KENYA STANDARD                    KS 2422 :2018   
           
 
 
 
 
 
 
 
 
 
 
  
Potassium sulphate fertilizer, technical 
grade - Specification  
 
 
 
 
 
 
 
 
 
        
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
     DRAFT STANDARD  AUGUST    2018  
        
 
  
ii     
 
 
 
 
 
  
TECHNICAL COMMITTEE  REPRESENTAT ION 
 
 
The following organizations were represented on the Technical Committee:  
 
Government Chemist  
Mea Ltd.  
Chemagro Ltd  
Kenya Plant Health Inspectorate Services (KEPHIS)  
Kenya Agricultural   and livestock research organization  
Yara East Africa Ltd  
Kenya Tea Development Agency  
University of Nairobi  
Ministry of Agriculture, Livestock and fisheries  
Amiran (K) Ltd  
Toyota Tshusho Fertilizers  
Elgon chemicals  
Osho chemicals  
OCP Kenya Ltd.  
Kel Chemicals  
Kenya Bureau of Standards — Secretariat  
 
 
 
 
 
REVISION OF KEN YA 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 Burea u of standards, 2012  
 
Copyright:  Users are reminded that by virtue of Section 6 of the Copyright Act, Cap. 130 of the Laws of Kenya, copyright subsists in all 
Kenya Standards and except as provided under Section 7 of this Act, no Kenya Standard may be rep roduced, stored in a retrieval 
system in any form or transmitted by any means without prior permission in writing from the Managing Director.  
 
 
 
 
 
 
 
 
 
  
KEBS 2018 — All rights reserved   iii  
 
 
 
 
 
 
 
 
 
 
 
 
 
KENYA STANDARD      KS 2422:2018              
 
                     
           
 
 
 
 
 
 
 
 
 
 
 
Potassium sulphate fertilizer, technical grade - 
Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
iv    KENYA BUREAU OF STANDARDS (KEBS)  
 
Head Office:  P.O. Box 54974, Nairobi -00200, Tel.: (+254 020) 605490, 602350, Fax: (+254 020) 604031  
E-Mail: info@kebs.org,  Web:http://www.k ebs.org   
 
Coast Region     Lake Region          Rift Valley Region  
P.O. Box 99376, Mombasa -80100   P.O. Box 2949, Kisumu -40100        P.O. Box 2138, Nakuru -20100Tel.: 
(+254 041) 229563, 230939/40                Tel.: (+254 057) 23549, 22396        Tel.: (+254 05 1) 210553, 
210555Fax: (+254 041) 229448    Fax: (+254 057) 2 027814 Foreword  
         
  Foreword      
 
This Kenya standard has been prepared by the technical committee on fertilizers and soil 
conditioners under the guidance of the standards projects committee in accordance with 
the procedures of the Kenya Bureau of standards.  
 
 
The rapid expansion of horticulture and irrigated farming has resulted in development  of 
new technologies that aim at maximising nutrient use efficiency and offer opportunities for 
quick  responses to plants nutrients needs. This has led to a need to develop special 
fertilizers that can be applied using these new technologies.  
 
 Like other fertilizer products, environmental aspects related to fertilizer raw materials have 
been taken care o f, thus  limits for heavy metals have been specified. Recent Association 
of official Analytical chemists (AOAC) methods of analysis have been adopted.  
 
 
 
During the preparation of this standard, reference was  made to the following document : 
 
1. FAO mineral fer tilizer specifications, 2012  
 
 
 
 
 
Acknowledgement is hereby made for assistance derived from the above source  
 
 
 
 
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           KENYA STANDARD             
 
 
Potassium sulphate  fertilizer , technical grade  — Specification  
 
1.0 Scope  
 
This Kenya Standard spe cifies the requirements, methods of sampling and tests 
for Potassium sulphate fertilizer, technical grade  
2.0. Definitions and terms  
The terms and abbreviations used in this standard are in accordance with the 
explanations contained in th e Standard: ISO 81 57: fertilizers  and soil 
conditioners - vocabulary  
 
 
 
3.0 Requirements  
 
3.1 Description   
The fertilizer shall be free flowing, in form of granules, pellets, crystals or; prills , free from 
any foreign matter and shall not cake on storage   
 
 
 
 
3.2 Physical  
The fertilizer shall be fully water soluble.  
 
 
3.3 Chemical  
The material shall comply with the requirements set out in table 1 when tested in 
accordance with the methods specified in the last column of the table.  
Table 1 : specific requirements for potassium sul phate  
SL.NO  Characteristic  requirement  Test method  
i) Potassium, as 
K2O,% by 
weight, min  51.5  
 AOAC  
ii Sulphur as 
S,% by weight, 
min 18 AOAC  
ii) Chloride, as cl-  
% max by 
weight  0.5 AOAC  
iii) pH(1% 
solution  4-5  AOAC  
iv Moisture,% by 
weight, Max,  0.5  AOAC  
 
  
 
 2.6 Heavy metal contaminants   
 
The heavy metal contaminants, if present, shall not exceed the limits stipulated in 
Table 2.  
 
 
 
Table 2 — Heavy metal contaminants limits  
 
SL NO  Parameter  Limits in 
ppm Test method  
i) Arsenic, As, max.  20.0 AOAC  
ii) Cadmium, Cd, max.  7.0 AOAC  
iii) Mercury, Hg, max.  0.1 AOAC  
iv) Selenium, Se, max.  1.0 AOAC  
v) Lead, Pb, max.  30.0 AOAC  
vi Chromium as  Cr, 
max 500 AOAC  
 
 
3 Packaging and marking  /labelling  
 
 
3.1 Packaging   
 
3.1.1 The fertilizer shall be packaged in materials that ensure  the product integrity  
and quality  and protect it against   physical  damage , chemical and moisture 
contamination.  
 
3.1’2. the fill of the package shall comply with the weight and measures act CAP 
513 of the laws of Kenya  
 
3.1.3 The disposal of used package and condemned fertilizer shall comply with 
EMCA 1999 no.8 of the disposal of solids and liquid wastes  
 
 
3.2 Marking / labelling  
The following information shall be clearl y and indelibly marked on each package or 
container.          
 
i. Name,  address and physical location of manufacturer/packer/importer;  
ii. name of the fertilizer, i.e.  “Potassium sulphate ‘     
iii.  Guaranteed  percentage by mass of the  water soluble  potassium( k2o and 
sulphur content  
iv. date of manufacture,   
 3 v.  expiry date  
   vi.      batch/lot number  
   Vii         the net weight of the fertilizer in the package; in metric units  
  Viii         Storage  and Handling instructions  
  ix             Instructions  for use  
   x           d isposal instructions  
   xi. Country  of origin;  
 
4 Certificat e of analysis  
 
Each consignment shall be accompanied by a certificate of analysis.  
 
5. Sampling  
 
This shall be carried out as outlined in the ISO Standards,  
ISO 8633 -Solid fertilizers -- Simple sampling method for small lots  
ISO 8634 - Solid fertilizers -- Sampling plan for the evaluation of a large delivery