AFRICAN 
STANDARD  DARS  
1099:2023 (E)  
First Edition 2023 
 
 Reference No. DARS 1099 :2023(E) 
ICS 67.060 
 
 
© ARSO 2023 
 
 
 
 
 
 
 
 
 
 
 
Good Warehousing Practice for bagged grains  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 DARS 1099 :2023(E) 
ii © ARSO  2023 — All rights reserved   
Table of contents  
 
1 Scope  ................................ ................................ ................................ ................................ .........  1 
2 Normative references  ................................ ................................ ................................ .................  1 
3 Definitions  ................................ ................................ ................................ ................................ ... 1 
4 Quality requirements  ................................ ................................ ................................ ..................  2 
4.1 General requirements  ................................ ................................ . Error! Bookmark not defined.  
4.2 Specific requirements  ................................ ................................ . Error! Bookmark not defined.  
5 Contaminants  ................................ ................................ .............  Error! Bookmark not defined.  
5.1 Heavy metals  ................................ ................................ ..............  Error! Bookmark not defined.  
5.2 Pesticide residues  ................................ ................................ ...... Error! Bookmark not defined.  
6 Hygiene  ................................ ................................ ......................  Error! Bookmark not defined.  
7 Packaging  ................................ ................................ ...................  Error! Bookmark not defined.  
8 Labelling  ................................ ................................ .....................  Error! Bookmark not defined.  
9 Sampling methods  ................................ ................................ ...... Error! Bookmark not defined.  
Bibliography  ................................ ................................ ............................  Error! Bookmark not defined.  
 
  DARS 1099 :2023 (E) 
© ARSO  2023 — All rights reserved  iii Foreword  
 
The African Organization for Standardization (ARSO) is an African intergovernmental organization 
established by the United Nations Economic Commission for Africa (UNECA) and the Organization of 
African Unity (AU) in 1977. One of the fundamental mandates of  ARSO is to develop and harmonize 
African Standards (ARS) for the purpose of enhancing Africa’s internal trading capacity, increase 
Africa’s product and service competitiveness globally and uplift the welfare of African communities. 
The work of preparing A frican Standards is normally carried out through ARSO technical committees. 
Each Member State interested in a subject for which a technical committee has been established has 
the right to be represented on that committee. International organizations, Regio nal Economic 
Communities (RECs), governmental and non -governmental organizations, in liaison with ARSO, also 
take part in the work.  
 
ARSO Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.  
 
The main task of techni cal committees is to prepare ARSO Standards. Draft ARSO Standards 
adopted by the technical committees are circulated to the member bodies for voting. Publication as an 
ARSO Standard requires approval by at least 75 % of the member bodies casting a vote.  
 
Attention is drawn to the possibility that some of the elements of this document may be the subject of 
patent rights. ARSO shall not be held responsible for identifying any or all such patent rights.  
 
This African Standard was prepared by the ARSO Technical  Committee on Cerels, Pulses and 
Derived Products  (ARSO/TC 12). 
 
 
 
 
 
© African Organisation for Standardisation 2023 — All rights reserved* 
 
ARSO Central Secretariat  
International House 3rd Floor  
P. O. Box 57363 — 00200 City Square  
NAIROBI, KENYA  
 
Tel. +254 -20-2224561, +254 -20-3311641, +254 -20-3311608  
 
E-mail: arso@arso -oran.org  
Web: www.arso -oran.org  
  
                                                 
* © 2023 ARSO — All rights of exploitation reserved worldwide for African Member States’ NSBs.  DARS 1099 :2023(E) 
iv © ARSO  2023 — All rights reserved   
Copyright notice  
 
This ARSO document is  copyright -protected by ARSO. While the reproduction of this document 
by participants in the ARSO standards development process is permitted without prior 
permission from ARSO, neither this document nor any extract from it may be reproduced, stored 
or tran smitted in any form for any other purpose without prior written permission from ARSO.  
 
Requests for permission to reproduce this document for the purpose of selling it should be 
addressed as shown below or to ARSO’s member body in the country of the reques ter: 
 
 
© African Organisation for Standardisation 2023 — All rights reserved  
 
ARSO Central Secretariat  
International House 3rd Floor  
P.O. Box 57363 — 00200 City Square  
NAIROBI, KENYA  
 
Tel: +254 -20-2224561, +254 -20-3311641, +254 -20-3311608  
 
 
E-mail: arso@arso -oran.org  
Web: www.arso -oran.org  
 
Reproduction for sales purposes may be subject to royalty payments or a licensing agreement. 
Violators  may be prosecuted.  
 
 
 
 
 
  DARS 1099 :2023 (E) 
© ARSO  2023 — All rights reserved  v  
 DARS 1099 :2023(E) 
© ARSO  2023 — All rights reserved    
Good Warehousing Practice for storage of cereals and pulses  
 
1 Scope  
 
This Code covers warehouse and warehousing practices relevant to handling, and storage and 
transport of bagged cereals and pulses  specifically for food consumption. It also considers the 
provisions of the Good Agricultural Practices (GAP) and Good Manufacturing Practices (GMP) to 
ensure food safety, quality of produce and worker’s health, safety and welfare.  
 
 
2 Normative references  
 
The following referenced documents are indispensable for the application of this document. For dated 
referen ces, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
 
i. ARS 1098 :2023 , Agricultural Structures – Warehouses for the Storage of Bagged Grains  
ii. CAC/RCP 1 -1969, Codex Recommended International Code of Practice General Principles of 
Food Hygiene  
 
3 Terms and definitions  
 
For the purpose of this standard the following definition s shall apply . 
 
3.1 
contaminant  
any biological, chemical or physical agent, or other substances not intentionally  added to food that 
may compromise food safety or suitability  
 
3.2 
contamination  
introduction or occurrence of a contaminant in the food or food environment  
 
3.3 
farm  
any premise or area in which crops especially cereals and pulses  are grown and harvested  
 
3.4 
fertilizer  
any solid or liquid substance either organic or inorganic nutrient elements – singly or in combination 
with other materials, applied directly to the so il, foliage or plant for the purpose of promoting plant 
growth, increasing crop yield or improving product quality  
 
3.5 
food  
substance, whether processed, semi -processed or raw, which is intended for human  
consumption, and includes drinks, chewing gum and any substance which has been used in the  
manufacture, preparation or treatment of “food” but does not include cosmetics or tobacco or 
substances  used only as drugs  
 
3.6 
food safety  
assurance that food will not cause adverse health effects to the consumer w hen it is prepared  
and/or eaten according to its intended use  
  
AFRICAN STANDARD  DARS 1099 :2023(E)  
2 © ARSO  2023 — All rights reserved  3.7 
Good Agricultural Practices (GAP)  
practices that address environmental, economic and social sustainability for on -farm processes, and 
result in safe and quality food and non -food agricultural products  
 
3.8  
Good Manufacturing Practices (GMP)  
quality assurance system aimed at ensuring that products are consistently manufactured, packed, 
repacked or held to quality standards appropriate for the intended use. It is thus concerned with  both 
manufacturing and quality control procedure  
 
3.9 
cereals  
food grains of plants, usually cultivated, belonging to the Poaceae  family   
 
3.10 
hazard  
biological, chemical , radioactive materials,  or physical agent in, or condition of, food with the potential 
to cause an adverse health effect  
 
3.11 
pest 
unwanted animals , insects or poisonous and/or obnoxious weeds  that affect the quality and safety of 
grains  
 
3.12 
pesticide  
substance or product, or  mixture thereof, including active ingredients, adjuvants and pesticide 
formulations, intended to control, prevent, destroy, repel or mitigate directly or indirectly, any pest  
 
3.13 
pulses  
dry seeds of leguminous plants which are distinguished from leguminous oil seeds by their low fat 
content  
 
3.14 
warehouse  
building for storage of cerea ls and pulses meant for trade, exchange and food security programmes   
 
3.15 
warehousing practices  
system or procedure of storing grains  to ensure that these are always available, accessible and in 
good condition  
 
3.16 
corrective action  
action to eliminate the cause of a  nonconformity  and to prevent recurrence  
 
4 Site Location and  Construction   
 
Site location and construction shall comply with the requirements specified in ARS 1098 :2023 .  
 
5 Warehouse design and specification  
 
This section shall conform to the provisions of ARS 1098 :2023, Agricultural Structures – Warehouses 
for the Storage of Bagged Grains.   
  DARS 1099 :2023(E) 
© ARSO  2023 — All rights reserved   6 Stacking  
 
In addition to the requirements specified in ARS 1098:2023,  stacking should be such that the stacks 
are geometric, well-constructed  and mechanically strong so that handling and pesticide treatment are 
possible. The use of a regular stacking pattern will allow the bags to be easily counted.  
 
Stacking around the pi llars or against walls should be avoided, as this makes inspection and 
fumigation difficult, and it can damage the building.  
 
Pathways should be wide enough (at least 1 m) to allow proper inspection and spraying. An 
inspection walkway shall always be left  between stacks and the store walls.  
 
The retention of impermeable sheets after fumigation prevents re -infestation but is not advised 
because of condensation problems.  
 
 
7 Good  Warehouse -keeping  
 
7.1 Warehouse  maintenance  
There should be a monthly scheduled inspection of roofs for the presence of any holes, leakages or 
damages in the roofing system. The Warehouse officer shall immediately act upon any report of leaks 
or damage. Structural defects in gutters and downspouts shall be  immediately  and properly  repaired.  
In case  of cracks  and crevices,  cement  plaster  shall be used to properly fill up the  damage.  
Maintenance and inspection should cover  the whole warehouse structure.  
7.2 Warehouse hygiene and  sanitation  
Prior to storage, the warehouse and its immediate surroundings shall be thoroughly cleaned. The 
warehouse must be free from unnecessary materials like pieces of lumber and  old machines.  The 
entire  warehouse  structure  must  be cleaned  and brushed  down  at least  once  a month  to prevent  
contamination  from dirt. Moreover,  the surrounding  areas of the warehouse should be  weed -free. 
A weekly cleaning of the periphery of the piles should be done to remove dust and webs and  to 
eliminate  the possible  breeding  place  of rats, birds,  and insects.  Warehouse,  as well as, pallets (used 
or unused) and machines must be cleaned immediately upon grain disposal to remove accumulated 
grain residues, dust, and  cobwebs.  
After cleaning, residual spraying shall be applied to the entire storage structure, which includes wall s, 
floors and posts.  
Torn or gnawed sacks should be immediately mended to avoid spillages, collapse of the pile, and 
further attack from pests. If possible, bags or containers should not be re -used since use of returned 
sacks is a serious source of insect infestation. Unserviceable empty sacks and totally damaged 
grains should be properly disposed.  
A separate room should be provided for pesticides and cleaning materials. Sacks and pallets should 
be properly stored in a separate portion of the warehouse and stacked neatly and orderly and 
provided with a physical separator. Proper signage should be provided for all rooms. Moreover, no 
portion of the warehouse should be used as living quarters.  
7.3 Stock maintenance and preservation  
 
Representative samples shall be  taken randomly from a batch of bagged grains and measured using 
calibrated moisture meters. Newly received grains with moisture content above 14% MC shall be 
temporarily stored and subjected to drying to 14% MC and below. Dried stocks may be grouped 
accor ding to their varietal characteristics.  DARS 1099 :2023(E)  
4 © ARSO  2023 — All rights reserved  Laborers shall be discouraged and prevented from using hook or “ gancho ” to maintain the  integrity  of 
the bags  and avoid  spillages.  The spillages  shall be immediately  collected. These collected grains 
may either be placed into bags (sacks) and piled separately or cleaned and added to busted  bags.  
At least 100 g sample of every variety of stocks of milled rice or shelled corn stored in  the warehouse  
should  be maintained  at the warehouse  office  for easy  reference.  It shall be packed in plastic 
containers or sample bottles with proper  identification.  
The recommended relative humidity (RH) for a warehouse is 65%. Thus, warehouse 
temperature/humidity as well as grain temperature must be checked and measured daily. Grain 
thermometer and thermohygrometer should be installed for monitoring purposes. Warehou se 
atmosphere must be controlled by either opening or closing windows/doors  or installing  ventilation  
fans.  Windows  and doors  must  be opened  during daytime  for proper  aeration  of stocks.  All windows  
and other  openings  except  doors  must be screened to avoid  pilferages and entry of  pests.  
Damaged grains that are no longer fit for consumption shall be disposed immediately. Daily inspection 
of stocks shall be done to detect signs of infestation so that pest control measures can be 
recommended and effected.  
7.4 Pest  control administration  
A pest monitoring and inspection program must be in place to prevent harborage and breeding  of 
pests  on the grounds  and within  the warehouse  facility.  Whenever  stocks  are disposed and the 
warehouse is vacated, residual spraying of t he whole or sections of the storage  structure  with 
chemical  pesticides  should  be carried  out after thorough  cleaning. Space treatment (fogging) should 
be conducted at dawn or dusk when flying insects are most  active.  For crawling  insects,  external  stock  
treatment  consisting  of spray  application of pesticides to the four sides and the top surface of the pile 
should be conducted regularly. For heavily infested stocks, fumigation, conducted or supervised by 
certified fumigators only, should be done as a reme dial measure to control internal infestation. Rodent 
control through the use of traps or poison baits should be carried out  regularly.  
Only pesticides for stored products approved by the competent authority shall be used. Monitoring of 
the efficacy of the treatment used should be done at least one week after the application.  
Fumigators should be equipped with protective gear such as gas masks. Proper disposal of 
pesticides/fumigants should be practiced , especially on packaging material . 
7.5 Transport  
The harvested  grains  or stored  grains  should  be transported  using  clean  vehicles  or other appropriate 
mode of transportation. Transport vehicles should be cleaned before and after usage to avoid 
contamination and residual  infestation.  The vehicles should be dr y to avoid increasing the moisture 
content of products, and have a covering for the consignment.   
 
8 Hygiene, w orker’s health, welfare and  training  
 
8.1 Personnel  hygiene  
There  shall be a strict  observance  of the “no smoking”,  “no spitting”  and “no eating”  policy inside the 
warehouse since these practices will induce contamination. Any person who has or appears to have 
an infectious disease, open lesion, including boils, sores, or infected wounds, or any other abnormal 
source of microbial contamination must be excluded from any operations. Hygienic practices through 
established/documented procedures including specific instructions should be made for all  personnel.  DARS 1099 :2023(E) 
© ARSO  2023 — All rights reserved   Grain handlers should follow personal hygiene recommendations as indicated in the Codex 
Recommended International Code of Practice General Principles of Food Hygiene (CAC/RCP 1 -
1969, Rev. 4 -2003) or the latest issuance. The following recommendations should include but not 
limited to:  
 
Wearing of appropriate clothing and shoes applicable  to the operation and can serve as protection for 
food contamination and an aid on the worker’s health and welfare.  
Wearing of appropriate masks during handling and transport of grain.  
 
Washing of hands thoroughly and sanitizing, if necessary, in the appro priate hand - washing facility 
before the start of any handling operation, after each absence from the work station, and at any given 
time when possible contamination can be encountered by the worker.  
 
8.2 Personnel training  
 
Before a job is assigned, the personnel shall be trained on good warehousing practices. Training and 
re-orientation of the warehouse personnel should be done at least every two (2) years. The following 
trainings are recommended for the personnel specific on his/her assigned task:  
 Inven tory and warehouse management  
 
 Acquisition and purchasing  
 
 Supply chain and logistics  
 
 Transportation and freight operations  
 
 Personnel hygiene and food safety  
 
9 Management and supervision  
Grain operators should have adequate knowledge on food hygiene principles and practices to be able 
to assess potential risks, take appropriate preventive and corrective action, and ensure that effective 
monitoring and supervision is carried out. Formal training on food safety (Good Manufacturing 
Practices) is necessar y and further trainings in Hazard Analyses and Critical Control Points (HACCP) 
are extremely helpful. Trainings on food safety for grains businessmen, grains operators and 
warehouse personnel should be conducted.  
 
10 Documentation and records  
All warehouse  practices  should be properly documented in a recommended form.  Appropriate 
records from all warehousing practices should be kept and retained for a period that exceeds the 
shelf life of the product. Records should be to facilitate recalls and product safe ty investigations, if 
required.  
 
Warehouses shall keep records of the:  
a) Origin, history of and volume of each lot of cereals and /or pulses kept;  
b) Laboratory tests carried out;  
c) Names of chemicals used for pest control;  
d) Names of employees and training undertaken;  
e) Authorization by the legal authority ; 
f) Servicing and calibration of all equipment;  DARS 1099 :2023(E)  
6 © ARSO  2023 — All rights reserved  g) Cleaning; and   
h) Pest control detailing the pesticide used, the date and method o f spray/dusting, person or 
company.  
 
11 Traceability  
Proper labeling  and record keeping should be made to facilitate any forward or backward tracing of 
food products. Records of deliveries should be kept (delivery receipt, personnel coming in and out of 
the warehouse, date of delivery, and classification of goods delivered ). 
The labeling information shall contain the following:  
 
 name of the grain  
 classification;  
 grade;  
 variety  (optional);  
 net weight;  
 name and address of owner; and  
 date of milling (for rice) ; 
 crop year  
 date of delivery.  
 
Geotagging of warehouses and farm site where the grain product came from should be considered.  
 
12 Recall  procedures  
Warehouse operators should ensure that effective procedures are in place to deal with any food 
safety hazard and to enable the complete, rapid recall of any implicated lot o f the bagged grains 
(finished food) from the market in case of complaint or issues regarding product quality and safety. 
Where a product is withdrawn because of an immediate health hazard, other products which are 
produced under similar conditions, and whi ch may present a similar hazard to public health, should 
be evaluated for safety. The need for public warnings should be considered.  
Recalled products should be held under supervision until they are destroyed, used for purposes other 
than human consumption, determined to be safe for human consumption, or reprocessed in a manner 
to ensure their safety.  
 
13 Corrective action  
It is recommended that the warehouse operators to establish the corrective action procedures for 
continuous improvements in case of non-conformities  or hazard problems associated with the 
warehouse practices.