DEAS 912: 2023  
ICS 65.080   
 
© EAC 2023                                                                                                                           Second  Edition 2023  
 DRAFT EAST AFRICAN STANDARD  
Fertilizer s — Nitrogen, phosphorous and potassium (NPK) compound  — 
Specification  
EAST AFRICAN COMMUNITY  DEAS 912: 2023  
ii © EAC  2023  – All rights reserved  
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 DEAS 912 : 2023  
© EAC 2023  – All rights reserved  iii 
 Foreword  
Develo pment of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged that through 
harmonized standardization, trade barriers that are en countered when goods and services are exchanged 
within  the Community will be removed.  
The Community has established an East African Standards Committee (EASC)  mandated to develop and 
issue East African Standards (EAS).  The Committee is composed of represen tatives of the National 
Standards Bodies in Partner States, together with the representatives from the public and private sector 
organizations in the community.  
East African Standards are developed through Technical Committees that are representative of ke y 
stakeholders including government, academia, consumer groups, private sector and other interested parties. 
Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the 
Partner States. The comments received are discussed and incorporated before finalization of standards, in 
accordance with the Principles and procedures for development of East African S tandards.  
East African Standards are subject to review, to keep pace with technological advances. Users of the Ea st 
African Standards are therefore expected to ensure that they always have the latest versions of the standards 
they are implementing . 
The committee responsible for this document is Technical Committee EASC/TC 020, Agriculture and 
agrochemicals.  DEAS 912: 2023  
iv © EAC  2023  – All rights reserved  
  
 DRAFT EAST AFRICAN STANDARD  DEAS 912: 2023  
 
© EAC 2023  – All rights reserved  1 
 Fertilizers — Nitrogen, Phosphorous and Potassium (NPK) compound  — 
Specification  
1 Scope  
This Draft East African Standard specifies  requirements , sampling and test methods for NPK fertilizer 
(compound ). 
2 Normative references  
The following documents are referre d 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 amendment s) applies.  
AOAC 937.02,  Magnesium ( water-soluble) in fertilizers  
AOAC 962.01, Calcium and magnesium in liming materials — EDTA Titrimetric method  
AOAC 965.08, Water (free) in fertilizers — Vacuum -desiccatio n  
AOAC 972.0 2, Manganese ( acid-soluble) in fert ilizers  — Atomic absorption spectophotometric method  
AOAC 97 5.02, Zinc in fertilizers — Atomic absorption spectophotometric method  
AOAC 975.01 , Copper in fertilizers  — Atomic absorption  spect ophoto metric method   
AOAC 980.01, Iron in fertilizers  — Atomic ab sorption spectophotometric method    
AOAC 2006.03, Arsenic, Cadmium, Cobalt, Chromium, Lead, Molybdenum, Nickel and Selenium in fertilizers  
ISO 5315, Fertilizers — Determination of total nitrogen content —Titrimetric method after distillation  
ISO 6598 , Fertilizers — Determination of phosphorus content — Quinoline phosphomolybdate gravimetric 
method  
ISO 8157 , Fertilizers , soil conditioners and beneficial substances — Vocabulary  
ISO 8397 , Solid fertilizers and soil conditioners  — Test sieving  
ISO 10084, Solid f ertilizers — Determination of mineral — Acid-soluble sulphate content  — Gravimetric 
method  
ISO 17318 , Fertilizers and soil conditioners — Determination of arsenic, cadmium, chromium, lead and 
mercury contents  
ISO 17319,  Fertilizers and soil conditioners ― Determination of water -soluble potassium content ― 
Potassium tetraphenylborate gravimetric method  
ISO 14820 -1, Fertilizers and liming materials - Sampling and sample preparation - Part 1: Sampling   
2 © EAC  2023  – All rights reserved  
  ISO 148 20-2, Fertilizers and liming materials - Sampling a nd sample preparation - Part 2: Sample preparation  
ISO 7409, Fertilizers  -Marking - Presentation and declarations  
 
3 Terms and d efinition s 
For the purpose s of this document , the terms and definition s given in ISO 8157 apply.  
ISO and IEC maintain terminolog ical databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
4 Requirements  
4.1 General requirements  
4.1.1  Description  
NPK fertilizer may be  in granular, prilled or crystalline forms. It shall be free from any foreign matt er. The 
particles shall be  free flowing and of uniform  colour  for complex and for single compacted granule .  
 
4.1.2  Particle size  
The particle size of the material  shall be s uch that not less than 90 % by mass of fertilizer  shall be of particles 
size range of 2 mm – 4 mm for granules  and for prill s/crystal s material shall be of particles size range of 1  mm 
– 4 mm when tested by the method given in ISO 8397 . 
4.2 Specific requir ements  
4.2.1  NPK fertilizer shall have a moisture content of not more than 1 .5 % by mass ( maximum ) when tested 
in accordance with AOAC 965.08.  
4.2.2  A compound fertilizer shall contain two or more of the following primary plant nutrient elements 
intended f or fertilizing crops: nitrogen (N), phosphorus (P) and potassium (K).  The lower limit of the declared 
value of any of the primary nutrients shall not be more than 0.7 units when tested in accordance with ISO 
5315  for nitrogen, ISO 6598  for phosphorus  and ISO 17319  for potassium  
4.2.3  Besides the primary nutrient elements, the fertilizer may also contain one or more of the following 
nutrient elements: Sulphur, calcium, magnesium, boron, cobalt, copper, iron, manganese, molybdenum, and 
zinc, which, when pres ent for the purpose of fertilizing crops and mentioned in any form or manner, shall be 
guaranteed on the elemental basis.  Sources of the elements guaranteed and proof of availability shall be 
provided upon request.  The nutrient elements shall be mentione d and guaranteed if their percentage values 
by mass are equal to or more than the values given in Table 1 when tested in accordance with the test 
methods prescribed therein .  
Table 1 — Requirements for additional nutrients in NPK fertilizer  
S/N Nutrient Element  Requirement,  
% min. Test method   
© EAC 2023  – All rights reserved  3 
 S/N Nutrient Element  Requirement,  
% min. Test method  
i.  Sulphur  (S) 1.00 ISO 10084  
ii.  Calcium  (Ca) 1.00 AOAC 962.01  
iii.  Magnesium (Mg)  0.60 AOAC 937.02  
iv.  Copper  (Cu) 0.05 AOAC  975.01 
v.  Iron (Fe)  0.10 AOAC 980.01  
vi.  Manganese (Mn)  0.050  AOAC 972.02  
vii.  Molybdenum (Mo)  0.0005  AOAC 2006.03  
viii.  Zinc (Zn)  0.05 AOAC 975.02  
5 Contaminants  
Heavy metal contaminants in NPK fertilizer  shall conform to the limits given in Table 2 when tested in 
accordance with the test methods prescribed therein . 
Table 2 — Requirements for heavy metal conta minants  for NPK fertilizer  
S/N Heavy metal  Requirement  Test method   
i.  Arsenic , mg/kg, max.   40  
ISO 17318  ii.  Cadmium , mg/kg, max.  30  
iii.  Mercury , mg/kg, max . 0.1 
iv.  Lead , mg/kg, max.  30 
v.  Chromium , mg/kg, max.  500 
vi.  Selenium , mg/kg , max.  1.0 AOAC 2006.03  
vii.  Nickel, mg/kg, max.  120 AOAC 2006.03  
 
7 Packaging  
The fertilizer shall be packaged in materials that are clean and non -defective that protect the product from 
physical, chemical and moisture contamination and withstand multiple stages of handling (tran sportation and 
storage).  
8 Labelling  
Each package shall be legibly and indelibly labeled in accordance with ISO 7409 in English and/or any other 
official language  in the destination country  with the following information:  
a) name of the fertilizer;  “Nitrogen  Phosphorus Potassium (NPK)"   
b)  brand name  if any ; 
c) name and address of the manufacturer/packer and importer/ distributor ; 
d) NPK grade in terms of percent by mass o f each of the primary nutrient;   
4 © EAC  2023  – All rights reserved  
 e) name and percent by mass of any other guaranteed element present ;  
f) net content by mass in metric units ;  
g) country of origin ;  
h) handling instructions including the words “Use No Hooks” ; 
i) production date  
j) expiry date ; 
k) batch number ; and  
l) storage conditions . 
9 Sampling  
Sampling and sample preparation of Nitrogen, Phosphorus and  Potassium (NPK) compound  fertilizers shall 
be carried out as prescribed in ISO 14820 -1 and ISO 14820 -2 respectively.  
 DEAS 912: 2023   
 
© EAC 2023  – All rights reserved