DRAFT UGANDA STANDARD FINAL DRAFT UGANDA 
STANDARD  
 FDUS 1501  
First Edition  
2013-nn-nn 
 
 
 Reference number  
FDUS 1501:201 3 
© UNBS 2013  
  
Fresh onions — Specification  
 DRAFT UGANDA STANDARDFDUS 1501: 2013 
ii © UNBS 2013 – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2013  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala 
Uganda 
Tel: 256 414 505 995 
Fax: 256 414 286 123 
E-mail: unbs@infocom.co.ug  
Web: www.unbs.go.ug  
 DRAFT UGANDA STANDARDFDUS 1501: 2013 
© UNBS 2012  – All rights reserved  iii 
 Foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of the Laws of Uganda.  UNBS is mandated to co-ordinate the 
elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agreements of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
This Final Draft Uganda Standard has been developed as a result of a need to provide guidance to industry in 
production and regulation of Fresh Onions.  
Committee membership 
The following organisations were represented under the Fruits and vegetables sub-committee of the Food and 
Agriculture Standards Technical Committee, UNBS/TC 2, during the development of this standard: 
 Federation of Uganda Exporters Association 
 Government Analytical Laboratory 
 Horticulture Exports Association of Uganda 
 Ministry of Agriculture, Animal industry and Fisheries  
 Ministry of Trade, Industry and Cooperatives 
 National Organic Agricultural Movement of Uganda 
 Sulma Foods Ltd 
 Uganda National Farmers Federation 
 Uganda Consumer Protection Association 
 
 DRAFT UGANDA STANDARDDRAFT UGANDA STANDARDFINAL DRAFT UGANDA STANDARD  FDUS 1501 : 2013 
 
© UNBS 2013– All rights reserved  1 
 Fresh onions — Specification 
1 Scope 
This Final Draft Uganda Standard specifies requirements for onions of varieties (cultivars) grown from Allium 
cepa L. to be supplied to the consumer in the natural state.  
This standard does not specify requirements for green onions with full leaves and onions for industrial 
processing. 
2 Normative references 
The following referenced documents are indispensable for the 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. 
US 7, General standard for labelling of pre-packaged foods  
US 28, Code of practice for hygiene in the food and drink manufacturing industry   
US 500, Requirements for nutritional labelling of foods  
US 508, Requirements for nutritional and health claims for foods  
US 738, General standard for contaminants and toxins in foods  
CAC/RCP 44, Recommended international code of practice for packaging and transport of fresh fruits and 
vegetables  
3 Terms and definitions 
For the purposes of this standard, the following terms and definitions shall apply. 
3.1 
damage 
any specific defect as described in Annex A; or any equally objectionable variation of any one of these 
defects, any other defect, or any combination of defects, which materially detracts from the appearance, or the 
edible or marketing quality of the onions 
3.2 
diameter 
greatest dimension measured at right angles to a straight line running from the stem to the root DRAFT UGANDA STANDARDFDUS 1501: 2013 
2 © UNBS 2013 – All rights reserved  
 4 Requirements  
4.1 General quality requirements 
Fresh onions shall be of a colour, flavour and taste appropriate for the species, free of organic and mineral 
impurities, free, as far as possible from damage caused by disease and insects.  
4.2 Specific quality requirements 
4.2.1  In all classes, subject to the special provisions for each class and the tolerances allowed, the bulb 
shall be: 
a) intact;  
b) sound; produce affected by rotting or deterioration such as to make it unfit for consumption is 
excluded; 
c) clean, practically free of any visible foreign matter; 
d) free from damage due to frost; 
e) sufficiently dry for the intended use (in the case of pickling onions, at least the first two outer skins and 
the stem shall be fully dried); 
f) without hollow or tough stems; 
g)  practically free from pests; 
h)  practically free from damages caused by pests; 
i) free of abnormal external moisture; and 
j) free of any foreign smell and/or taste. 
In addition the stems shall be twisted or clean cut and shall not exceed 6 cm in length (except for stringed 
onions). 
4.2.2  The development and condition of the onions shall be such as to enable them: 
a) withstand transport and handling, and 
b) arrive in satisfactory condition at the place of destination. 
5 Classification  
5.1 General 
Fresh onions may be classified in t wo classes defined below: 
 Class I, and 
 Class II  
5.2 Class I 
5.2.1 Onions in this class shall be of good quality and their characteristics typical of the variety. DRAFT UGANDA STANDARDFDUS 1501: 2013 
© UNBS 2013 – All rights reserved  3 
 The bulbs shall be: 
a) firm and compact; 
b) unsprouted (free from externally visible shoots); 
c) free from swelling caused by abnormal vegetative development; and 
d) practically free of root tufts; however, for onions harvested before complete maturity, root tufts are 
allowed. 
5.2.2 The following defects, however, may be allowed, provided they do not affect the general appearance of 
the produce, the quality, the keeping quality or presentation in the package: 
a) a slight defect in shape; 
b) a slight defect in colouring; 
c) light staining which does not affect the last dried skin protecting the flesh, provided it does not cover 
more than one fifth of the bulb’s surface ; and  
d) superficial cracks in, and partial absence of the outer skins, provided the flesh is protected. 
5.3 Class II 
5.3.1 This class includes onions which do not qualify for inclusion in Class I, but satisfy the requirements 
specified in 4.2. They shall be reasonably firm. 
5.3.2 The following defects may be allowed provided the onions retain their essential characteristics as 
regards the quality, the keeping quality and presentation: 
a) defect in shape; 
b) defect in colouring; 
c) early evidence of externally visible shoot growth (no more than 10 % by number or weight by unit of 
presentation); 
d) traces due to rubbing; 
e) slight marking caused by parasites or disease; 
f) small healed cracks; 
g) slight bruising, healed, unlikely to impair keeping qualities; 
h) root tufts; 
i) stains which do not affect the last dried skin protecting the flesh, provided they do not cover more than 
half the bulb’s surface ; and  
j) cracks in the outer skins and partial absence of over a maximum of one third of the bulb’s surface, 
provided the flesh is not damaged. DRAFT UGANDA STANDARDFDUS 1501: 2013 
4 © UNBS 2013 – All rights reserved  
 6 Provisions concerning sizing 
Size is determined by the maximum diameter of the equatorial section. The difference between the diameters 
of the smallest and largest onions in the same package shall not exceed the limits specified Table 1. 
Table 1 — Requirements for sizing 
Diameter of smallest onion  Difference in diameter (mm)  between smallest and 
largest onion not to exceed  
10 to 19  <5 
20 to 39  15 
40 to 69  20 
70 and over  30 
NOTE The minimum diameter is fixed at 10 mm.  
7 Provisions concerning tolerances 
7.1 General 
Tolerances in respect of quality and size shall be allowed in each package (or in each batch, for onions in 
bulk) for produce not satisfying the requirements of the class indicated. 
7.2 Quality tolerances 
7.2.1 Class I 
10 % by number or weight of onions not satisfying the requirements of this class, but meeting those of Class II 
or, exceptionally, coming within the tolerances of that clas s. 
7.2.2 Class II 
10 % by number or weight of onions satisfying neither the requirements of the class nor the minimum 
requirements with the exception of produce affected by rotting or any other deterioration rendering it unfit for 
consumption. 
7.3 Size tolerances 
For all classes: 10 % by number or weight of onions not satisfying the size identified, but with a diameter of no 
more than 20 % below or above it. 
8 Provisions concerning presentation 
8.1 Uniformity 
8.1.1 The contents of each package (or lot, for produce presented in bulk) shall be uniform and contain only 
onions of the same origin, variety, quality and size. 
8.1.2 However, sales packages, of a net weight not exceeding three kilograms, may contain mixtures of 
onions of different colours, provided that they are uniform in quality, and, for each colour concerned, in origin, 
variety and size. DRAFT UGANDA STANDARDFDUS 1501: 2013 
© UNBS 2013 – All rights reserved  5 
 8.1.3 The visible part of the contents of the package (or lot, for produce presented in bulk) shall be 
representative of the entire contents. 
8.2 Packaging 
8.2.1 Fresh onions shall be packed in such a way as to protect the produce properly. Fresh onions shall be 
packed in each container in compliance with CAC/RCP 44. 
8.2.2 The materials used inside the package shall be of food grade quality such as to avoid causing any 
external or internal damage to the produce during handling. The use of materials, particularly of paper or 
stamps bearing trade specifications is allowed, provided the printing or labelling has been done with non-toxic 
ink or glue. 
8.2.3 Packages shall be free of all foreign matter. 
8.3 Presentation 
8.3.1 Onions may be presented as below: 
(a) arranged in layers; 
(b) loose in a package (including bulk bins); 
(c) transported in bulk; 
(d) in strings ;  
(e) either of a certain number of bulbs, in which case the strings shall contain at least six onions (with fully 
dried stems); or 
(f) of a certain net weight. 
8.3.2 For stringed onions, the characteristics of the strings in any one package (number of bulbs or net 
weight) shall be uniform. 
9 Hygiene 
Fresh onions shall be produced and handled in accordance with US 28.  
10 Contaminants 
10.1 Pesticide residues 
Fresh onions shall comply with those maximum pesticide residue limits established by the Codex Alimentarius 
Commission for this commodity. 
10.2 Heavy metals 
Fresh onions shall comply with those maximum levels for heavy metals as established by the Codex 
Alimentarius Commission for this commodity.  DRAFT UGANDA STANDARDFDUS 1501: 2013 
6 © UNBS 2013 – All rights reserved  
 11 Weights and measures  
Containers shall be as full as practicable without impairment of quality and shall be consistent with a proper 
declaration of contents for the product.  
12 Labelling 
Fresh onions shall be labelled in accordance with the requirements of US 7. In addition the following specific 
provisions shall apply:  
a) name and address of exporter, packer and/or dispatcher and identification code;  
b) name of the produce if the contents are not visible from the outside ;  
c) name of the variety or commercial type (optional) ; 
d) name of country of origin and, optionally district where grown; 
e) commercial Identification;  
f) class;  
g) net weight; and  
h) official inspection mark (optional) . 
Nutritional and health labelling claims may be made in accordance with US 500 and US 508. DRAFT UGANDA STANDARDFDUS 1501: 2013 
© UNBS 2013 – All rights reserved  7 
 Annex A 
(normative) 
 
Types of defects/damage  
The following specific defects shall be considered as damage: 
 seedstems which are tough or woody, or which are more than 6.35 mm in diameter; 
 when onions have splits with two or more hearts that are not practically covered by one or more outer 
scales; 
 when more than 30 % of the onions in a lot have tops 76 mm or more in length; 
 when most new roots on an individual onion have grown to a length of 50 mm or more in length; 
 when more than 20 % of the onions in a lot have practically all dry roots of 50 mm or more in length; 
 when the dry sunken areas exceed the equivalent to that of a circle 12.7 mm in diameter on an onion 
70 mm in diameter which does not have the outer papery scale covering the affected areas or when 
the affected areas exceed the equivalent to that of a circle 19 mm in diameter on an onion 70 mm in 
diameter which has the outer papery scale covering the affected areas. Correspondingly lesser or 
greater areas are allowed on smaller or larger onions; 
 when more than 33 % of the onions in a lot have a medium colour caused by sunburn on one-third of 
the surface; 
 when sprouts are visible, or concealed within the dry top and more than 19 mm in length on an onion 
5 cm or larger in diameter, or proportionately shorter on smaller onions; 
 when more than one-half of the thin papery skin is missing, leaving the underlying fleshy scale 
unprotect ed; 
 when at least one of the fleshy scales are cracked; 
 when more than the equivalent of the entire outer fleshy scale is affected by an off-colour, water-
soaked condition. The off-colou r shall be of some shade of brown or yellow; 
 when more than 20 % of the onions in a yellow, brown or red lot, or more than 15 % of the onions in a 
white lot are appreciably stained. Onions with adhering dirt or other foreign matter shall be judged on 
the same basis as stained onions; 
 when any cut extends deeper than one fleshy scale, or when any bruise breaks a fleshy scale; and 
 when more than the equivalent of two entire outer fleshy scales have a water-soaked condition. DRAFT UGANDA STANDARDFDUS 1501: 2013 
8 © UNBS 2013 – All rights reserved  
 Bibliography 
[1] United States Standards for Grades of Onions (Other Than Bermuda-Granex-Grano and 
Creole Type), Effective October 10, 1995 (Reprinted — January 1997) 
[2] UNECE STANDARD FFV 25:2003 , Marketing and commercial quality control of onions  
[3] Codex Alimentarius website: http://www.codexalimentarius.net/mrls/pestdes/jsp/pest_q-e.jsp 
[4] USDA Foreign Agricultural Service website: http://www.mrldatabase.com  
 DRAFT UGANDA STANDARDDUS 1501: 2012  
© UNBS 2013– All rights reserved  9 
 Certification marking 
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certification mark scheme operated by 
the Uganda National Bureau of Standards and in conjunction with the relevant Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision, control and testing in accordance with the 
certification mark scheme of the Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 DRAFT UGANDA STANDARDFDUS 1501 : 2013   
 
ICS 67.080.20 
Price based on nn pages 
© UNBS 2013 – All rights reserved