DRAFT UGANDA STANDARD  
  DUS 2228  
First Edition  
2020 -mm-dd 
 
 
 Reference number  
DUS 2228 : 2020 
© UNBS 2020   
  
Cobweb duster  — Specification  
 DUS 2228 : 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 applicatio n 
© UNBS 2020   
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 UNB S. 
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 4 333 2 50/1/2/3  
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  
 DUS 2228 : 2020  
© UNBS 20 – 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 World T rade 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, aca demia, 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 recommendin g 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 05, Chemicals and 
Environmen t, Subcommittee SC 03, Plastics and related pro ducts . DRAFT UGANDA STANDARD  DUS 2228 : 2020  
 
© UNBS 2020  – All rights reserved  1 
 Cobweb duster — specification  
1 Scope  
This Draft Uganda  Standard specifies the requirements, methods of sampling and test for cobweb  dusters 
used for removing cobwebs  on ceilings a nd part of the walls that are not easily reached by human hands.  
2 Normative references . 
There are no normative references in this document.  
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  
3.1  
plastic  
synthetic material made from a wide range of organic polymers such as polyethylene, Polyvinyl chloride 
(PVC), nylon, high -density polyethylene (HDPE), po lyethylene terephthalate (PET), Phenolic resin, 
Polypropylene, and ultra -high-molecular -weight polyethylene (UHMWPE, UHMW) . 
3.2  
wood 
hard fibrous material that forms the main substance of the trunk or branches of a tree or shrub  
3.3  
lot 
definite amount o f same product, material or service collected together  
3.4  
tuft 
bunch or cluster of bristles, usually flexible, attached or fixed closely together at the base and loose at the 
upper ends  
3.5  
block  
part to which the filling material “bristle s” are secured  
3.6  
bristle  
stiff animal hair, feather, extruded plastic, metal or natural material e.g. sisal fibre, coconut fibre, on a cobweb 
duster  head . 
3.7 
cobweb 
tangles of the silken threads of a spider web  usually covered with accumulated dirt and dust  DUS 2228: 2020  
2 © UNBS 2020  – All rights reserved  
 3.8  
pith 
a tissue located in the center of the stem of vascular plants, which  is composed of soft, spongy parenchyma 
cells 
3.7 
bristle length  
length of the monofilament that protrudes from the block  
3.8 
handle length  
part of handle th at protrudes from the block  
 
4 Requirements  
4.1 General requirements  
4.1.1  The cobweb duster shall have smooth finish and  all components (block, bristles  and handle) shall be 
free from imperfections and defects which  may affect its appea rance or serviceability  
4.1.2  The cob web duster  may be extendable and coloured  
4.1.3  All metallic components of the brush shall be corrosion resistant  
4.1.3 Block and handle  
4.1.3.1 The material used for the block and handle  shall be made of plastic, metal, wood or any suitable 
material.  
4.1.3.2  For plastic cobweb duster, the handle and block shall be made of hard plastic which does not 
deflect while dusting. The handle shall fit firmly in the block hole and shall not come out during dusting  
4.1.3.3  The block and handle  for wooden cobweb duster, shall b e free from brashness, any kind of 
biological or non -biological deterioration, insect attack, pith, knots (except pin knots), cracks and any other 
defect that may reduce the life of the brush and affect its serviceability  
4.1.4  Bristles  
4.1.4.1 Shall be ma de of animal hair, metal, plastic (synthetic), natural material such as coconut fibre, 
sisal fibre or any suitable material  
4.1.4 .2 Suitable  adhesive,  wire, nails o r staple shall be used to fix  the bristles in the  tuft holes.  
4.1.4.3 Each  tuft shall conta in bristles of uniform length, diameter, quantity and same synthetic material. . 
4.2 Specific requirements  
4.2.1  The cob web duster shall conform to the requirements given in Table 1 when tested in accordance 
with the test methods specified therein . DUS  2228 : 2020  
© UNBS  2020  – All rights reserved  3 
 Table 1 — Specific requirements for cob web duster  
Characteristic  Requirement  Test method  
wooden  plastic  
Moisture content,%, max  15 - Annex A  
Tuft anchorage  Neither a tuft nor its individual bristle shall 
dislodge.  Annex B  
 
4.2.2 All metallic components of  the br ush shall be corrosion resistant or shall be protected from corrosion, 
when tested in accordance with Annex C, the surfaces shall show no sign of corrosion  
5 Dimensions  
Cobweb dusters  shall conform to the minimum dimensions given in Tab le 2  
Table2  — Table for minimum dimensions  
SN Parameter  Quantity  
i.  Bristle diameter(mm)  0.25 
ii.  Bristle length (mm)  90.0 
iii.  Handle length(mm)  1000.0  
iv.  Number of bristles per head  6300.0  
v.  Pull Strength for 1 min (N)  50.0 
6 Tests  
6.1 Bristle diameter  
The bristle diamet er shall be measured by a micrometer screw gauge or a vernier calliper  or any instrument 
that can measure to the nearest 0.01 mm , measure the diameter  of six bristles to the nearest 0.01 mm. Select 
the six bristles from six random t ufts from the same brush  head, ten c alculate the average bris tle diameter   
6.2 Bristle length  
The bristle length shall be measured using a vernier calliper, measure the length of six bristles to the nearest 
0.01 mm. Select the six bristles from six random tufts from the same brus h head. Calculate the average bristle 
length.  
6.3 Handle length  
The handle length  shall be measured using a graduated ruler with a scale of 1 mm or any other suitable 
means, capable of  measuring length to the nearest 1 mm.  
7 Labelling  
The cobweb duster  shall be legibly marked with the following  DUS 2228: 2020  
4 © UNBS 2020  – All rights reserved  
 a) Name of product as “cob web duster “  
b) name and address of manufacturer;  
c) batch number;  
d) extendable or non -extendable.  
7. Sampling  
Sampling shall be done in accordance with  Annex D 
8 Packaging  
The toilet brush shall be  packaged in suitable packages , the head may be. detached from the handle  DUS  2228 : 2020  
© UNBS  2020  – All rights reserved  5 
 Annex  A 
(normative)  
 
Determination of Moisture C ontent for wooden cob web duster  
A.1 Test Specimen  
The entire block used in brush may form the test specimen for the determination of m oisture content or apiece  
cut from it. Smaller specimens may be used when deemed necessary. The test shall be carried out 
immediately after cutting the specimen  
A.2 Procedure  
Weigh accurately each test specimen. This specimen shall then be dried in a venti lated oven at a temperature 
of 105 °C ± 2 °C until the mass becomes constant between two successive weighing made at an interval of 
not less than one hour  
A.3 Calculation  
% Moisture content 
100
www
oo 1  
Where:  
W1   initial mass in grams of test  specimen, an d 
W0   oven -dry mass in grams of the test specimen   DUS 2228: 2020  
6 © UNBS 2020  – All rights reserved  
 Annex  B 
(normative)  
 
Determination of Pull Strength  
B.1 General  
A simple instrument as shown in Fig. 1 can be used for testing the pull strength. This unit is suitable for 
mounting on wall. I t consists of dial force gauge /weighing scale (0 -10 kg) operating on spring (A) mounted on 
wooden plate (B). A tubular tuft holder (C) is hung on the hook of dial gauge. A  clamp for holding cobweb  
duster head  (E) is provided which is movable downward and upward with a screw (F). The dial force 
gauge/weighing scale shall be calibrated having traceability  
B.2 Procedure  
B.2.1 Fix the head  with bristles in upward direction in the  holder with the help of screw (G). Divide the 
bristles into segments of about 10 mm length.  
B.2.2 Insert all bristles of one segment in the hole provided at the bottom of tubular tuft holder (C). Care 
should be taken not to allow bristles from adjacent segment to enter in to the hole. Fix the bristles firmly with 
the help of screw (D) . 
B.2.3 Adjust the pointer on dial to zero by adjustment of screw (F).  
B.2.4 Move down the brush holder slowly with screw (F) watching the pointer on dial carefully till it reaches 
5 kg mark and keep it there for 1 min. Then remove the brush from the gadget  and examine. The bristles of 
any segment shall not come out of the cement during the test.  
Note: The tufts shall not fail when subjected to a pull by thumb and finger grip or the force required for pulling out an 
individual tuft shall not be less than 50. 0 N for 1 m  
 
DUS  2228 : 2020  
© UNBS  2020  – All rights reserved  7 
 Annex  C 
(Normative)  
 
Determination of Corrosion Resistance  
Submerge all metal components for 7 h in distilled water, then dry them as rapidly as possible at a 
temper ature not exceeding 70 °C and examine the surfaces that are required to be corrosion resistant for 
freedom from corrosion . Check for compliance with 4.2 .2 
 DUS 2228: 2020  
8 © UNBS 2020  – All rights reserved  
 Annex  D 
(Normative)  
 
Sampling of Cob web duster  and Criteria for Conformity  
D.1 Scale of Sampling  
D.1.1 Lot – In any consignment, all the dusters of the same size and quantity shall be divided into groups of 
500 dusters or less and each such group shall constitute a lot. Care shall be taken to ensure that  cobweb  
dusters included in a lot do not differ in construction as far as possible  
D.1.2 The conformity of the cobweb  dusters in a lot to the requirements of this specification shall be 
ascertained for each lot separately. The number of cobweb  duster to be  selected for this purpose shall be in 
accordance w ith col. 1 and col. 2 of Table 3  
Table 3  Scale of Sampling  
No. of dusters  in a lot  
N No. of dusters  to be selected  
n 
Up to 10 2 
11 to 25  3 
26 to 50  4 
51 to 100  5 
101 to 150  6 
151 to 300  7 
301 to 500  8 
 
D.1.3 The cobweb  dusters shall be selected at random. To ensure randomness of selection one of the 
following procedures is recommended for use:  
a) If all the cob web duster s in a lot are packed in a one box, then starting from any brush, count them 
in any suitable order as 1, 2, …… up to r and so on, where r is the integral part of N/n (N and n being 
the lot size and sample size respectively). Every r th cob web duster thus counted shall be withdrawn 
to constitute the sample.  
b) If the cobweb  dusters i n a lot are packed in more than one box, approximately equal number of 
cobweb  dusters shall be picked up at random from as many boxes as possible so as to obtain the 
required number of cob web  dusters as specified in Table 3  
D.2 Criteria for Conformity  
For declaring the conformity of the lot to the requirements of this specification, all the cobweb  dusters selected 
according to C.1.3 shall satisfy the relevant requirements given in clause 5 
 DUS  2228 : 2020  
© UNBS  2020  – All rights reserved  9 
 Bibliography  
[1] IS 11750:1986, Brushes  — Fitch flat with long han dle  
[2] IS 4301:1999, Brushes,  — brushes foundry flat   
 DUS 2228 : 2020  
© UNBS 2020  – All rights reserved  11 
 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 Certi fication 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 U ganda 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 sch eme 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 2228:  2020    
 
ICS 49.025.40  
Price based on nn pages  
© UNBS 2020 – All rights reserved