DRAFT UGANDA STANDARD  
  DUS 1511  
Second  Edition  
yyyy -mm-dd 
 
 
 Reference number  
DUS 1511:2022  
© UNBS 2022   
  
Oxygen for medical use — Specification  
 DUS 1511:2022  
ii © UNBS 2022  – 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 a pplication  
© UNBS 2022  
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Fax: +256 41 4 286 123  
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Web: www.unbs.go.ug  DUS 1511:2022  
© UNBS 2022  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Requirements  ................................ ................................ ................................ ................................ .........  1 
4.1  General requirements  ................................ ................................ ................................ ..........................  1 
4.2  Physical and chemical requirements  ................................ ................................ ................................ . 2 
5  Packaging  ................................ ................................ ................................ ................................ ...............  2 
6  Labelling  ................................ ................................ ................................ ................................ ................  2 
7  Storage  ................................ ................................ ................................ ................................ ..................  3 
8 Sampling and criteria for conformity  ................................ ................................ ................................ .. 3 
Annex A  (normative)   Determination of moisture content  ................................ ................................ ...........  4 
A.1  Apparatus  ................................ ................................ ................................ ................................ ...............  4 
A.2  Reagents  ................................ ................................ ................................ ................................ ................  4 
A.3  Procedure  ................................ ................................ ................................ ................................ ..............  4 
Annex B  (normative)   Determination of acidity and alkalinity  ................................ ................................ ..... 6 
B.1  Apparatus  ................................ ................................ ................................ ................................ ...............  6 
B.2  Reagents  ................................ ................................ ................................ ................................ ...............  6 
B.3  Procedure  ................................ ................................ ................................ ................................ ..............  6 
Annex C  (normative)   Determination of oxidising substance  ................................ ................................ ...... 8 
C.1  Apparatus  ................................ ................................ ................................ ................................ ..............  8 
C.2  Reagents, solutions and preparations  ................................ ................................ ...............................  8 
C.2.2  Pota ssium iodide -starch solution.  ................................ ................................ ................................ ....... 8 
C.3  Procedure  ................................ ................................ ................................ ................................ ...............  8 
Annex D  (normative)   Determination of purity ................................ ................................ ...............................  9 
D.1  Apparatus  ................................ ................................ ................................ ................................ ..............  9 
D.2  Reagents and preparation  ................................ ................................ ................................ ...................  9 
D.3  Procedure  ................................ ................................ ................................ ................................ ...............  9 
Annex E  (normative)   Determination of carbon dioxide  ................................ ................................ .............  11 
E.1  Apparatus  ................................ ................................ ................................ ................................ .............  11 
E.2  Procedure  ................................ ................................ ................................ ................................ ............  11 
Annex F  (normative)   Determination of carbon monoxide  ................................ ................................ .........  12 
F.1  Apparatus  ................................ ................................ ................................ ................................ .............  12 
F.2  Procedure  ................................ ................................ ................................ ................................ .............  12 
Bibliography  ................................ ................................ ................................ ................................ ......................  13 
 DUS 1511:2022  
iv © UNBS 2022  – 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 the WHO/FAO Codex Al imentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT  Agreement  of the World Trade Organisation (WTO).  
The work o f preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to del iberate 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 recommending 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 301, Chemistry . 
This second edition cancels and replaces the first edition ( US 1511 :2014 ), which has been technically revised.  DUS 1511:2022  
© UNBS 2022  – All rights reserved  v 
 Introduction  
Oxygen is an essential medicine that is used to treat hypoxaemia at all levels of the  health care system. It is 
required for surgery, acute respiratory illnesses such as severe pneumonia, chronic pulmonary diseases, 
emergencies and cardiovascular diseases, among others.  
  
 DRAFT UGANDA STANDARD  DUS 1511: 2022  
 
© UNBS 2022  – All rights reserved  1 
 Oxygen for medical use — Specification  
1 Scope   
This Draft Uganda Standard specifies the requirements , methods of sampling and test ing of oxygen for 
medical use only.  
2 Normative references   
 The following referenced documents referred to in the text in such a way that some or all of their content 
constitute s requirements 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.  
ISO 32, Gas cylinders for medical use — marking  for identificat ion of content  
ISO 5145, Cylinder valve outlets for gases and gas mixtures — Selection and dimensioning  
ISO 7225; Gas cylinders — Precautionary labels  
3 Terms and definitions   
For the purposes of this document, the following terms and definitions apply.  
3.1 
medical oxygen  
gaseous or liquid oxygen, having a chemical formula O 2, intended for medical use  
 
3.2 
lot 
oxygen filled in container of the same type and size at the same period  
 
3.3 
body  
cylindrical part of a gas cylinder   
 
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  
4 Requirements  
4.1  General requirements  
4.1.1  Medi cal oxygen shall be manufacture d from a hygienic facility   
  
2 © UNBS 2022  – All rights reserved  
 4.1.2  Medical Oxygen in gaseous form shall be odourless and colourless. In case of liquid form, it  shall be 
odourless and of a light blue colour.  
4.2  Physical and chemical requirements  
Oxygen for medical use shall comply with the requirements specified in Table 1 when tested in accordance 
with the methods prescribed therein.  
Table 1 — Physical and che mical requirements  
S. No  Characteristic  Requirement  Test method  
1  Moisture, mg/dm3, max.  0.12  Annex A  
2  Acidity or alkalinity  Shall pass the test  Annex B  
3  Oxidising substance*  Shall pass the test  Annex C  
4  Purity by volume,  %, min.  99.5  Annex D  
5  Carbon dioxide, mm3dm3, max.  300  Annex E  
6  Carbon monoxide, mm3dm3, max.  5  Annex F  
*In case the process is air -liquefaction and use adsorption technique by alumino silicate or activated alumina as carbon dioxide and 
moisture remo ver, acidity or alkalinity and oxidizing substance tests are not required.  
 
5  Packaging  
5.1  Containers for medical oxygen shall be clean, free from pollutants and contaminants and shall be used 
for medical oxygen only.  
5.2  Containers in the form of cyl inders shall be in accordance with ISO 5145.  
5.3  The medical oxygen cylinder shall be white on its neck and shoulder in accordance with ISO 32.  
5.4  The medical oxygen cylinder connectors shall be provided with wrapping material to protect against 
entry o f dust and to sort the used cylinders from the unused cylinders. The name and trademark of filler shall 
be provided on the wrapping material.  
 
6  Labelling  
Each container or the attached label shall at least bear a number, letter or mark indicating legibly  and clearly 
the following information:  
  
i)  the term " MEDICAL OXYGEN" together with its chemical formula "O 2" written on the container body 
in white letters of the size not smaller than one -eighth (1/8) of the cylinder diam eter;.  
ii)  name of manufacturer or factory or registered trade mark and packer or distributor with address;  
iii)  lot identification;  
iv)  net content  at a pressure of 0.1 Mpa and filling pressure in mega  Pascals (Mpa) at a temperatu re of 
27oC± 2oC; and  
v)  safety precaution for use, handling and storage  
  DUS 1511:2022  
© UNBS 2022  – All rights reserved  3 
   
7  Storage  
7.1 Oxygen sh all  be kept as compressed gas or liquid at cryogenic temperature, in appropriate containers 
complying with the safety regulations of the national authority .  
7.2 Valves or taps sh all  not be lubricated with oil or grease.  
8 Sampling and criteria for confor mity 
8.1  Sampling and acceptance shall be in accordance with the sampling plan in 7.2 and 7.3  or its technical 
equivalent.  
8.2  In the case of cylinders, a number of container(s) shall be taken at random in accordance with the plan 
given in Table 2 for conformity tests on requirements, containers and packaging, and marking and labelling.  
Table 2 — Sampling plan  
Lot size container  Lot size container  
1 - 30  1  
31 - 60  2  
60 and above  3  
 
8.3  In case of tanks, the sample shall be taken in liquid fo rm from the storage tank and transferred into a 
Dewar flask or other equivalent vessels in an amount not less than 2 dm3 for requirement inspection  
  
4 © UNBS 2022  – All rights reserved  
 Annex  A  
(normative )  
 
Determination of moisture content  
A.1  Apparatus  
The apparatus shall be as shown i n Figure A.1.  
A.2  Reagents  
A.2.1   Dry ice  
A.2.2   Acetone or ethanol  
A.3  Procedure  
A.3.1   Pass the sample gas through the inlet tu be at a rate of approximately 1 dm3min - 5 dm3min. Add 
acetone or ethanol approximately half of the height into the cylindrica l vessel.  
A.3.2   Gradually add small pieces of dry ice and stir well until water vapour is formed on the external 
surface of the cylindrical vessel A at the end of the inlet tube. Immediately read the temperature.  
A.3.3   Repeat the test by allowing the tem perature to go up until all water vapour disappears. Then repeat 
A.3.2 until constant temperature is obtained. Provided that the temperature me asured is not higher than - 40 
oC, the sample is deemed to have moisture content not exceeding 0.12 mg/dm3. 
 
Figure A.1 — Apparatus for analysis of moisture content  
 
 DUS 1511:2022  
© UNBS 2022  – All rights reserved  5 
 Key 
A  is a thin -walled cylindrical vessel made of metal, for example copper coated with chromium, with approximately 4 - 
mm diameter and 7.5 cm - 12.7 cm  high, the external surface being polished and n ot causing any difference in 
temperature at the internal and external surfaces.  
B  is a glass or transparent vessel with a lid.  
C  is an inlet tube;  made of copper with an orifice of 6 mm. End of tube is approximately 2.5 mm above the bottom of the 
vessel.  
D  is an outlet tube, made of copper with an orifice of 6 mm. The other end is connected to gas volume meter.  
E  is a thermometer capable of r eading a temperature below – 40 oC.  
6 © UNBS 2022  – All rights reserved  
 Annex B  
(normative ) 
 
 Determination of acidity and alkalinity  
B.1  Apparatus  
B.1.1  Three glass cylinders  of 30 -mm internal diameter and approximately 180 mm in height with stoppers 
(see Figure B.1). The second cylinder shall be provided with a rubber stopper, fitted with an inlet tube having 
an orifice of 0.5 mm in internal diamet er with length almost reaching the bottom of glass cylinder, and an outlet 
tube connected to gas volume meter.  
B.1.2  Gas volume meter  
B.2  Reagents  
B.2.1   Hydrochloric acid solution, 0.01 mol/dm3 
B.2.2   Methyl red indicator solution, 0.5 by weight. Dissol ve 0.5 g of methyl red in 100 dm3 of distilled water.  
B.3  Procedure  
B.3.1 Transfer 1cm3 of methyl red indicator solution into 350 cm3 of distilled water and heat to boiling for 5 
min.  
B.3.2 Then transfer the warm solution into three glass cylinders, 100 cm3 each.  
B.3.3 In the first cylinder drop 0.1 cm3 of hydrochloric acid solution.  
B.3.4 In the second and the third cylinders drop 0.2 cm3 of hydrochloric acid solution.  
B.3.5 Stopper the first and the third cylinders and pass 2 dm3 of the sample gas th rough the second cylinder 
within 30 min.  
B.3.6 Compare the colour in the three cylinders by placing them on white surface.  
B.3.7 Remove the stopper and view the colour from top of the cylinder.  
B.3.8 Samples shall be deemed to comply with the specificati on if colour of solution in the second cylinder is 
not more yellow than in the first cylinder or pink intensity in the second cylinder is not more than in the third 
cylinder.  DUS 1511:2022  
© UNBS 2022  – All rights reserved  7 
 
 
Figure B.1 — Apparatus for analysis of acidity  
  
8 © UNBS 2022  – All rights reserved  
 Annex C  
(normative ) 
 
 Determin ation of oxidising substance  
C.1  Apparatus  
Two glass cylinders, the same as the first and the second cylinders in B.2  
C.2  Reagents, solutions and preparations  
C.2.1   Glacial acetic acid, of density 1.049 g/cm3 
C.2.2   Potassium iodide -starch solution.  
C.2.2.1  Dissolve 0.75 g of potassium iodide in 100 cm3 of distilled water.  
C.2.2.2  Boil and add all starch solution (dissolve 0.5 g of starch in 35 cm3 of distilled water), then agitate 
and continue to boil for a few minutes, and allow to cool.  
C.2.2.3  Test for solution activity by adding 0.05 cm3 glacial acetic acid and 0.25 cm3, 0.5 m mol/ dm3 
iodine into 15 cm3 of the solution.  
C.2.2.4  The solution colour shall be changed into blue.  
C.3  Procedure  
C.3.1  Add into both cylinders 50 cm3 of the freshly prep ared potassium iodide -starch solution and 0.2 cm3 of 
glacial acetic acid.  
C.3.2  Pass 5 dm3 of sample gas through the second cylinder.  
C.3.3  Provided the intensity of the solution in the second cylinder is the same as that of the first, the sample 
is deem ed to have passed the test.  
Note:  The test shall be carried out at a place not being exposed to light.  DUS 1511:2022  
© UNBS 2022  – All rights reserved  9 
 Annex D  
(normative ) 
 
 Determination of purity  
D.1  Apparatus  
It shall be as shown in Figure D.1.  
D.2  Reagents and preparation  
D.2.1  Ammonium chloride -ammonium hydroxide solution.  
D.2.1 .1 Dissolve 550 g of ammonium chloride in 1 250 cm3 of water and  
D.2.1.2 add 750 cm3 of concentrated ammonium solution, with density of 0.88 g/cm3. 
D.3  Procedure  
D.3.1   Assemble the apparatus ( Figure D.1) with tube ends co nnection.  
D.3.2  Put a suitable amount of ammonium chloride -ammonium hydroxide solution into the absorption 
pipette and the levelling bottle.  
D.3.3  Exhaust the air in the burette, the absorption pipette and stopcock C, and then  allow the sample gas 
into th e absorption pipette until a volume of 100 cm3 is obtained  
D.3.4  Drive the gas back and forth between the burette and the absorption pipette until constant volume of 
gas in the burette is obtained  
D.3.5  The lost volume of gas in the burette is the purity  of the sample gas in percentage by volume. Newly 
prepared ammonium chloride -ammonium hydroxide solution shall be a few times subjected to trial oxygen 
analysis prior to the actual analysis. The solution can be used several times unless poor oxygen absorpt ion 
and formation of sediment is presented.  
NOTE  The absorption pipette should be always filled with copper.   
10 © UNBS 2022  – All rights reserved  
 
 
Figure D.1 — Apparatus for analysis of purity  
Key 
A  is a burette of 100 cm3 capacity, and scales from 99 cm3 - 100 cm3 having scale readable to  0.1 cm3 
B  is an absorption pipette fully containing copper wire spirals, bars or fragments inside  
C  is three -way capillar y stopcock with an orifice of 1 mm. internal diameter  
D  is levelling bottle of 175 cm3 capacity  
E  A rubber hose of approximately 750  mm long connected to the burette, A, and levelling bottle, D  
 DUS 1511:2022  
© UNBS 2022  – All rights reserved  11 
 Annex E  
(normative ) 
 
 Determination of carbon dioxide  
E.1  Apparatus  
E.1.1   Carbon dioxide detector tube  
E.1.2  Gas volume meter  
E.2  Procedure  
E.2.1  Pass 1 dm3 of sample gas through the carbon  dioxide detector tube, connected to the gas volume 
meter,  the calibration of which is verified according to the manufacturer's instructions , at the speed specified 
on each individual type.  
E.2.2 Read the obtained value from the detector tube  
  
12 © UNBS 2022  – All rights reserved  
 Annex F  
(normative )  
 
Determination of carbon monoxide  
F.1  Apparatus  
F.1.1   Carbon monoxide detector tube  
F.1.2   Gas volume meter  
F.2  Procedure  
F.2.1  Pass 1dm3 of sample gas through the carbon m onoxide detector tube , connected to the gas volume 
meter,  the calibrat ion of which is verified according to the manufacturer's instructions , at the speed specified 
on each individual type.  
F.2.2 Read the obtained value from the detector tube.  DUS 1511:2022  
© UNBS 2022  – All rights reserved  13 
 Bibliography  
 
[1] TIS 540 -2545 (2002), Thai Industrial Standard for medical use.  
[2] US 1511: 2014,  Oxygen for medical use — Specification  
[3]  6.1.260.Oxygen -(Oxygenium)  
 DUS 1511:2022  
© UNBS 2022  – All rights reserved  15 
 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 i n 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 accordanc e 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 Di rector, Uganda 
National Bureau of Standards.  
 
 DUS 1511:2022    
 
ICS 11.040 
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