  
For the purposes of this standard the following terms and definitions shall apply  
 
3.1 
grain   
© KEBS 2020  – All rights reserved  iii 
  Small hard dry seed with or without an attached hull or fruit layer harvested for human or animal 
consumption  
 
3.2 
food grade material  
packaging material, made of substances which are safe and suitable for the intended use and which 
will not impart any toxic substances or undesirable odour or flavor to the products.  
3.3 
Base fabric  
This is the inner material between the coatings.  
 
3.4  
Agricultural Produce  
Any product or commodity form cultivated plants or animals intended for human consumption  
 
4 Requirements  
 
4.1 General requirements   
 
4.1.1  The base fabric shall be woven from high density polyethylene (HDPE) tapes of virgin resin.  
 
4.1.2  The base fabric shall be coated on both sides  
 
4.1.3 Edge sealing   
 
All raw edges of the tarpaulins shall be heat sealed or hemmed to prevent fraying  
 
4.1.4 Finish   
On visual examination, the coating of the material shall be uniformly applied and shall be free from cracks and 
flaws.  
 
4.1.5 UV treatments  
The tarpaulins shall be treated with UV stabilizers  
 
5. Specific requirements   
 
5.1 The Tarpaulins shall meet the physical requirements as specified in Table 1  
5.2 The colorfastness requirements of  tarpaulins shall be as specified in Table 2  
iv © KEBS 2020  – All rights reserved  
 Table 1 — Specific requirements for Woven High Density Polyethylene Tarpaulin  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Table 2 — colourfastness requirements for Woven High Density Polyethylene Tarpaulin  
 
 
 
 
 
 
 
 
 
 
 
 
  Characteristic  Requirements  
 Test method  
  Total mass per unit  area,   g/m2, 
min. 140 KS ISO 2286 -1 
 Loss of volatile matter, %,       max  
5 KS 1077 -7 temperature  
Duration to be determined  
 Resistance to water  penetration 
(hydrostatic test ) cm head of water, 
min. 150 KS ISO 811 -hydrostatic 
test 
Water resistance, Rain test g,  
Max 1 KS ISO 22958  
Breaking 
strength, N, min.  Warp  700 
KS ISO 1421  
Weft 690 
 Tear strength, N, 
min. Warp  130 KS ISO 4674 -1 
Trouser shape  
 Weft 130 
Retention of 
breaking strength 
after UV 
exposure ,min  Warp  85 percent of original actual 
value of the tarpaulin  Retention of breaking 
strength after UV exposure 
,min 
 
Agency  Numerical rating (min)   
Test method  Change in colour  Staining  
Light  5 — KS ISO 105 B02 
 
Washing  4 4 KS ISO 105 -C10  
Rubbing  
 dry 4 
 4  
KS ISO 105 -X12 
wet 3-4 3-4 
  
© KEBS 2020  – All rights reserved  v 
   
5.3 Dimensions  
When tested in accordance to KS ISO  2286 -1 the nominal dimensions of the  tarpaulins used in post -harvest 
handling of agricultural produce shall be as declared subject to a tolerance of ± 2 % of the declared dimensions  
 
 
5.4 Food grade requirements  
 
5.4.1 Overall migration  
When tested in accordance with the method specified in FDEAS 985 -1, woven high density polyethylene 
Tarpaulins shall comply with the overall migration limits of 60 mg/kg (max.)  
 
5.4.2  Pigments, colorants and heavy metals  
When tested in accordance with FDE AS 985 -1, woven high density polyethylene Tarpaulins shall comply with 
the list and limits of the pigments, colorants and heavy metals specified therein.  
 
6 Packaging  
 
6.1. Woven high density polyethylene Tarpaulins shall  be packed in materials that prevents it from damage, 
contamination during handling, storage and transportation.  
 
7 Labelling  
 
The woven high density polyethylene tarpaulin shall be legibly and indelibly marked with the following 
information  
 
i. Manufacturer’s name, address and /or registered trade mark.  
 
ii. Dimensions of woven high density polyethylene tarpaulin.  
 
iii. Batch number  
 
iv. Instruction for correct use  
 
v. Instruction for storage  
 
i. country of manufacture  
 
7 SAMPLING  
Sampling shall be done in accordance with ISO 24153.  
7.1 Lot  
 7.1.1  The quantity of the same type and quality delivered to one buyer against one dispatch note shall constitute 
a lot.  
7.1.2  The conformity of the lot to the requirements of this Standard shall be determined on the basis of tests 
carried out on the samples selected from the lot.   
vi © KEBS 2020  – All rights reserved  
 7.1.3  The number of pieces to be selected at random from a lot shall be in accordance with Table 3.  
Table 3  Sampling size and permissible number of non -conforming pieces  
 
Number of pieces   
in the lot  Sample size for visual 
inspection  Permissible no. 
Nonconforming pieces   Sub-sample size for  
testing  
  
Up   to 25  
26   to 50  
51   to 150  
151 to 300  
301 to 500  
501 to 1000  
1000 and above    
3  
5  
8  
13  
20  
32  
50    
0  
0  
0  
1  
1  
2  
3   
2  
2  
3  
3  
5  
5  
8  
 
 
  
© KEBS 2020  – All rights reserved  vii 
  Annex  A 
(normative)  
 
UV resistance test  
 
A.1TEST SPECIMENS  
The test specimens for breaking strength shall be cut from the sample as specified in KS ISO 13934 
(Part 1).  
 
A.2TEST CONDITIONS  
 
A.2.1 The test shall be carried out with  Fluorescent -B lamp (313 nanometer or its equivalent).  
 
A.2.2 The duration of the test shall be 144 h (that is 6 days).  
 
A.2.3 The test cycle shall be 8 h at 60 ± 3°C with UV radiation alternating after 4 h at 50 ± 3°C with 
condensation.  
 
A.2.4 Irradiation  level throughout the test shall be maintained at 0.63 +0.03 W/m².  
 
A.3 TEST PROCEDURE  
A3.1 Determine the original average breaking strength of fabric specimens separately as per the 
test Specified in KS ISO 13934 (Part 1).  
 
A3.2 Expose the specimens alter nately to ultraviolet light alone and to condensation in one 
respective cycle.  
 
A3.2.1 The type of fluorescent UV lamp, the timing of the UV exposure and the temperature of 
condensation shall be as specified in A -2 
 
A3.3 Determine the average breaking strength of the specimens separately after UV exposure as 
KS ISO 13934 (Part 1).  
 
A3.4 Determine the percent retention of original strength as follows:  
 
Percent retention of original breaking strength =𝒃
𝒂𝑿 𝟏𝟎𝟎 
 
Where  
 
a = average breaking strength before UV exposure as obtained in A -3.1; and  
 
b = average breaking strength after UV exposure as obtained in A -3.3. 
 
 
NOTES  
1 The UV source is an array of fluorescent lamps (with lamp emission concentrated in the UV range).  
2 Condensation is produced by exposing the test surface to a heated, saturated mixture of air and water vapour, while the  
reverse side of the test specimen is exposed to the cooling influence of ambient room air.  
 
 
  
viii © KEBS 2020  – All rights reserved