DRAFT UGANDA STANDARD  
  DUS 950  
Second Edition  
2018 -mm-dd 
 
 
 Reference number  
DUS 950: 2018  
© UNBS 20 18  
  
Disposable baby diapers  — Specification  
 DUS 950: 2018  
ii © UNBS 2018  – 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 20 18  
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 
permissio n 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 41 7 333 250/1/2  
Fax: 256 41 4 286 123  
E-mail: unbs@infocom.co.ug  
Web: www.unbs.go.ug  DUS 950:2018  
© UNBS 2018  – All rights reserved  iii 
 Contents  Page 
Foreword ................................ ................................ ................................ ................................ ................  iv 
1 Scope ................................ ................................ ................................ ................................ ..........  1 
2 Normative references  ................................ ................................ ................................ ..................  1 
3 Terms and definitions  ................................ ................................ ................................ .................  1 
4 Class ification  ................................ ................................ ................................ ..............................  2 
5 Requirements ................................ ................................ ................................ ..............................  2 
5.1 General Requirements  ................................ ................................ ................................ ................  2 
5.2 Mate rials ................................ ................................ ................................ ................................ ..... 2 
5.3 Other physical characteristics  ................................ ................................ ................................ .... 3 
5.4 Microbiological requirements  ................................ ................................ ................................ ..... 3 
6 Packaging and marking  ................................ ................................ ................................ ..............  4 
6.1 Packing and/or packaging ................................ ................................ ................................ ...........  4 
6.2 Marking  ................................ ................................ ................................ ................................ .......  4 
7 Testing  ................................ ................................ ................................ ................................ ........  4 
8 Proof of compliance  ................................ ................................ ................................ ....................  4 
Annex  A (normative)  Determination of rate of absorption, absorptive capacity and rewet under 
load ................................ ................................ ................................ ................................ .............  5 
A.1 Principle  ................................ ................................ ................................ ................................ ...... 5 
A.2 Apparatus and materials  ................................ ................................ ................................ .............  5 
A.3 Sample preparation and set -up ................................ ................................ ................................ ... 6 
Annex  B  (normative)  Microbiological examination ................................ ................................ ................  8 
B.1 Apparatus and equipmen t................................ ................................ ................................ ...........  8 
B.2 Media and reagents ................................ ................................ ................................ .....................  8 
B.2.1  General  ................................ ................................ ................................ ................................ .......  8 
B.2.2  Bacteriologic al peptone  ................................ ................................ ................................ ..............  8 
B.2.3  Plate count agar  ................................ ................................ ................................ ..........................  8 
B.2.4  Neutral red -bile salt peptone glucose medium ................................ ................................ ............  8 
B.2.5  Fluid soybean -casein digest medium ................................ ................................ ..........................  9 
B.2.6  Cetrimide agar medium  ................................ ................................ ................................ ...............  9 
B.2.7  Pseudomonas agar mediu m for detection of fluorescein  ................................ ...........................  9 
B.2.8  Pseudomonas agar medium for detection of pyocyanin  ................................ ...........................  10 
B.3 Preparation of test suspension  ................................ ................................ ................................ . 10 
B.4 Procedure  ................................ ................................ ................................ ................................ . 10 
B.4.1  Total viable bacterial count  ................................ ................................ ................................ .......  10 
B.4.2  Examination for the presence of Enterobacteriaceae  ................................ ...............................  10 
B.4.3  Examination for the presence of Staphylococcus aureus ................................ .........................  10 
B.4.4  Exami nation for the presence of Pseudomonas aeruginosa ................................ .....................  10 
Bibliography  ................................ ................................ ................................ ................................ .........  12 
 DUS 950: 2018  
iv © UNBS 2018  – All rights reserved  
 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 t he WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT Agreement 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 key stakeholders 
including government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Technical Committee are w idely 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.  
The committee responsible f or this document is Technical Committee UNBS/TC 7, Textile, Leather, Paper and 
related products , Subcommittee SC 1, Textile and related products  
This second edition cancels and replaces the first edition (US 950:2011 ), which has been technically revised.  DUS 950:2018  
© UNBS 2018  – All rights reserved  v 
 
Introduction  
Baby diapers and pants are personal hygiene products that are designed to contain the baby’s urine and 
faeces in order to avoid soiling the baby’s clothing, beddings and the surrounding environment. They are 
fastened around the baby’s legs and  bottom to help prevent leakage. These products aim to provide maximum 
comfort for the baby and maximum convenience to the care  giver 
A disposable diaper consists of an absorbent core sandwiched between two or more sheets of nonwoven 
fabric. The core is sp ecifically designed to absorb and retain urine and faeces, and the nonwoven fabric may 
be soft and cut in such a way that it is comfortable to wear and prevents leakage. When properly fitted, the 
diaper will retain the body fluids which pass through the to p sheet and are absorbed into the core . 
The baby diapers are generally  available according to size and weight of the baby . Typical functions of baby 
diapers include : 
 absorb body fluids ; 
 retain body fluid inside the absorbent core ; 
 isolate wetness from the baby’s skin ; and  
 isolate other excretion from baby’s environment (cloth, bed etc) . 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 1 — Baby diaper  (classical form)  DUS 950: 2018  
vi © UNBS 2018  – All rights reserved  
 
 Figure 2  — Baby diaper  (pants form)  
 DRAFT UGANDA STANDARD  DUS 950: 2018  
 
© UNBS 2018 – All rights reserved  1 
 Disposable baby diapers  — Specification  
1 Scope  
This draft Uganda Standard spe cifies  the requirements and test methods for disposable baby diapers.  
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 refere nces, the latest edition of the referenced 
document (including any amendments) applies.  
US ISO 187, Paper, board and pulps — Standard atmosphere for conditioning and testing and procedure for 
monitoring the atmosphere and conditioning of samples  
US ISO 307 1: Textiles — Determination of pH of aqueous extract  
US ISO 6887 -1, Microbiology of the food chain — Preparation of test samples, initial suspension and decimal 
dilutions for microbiological examination — Part 1: General rules for the preparation of the in itial suspension 
and decimal dilutions  
US ISO 6887 -4, Microbiology of the food chain — Preparation of test samples, initial suspension and decimal 
dilutions for microbiological examination — Part 4: Specific rules for the preparation of miscellaneous produ cts 
3 Terms and definitions  
For the purposes of this standard, the follow ing terms and definitions shall  apply . 
3.1  
disposable baby diapers  
disposable hygienic pad for babies having capability to absorb urine and prevent stool and fluid from leaking  
3.2  
Super Absorbent Polymer (SAP)  
granular cross -linked sodium polyacrylates material  used as absorbent core with improved retention capacity 
in disposable diapers  
3.3  
Acquisition/Distribution  Layer (ADL)  
component of an absorbent hygiene product through whic h the fluid is transferred and distributed within the 
absorbent core  
3.4  
top sheet (coverstock)  
the outer layer of an absorbent hygiene product that is in direct intimate contact with th e user’s skin. It allows 
gradual  transfer of the fluid from the point  of contact to the inside of the product .   
2 © UNBS 2018  – All rights reserved  
 3.5  
back sheet  
layer of an absorbent hygiene product made of either polymer film or nonwoven film designed to prevent 
wetness transfer from the wearer to their bed or clothes  
4 Classification  
Diapers are generall y marketed and sold according to the w eight of the baby as in Table 1  
Table  1 — Classification of baby diapers  
Category (informative)  Baby weight , 
kg 
New born / Extra small  Up to 4  
Small  3 - 6 
Medium  4 - 9 
Large  7 and above  
 
NOTE 1 The diapers are classified according to the baby weight and not according to category . 
NOTE 2 There is an overlap in the weight ranges for the various sizes to allow for the unique characteristics of 
individual babies i.e. some babies may have attained a higher weight for  their age and will therefore use a different size of 
diaper.  
NOTE 3 The categories listed above are solely for informative purposes and should not be interpreted in a restrictive 
manner as various manufacturers may opt to label their diapers differently.  
5 Requirements  
5.1 General Requirements  
Baby diapers shall be manufactured, stored and packed under hygienic conditions to minimise contamination 
of the product  and shall be disposable. The diapers shall present a neat, well finished appearance and shall 
be free from all defects which might affect the functionality of the diaper .  
5.2 Materials  
The materials used for making the diapers shall be clean, highly absorbent and shall not harm the baby’s skin . 
5.2.1  The absorbent core shall :  
a) consist of cellulose  fibres and superabsorbent polymer and shall be contoured for better fit between 
the legs. It shall have a comfortable feel and help keep the baby’s bottom dry when used correctly  
b) be clean, free from harmful foreign materials, lumps, splits, holes, and pro truding points when visually 
examined ; and  
c) be arranged in a manner that will speed up the absorption of urine and keep it away from the baby’s 
skin.  
5.2.2  The top sheet (the layer which contacts the baby’s skin)  shall: DUS  950: 2018  
© UNBS 2018  – All rights reserved  3 
 a) be of material capable of allowing fl uid to pass readily through to the next layer and shall  resist 
moisture return to the skin. It shall  have no harmful effects ; 
b) cover the absorbent core completely and prevent the core from reaching the baby’s skin or clothes 
under normal handling ; and  
c) have high degree of softness and shall cause no irritation to the skin .  
5.2.3  The back sheet (outer cover)  
a) shall be moisture impervious and shall prevent direct contact of the absorbent core with the baby’s 
clothing and there shall be no liquid leakage out of  the diapers ; and  
b) should be breathable and comfortable for the baby . 
5.2.4  There shall be a device e.g. elastic band or sticky fasteners for ensuring a good fit of the diapers on 
the baby’s femurs and to prevent leakage at the femurs with out causing rubefa cient effects  
5.2.5  There shall be a suitable device for fastening the diaper at the waist for secure use without causing 
rubefacient effects.  
5.2.6  Adhesive used shall prevent shifting of the absorbent core . 
5.2.7 Each material component of the diaper sho uld be bounded to the adjacent component to enhance 
strength and prevent shifting of the absorbent core  
5.3 Other physical characteristics  
Other physical characteristics of the diapers shall comply with the requirements given in Table 2 . 
Table  2 — Characte ristics of disposable diapers  
Characteristics  Newborn / 
Extra small  Small  Medium  Large  Test methods  
Rate of absorption per gush, min, 
(max)  5 5 5 5 Annex A  
Absorptive capacity, mL (min)  3 x 20  3 x 35  3 x 50  3 x 60  Annex A  
Rewet under load,g (max)  5 5 5 5 Annex A  
pH  6 – 8.5 6 – 8.5 6 – 8.5 6 – 8.5 US ISO 3071  
NOTE  Re-wet test: the purpose of this test is to examine the ability of diapers’ top  sheet to resist transportation back  on 
to the skin of a liquid which has already penetrated the top  shee t. The rewet under load  simulates the effect of a baby 
sitting on a wet diaper. The lesser the rewet value, the better the performance of the diaper.  
 
5.4 Microbiological requirements   
The microbiological limits shall be as defined below;  
a) the total viable bacter ial count, when  determined in accordance with B .4.1 shall not exceed 1 ,000 
CFU / g ; and 
b) when tested in accordance with B.4.4.1, B.4.4.2 and B .4.4.3, disposable diapers shall be free from 
Enterobacteriaceae, Staphylococcus aureus, and Pseudomonas aeruginosa .   
4 © UNBS 2018  – All rights reserved  
 6 Packaging and marking  
6.1 Packing and/or packaging  
Diapers shall be packed in a suitable package that shall protect them from any form of contamination and 
damage.  Packaging for shipment shall be in accordance with the manufacturer's standard practice  and in a 
manner readily accepted by  the market.  Within the shipping carton, units shall be packed in manner designed 
to minimize damage during shipment due to rough or improper handling.  
6.2 Marking  
The diaper packs shall be marked with legible and indel ible pre -printed marking or a securely affixed and 
durable label bearing the following information:  
a) name of contents;  
b) name and address of the manufacturer;  
c) number of diapers;  
d) size and the recommended baby weight  that the diapers is meant for ; 
e) instruction for storage and disposal;  
f) date of manufacture and expiry;  
g) batch/ lot number;  
h) country of origin; and  
i) any perfume, lotion , powder and any other substance added on to the diaper shall be declared . 
7 Testing  
Testing shall be done by, or at the directio n of, the receiving agency  and the  cost of the testing shall be borne 
by the distributor/ supplier /importer . Tests shall be performed on products from shipments to ordering 
agencies. In the event that products tested fail to meet or exceed all conditions and req uirements of this 
specification, the product shall be destroyed at the cost of the su pplier . 
8 Proof of compliance  
The manufacturer or the distributor/ supplier /importer  shall bear the burden of proof of compliance with this 
specification . DUS  950: 2018  
© UNBS 2018  – All rights reserved  5 
 Annex  A 
(normativ e) 
 
Determination of rate of absor ption, absorptive capacity and rewet under 
load  
A.1 Principle  
The intention of this method is to test the minimum fluid handling performance requirement of diapers; the 
outcome of the test will be a “Pass” or “Fail” result . 
This test simulates the introduction of urine into a diaper under the following conditions;  
a) The diaper is tested under pressure to simulate real wearing conditions  i.e. to mimic the pressure that 
the baby applies onto the diaper when wearing it.  
b) Specific  loading volumes are used for each diaper size  
A.2 Apparatus and materials  
A.2.1  A rigid cover plat e with a weight as shown in Figure A.1  
Dimensions of the plate 200 mm x 70 mm. Inner diameter of cylinder 40 mm, total Weight: 6300 g (plate 605.3 
g, weight 5694,7 g) representing a pressure of 4.41 kPa (0,64 psi) for all sizes  
A.2.2  Tray  
A.2.3  Filter paper , having a diameter of 40  mm and conditioned togethe r with the test samples.  
A.2.4 Graduated cylinder (1 ml graduation)  
A.2.5 Stopwatch  
A.2.6 Ruler (at lea st 2 cm longer as absorbent core of the sample, 1mm graduation)  
A.2.7 Pen 
A.2.8  0.9% Saline solution (22 – 24 ºC) : 9 g sodium chloride, and 1 g of blue dye added into 200 mL 
distilled water at ambient temperature after which the solution is made up to 1 L.  The pH shall be between 6.2 
– 6.7. When not within this range adjust by using 0.1 mol/L sodium hydroxide solut ion or acetic acid as 
required.  
Depending on the size of the diaper, the following amount of s aline solution  shall be used  
Table A.1: Volume  of saline solution per size of Diaper  
Category (informative)  Baby weight,  
Kg Volume of saline 
solution (mL ) 
Newborn / Extra s mall Up to 4  3 x 20   
6 © UNBS 2018  – All rights reserved  
 Small  3 – 6 3 x 35  
Medium  4 – 9 3 x 50  
Large  7 and above  3 x 60  
 
A.3 Sample preparation and s et-up 
A.3.1  Condi tion the test samples in accordance with US ISO 187 before taking the test specimens required 
for the tests  
A.3.2  Take 5 test specimens randomly from the test samples  
Determination of absorption capacity  
A.3.3  Mark the loading point in the middle of the ab sorbent core. Note that the absorbent core does not 
cover the full length of the diaper but it is more concentrated in the front of the diaper. Therefore, the middle of 
the absorbent core will not be the same as the middle of the diaper: Measure the length  and width of the 
absorbent core. Mark the midpoint, which will be the loading point.  
A.3.4  Place core with top  sheet facing upward on the tray  
A.3.5  Place the rigid cover plate  onto the diaper ensuring that  the plate is centered towards the width of the 
diaper core and the cylinder opening is pl aced over marked loading point as per Figure A.1. The diaper should 
be stretched showing minimum number of wrinkles . 
 
Fig A.1: apparatus and set up  
A.3.6  Gently place weights on the plate (ideally use weight in a ring form to allow for equally applied 
pressure)  
A.3.7  Fill the measuring cylinder with respective amount of saline solution  
A.3.8  Set the stopwatch to 5 minutes  
A.3.9  Gently pour the saline solution onto the diaper via cylinder and immediately start the stopwatch.  
A.3.10  If the saline solution is absorbed after 5 minutes (i.e. no more liquid observed in the cylinder and no 
liquid on the tray outside the diaper), then proceed to the next step.  
A.3.11  Leave the diaper undisturbed for 5 min  DUS  950: 2018  
© UNBS 2018  – All rights reserved  7 
 A.3.12  Repeat ste p A.3.7  to A.3.11  twice  more on the same diaper  (i.e. a total of 3 loads of saline solution 
with 5 -minute intervals between successive loads) and observe for any liquid leaking out of the sides of the 
diaper onto the tray.  
Note your observations after a to tal of 3 loads of the specified amount of fluid and score the diaper based on 
the minimum volumes specified in Table A.1  
A.3.13  Acceptance criter ia 
Pass : No fluid observed leaking out of the diaper  
Fail: Fluid observed leaking out of the diaper  
Determinati on of rewet under load  
A.3.14  Weigh a stack of 5 dry filter paper s and record as weight “W1”.  
A.3.15  Lift the weight and cover plate and p lace the filter paper stack on the absorption point of the diaper.  
A.3.16  Place the cover plate and weight on top of the stack of filter paper and leave undisturbed for 2 min . 
A.3.17  After 2 min, remove the weight and cover plate and immediately determine and record the weight of 
the wet filter paper stack as “W2”. 
A.3.18  Repeat A.3.13 to A.3.16  on the remaining 4 test s pecimens  and record  each result separately.  
A.3.19  Calculation of results  
A.3.18.1  Rewet  (g) = W2 ( Weight of stack of wet filter paper ) - W1 (Weight of stack of dry filter paper).  
Record the average rewet of the 5 samples tested and score the samples as fo llows:  
Pass:  Average rewet weight is less than or equal to the maximum limit specified in Table 2.  
Fail:  Average rewet weight exceeds the maximum limit specified in Table 2 .  
8 © UNBS 2018  – All rights reserved  
 Annex  B  
(normative)  
 
Microbiolo gical examination  
B.1 Apparatus and equipment  
Use apparatus and equipment complying with the re levant requirements of US ISO 6887 -1.  
B.2 Media and reagents  
B.2.1 General  
Ensure compliance with the general requirements for the ingredients and for the pr eparation of media  and 
reagents given in US ISO 6887 -1.  
B.2.2 Bacteriological peptone  
Peptone               10 g  
Disodium phosphate dodecahydrate         1 g  
Sodium chloride             5 g  
Mono -potassium phosphate          1.5 g  
Dissolve the ingredients  in distilled water and make up to 1 L. Adjust the pH value to be 7.0 ± 0.1 after 
sterilization. Dispense 300 mL volumes into flasks of capacity 500 mL and sterilize by autoclaving at 121 °C ± 
2 °C for 20 min.  
B.2.3 Plate count agar  
Agar              15 g  
Glucose               1 g  
Tryptone               5 g  
Yeast extract              2.5 g  
Dissolve the ingredients in distilled water, made up to 1litre, and adjust the pH value to 7.2 ± 0.2. Dispense 15 
mL volumes into bottles and sterilize by autoclaving at 121 °C ± 2 °C for 20 min.  
B.2.4 Neutral red -bile salt peptone glucose medium  
Peptone               20 g  
Glucose               10 g  
Bile salts No. 3             1.5 g  DUS  950: 2018  
© UNBS 2018  – All rights reserved  9 
 Sodium chloride           5 g  
Neutral red            0.03 g  
Crystal violet            0.002 g  
Dissolve the ingredients in 400 mL of distilled water and make up to 500 mL boiling to aid solution. Adjust the 
pH value to 7.4 and filter to a clear solution. Dispense 10 mL volumes into bottles each containing a Du rham 
tube and sterilize by auto claving at 121 °C ± 2 °C for 20 min.  
B.2.5 Fluid soybean -casein digest medium  
Pancreatic digest of casein         17 g 
Papaic digest of soybean meal        3 g  
Sodium chloride           5 g  
Dibasic potassium phosphate        2.5 g  
Dextrose             2.5 g  
Dissolve the ingredients in distilled water and make up to 1 L, warming slightly to aid solution. Cool the 
solution to room temperature and adjust the pH value to be 7.3 ± 0.2 after sterilization. Filter to clarify (if 
necessary), dispense into suitable  containers, and sterilize by autoclaving at 121 °C ± 2 °C for 20 min.  
B.2.6 Cetrimide agar medium  
Pancreatic digest of gelatine        20 g  
Magnesium chloride          1.4 g  
Potassium sulphate          10 g  
Agar            13.6 g  
Cetyl trimethylammoniu m bromide  (Cetrimide)    0.3 g  
Glycerine            10 mL  
Dissolve all the solid ingredients in distilled water, make up to 1 L, and then add the glycerine. Heat, agitating 
frequently, and boil for 1 min. Adjust the pH value to be 7.2 ± 0.2 after steriliz ation. Dispense into suitable 
containers and sterilize by autoclaving at 121 °C ± 2 °C for 20 min .  
B.2.7 Pseudomonas agar medium for detection of fluorescein  
Pancreatic digest of casein         10 g  
Peptic digest of animal tissue        10 g  
Anhydr ous di basic potassium phosphate      1.5 g  
Magnesium sulphate (MgSO4.7H2O)      1.5 g  
Glycerine            10 mL  
Agar            15 g   
10 © UNBS 2018  – All rights reserved  
 Dissolve all the solid ingredients in distilled water, make up to 1  L, and then add the glycerine. Heat, agitating 
frequently,  and boil for 1 min. Adjust the pH value to be 7.2 ± 0.2 after sterilization. Dispense into suitable 
containers and sterilize by autoclaving at 121 °C ± 2 °C for 20 min.  
B.2.8 Pseudomonas agar medium for detection of pyocyanin  
Pancreatic digest of casein           20 g  
Anhydrous magnesium chloride          1.4 g  
Anhydrous potassium sulphate          10 g  
Agar              15 g  
Glycerine              10 Ml  
Dissolve all the solid ingredients in distilled water, make up to 1 L, and then add the glycerine. He at, agitating 
frequently, and boil for 1 min. Adjust the pH value to be 7.2 ± 0.2 after sterilization. Dispense into suitable 
containers and sterilize by autoclaving at 121 °C ± 2 °C for 20 min.  
B.3 Preparation of test suspension  
Transfer 300 mL of the s terile soluti on of bacteriological peptone (B .2.2) to a sterile wide -mouthed jar of 
capacity not less than 1 L and not more than 2 L. The jar shall have a mouth of diameter not less than 150 
mm and not more than 250 mm, and is fitted with a hermetically cl osing glass or metal -and-glass lid. 
Aseptically place the diaper under test in the solution in the jar, fit the lid, agitate the contents of the jar for 2 
min and then allow the jar to stand for 10 min. Repeat this agitating and standing procedure twice mo re. 
Aseptically remove about 100 m L of the test suspensi on for testing as described in B .4 below.  
B.4 Procedure  
B.4.1 Total viable bacterial count  
Into each of three sterile petri dishes aseptically pipette a 1 mL portion of the test suspension. To each  dish, 
add 15 mL of fr eshly melted plate count agar (B .2.3) that has been cooled to 45 °C, and mix well. Incubate, 
count and calculate the total count  
B.4.2 Examination for the presence of Enterobacteriaceae  
Aseptically add 10 mL of the test suspension to  a bottle that contains neutral red -bile salt peptone glucose 
medium (B .2.4). Incubate the bottle for 24 h to 36 h at 37 °C ± 0.5°C and examine for the presence of 
Enterobacteriaceae as evidenced by the formation of acid and gas.  
B.4.3 Examination for the  presence of Staphylococcus aureus  
Use the media, reagents and p rocedure described in US ISO 6887 -4 to ex amine the test suspension (see 
B.3). As a control, pipette 0.1 mL of a 1:1000 dilution of an 18 h to 24 h culture of Staphylococcus aureus 
SATCC Sta 1 0 into Staphylococcus medium and proceed as with the test suspension.  
B.4.4 Examination for the presence of Pseudomonas aeruginosa  
B.4.4.1 Aseptically pipette 10 mL of the test suspension into 90 mL of fluid  soybean -casein digest 
medium (B .2.5) and mix w ell. Incubate for 24 h at 30 °C to 35 °C. By means of an inoculating loop transfer a 
portion from the 24 h incubated sample tube of fluid soybean -casein digest medium to the dry surface of Petri 
dishes each containing approximately 2 0 mL of Cetrim ide agar medium (B .2.6). Incubate at 30 °C to 35 °C DUS  950: 2018  
© UNBS 2018  – All rights reserved  11 
 and examine after 24h, and again after 48 h incubation, for suspect colonies, bearing in mind that in general 
greenish fluorescent colonies are typical of Pseudomonas aureginosa and that in its presence a gram sta in 
examined microscopically will reveal gram -negative slender rod -shaped cells.  
B.4.4.2  As a control, add 0.1 mL of a 1:1 000 dilution of an 18 h to 24 h culture of Pseudomonas 
aeruginosa SATCC Pse 11, mL to 100 mL of fluid  soybean -casein digest medium (B .2.5), and proceed as with 
the test suspension.  
B.4.4.3  If none of the colonies obtained from the test suspension conform s to the description given in 
(B.4.4.1) above and the control culture has been satisfactorily recovered, deem the test sample to be fr ee 
from Pseudomonas aeruginosa.  
B.4.4.4  If colonies conforming to the descrip tion given in (B .4.4.1) above are found, streak representative 
suspect colonies from the Cetrimide agar onto the surfaces of Pseudomonas agar medium for  the detection of  
flouresc ein (B .2.7) and Pseudomonas agar medium f or the detection of pyocyanin (B .2.8) to obtain isolated 
colonies. Cover and invert the Petri dishes and incubate at 30 °C – 35 °C for at least three days. Examine the 
streaked surfaces under ultraviolet light for s uspect c olonies, as described in Table C .1. 
Table B .1 — Description of colonies  
 
Medium  Description of colonies  
Pseudomonas agar for the detection of fluorescein  Generally colourless to yellowish  
Yellowish fluorescence in ultra violet light  
Pseudomonas  agar for the detection of pyocyanin  Generally greenish. Blue fluorescence in ultraviolet light  
 
If any further doubt exists as to the identity of the colonies, obtain final confirmation by inoculating the suspect 
colonies to the wells on commercially ava ilable diagnostic kits in accordance with the manufacturer’s 
instructions.   
12 © UNBS 2018  – All rights reserved  
 Bibliography  
[1] US 950:2011, Disposable baby diapers (First Edition)  
 DUS 9 50: 2018  
© UNBS 2018 – 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 o perated 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 
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 DUS 950: 2018    
 
ICS nn.nnn.nn  
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