DRAFT UGANDA STANDARD  
  DUS 2276  
First Edition  
2020 -mm-dd 
 
 
 Reference number  
WDUS 2276 : 2020 
© UNBS 2020   
  
Medical cotton swabs — Specification  
 DUS 2276:  2020  
ii © UNBS 2020  – 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 app lication  
© UNBS  2020  
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Uganda  
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Web: www.unbs.go.ug  DUS 2276 : 2020  
© UNBS 2020  – 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 , as amended .  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  Agreement  of the Wo rld 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 key stakeholders 
including government , academia, consumer groups, private sector and other interested parties.  
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 recomm ending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The committee responsible for this document is Technical Committee UNBS /TC 14, Medical devices .DRAFT UGANDA STANDARD  DUS 2276 : 2020  
 
© UNBS  2020 – All rights reserved  1 
 Medical cotton swabs — Specification  
1 Scope   
This Draft Uganda  Standard specifies requirements, sampling  and methods of test  for medical cotton swabs . 
2 Normative references   
The following referenced documents referred to in the text in such a way that some or all of their content 
constitutes requiremen ts 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.  
DUS ISO 1833 - 11, Textiles — Quantitative chemical analysis  — Part 11: Mixt ures of certain cellulose fibres 
with certain other fibres (method using sulfuric acid)  
US EAS 104, Alcoholic beverages – Method of sampling and test  
US ISO 3071 , Textiles — Determination of pH of aqueous extract  
US ISO 2859 -1, Sampling procedures for insp ection by attributes — Part 1: Sampling schemes indexed by 
acceptance quality limit (AQL) for lot -by-lot inspection  
3 Terms and definitions   
For the purposes of this document, the following terms and definitions apply.  
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
Swab  
absorbent pad or piece of  material used in  surgery and  medicine for cleaning wounds, applying  medication, or 
taking s pecimens  
4 Requirements  
4.1 General requirements  
4.1.1  Cotton swabs may consist of one or two small wads of cotton  wrapped around one or both ends of a 
short rod made of wood, rolled paper or  plastic   
4.1.2  The cotton fibres shall be well carded and bleached to a good white, free from pieces of thread and 
reasonably free from leaf, shell,  fibre-dust and foreign matter.  It may b e slightly off white if it is sterilized . 
4.13 The fibre composition of the cotton swab shall be 100 % cotton. This shall be tested by a microscope 
and in accordance with DUS ISO 1833 - 11. DUS 2276: 2020  
2 © UNBS 2020  – All rights reserved  
  
4.3 Specific requirements  
Cotton swabs shall conform to the requir ements specified in Table 1when tested in accordance with the test 
methods prescribed therein.  
Table 1 — Specific requirements for cotton swabs  
Characteristic  Requirement  Test method  
Submersion time  Complete submersion  shall not be more than 10s.  Annex A  
Absorbency , g, min  Mass of water shall be 16 g for each gram of dry 
cotton  Annex A  
pH Value  6 - 8. US ISO  3071  
Soluble substance s, max  0.5 % of the mass of cotton  Annex B  
 
4.4 Fluorescent brightening agents  
Fluorescent brightening agents shall not be u sed in the manufacture of cotton swabs and when tested in 
accordance with Annex C, not more than occasional point of fluorescence shall be visible . 
4.5 Freedom from microorganisms  
Cotton swabs shall be sterile when tes ted in accordance with Annex D . 
4.6 Isopropyl alcohol or spirit  
Isopropyl alcohol, or “spirit” used in the manufacture of the cotton swabs shall be 70% Isopropyl alcohol or 
2Propanol when tested in accordance with US EAS 104 . 
5 Packaging  
Cotton swabs shall be packaged in suitable containers which guarantee product safety , sterility  and integrity.  
6 Labelling  
Each container shall be legibly and indelibly marked with the following information:  
a) name and  physical address of m anufacturer and registered trade mark, if any ; 
b) name of product as “cott on Swabs”  
c) size declaration;  
d) instructions for use;  
e) precaution, “for external use only”;  
f) lot/batch number;  
g) country of origin;  DUS 2276 : 2020  
© UNBS  2020  – All rights reserved  3 
 h) sterile  
i) date of manufacture; and  
j) expiry date  
8 Sampling  
Sampling shall be done in accordance with US ISO 2859 -1. Acceptance criteria : No defects  DUS 2276: 2020  
4 © UNBS 2020  – All rights reserved  
 Annex  A 
(normative)  
 
Determination of submersion time and water absorption  
A.1 Principle  
Cotton is placed in metallic basket and allowed  to sink in tub of water. The time taken to submerge com pletely 
is noted and amount of water absorbed is measured.  
A.2 Apparatus  
A.2.1  Cylindrical basket, weighing 0.54±0.069 g, of height 16 mm, diameter 10 mm with square openings of 
15 mm to 20 mm, made of copper wire of 0.4 mm diameter.  
A.2.2  Tub of water, of  10 cm –20 cm.  
A.2.3  Thermometer  
A.2.4  Stop watch, 0.2 s accuracy.  
A.2.5  Container  
A.2.6  Weighing balance  
A.3 Procedure  
A.3.1  Take  random specimen  of 5  g  of  cotton  wool  from  several  containers  of  cotton  swabs  and  
place  them loosely in the cy lindrical basket.  
A.3.2  Weigh the basket using a weighing balance before placing the specimen. Weigh again after placing 
the specimen.  
A.3.3  Drop  the  basket  with  its  contents  in  a  horizontal  position  into  a  tub  of  water,  with  water  at  
abou t  20ºC reaching a height of approximately 100 mm.  
A.3.4  Measure by means of stop watch, the time required for the basket to sink below the surface of water 
in seconds.  
A.3.5  Repeat the procedure above two more times.  
A.3.6  After testing the submersion tim e for each cotton ball, leave the submerged basket at the bottom of 
the water for 3 minutes.  Remove the basket with its contents from water.  Leave it for 30 s in a horizontal 
position above the tub so as to drain the remaining water.  
A.3.7  Place the bask et in a container of known weight (M 1), weigh it (M 2) DUS 2276 : 2020  
© UNBS  2020  – All rights reserved  5 
 A.4 Calculation  
A.4.1  Submersion time  
Take the average of the three measurements in A.3.4 and A.3.5 as the sinking time in seconds.  
A.4.2  Water absorption  
Water absorbed  = 
  
Where  
M2 mass of  container + basket + cotton wool after absorption  
M1 mass of container.  
Water absorbed by each gram of cotton wool  
 
 
A.5 Report  
A.5.1 Report the value calculated in A.4.1 as the submersion time in seconds.  
A.5.2  Report the value calculated A.4.2 as the absorbency  DUS 2276: 2020  
6 © UNBS 2020  – All rights reserved  
 Annex B  
(normative)  
 
Determination of water soluble substances  
B.1 Principle  
Cotton wool is extracted in hot water and the extract is dried and then weighed.  
B.2 Apparatus  
B.2.1  Weighing balance  
B.2.2  Graduated flask  
B.2.3  Burner  
B.2.4  Funnel  
B.2.5 Filter paper  
B.2.6  Drier, with temperature control.  
B.2.7  Clock  
B.3 Procedure  
B.3.1  To 1 g of cotton ball from container, add 100 mL of water and boil gently for 30 minutes, adding 
sufficient water to maintain the original volume.  
B.3.2  Pour the extrac t through a funnel into another vessel, transfer the cotton to the funnel and press out 
the water absorbed therein. With a glass rod, wash the cotton with two 150 portions of hot water, pressing the 
cotton dry after each washing.  
B.3.3  Filter the combined extracts and washings, evaporate to concentrate, transfer to the weighing bottles 
and dry at 105 ºC to constant weight. Weigh the residual (M) in grams.  
B.4 Calculation  
Soluble substances, % = 
  
B.5 Report  
Report the value in B.4 as the percentage of water  soluble substances . DUS 2276 : 2020  
© UNBS  2020  – All rights reserved  7 
 Annex C  
(normative)  
 
determination of fluorescent brightening agents  
C.1 Principle  
A layer of cotton wool is examined under the UV light for detection of any fluorescent materials.  
C.2 Apparatus  
C.2.1  Ultra -violet light source  
C.2.2  Scale, graduated in mm.  
C.3 Procedure  
Examine a layer, about 5 mm in thickness, under the UV light, of wavelength 365 nm.  
C.4 Report  
The sample may show only a slight brownish -violet fluorescence and not more than an occasional yellow 
particle. It shows no i ntense blue fluorescence except that which may be shown by a few isolated fibres.  DUS 2276: 2020  
8 © UNBS 2020  – All rights reserved  
 Annex D  
(normative)  
 
Sterility test  
D.1 Introduction  
The following culture media have been found to be suitable for the test for sterility. Fluid thioglycollate medium 
is pr imarily intended for the culture of anaerobic bacteria; however, it will also detect aerobic bacteria. 
Soyabean casein digest medium is suitable for the culture of both fungi and aerobic bacteria.  
D.2 Fluid thioglycollate medium  
L-Cystine                                                                                                                                     0.5 g  
Agar                                                                                                                                            0.75 g  
Sodium chloride                                                                                                                         2.5 g  
Glucose monohydrate/anhydrous                                                                                             5.5 g/5.0 g  
Yeast extract (water -soluble)                                                                                                    5.0 g  
Pancreatic digest of casein                                                                                                      15.0 g  
Sodium thioglycollate or                                                                                                           0.5 g  
Thioglycollic acid                                                                                                                     0.3 mL  
Resazurin sodium solution (1 g/L of resazurin sodium), freshly prepared                             1.0 mL  
Water R                                                                                                                                  1 000 mL  
pH after sterilization                                                                                                                7.1 ± 0.2  
D.2.1  Mix the L -cystine, agar , sodium chloride, glucose, water -soluble yeast extract and pancreatic digest 
of casein with the water R and heat until solution is effected.  
D.2.2  Dissolve the sodium thioglycollate or thioglycollic acid in the solution and, if necessary, add 1 M 
sodium hydroxide so that, after sterilization, the solution will have a pH of 7.1 ± 0.2. If filtration is necessary, 
heat the solution again without boiling and filter while hot through moistened filter paper.  
D.2.3  Add the resazurin sodium solution, mix and pla ce the medium in suitable vessels which provide a 
ratio of surface to depth of medium such that not more than the upper half of the medium has undergone a 
colour change indicative of oxygen uptake at the end of the incubation period. Sterilize using a vali dated 
process. If the medium is stored, store at a temperature between 2 °C and 25 °C in a sterile, airtight container.   
D.2.4  If more than the upper one -third of the medium has acquired a pink colour, the medium may be 
restored once by heating the contai ners in a water -bath or in free -flowing steam until the pink colour 
disappears and cooling quickly, taking care to prevent the introduction of non -sterile air into the container. Do 
not use the medium for a longer storage period than has been validated. Fl uid thioglycollate medium is to be 
incubated at 30 °C - 35 °C.  DUS 2276 : 2020  
© UNBS  2020  – All rights reserved  9 
 D.2.5  For products containing a mercurial preservative that cannot be tested by the membrane -filtration 
method, fluid thioglycollate medium incubated at 20 °C - 25 °C may be used instead of so ya-bean casein 
digest medium provided that it has been validated as described in growth promotion test.   
D.3 Alternative thioglycollate medium  
Where prescribed, justified and authorized, the following alternative thioglycollate medium may be used. 
Prepar e a mixture having the same composition as that of the fluid thioglycollate medium, but omitting the 
agar and the resazurin sodium solution, sterilize as directed above. The pH after sterilization is 7.1 ± 0.2. Heat 
in a water -bath prior to use and incubat e at 30 °C - 35 °C under anaerobic conditions.  
D.4 Soya -bean casein digest medium  
Pancreatic digest of casein                                                                            17.0 g  
Papaic digest of soya -bean meal                                                                    3.0 g  
Sodium chloride                                                                                              5.0 g  
Dipotassium hydrogen phosphate                                                                  2.5 g  
Glucose monohydrate/anhydrous                                                                  2.5 g/2.3 g  
Water R                                                                                                         1 000 mL  
pH after steriliza tion                                                                                       7.3 ± 0.2  
D.4.1  Dissolve the solids in water R, warming slightly to effect solution. Cool the solution to room 
temperature. Add 1 M sodium hydroxide, if necessary, so that after sterilization the solution will have a pH of 
7.3 ± 0.2.  
D.4.2  Filter, if necessary, to clarify, distribute into suitable vessels and sterilize using a validated process. 
Store at a temperature between 2 °C and 25 °C in a sterile well -closed container, unless it is intended for 
immediate use. Do not use the medium for a longer storage period than has been validated. Soya -bean 
casein digest medium is to be incubated at 20 °C - 25 °C.   
D.4.3  The media used shall comply with the following tests given in D.6, carried out before or in parallel 
with the test on the product to be examined.   
D.5 Sterility  
Incubate portions of the media for 14 days. No growth of micro -organisms occurs.  
D.6 Growth promotion test of aerobes, anaerobes, and fungi  
D.6.1 Test each lot of ready -prepared medium and each batch of medium prepared either from dehydrated 
medium or from ingredients. Suitable strains of microorganisms are indicated in Table D1.  
D.6.2  Inoculate portions of Fluid Thioglycollate Medium with a smal l number (not more than 100 cfu) of the 
following microorganisms, using a separate portion of medium for each of the following species of 
microorganism, Clostridium sporogenes, Pseudomonas aeruginosa , and Staphylococcus aureus . Inoculate 
portions of altern ative thioglycollate medium with a small number (not more than 100 cfu) of Clostridium 
sporogenes .F Inoculate portions of Soybean –Casein.  DUS 2276: 2020  
10 © UNBS 2020  – All rights reserved  
 D.6.3  Digest medium with a small number (not more than 100 cfu) of the following microorganisms, using a 
separate port ion of medium for each of the following species of microorganism, Aspergillus brasiliensis , 
Bacillus subtilis , and Candida albicans . Incubate for not more than 3 days in the case of bacteria and not more 
than 5 days in the case of fungi.   
D.6.4  Seed lot c ulture maintenance techniques (seed -lot systems) are used so that the viable 
microorganisms used for inoculation are not more than five passages removed from the original master seed  
lot. The media are suitable if a clearly visible growth of the microorgan isms occurs.  
Table D.1 — Strains of the test microorganisms suitable for us e in the growth promotion test  
Test microorganisms  
Aerobic bacteria  Fungi  Anaerobic bacterium  
Staphylococcus aureus  ATCC 
6538, CIP 4.83, NCTC  10788, 
NCIMB 9518, NBRC 13276  
Bacil lus subtilis  ATCC 6633, CIP 
52.62, NCIMB 8054, NBRC 3134  
Pseudomonas aeruginosa  ATCC 
9027, NCIMB 8626, CIP 82.118, 
NBRC 13275  
 Candida albicans  ATCC 10231, IP 
48.72, NCPF 3179, NBRC 1594  Clostridium sporogenes  ATCC 
19404, CIP 79.3, NCTC 532 or 
ATCC 11437 , NBRC 14293  DUS 2276 : 2020  
© UNBS  2020  – All rights reserved  11 
 Bibliography  
KS 2556 : 2018, Impregnated Cotton swabs —Specification  
 DUS 2276: 2020  
© UNBS  2020  – All rights reserved  13 
 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 conjun ction 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 t he 
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.  
 
  DUS 2276 : 2020   
 
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