KENYA STANDARD   DKS 03-391:2024 
ICS 61.060 
Second  Edition  
 
 © KEBS 2024  
 Specification for general purpose rubber 
boots  
 
 
 
 
 
 
 
 
PUBLIC REVIEW DRAFT  MARCH  2024KENYA STANDARD       DKS 03-
391:2024 
ICS 61.060 
Second  Edition  
 
© KEBS 2024 – All rights reserved  ii 
 TECHNICAL COMMITTEE REPRESENTATION  
The following organizations were represented on the Technical Committee:  
Kenya Industrial Research and Development Institute (KIRDI)  
Kenya Association of Manufacturers (KAM)  
Bata Shoes Company  
Dedan Kimathi University of Technology(DeKUT)  
Technical University of Kenya (TUK)  
Environmental Institute of Kenya (EIK)  
Kenya Leather Development Council (KLDC)  
Department of Veterinary Services (DVS)  
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  2024 
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 and except as provided under Section 25 of this Act, no Kenya Standard produced by Kenya Bureau of Sta ndards 
may be reproduced, stored in a retrieval system in any form or transmitted by any mea ns without prior permission in writing from the 
Managing Director.  KENYA STANDARD       DKS 03-
391:2024 
ICS 61.060 
Second  Edition  
 
© KEBS 2024 – All rights reserved  iii 
   KENYA STANDARD       DKS 03-
391:2024 
ICS 61.060 
Second  Edition  
 
© KEBS 2024 – All rights reserved  iv 
 Specification for general purpose rubber 
boots  
 
 
  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)  
KENYA STANDARD       DKS 03-
391:2024 
ICS 61.060 
Second  Edition  
 
© KEBS 2024 – All rights reserved  v 
 Foreword  
This Kenya  Standard was prepared by the Leather and Leather Products  Technical Committee under the 
guidance of the Standards Projects Committee, and it is in accordance with the procedures  of Kenya Bureau of 
Standards.  
 
In this second Edition , the format of presentation has been updated and the standard has also undergone.  
some minor revision.  
This standard cancel and replaces KS 03-390:1983 , specification for general purpose rubber knee boots for 
adults . 
 
In the preparation of this standard, assistance was derived from the following publications:  
 
 BS 5145 Lined industrial rubber boots.  
 
 ISO/R 36: 1957 Determination of adhesion strength of vulcanized rubbers to textile fabrics.  
  
 IS 3400: 1975 Methods of test for vulcanized rubbers.  
  
 IS 3738: 1975 Specification for industrial and safety rubber knee boots.  
  
Acknowledgement is made for the assistance derived from these sources.DKS 03-391:2024   
 
© KEBS 2023 – All rights reserved   
 Specification for general purpose rubber boots  
1 Scope  
This Kenya Standard specifies the requirements, test methods and sampling for general purposes gumboots 
made of rubber . 
 
 
2 Normative Reference s 
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.  
 
ISO 37, Rubber, vulcanized - Determination of  tensile stress -strain properties.  
ISO 48 , Vulcanized rubbers - Determination of  hardness (Hardness between 30 and 85 IRHD).  
ISO 176 , Plastics - Determination of loss of  plasticizers - Activated carbon method.  
ISO 458 -1, Plastics - Determination of stiffness  in torsion of f lexible materials - Part 1: General  method.  
ISO/TR 463 , Dial gauges reading in 0.01 mm,  0.001 in and 0.000 1 in.   
ISO 10335, Rubber, and plastics footwear - Nomenclature . 
 ISO 4643,  Moulded plastics footwear — Lined or unlined poly (vinyl chloride) boots for general industrial use 
— Specification  
ISO 5423, Moulded plastics footwear — Lined or unlined polyurethane boots for general industrial use — 
Specification  
 
3 Terms and definitions  
For the purposes of this document, the terms and definitions given in ISO 19952 :2005 apply. : 
 
4 Requirements   
4.1 General requirements  
The lining shall be made of suitable fabric material.  
4.1.2 The boots shall be made in sizes 3 to13.  
4.1.3 The minimum height of the boot, when measured on the inside at the back of the boot from the insole to 
the top ( see Figure 1), shall be as shown in Table 1.  
Table 1.  Height of the rubber gumboots,  in mm    
© KEBS 2024 – All rights reserved  iii 
   
     
  
  
Half knee  
  
Short knee  
  
 Knee   MEN’S    
WOMEN’S  
  
  
180-239   
 
240-329 
 
330-429      
153-203   
 
204-279 
 
280-380 
         
4.2  Materials  
4.2.1 Upper materials  shall be of rubber conforming to physical requirements given in Table 3.  
4.2.2 The rubber -mix of the material shall be  made of  natural rubber, synthetic rubber or a combination of both.                                               
4.3  COMPONENTS  
 4.3.2  The rubber components shall comply with the physical requirements specified in Table 3.        
                
4.4 Weathering Test ⎯ All rubber components shall be capable of withstanding ageing in an air -oven at a 
temperature of 100 ± 1 0C for a period of 24 h according to the procedure given in ISO 14191, without developing 
any brittleness or tackleness.   
NOTE: For the purpose of this test, the test pieces may be entire articles or pieces cut from them.  
4.5 Leakage Test ⎯ On immersion in water, gumboots shall show no sign of leakage in the form of damp patches 
on the inside surface  when in  accordance with KS ISO 20344 .  
  
Table 2 - Minimum thickness  
s/n Boot 
component  Minimum thickness , mm  Test method  
 Boot upper  1.5 of which not less than 1 .0 shall be of PVCor PU  
compound   
 
 
 
 
 
 
 1 Foxing  
a) at the heel  
b) elsewhere   
4.0  
3.0 
2 Boot bottom  
 
               Over cleats                       Between 
cleats  
 Men  Women  Men  Women  
 
1  
   
© KEBS 2024 – All rights reserved  iv 
  a) full 
thickness  
 
b) outsole 
only 12.0 
 
8.0 10.0 
 
6.0 7.0 
 
3.0 5.0 
 
2.5 ISO 4643  
3 Heel  
a) full 
thickness  
 
b) wearing 
surface to 
filier block   
25.0 
 
9.0  
20.0 
 
4.0  
19.0 
 
3.0  
14.0 
 
2.5 
 
                        TABLE 3.  PHYSICAL REQUIREMENTS FOR INDIVIDUAL, RUBBER COMPONENTS  
  
S/No.  Characteristic  Requirements  Test methods  
Upper  Foxing  Soling  
1. Relative density, max.  1.4 1.4 1.5 KS ISO 2420  
2. Hardness, IRHD  50 – 60 50 – 60 60 – 70 KS ISO 48(1 -5) 
3. Flex 
resistance 
number of 
cycles, min  Initial crack  150000   - 50000   
KS ISO 4643  
 600 per cent    
     growth   -  - 65000  
4. Tensile  strength  , Mpa, Min.  7  7  
5. Elongation  at break, %, min. 300  300  
 
 4.6    FINISH  
Boots shall be either matt or gloss finished.  
5 Marking  
 
5.1 Rubber gumboot  
 
 
 The rubber gumboot  shall be legibly and indelibly marked  with the following : 
 
a) size and fitting number;  
b) batch number;  
c) manufacturer’s name or registered trade mark and address;  
d)  country of Manufacture/origin.   
© KEBS 2024 – All rights reserved  v 
 5.2 Bulk packaging  
Each bulk package (bale) shall be legibly and indelibly labelled with the following information:  
a) name of product as “ Rubber  gumboot ”; 
b) quantity;  
c) manufacturer or local supplier’s name and/or registered trademark  and address;  
d) country of manufacture/origin.  
 
6 Packaging  
The rubber gumboots shall be packed in a suitable material to avoid contamination and damage during 
transportation and storage . 
 
 
7 Sampling  
Sampling and acceptance criteria should be as given in annex A  
 
 
 
 
Annex A  
(normative)  
 
Sampling and criteria for conformity  
 
A.1 Definitions  
 
A.1.1  Lot 
 
All gumboot  pairs in a consignment belonging to the same pattern/design and batch of manufacture  
 
A.1.2  Defect  
 
A fault or failure of a gumboot  pair to meet the requirements of this standard.  
 
A.1.3  Defective footwear  
 
A gumboot  pair with one or more defects as mentioned in this standard.  
 
A.2 Scale of sampling  
 
A.2.1  Samples shall be selected and examined for each lot separately for ascertaining the conformity of the 
gumboot  to the requirements of this standard.  
 
A.2.2  Gumboot  shall be considered to be of different lots if they differ in shape and design.  
 
A.2.3  The number of gumboot  pairs to be selected from any lot shall depend on the size of the lot and shall 
be in accordance with Columns 1 and 2 of Table A.1.  
 
A.3 Method of selection  
 
A.3.1  Gumboot to be selected from the lot shall be chosen at random.  To ensure randomness the procedure 
in A.3.2 shall be used.  
  
© KEBS 2024 – All rights reserved  vi 
 A.3.2  When the gumboot  pairs in a lot are not packed in a number of cases (boxes), the sampling shall be as 
follows:  
 
Starting from any gumboot  pair in the lot, count the pairs as 1,2, etc ---up to r and so on in one order.  Every rth 
pair thus counted shall be withdrawn to constitute a sample ( r is an integral part of N/n where N is the 
lot size and n is the sample size).  This procedure shall be stopped as soon as the required number of 
pairs is obtained.  
  
For example, if a sample of 125 pairs is to be selected from a lot of 3,000 pairs, compute r as equal to integral 
part of 3,000/125=24.  Starting from any pair, the footwear shall be counted in one order and every 24th 
pair shall be withdrawn.  
 
A.3.3  When the gumboot  pairs in a lot are packed in different cases (boxes), a suitable number of boxes (not 
less than 30 percent of the total boxes in the lot) shall be first chosen at random.  For each of the boxes 
so chosen, an approximately equal number of pairs shall be pi cked up from its different parts so as to 
obtain the required number of pairs.  
 
 
For example, if a lot consists of 1 000 pairs of gumboots  packed in 50 boxes, each containing 20 pairs, choose 
more than 15 boxes at random.  If it is decided to open 20 boxes, then 4 pairs shall be picked up from 
different parts of each of the 20 boxes to give a total of 80 pairs as specified in Table 1.  
    
 
                                 Table A.1 — Scale of sampling and permissible number of defects  
  
 
No. of gumboot  
pairs in a lot  
 
 
  
Samples for 
visuall
y 
observ
ed 
defect
s 
(pairs)   
Permissible no. 
of 
defectiv
es 
(pairs)   
Sample size for 
laboratory 
testing  
(pairs)   
Permissible 
no. of 
defecti
ves 
(pairs)  
(1) (2) (3) (4) (5) 
Up to 50  13 0 2 0 
51 to100  20 1 3 0 
101 to 300  32 1 3 0 
301 to 500  50 2 5 1 
501 to 1000  80 3 6 1 
1001 to 3000  125 5 7 2 
3001 and above  200 7 8 3 
 
A.4 All randomly selected gumboot  pairs (Table A.1, Column 2) shall be inspected for visually observed 
defects, i.e.  
 
i) Difference in shape, design and colour.  
 
ii) Odd pairing and incorrect size.  
 
iii) Distorted shapes.  
 
iv) Faulty jointing and adhesion of sole, heel, toe guard, toe cap and insole.  
  
© KEBS 2024 – All rights reserved  vii 
 v) Finish not even and unpolished.  
 
  
A.5 The number of defective gumboots  pairs shall not exceed the permissible number given in Table A.1, 
Column 3.  If, however, the number of defective pairs exceeds the permissible number of defectives, 
the lot shall be rejected.  
 
A.6 In case the lot has been found satisfactory for visually observed defects, sample pairs for laboratory 
testing (Table A.1, Column 4) shall be taken from among those drawn (Table A.1, Column 2).  The pairs 
shall be chosen at random and tested for dimens ional, physical and chemical characteristics.  If the 
number of defective gumboot  pairs is less than or equal to the corresponding permissible number of 
defectives given in Table A.1, Column 5, the lot shall be declared to have met the requirements of this  
standard.  Otherwise, if the defective gumboot  pairs are more than the corresponding permissible 
number of defectives the lot shall be rejected.