ICS 55.220  
 
Reference number  
DRS 2 64: 201 9 
© RSB 2019  
  
 RWANDA 
STANDARD  DRS 
264  
 
First edition  
2019-mm-dd 
(Reaffirmed 2019 -mm-dd) 
Warehouse and warehousing for  storage 
of  bagged grains— Requirements  
   
DRS 228: 201 9 
©RSB 2019  - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2019  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reprodu ce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw   DRS 2 64: 201 9 
iii                ©RSB 2019  - All rights reserved  
 Contents  Page 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 General guidelines  ................................ ................................ .................... Error! Bookmark not defined.  
5 Specific guidelines  ................................ ................................ .................... Error! Bookmark not defined.  
5.1 Pre-harvesting  ................................ ................................ ........................... Error! Bookmark not defined.  
5.2 Harvesting  ................................ ................................ ................................ ..Error! Bookmark not defined.  
5.3 Drying of earhea ds ................................ ................................ .................... Error! Book mark not defined.  
5.4 Threshing  ................................ ................................ ................................ ...Error! Bookmark not defined.  
5.5 Drying of grain  ................................ ................................ ........................... Error! Bookmark not defined.  
5.6 Cleaning a nd sorting  ................................ ................................ ................. Error! Bookmark not defined.  
5.7 Packaging  ................................ ................................ ................................ ...Error! Bookmark not defined.  
5.8 Transportation  ................................ ................................ ........................... Error! Bookmark not defined.  
5.9 Storage  ................................ ................................ ................................ .......Error! Bookmark not defined.  
6 Major storage pests and their control measures  ................................ ...Error! Bookmark not defined.  
Annex  A (informative)  Major stored grain pests of sorghum and their control measures  ......................  12 
Annex  B (informative)  —................................ ................................ ................................ ................................ . 14 
 DRS 228: 201 9 
©RSB 2019  - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepa red by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards 
adopted by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and 
gazettment as Rwanda Standards.  
RS 264 was prepared by Technic al Committee RSB/TC 003, Cereals, pulses, legumes and derived products . 
In the preparation of this standard, reference was made to the following standard  (s): 
1) XYZ: Title  
2) XYZ:  Title 
The assistance de rived from the above source is hereby acknowledged with thanks.  
This second/third/... edition cancels and replaces the first/second/... edition (RS  nnn-n: yyyy), [clause(s) / 
subclause(s) / table(s) / figure(s) / annex(es)] of which [has / have] been technically revised.  
(The first/second/third/... edition (RS  nnn-n: yyyy) has been re affirmed  by the Board on dd-mm-yyyy. ) 
RS nnn consists of the following parts, under the general title Introdu ctory element — Main element : 
 Part n: Part title  
 Part [n+1]: Part title  
Part [n+2]: Part title  
Committee membership  
The following organizations were represented on the Technical Committee on  Cereals, pulses, legumes and 
derived products  (RSB/TC 003) in the preparation of this standard.  
Paragraph of p articipants  
Rwanda  Standards Board  (RSB) – Secretariat  DRS 2 64: 201 9 
v                ©RSB 2019  - All rights reserved  
 Introduction   
Wareh ouses are intended for the storage and physical protection of grains from the weather, prevention of the 
entry of pests and security. They also include materials and equipment required for inspection, drying, 
screening, sorting, grading, packaging and hand ling of bagged grain and storage pest control. The structure 
should be properly built to provide good storage conditions, easy access and safe working conditions, and 
should not provide harbourage for pests.  
In general, the condition of grain changes slow ly while in storage; the extent of any change depends on 
ambient conditions at harvest. Changes in moisture content and temperature are limited to the periphery of a 
bulk or to the outer bags of a stack, unless the storage period is prolonged or the grain is ventilated. Heavy 
infestations of insects, however, may cause a rise in temperature in the grain mass, possibly due to the 
development of fungi. Ideally, the warehouse should permit some control of temperature and humidity, to keep 
the grain cool, dry a nd at a uniform temperature as much as possible.  
 The objective of this standard is to provide guidance to industry regarding appropriate storage of cereals and 
pulses in order to reduce on the level of post -harvest losses incurred in these commodities. Th is standard as 
well will be invaluable in promoting the Structured Trading Systems (STS) in the region to promote both 
regional and International trade in cereals and pulses. The standard will play a major role in the 
implementation of the Warehouse Receip t System (WRS) and the Commodity Exchange in the region.  
 
 
 
 
 DRS 2 64:2019 
1                ©RSB 2019  - All rights reserved  
 Warehouse and warehousing for storage of bagged grains— 
Requirements  
1 Scope   
This  Draft Rwanda Standard  specifies  requirements for  location, structur e, facility, safety and management 
of  a warehouse  intended to store bagged grains.  
2 Normative references   
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) ap plies.  
ISO 6322 -3, Storage of cereals and pulses — Part 3: Control of attack by pests  
3 Terms and definitions  
For the purposes of this standard, the follow ing terms and definitions apply  
3.1 
warehouse  
building  for storage of grains meant for trade, exchange and food security programmes  
3.2 
pallet  
wooden, plastic or any other suitable frame used on floor for stacking bags to prevent direct  contact between 
the grains and the floor  
3.3 
competent authority  
any person or organization that has the legally delegated or invested authority, capacity, or power to perform a 
designated function  
3.4 
warehousing  
performance of administrative and physical functions associated with storage of grains. These functions  
include cleaning and maintenance of a warehouse, drying, screening, sorting and grading of grains,  
©RSB 2019  - All rights reserved                  2 
 packaging, labelling, stacking,  pests prevention and control, records keeping and any other activity necessary 
to store grains safely.  
4 Requirements  
4.1 Location  
4.1.1 The location of a warehouse shall be authorized by competent authority  
4.1.2 The site shall be located at relatively high elevation to avoid water logging and safe from natural  
flooding calamities.  
4.1.3 The orientation of the warehouse sh ould  be such that radiant heat gain from the sun is minimal.  
4.1.4 The warehouse shall be accessible by road.  
4..15 The warehouse shall have facilities such as clean water, communication facilities and power supply.  
4.1,6 Warehouse shall not be located near the s ite for waste disposal and surroundings shall be kept clear of  
vegetation and rubbish.  
4.1.7 The warehouse shall not be near any facility where the danger of fire is constantly present.  
4.1.8 Warehouses shall not be located near busy public facilities such  as schools and hospitals. Existing  
warehouse near public facilities shall take necessary measures to mitigate the effects of their operations.  
4.1.9 There should be ample space to facilitate movement  ,parking and  loading and off loading  
4.2 Structu re 
4.2.1  General  
4.2.1.1  The construction and building materials shall conform to the National Building Regulations and  
relevant standards.  
4.2.1.2  The material shall be durable, non -toxic ,wind and water tight.  
4.2.2  Foundation  
The foundations shall be of adequate strength to take the weight of the building and of the grain filling, and  
should be termite proofed.  
4.2.3  Floor  
4.2.3.1  The floor shall be adequately strong and capable of withstanding heavy loads and vibrations.  DRS 2 64:2019 
3                ©RSB 2019  - All rights reserved  
 4.2.3.2  The floor shall be elevated or construct ed higher than the existing ground.  
4.2.3.3  The floor shall be smooth, hard and easy to clean.  
4.2.3.4  The floor shall be free from cracks where moisture from the ground may affect the stored grains.  
Moisture sealing compound or asphalt should be provided to fill the floor cracks against moisture.  
4.2.3.5  General warehouse space shall be floored with a concrete slab to carry wheel loads and withstand the  
abrasion generated by the continual use of hard rubber and steel -wheeled forklift and trucks.  
4.2.4  Walls  
4.2.4.1  The internal surfaces of the walls shall be smooth and free from projections to eliminate dust -laden 
surfaces, facilitate cleaning of the store and avoid interference with other operations.  
4.2.4.2  The junction between walls and roof shall be well sealed in order avoid birds and rodents to access 
the store rooms.  
4.2.4.3  A water/damp -proof barrier shall be incorporated into the base of the walls. Water proofing compound 
may be incorporated during the plastering and finishing of the walls.  
4.2.5  Roofs  
4.2.5.1  Roof design shall be in a way that facilitates pest control and other stock management procedures.  
4.2.5.2  Internal pillars supporting roof frames should be avoided as much as practicable  
4.2.5.3  Roof shall be provided with the necessary lateral and v ertical wind brace to resist forces due to strong  
winds and earthquakes.  
4.2.5.4  The roof covering materials shall be reflective and keep the warehouse dry  
4.2.5.5 The inclination of the roofs shall be sufficient to drain rainwater quickly, taking into account that the  
water may be forced up by the wind.  
4.2.5.6 Roofs shall be watertight and gulleys kept clear of debris and leaves.  
4.2..5.7 The roof shall be a good thermal insulator  ,  not affected by condensation, and give protection against  
attack by p ests and moulds ,  
4.2..5.8 It shall be designed so as not to provide harbourage for insects and mites. An internal ceiling is not  
advised, as it may provide harbourage for predators.  
4.2..5.9 Rainwater drainpipes shall be not less than 90 mm in diameter.   
©RSB 2019  - All rights reserved                  4 
 4.2.5.10  All drain pipes from roof gutters shall be external, well fitted and shall have mesh baffles fitted inside  
their lower open ends.  
4.2.6  Doors  
4.2.6.1 The number of doors shall be determined by the frequency of access to the stored product , and 
number of doors shall not be less than two 4.2.6.2 The door shall fit tightly for insect control and fumigation.  
4.2..6.3 The door shall be made of steel. If it is made of timber, the lower part of both the door and the frame  
should be covered by a steel strip protecting them against attack by rodents.  
4.2.6.4 The door shall be provided with a secure locking system.  
4.2.6.5 The size of the entrance shall depend on loading and unloading operations and shall be not less than  
2.5 m wide and 2.5 m high.  
4.2.7  Ventilation  
4.2..7.1 Vents shall be provided near the floor level in the wall, at the top of the walls near the grid line. A  
suitable meshed ventilation duct should be placed in each gable so that warm air accumulating under the roof  
can escape  
4.2.7.2 Ventilation openings shall be fitted on the outside with anti -bird grills and on the inside with insect  
screens, which will deter most insects.  
4.2.7.3 In addition to natural ventilation exhaust, fans may be introduced for forced ventilation  
4.2..7.4 Windows should be  kept to a minimum or avoided. They should be left open as little as possible.  
Windows shall be protected by mesh grilles to keep birds out when the windows are open  
4.2.8   Lighting  
4.2..8.1 Lighting  inside the warehouse shall be sufficient that lights shall not  be too bright or too dim.   
4.2.8.2 Artificial lighting is preferable for the interior of the warehouse, where sky lighting is used; it shall be  
aligned along the corridors and not directly above the grain stacks.  
4.2.8.3  Light s shall be made in a way that  minimize s risks of contamination.  
4.2.9  Fence  
4.2..9.1 The site shall be secured against the unauthorised entry of person and animals.  
4.2.9.2 Gates shall be adequate for their purpose and wide enough to allow easy vehicular access.  DRS 2 64:2019 
5                ©RSB 2019  - All rights reserved  
 4.3 Facility  
There shall be annex rooms separate from the grain storage areas and shall include the facilities for  reception, 
offices, laboratory, equipment and chemical store, toilets and urinals, changing room and shower.  
4.3.1  Office space and related facilities  
The office space shall b e: 
a) easily accessible for staff and other visitors;  
b) clearly signposted;  
c) well aerated;  
d) safe and unobstructed; and  
e) clean, naturally well-lit and suitably furnished.  
4.3.2  Toilets and urinals  
4.3.2.1 Toilets and urinals for male and female shall be separately provided in the premises of the  
warehouse.  
4.3.2.2 The floor of the toilets and urinals shall be non -absorbent, washable and non -slip materials;  
4.3.2.3 The wall shall be constructed from non - absorbent, washable materials and shall be light coloured, up  
to a height of 2 metres and they shall be smooth and without crevices and shall be easy to clean and disinfect;  
4.3.2.4 The toilets and urinals shall be furnished with hand washing facilities.  
b) clearly signposted;  
4.3.2.5 The number of toilets shall be a dequate for the number of employees. The number of toilets may be  
determined using table 1 below : 
Table 1 — Number of toilets and urinals in accordance with number of employees  
S/N  Number of employees  Number of toilets and urinals  
i.  1 - 15 1 
ii.  16 - 35 2 
iii.  36 - 55 3 
iv.  56 - 80 4 
v.  81 - 110 5 
vi.  111 - 150 6  
©RSB 2019  - All rights reserved                  6 
 NOTE: Over 150 employees one additional fixture for each additional 40 employees  
4.3.3  Changing room and shower  room  
4.3.3.1 The warehouse shall provide suitable changing room and shower  room  for workers  
4.3..3.2 Changing rooms shall be furnished with lockers.  
4.3..3.3 All cleaning materials shall be provided  
4.3.4   Equipment store  
4.3..4.1 Stores for Equipment used  for fumigation, sampling  and cleaning shall be separate d from the grain 
storage and chemical storage  areas.  
4.3..4.2 The floor shall be non -absorbent and washable  
4.3.5   Chemical store  
4.3..5.1 Chemicals such as pesticide, rodenticides and fumigants may be stored at the warehouse. Such  
chemicals shall be stored in a separate room under lock and key.  
4.3.5.2 Chemicals shall be clearly labelled for easy identification.  
4.3.5.3 The floor and the wall shall be easy to clean.  
4.3.5.4 Chemical store shall be clearly identified as such  
4.3.6  Laboratory  
4.3..6.1 The warehouse shall be provided with laboratory for internal control.  
4.3..6.2 The laboratory shall have facilities to undertake basic tests such as moisture content , aflatoxin 
screening and grading.  
4.3.6.3 The laboratory shall have equipment  and sufficient  area for test to be conducted These equipment  
may include moisture meters, sieves, aflatoxin screening kits, weighing balance.  
4.3.6.4 The floor and the wall shall be easy to clean.  
4.3.6.5 The testing area shall be sufficiently lit.  DRS 2 64:2019 
7                ©RSB 2019  - All rights reserved  
 4.4 Safety  
4.4.1 Warning signs or boards shall be fixed in hazardous/dangerous places.  
.4.4.2 Fire fighting  equipment in working condition (fire extinguishers, fire hydrants) shall be provided and be  
installed in a n appropriate  and easily accessible location.  
4.4.3 There shall be provisions for first aid facilities.  
4.4.4 Safety signs, fire exits shall be indicated.  
4.5  Management  
4.5.1  Cleaning and maintenance  
4.5.1.1 The buildings, equipment, utensils and all other physical facilities of the establishment, including  drains 
shall be maintained in good repair and in an orderly c ondition.  
48.1.2 The store shall be cleaned and treated prior to any storage operation.  
8.1.3 The store and environment of the warehouse shall be kept clean and shall be disinfected regularly to  
prevent insect and mites infestation.  
8.1.4 Waste from sortin g and screening shall be disposed in such way that does not harbour rodents and  
pests.  
8.1.5 Waste from the warehouse shall be collected and disposed in environment friendly manner.  
8.1.6 Changing facilities and toilets shall be kept clean.  
4.5.2  Inspection, dry ing, screening, sorting and grading  
4.5.2.1  General  
Prior to introduction into the store, incoming  grains shall be inspected, dried and sorted as required to remove  
unfit materials. Such operations shall be carried out in a clean and sanitary manner. Only clean an d sound  
product shall be stored.  
4.5.2.2  Inspection  
4.5.2.2.1 The general appearance of the products shall be observed   during the process of unloading; if the  
grains are moist, insect infested, insect damaged, or contain an unusual amount of dirt, debris or other  foreign  
material.  
4.5.2.2.2 If the observations from sensory analysis do not allow taking the decision, a sample from the   
©RSB 2019  - All rights reserved                  8 
 suspected lots shall be taken and accurate tests conducted before any acceptance of the lot.  
4.5.2.3  Drying  
4.5..2.3.1 If grains brought to t he warehouse do not comply with maximum moisture content stated in  relevant  
Standards, the grains shall be dried and moisture content reduced to the specified level.  
4.5.2.3.2 If heated air is used for moisture reduction, temperature and drying time shall  be synchronized so  
that they do not result in adverse effect on the nutritional composition and quality of the grain in its intended  
use. 
4.5.2.3.3 If drying is done under the sun, drying should be held on plastic sheets, preferably black. The  grain 
should be spread in a thin layer and raked at intervals, to remove the evaporated moisture.  
4.5.2.3.4 Whatever the drying system, care shall be taken to avoid attack by insects, rodents and birds.  
4.5.2.4  Screening, sorting and grading  
8.2.4.1 Ungraded grains shal l be screened and sorted before being graded according to relevant standards as 
soon as they reach the warehouse.  
8.2.4.2 Grains shall be screened and/or aspirated to remove all straw, chaff and other leafy vegetable  matter, 
grains other than the main cons tituent grain, weed seeds and defective grains  
8.2.4.3 Screening shall be done in such way as the operation does not pollute the other places.  
8.2.4.4 Sorting shall be performed before any grain treatment to ensure the removal of mould  contaminated  
grain effectively.  
8.2.4.5 Defective grains such as mouldy, discoloured, , rotten , shrivelled, insect damaged, diseased  shall be 
bagged separately and tagged as unsuitable for human consumption.  
8.2.4.6  Containers of defective grains shall be removed as soon as practicable from the warehousing  area 
and materials which carry the danger of contamination by mycotoxin shall be diverted to non -food uses.  
4.5.3  Loading and unloading  
8.3.1 Loading and unloading may be done mechanically or manually.  
8.3.2 If manual loading and  unloading is used, the floor should be 1m above the ground to permit easy  loading 
or unloading into trucks at the sides of the warehouse.  
8.3.3 Loading and unloading shall not take place in open area when it is raining. A canopy should be  
constructed over  every entry door to allow continuous loading and unloading even when it rains  
-Maximum package weight of 50kg where human loading and offloading is involved  DRS 2 64:2019 
9                ©RSB 2019  - All rights reserved  
 4.5.4  Provision of spacers  
8.4.1 The spacers (pallets) shall be used to avoid the sacks being in  direct contact with the ground and shall 
be strong enough to resist the weight  
8.4.2 Spacers should be standard pallets, of manageable size, and therefore easy to lift. They shall be  treated 
with pesticides and stacked neatly when not in use.  
4.5.5   Stacking  
While deci ding the whereabouts of bag stacks the following shall be considered:  
a) bags of grains in each lot shall be stacked in basic patterns of cluster formation so that bags can be easily  
counted and quality maintained;  
b) stacking around pillars shall be avoid ed, as this makes inspection and fumigation difficult, and it can  
damage the building;  
c) the bag stack shall be built at least one (1) meter away from the walls of a store. This allows easy  
inspection, prevents moisture ingress from contact with the wall and facilitates fumigation treatments  since a 
gas-tight sheet can be placed over all sides of the stack;  
d) gangways leading to the doors shall be at least one (1) meter wide to allow for proper inspection and  
spraying. An inspection walkway shall always b e left between stacks;  
e) the bag stack shall not be built too high and not closer than 1.5 m to the store roof beams so that staff can  
work on top of stacks;  
f) when using jute or sisal bags the bag stack can be built to around 18 - 20 layers, any higher then there is a 
risk to stability and it is difficult for storage workers. When using polypropylene or plastic bags the stack  
heights shall be lower as they are less stable than jute or sisal;  
g) the size of the piles shall conform with fumigating sheets i n situations where warehouses cannot be made  
airtight; and  
h) different commodities, different consignments (new and old) shall be placed in different stacks, i.e.  
separated in batches based also on the time of their reception in store, as far as the avail able space will  allow.  
4.5.6   Pests prevention and control  
8.6.1 Pests can be prevented and controlled by:  
a) keeping grains below the temperature or the humidity necessary for increase in pest numbers (for  example 
drying, aerated storage, refrigerated storage);  
b) spraying the floors and walls with approved pesticides;   
©RSB 2019  - All rights reserved                  10 
 c) dusting of grains by approved pesticides; and  
d) by fumigation.  
e) by using rodent baits  
8.6.2 Where control is by fumigation the following provisions shall apply:  
a) approved fumigants shall only be used by properly trained and authorized persons /organizations  who know 
the dangers and the  necessary safeguards;  
b) there shall be no human habitations within 100 m of the planned fumigation; if there are, the  arrangements 
shall be made for people to be relocated during the treatment;  
c) fumigated piles shall be kept closed and post warning signs displayed until the gas concentration is below  
the concentration which does not cause any effect to the workers;  
d) the stacks shall be well sheeted and th ere shall be no store imperfections, e.g. cracks in the floor, unfilled  
floor joints, roof leaks etc., which might jeopardise the success of the fumigation; and  
e) at the end of the fumigation, warehouse shall be aerated carefully to minimize dangers.  
8.6.3 The control of attacks by pests shall be done in accordance with ISO 6322 -3. 
4.5.7   Record keeping  
Warehouse shall keep records of:  
a) origin, and volume of each lot of grains  kept;  
b) laboratory tests carried out;  
c) names of chemicals used for pests control;  
d) fumigation detailing the fumigant used, the date and method of fumigation, person or company;  
e) names of employees and training undertaken;  
f) authorization on environment  by a competent authority  
g) servicing and calibration of all equipment;  
h) clean ing; and  
i) pest control detailing the pesticide used, the date and method of spray/dusting, person or company.  DRS 2 64:2019 
11                ©RSB 2019  - All rights reserved  
  
 
 
 
 
 
 
 
 
 
 
 
  
©RSB 2019  - All rights reserved                  12 
 Annex  A 
(informative)  
 
Typical grain storage warehouse  
 
Figure A.1 — Warehouse floor plan  
 
DRS 2 64:2019 
13                ©RSB 2019  - All rights reserved  
  
Figure A.2 — Warehouse front and back views  
 
Figure A.3 — Warehouse section  
 
 
 
  
 
©RSB 2019  - All rights reserved                  14 
 Annex  B 
(informative)  
 
— DRS 2 64:2019 
15                ©RSB 2019  - All rights reserved  
 Bibliography  
[1] ISO 6322 -1: 1996 , Storage of cereals and pulses -- Part 1: General recommendations for the keeping 
of cereals  
[2] ISO 6322 -2: 2000, Storage of cereals and pulses -- Part 2: Practical recommendations  
[3] PAES 419: 2000, Agricultural structures — Warehouse for bagged storage of grains  
 DRS 264: 2019  
 
Price based on  12 pages  
©RSB 2019  - All right s reserved