Cereals — Rice grains — Specification BOTSWANA STANDARD BOS 273: 2022 
Edition  3.0 
BOTSWANA BUREAU OF STANDARDS  BOS 273:2 022 Copyright Protection Notice
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 rights reserved  
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Botswana Bureau of Standards  
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E-mail: infoc@hq.bobstandards.bw  
Website:  www.bobstandards.bw  
ICS 67.060  
Pub
lished in Botswana  
BOS 273:2022  
Edition 3.0 
i Contents Page  
Foreword ............................................................................................................................................. ............ii    
1 Scope  ................................................................................................................................................. 1  
2
 Normative  references  ....................................................................................................................... 1  
3 Definitions  ......................................................................................................................................... 1  
4 Essential  composition and quality  factors ..................................................................................... 2  
4.1 General  quality  factors  ..................................................................................................................... 2  
4.2 Specific quality factors  ..................................................................................................................... 3  
5 Contaminants  .................................................................................................................................... 4  
5.1 Heavy metals  ..................................................................................................................................... 4  
5.2 Pesticides  .......................................................................................................................................... 4  
5.3 Mycotoxins  ........................................................................................................................................ 4  
6 Hygiene  .............................................................................................................................................. 4  
7 Classification  ..................................................................................................................................... 4  
8 Sampling  ............................................................................................................................................ 4  
9 Packaging  and labelling  ................................................................................................................... 5  
  Annex A (informative) Informative references ....................................................................................... .......      6       
© BOBS (2022] -All rights reserved BOS 273:2022  
Edition 3.0 
ii Foreword 
This Botswana standard was approved by the Technical Advisory Committee of the Standards Council on 
2022-11-08.  
The Botswa na Bure au of Standards ( BOBS) w as es tablish ed under t he Standards A ct No. 16 of 19 95 with a 
primary r esponsibility of pr eparing Botswana standards. 
During the preparation of t his standard, as sistance was derived from ISO 73 01 Rice – Specification, p ublished 
by the International O rganization f or Standardization. 
This B otswan a Standar d is a revision of, c ancels an d replaces BOS 273:2015 ( Second  edition) C ereals – Rice 
grains — Specification.  
During the review of this standard, the following organizations were directly represented in the Technical 
Committee, AFD 3
 – Cereals and Pulses: 
Botswana  University  of Agriculture  Mr G Legwaila  (Chairperson)  
and Natural  Resources  – Department  of Crop  
and Soil Sciences  
Botswana Bureau of Standards  Mr O J Moje  (Technical  Secretary)  
Bokomo  Mr J Venter  
Bolux  Group  Ms G Ntope  
Botswana University  of Agriculture  
and Natural  Resources  – Department  of Crop 
and Soil Sciences  Dr. G Malambane  
Botswana University  of Agriculture  
and Natural  Resources  – Department  of 
Food Science and Technology  Prof.     G Bultosa  
Jagwa Inves
tments  Mr J O Jagwer  
Honey  Guide  Ms T M Phiri 
Ministry of Agriculture,  
Department  of Crop Production  Mr M Khukhutha  
National  Food  Technology Research  Centre  Mr S Mpotokwane 
© BOBS [ 2022] – All rights reserved  Cereals -Rice grains -Specification 
1 Scope BOS 273:2022 
Edition 3.0 
This Botswana Standard specifies requirements for rice grains (Oryza sativa L.) and covers de-husked rice, de­
hulled rice and parboiled rice. 
2 Normative references 
The following referenced documents are indispensable for tihe application 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. Botswana Bureau of Standards (BOBS) mainta ins registers of currently 
valid documents. 
BOS CAC/RCP 1, Recommended code of practice- General principles of food hygiene 
Codex Stan 1, General standard for the labelling of pre-packaged foods 
ISO 712, Cereals and cereal products -Determination of moisture content- Routine reference method 
ISO 1026, Fruit and vegetable products -Determination of dry matter content by drying under reducedpressure 
and of water content by azeotropic distillation 
ISO 5223, Test sieves for cereals 
ISO 7301, Rice -Specification 
ISO 13690, Cereals, pulses and milled products -Sampling of static batches 
ISO 16050, Foodstuffs- Determination of af/atoxin 81, and the total content of af/atoxins 81, 82, G1 and G2incereals, 
nuts and derived products -High performance liquid chromatographic method 
3 Definitions 
For the purposes of this Botswana Standard, the following terms and definitions apply: 
3.1 chalky grain: non-parboiled rice whose whole surface has an opaque and floury appearance. This 
excludes waxy rice 
3.2 chips: fragments of rice grain which pass through a sieve with round perforations of 1.4 mm diameter 
3.3 damaged grain: grains showing evidence of deterioration either due to moisture, pests, disease or 
other causes, but excluding heat-damaged grains 
3.4 dehusked rice: rice from which the husk only has been removed. Dehusked rice is also referred 
to as brown rice or cargo rice 
3.5 dehulled rice: brown rice from which all or part of the bran and germ have been removed. Dehulled 
rice is also referred to as milled rice or white rice 
1 © BOBS (2022] -All rights reserved