DRAFT UGANDA STANDARD  
  DUS 2296 -6 
First  Edition  
2022-mm-dd 
 
 
 Reference number  
DUS 2296 -6: 202 2 
© UNBS 202 2  
  
Skin applied mosquito repellents — Specification —Part 6: 
Petroleum jelly  
 DUS 2296 -6: 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. User s are 
responsible for its correct application  
© UNBS 2021  
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 microfil m, 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 41 4 333 2 50/1/2/3  
Fax: +256 41 4 286 1 23 
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS 2296 -6:2022 
© UNBS 202 2 – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ .............................  v 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Active ingredients  ................................ ................................ ................................ ................................ . 2 
4.1 Natural repellents  ................................ ................................ ................................ ................................ .. 2 
4.2 Synthetic repellents  ................................ ................................ ................................ ..............................  3 
5 Requirements  ................................ ................................ ................................ ................................ .........  3 
5.1 General requirements  ................................ ................................ ................................ ...........................  3 
5.2 Specific requirements  ................................ ................................ ................................ ...........................  3 
5.3 Heavy metal contaminants  ................................ ................................ ................................ ...................  4 
5.4 Biological efficacy  ................................ ................................ ................................ ................................ . 4 
6 Packaging  ................................ ................................ ................................ ................................ ...............  4 
7 Labelling  ................................ ................................ ................................ ................................ .................  4 
8 Sampling  ................................ ................................ ................................ ................................ ................  5 
Annex A  (normative)   Determination of melting point  ................................ ................................ ..................  6 
Annex B  (normative)   Determination of saponifiable matter  ................................ ................................ ....... 7 
B.1 Reagents  ................................ ................................ ................................ ................................ ................  7 
B.2  Procedure  ................................ ................................ ................................ ................................ ..............  7 
Annex C  (normative)   Determination of organic acids  ................................ ................................ .................  8 
C.1  Reagents  ................................ ................................ ................................ ................................ ...............  8 
C.2  Procedure  ................................ ................................ ................................ ................................ ...............  8 
Annex D  (normative)   Determination of sulphated ash  ................................ ................................ ................  9 
D.1 Reagents  ................................ ................................ ................................ ................................ .......................  9 
D.2 Procedure  ................................ ................................ ................................ ................................ .....................  9 
D.3 Calculation  ................................ ................................ ................................ ................................ ....................  9 
Annex E  (normative)   Determination of sulphur and sulphides  ................................ ................................  10 
E.1 Reagents  ................................ ................................ ................................ ................................ ..............  10 
E.2  Procedure  ................................ ................................ ................................ ................................ .............  10 
Annex F  (normative)   Determination of i odine value  ................................ ................................ ..................  11 
F.1  Apparatus  ................................ ................................ ................................ ................................ .............  11 
F.2  Reagents  ................................ ................................ ................................ ................................ ..............  11 
F.3  Procedure  ................................ ................................ ................................ ................................ .............  12 
F.4  Calculation  ................................ ................................ ................................ ................................ ..........  12 
Annex  G (normative)  Determination of DEET content  ................................ ................................ .................  13 
G.1 General  ................................ ................................ ................................ ................................ .................  13 
G.2 Apparatus  ................................ ................................ ................................ ................................ .............  13 
G.3 Preparation of calibration curve  ................................ ................................ ................................ ........  13 
G.4 Procedure  ................................ ................................ ................................ ................................ .............  13 
G.5 Calculation  ................................ ................................ ................................ ................................ ...........  14 
Annex H (normative)   Determination of total pyrethrins  ................................ ................................ .............  15 
H.1  General  ................................ ................................ ................................ ................................ .................  15 
H.2  Reagents  ................................ ................................ ................................ ................................ .............  15 
H.3  Apparatus  ................................ ................................ ................................ ................................ .............  15 DUS 2296 -6: 2022 
iv © UNBS 2022 – All rights reserved  
 H.4  Operating conditions  ................................ ................................ ................................ .........................  15 
H.5  Preparation of the standard  ................................ ................................ ................................ ..............  15 
H.6  Sample preparation  ................................ ................................ ................................ ............................  16 
H.7  Procedure  ................................ ................................ ................................ ................................ ...........  16 
H.8  Calculation of the % total pyrethrins (active ingredient)  ................................ ................................  16 
Bibliography  ................................ ................................ ................................ ................................ .....................  17 
 DUS 2296 -6:2022 
© UNBS 202 2 – All rights reserved  v 
 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 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 governme nt, 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 reco mmending 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  
WDU S 2296  consists of the following parts, under the general title Skin applied mosquito repellents — 
Specification:  
 Part 1: Lotions, creams, gels and ointments  
 Part 2: Sprays and roll -ons  
 Part 3: Wipes  
 Part 4: Bathing soaps  
 Part 5: Bracelets, wristbands and patches   
 Part 6: Petroleum Jelly 
 
 DRAFT UGANDA STANDARD  DUS 2296 -6: 202 2 
 
© UNBS 2022 – All rights reserved  1 
 Skin applie d mosquito rep ellents — Specification — Part 6 : 
Petroleum jelly   
1 Scope   
This Draft Uganda  Standard specifies  the requirements, sampling and test methods for skin applied mosquito 
repellents in form of petroleum jelly   
2 Normative references   
The followin g referenced documents referred to in the text in such a way that some or all of their content 
constitutes requirements of this document. For dated references, only the edition cited applies. For undated 
references, the latest edition of the referenced doc ument (including any amendments) applies.  
US ISO 2137 , Petroleum products and lubricants — Determination of cone penetration of lubricating greases 
and petrolatum  
US EAS 123, Distilled water — Specification  
US EAS 346, Labelling of cosmetics — General requ irements  
US EAS 377 -2, Cosmetics and cosmetic products — Part 2: List of substances which cosmetic products must 
not contain except subject to the restrictions laid down  
US EAS 377 -3, Cosmetics and cosmetic products — Part 3: List of colorants allowed in c osmetic products  
US EAS 846, Glossary of terms relating to the cosmetic industry  
US EAS 847 -16, Cosmetics —Analytical methods —Part 16: Determination of heavy metal content  
US ISO 24153, Random sampling and randomization procedures  
FDUS 2373 -1, Mosquito re pellents ― Performance test guidelines ― Part 1: Skin applied repellents  
US 191:2021 , Petroleum jelly — Specification  
3 Terms and definitions   
For the purposes of this document, the terms and definitions given in US EAS 846 and the following 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  
mosquito  
blood -sucking dipterous insect of the family Culicidae. Aedes, Anopheles, Culex , Mansonia, and Stegomyia 
are genera containing most species involved in the transmission of protozoan and other disease -producing 
parasites.   
2 © UNBS 202 2 – All rights reserved  
   
3.2  
mosquito repellent  
substance applied to skin, clothing, or other surfaces which deters mosquito from approa ching  or settling .  
3.3  
natural repellents  
repellents that contain , plant -based compounds  
3.4  
synthetic repellents  
conventional repellents containing  chemical compounds  manufactured to imitate the natural compounds.  
3.5  
DEET  
N,N-Diethyl -meta -toluamide or diethyltoluamide  
3.6  
IR3535  
ethyl butylacetylaminopropionate  
3.7  
picaridin  
1-(1-methylpropoxycarbonyl) -2-(2-hydroxyethyl) piperidine or 2 -(2-hydroxyethyl) -1-piperidinecarboxylic acid 1 -
methylpropyl ester  
4 Active ingredients  
4.1 Natural repellents  
4.1.1 Active ingredients used in natural repellents shall be plant based compounds that are able to  deter 
mosquito es from approaching or settling  on the surface.  Such shall be essential oils or any other plant extract 
approved as mosquito repellents . 
4.1.2 The manufacturer shall provide adequate data on the repellence of such ingredients.  
4.1.3 The manufacturer shall have adequate data justifying the proportion of ingredient(s) for which claims 
are made, used in the product.  
4.1.4 The essential oils and other  plant extracts used in natural repellents shall be, but not limited to: : 
a) cedarwood oil;  
b) tea tree oil;  
c) geranium oil;  
d) rosemary oil;  
e) lemongrass oil;  
f) citronella oil;  
g) eucalyptus oil;  
h) cinnamon oil; and  DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  3 
 i) neem oil  
4.1.5 The proportion of single or blended active i ngredient (s) in natural repellent shall be set by the 
manufacturer in accordance with specific standard and records shall be availed.  
4.2 Synthetic repellents  
4.2.1 Synthetic repellents shall contain chemical compounds which are able to deter  mosquitoes from 
approaching or settling  on the surface .  
4.2.2  If a synthetic active ingredient is blended with other active ingredient (s), either natural or synthetic, 
the proportion shall be set by the manufacturer based on scientific research and records shall be availed . 
4.2.3 Synthetic repellents and their active ingredients shall be approved and registered by competent 
authority before being released to the market.  
5 Requirements  
5.1 General  requirements  
5.1.1 The product shall constitute a mosquito repellent th at is formulated as petroleum jelly  and shall be 
essentially a product which has active ingredient (s) added to a certain level.  
5.1.2 All ingredients shall mee t the requirements of US EAS 377 -2 and  US EAS 377 -3. 
5.1.3 The products shall not cause any harm ful effect to the skin when applied.  
 
5.2 Specific requirements  
5.2.1  The product shall comply with the specific requirement s given in table 1 when tested in accordance 
to the methods described therein.  
Table 1— Specific requirements for skin applied  mosqu ito repellents in form of petroleum jelly  
S/N  Characteristic  Requirements  Test methods  
i Melting point, °C  38 – 60 Annex A 
ii Saponifiable m atter To pass test  Annex B 
iii Organic acids, ml, max.  1 Annex C 
iv Sulphated ash, %, by mass, max.  0.2 Annex D 
v Sulphur and sulphides  To pass the test  Annex E 
vi Iodine value (Wijs), max.  1.5 Annex F 
vii Cone penetration value at 25 °C  100 - 275 1/10 mm in checking for 
consistency and hardness of jellies  US ISO 2137  
 
 
 
  
4 © UNBS 202 2 – All rights reserved  
 5.2.2  Active ingredients and their content in   repellents shall meet the requirements prescribed in table 2. 
Table 2 — Active ingredients  content for repellents  
S/N  Characteristic  Requirements  Test methods  
Synthetic  
i DEET  4 – 50 Annex G 
ii Picaridin  5 – 20 CIPAC 740  
iii IR3535  7.5 – 20 CIPAC 667  
Natural  
iv Pyrethrins, % w/w, min 0.5 Annex H 
 
  
 
 
5.3 Heavy metal contaminants   
The pro duct shall comply  with the heavy metal contaminants  given  in Table 3 when tested in accordance  with 
the test methods  specified therein . 
Table 3— Heavy metal contaminants for skin applied mosquito repellent in form of petroleum jelly  
S/No Heavy metals.  Limit, mg/kg, max  Test method  
i Lead  10  
US EAS 847 -16 ii Arsenic  2 
iii Mercur y  2 
 
5.3.2  The total amount of heavy metals as lead, mercury and arsenic, in combination in the finished product 
shall not exceed 10 mg/kg  
5.4 Biological efficacy  
When test ed in accordance with FDUS 2373 -1, the product shall repel 100 % of the mosquitoes from 
approaching or climbing on that surface, within protection time indicated by the manufacturer.  
6 Packaging  
The product shall be packaged in securely closed containers t hat shall protect; effectively screen the content 
from UV light when stored; and not cause any contamination or reaction with the product.  
7 Labelling  
In addition to the labelling requirements given in US EAS 346, the package shall be legibly and indelibly  
marked with the following information:  DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  5 
 a) name of the product;  as “skin  applied mosquito repellent”  
b) form of product as petroleum jelly  
c)  instructions for use  
d) active ingredient (s) content  
e) list of ingredients  
f) protection time  
g) age group and/or health condition for which use is prohibited  
h) storage conditions  
i) safety precaution  
j) manufacturing & expiry dates  
k) batch number  
l) disposal instructions  
 
8 Sampling  
Sampl ing shall be done in accordance with US ISO 24153 .    
6 © UNBS 202 2 – All rights reserved  
 Annex A  
(normative ) 
 
 Determination of melting point  
A.1 Melt a quantity of the sample slowly while stirring until it reaches a temperature of 90 °C - 92 °C. 
Remove the source of heat and allow the molten sample to cool to a temperature of 8 °C - 10 °C above the 
expected melting point. Chill the bulb of a thermometer (range: 1 °C - 100 °C) to 5 °C, wipe it dry and while it 
is still cold, dip it into mo lten sample so that approximately half of the bulb is “submerged". Withdraw it 
immediately and hold it vertically away from heat until the wax surface dulls, then dip it for 5 min into a water 
bath having a temperature not higher than 16 °C.  
A.2 Fix the th ermometer prepared in A.1 securely in a test tube so that its lowest point is about 15 mm 
above the bottom of the test tube. Suspend the test tube in a water bath adjusted to 16 °C, and raise the 
temperature of the bath at a rate of 1 °C/min and note the t emperature at which the first drop of the melted 
sample leaves the thermometer. Repeat the determination twice on a freshly melted portion of the sample. If 
the variation in three determinations is less than 1 °C, take the average of three as the melting p oint. If the 
variation in the three determinations is more than 1 °C, make two additional determinations and take the 
average of the five  DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  7 
 Annex B  
(normative)   
 
Determination of saponifiable matter  
B.1 Reagents  
B.1.1  Methyl ethyl ketone, analytical grade, stored in amber coloured bottle  
B.1.2   Standard alcoholic potassium hydroxide solution, 0.5 mol/L standar dized before use  
B.1.3   Petroleum ether, boiling range 80 °C - 100 °C  
B.1.4   Standard hydrochloric acid, 0.5 mol/L accurately standardized  
B.1.5   Phenolphthalein indicator solution, 1 % solution in 95 % rectified spirit  
B.2  Procedure  
B.2.1  Accurately weigh in  flask about 5 g of the sample and add 25 ml ± 1 ml of methyl ethyl ketone, 
followed by 25 ml standard alcoholic potassium hydroxide solution from a burette. Connect the flask to a 
condenser and heat for half an hour after refluxing begins. Disconnect the condenser, add 50 ml of petroleum 
ether and titrate the solution while hot (without heating) with standard hydrochloric acid, using three drops of 
phenolphthalein indicator. When the indicator colour is discharged add three drops more of the indicator. If 
this addition restores the colour, continue the titration. Proceed in this manner until the end point is reached 
when the indicator colour is discarded and does not immediately reappear upon the addition of three more 
drops of indicator.  
B.2.2   Run a blank under identical conditions.  
B.2.3   The sample shall be taken to have passed the requirement specified in Table 1 if the blank reading 
does not differ from the sample reading by more than 0.1 ml.   
8 © UNBS 202 2 – All rights reserved  
 Annex C  
(normative)  
 
 Determination of organic acids  
C.1  Reagents  
C.1.1   Dilute rectified spirit, prepared by diluting one volume of 95 % rectified spirit with two volumes of 
water, and neutralized to phenolphthalein indicator  
C.1.2   Phenolphthalein indicator, same as in B.1.5  
C.1.3   Standard sodium hydroxide  solution, exactly 0.1 mol/L  
C.2  Procedure  
C.2.1   Add 100 ml of dilute rectified spirit to 20 g of the sample, agitate thoroughly, and heat to boiling. Add 1 
ml of phenolphthalein indicator and titrate rapidly with standard sodium hydroxide solution with vigo rous 
agitation to a sharp pink endpoint in the alcohol water layer.  
C.2.2   The material shall be taken to have passed the test if not more than 1 ml of standard sodium 
hydroxide solution is required for the titration  DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  9 
 Annex D  
(normative)   
 
Determination of sulphated ash  
D.1 Reagents  
Dilute sulphuric acid, approximately 2.5 mol/L  
D.2 Procedure  
Heat a platinum dish to redness for 10 min; allow to cool in a desiccator and weigh. Place 1 g of the sample in 
the dish, moisten with sulphuric acid, and ignite gently by means of a Bu nsen burner. Again, moisten with 
sulphuric acid and ignite at about 800 °C in a muffle furnace. Cool and weigh. Again, ignite for 15 min and 
repeat this procedure until two successive weighings do not differ by more than 0.5 mg.  
D.3 Calculation  
Sulphated a sh, expressed as percent by mass, shall be calculated using the formula below:  
 
where  
m1  is the mass, in grams, of the residue; and  
m2  is the mass, in grams, of the sample taken for the test   
10 © UNBS 202 2 – All rights reserved  
 Annex E  
(normative)  
 
 Determina tion of sulphur and sulphides  
E.1 Reagents  
Copper strips, 1 cm in width, and freshly polished  
E.2  Procedure  
E.2.1  Melt in a beaker about 100 g of the sample and keep on a water bath at a temperature of 95 °C. Then 
place a strip of copper in the melted samp le so that it is partially immersed in it and allow to remain for 10 min.  
E.2.2  The material shall be taken to have passed the test if the copper strip used in the test shows no 
tarnishing when compared with another freshly polished copper strip.  DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  11 
 Annex F  
(normative)   
 
Determination of iodine value  
F.1  Apparatus  
Thermometer, an engraved stem thermometer, calibrated between 10 °C and 65 °C in 0.1 -degree intervals 
and with the 0 °C point marked on the steam is recommended. The thermometer shall have an auxiliary 
reservoir at the upper end, and length of about 370 mm and diameter of about 6 mm.  
F.2  Reagents  
F.2.1  Carbon tetrachloride or chloroform  
F.2.2   Acetic acid, glacial, 99 %, having a melting point of 14.8 °C and free from reducing impurities. 
Determ ine the melting point of the acetic acid in accordance with F.2.2.1 and test it for reducing impurities in 
accordance with F.2.2.2.  
F.2.2.1   For the melting point determination, take a 15 -cm long test tube and fill it to about two thirds with 
the acetic aci d. Insert into the acid a thermometer complying with the requirements specified in F.1 through a 
cork stopper fitting the test tube. The amount of acid should be at least double the quantity required to cover 
the bulb of the thermometer when the bottom of the latter is 12 mm from the bottom of the test tube. Suspend 
this tube within a larger test tube through a cork. Cool the acid by immersing the assembly in ice water until 
the temperature is 10 °C, then withdraw the assembly from the ice water and stir th e acid rather vigorously for 
a few moments, thus causing the super -cooled liquid to crystallize partially and give a mixture of liquid and 
solid acid. Take thermometer readings every 15 s and consider the temperature at which the reading remains 
constant f or at least 2 min as the true melting point.  
F.2.2.2   For the determination of reducing impurities (potassium permanganate test), dilute 2 ml of acetic 
acid with 10 ml of water and add 0.1 ml of 0.5 mol/L potassium permanganate solution and maintain at 27 ° C 
± 2 °C. The test shall be taken as having been satisfied if the pink colour is not discharged at the end of 2 h.  
F.2.3   Potassium dichromate, finely ground  
F.2.4   Starch solution; mix 5 g of starch and 0.01 g of mercuric iodide with 30 ml of cold water and  slowly 
pour it while stirring into 1 L of boiling water. Boil for 3 min. Allow the solution to cool and decant off the 
supernatant clear liquid.  
F.2.5   Standard sodium thiosulfate solution, 0.2 mol/L  
F.2.6   Chlorine gas, dry  
F.2.7   Iodine trichloride  
F.2.8   Wijs iodine monochloride solution; prepare this solution by one of the following methods, and store in 
a glass stoppered bottle in a cool place, protected from light and sealed with paraffin until taken for use:  
a)  dissolve 3 g of re -sublimed iodine in 1 L of acetic acid, using gentle heat if necessary, and determine the 
length by titration with standard sodium thiosulfate solution. Set aside 50 ml - 100 ml of solution and 
introduce washed and dried chlorine gas into the remainder until the characteristic co lour change occurs 
and the halogen content is nearly doubled as ascertained again by titration. If the halogen  content has  
12 © UNBS 202 2 – All rights reserved  
 been more than doubled, reduce it by adding the requisite quantity of the iodine -acetic acid solution. A 
slightly excess of iodine doe s not harm, but avoid an excess of chlorine.  
Example, if the titration of 20 ml of original iodine -acetic acid solution requires 22 ml of standard sodium 
thiosulfate solution, then 20 ml of the finished Wijs solution should require between 43 ml and 44 ml (and not 
more than 44 ml) of the same sodium thiosulfate.  
b)  as an alternative method of preparing Wijs solution, dissolve 8 g of iodine trichloride in approximately 450 
ml of acetic acid. Dissolve separately 9 g of iodine in 450 ml, of acetic acid using h eat if necessary. Add 
gradually the iodine solution to the iodine trichloride solution until the colour has changed to reddish 
brown. Add 50 ml more of iodine solution and dilute the mixture with acetic acid till 10 ml of the mixture 
are equivalent to 20 m l standard sodium thiosulfate solution when the halogen content is estimated by 
titration in the presence of an excess to potassium iodine and water. Heat the solution at 100 °C for 20 
min and cool. Prevent access of water vapour in preparing the solution.  
F.3  Procedure  
F.3.1   Melt the material and filter through the filter paper to remove any impurities and the last trace of 
moisture. Make sure that the glass apparatus used is absolutely clean and dry. Weigh accurately by 
difference, about 10 g of the sampl e, into a clean, dry 500 -ml glass stoppered bottle to which 25 ml of carbon 
tetrachloride or chloroform have been added, and agitate to dissolve the contents. Add 25 ml of Wijs solution 
(the quantity of Wijs solution added is 50 % - 60 % more than the quan tity required).  
F.3.2   Replace the glass stopper after wetting with potassium iodine solution, swirl for intimate mixing, and 
allow to stand in the dark for 45 min. Carry out a blank test simultaneously under similar experimental 
conditions. After standing,  add 15 ml of potassium iodide solution and 100 ml of water, and titrate the liberated 
iodine with standard sodium thiosulfate solution, swirling the contents of the bottle continuously to avoid any 
local excess, until the colour of the solution is straw y ellow. Add 0.5 ml of starch solution and continue the 
titration until the blue colour disappears.  
F.4  Calculation  
The Iodine value, expressed in Wijs, shall be calculated using the formula below:  
 
 
where  
V1  is the volume, in millilitres, of standard sodium t hiosulfate, required for the blank;  
V2  is the volume, in millilitres, of standard sodium thiosulfate solution, required for the material;  
M  is the molarity, of standard sodium thiosulphate; and  
m  is the mass, in grams, of the material taken for the test.  DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  13 
 Annex  G 
(normative)  
 
Determination of DEET content  
G.1 General  
The sample is dissolved in carbon disulfide and the difference in absorbance at 14.18 μm and at 14.48 μm is 
determined. The quantity of meta -isomer is obtained from this value by means of a calibration curve prepared 
by the use of a reference stand ard 
G.2 Apparatus  
G.2.1 Double -beam infrared spectrophotometer. Perkin -Elmer model 21 or equivalent  
G.2.2 Two equivalent infrared absorption cells, with sodium chloride windows and a path length of 
approximately 0.4 mm.  
G.3 Preparation of calibration curve  
G.3.1 Weigh (to the nearest 0.1 mg) into four volumetric flasks sufficient amounts of the reference DEET 
standard of known purity to give concentrations of approximately 20, 40, 60 and 80 g/L when dissolved in 
carbon disulfide . 
G.3.2 Fill the reference ce ll with carbon disulfide and the sample cell with each of  the standard solutions in 
turn, and record the spectra. The spectrum may be scanned rapidly, except for the region 12 – 15 μm, where 
a normal speed should be used. Carry out a blank measurement with carbon disulfide to correct for any 
inequality in the pa ired cells and to determine whether a cell correction is required . 
G.3.3 Measure the absorbance at 14.18 μm and at 14.48 μm and calculate the difference between these 
values, ΔA, for each of the solutions. Plot the values of ΔA against the concentration (g /L) of the meta -isomer.  
G.3.4 If a cell correction is required, the value of ΔA is determined from the formula:  
ΔA = [A14.18 – A14.48]ref. - [A14.48]blank  
Where ref. = determination with reference standard  
blank = determination on CS2 blank  
G.4 Procedure  
Weigh (to the nearest 0.1 mg)  about 0.5 g of the sample, transfer quantitatively to a 10 mL volumetric flask, 
and make up to the mark with carbon disulfide. Measure the infrared absorption at 14.18 μm and 14.48 μm 
using the same conditions as described in c lauseA.3. Determine the concentration of meta -isomer by 
comparing this value with the calibration curve. A standard sample should be run each day to check the 
calibration of the instrument.   
14 © UNBS 202 2 – All rights reserved  
 G.5 Calculation  
DEET content (g/kg) =  (𝐶1 𝑥 𝑃)/𝐶2 
where,  
C1 = concentration (g/L) of standard DEET found from calibration curve  
C2 = concentration (g/L) of sample taken  
P = purity (g/kg) of the reference standard  
  
  DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  15 
 Annex H 
(normative)  
 
 Determination of total pyrethrins  
H.1  General  
The active ingredients in pyr ethrum extract may be determined using a HPLC system first by injecting a 
solution of the analyte into the chromatograph, followed by the separation and comparison of peaks areas of 
the analytes in the sample with that of an external standard containing a known amount of the analytes. The 
peaks are eluted in the following order: Cinerin II, Pyrethrin II, Jasmolin II (total Pyrethrins II) and Cinerin I, 
Pyrethrin I, Jasmolin I (total Pyrethrins I).  
H.2  Reagents  
H.2.1 World pyrethrum standard, 50 %  
H.2.2 Acetonitrile, HPLC grade  
H.2.3 Water, HPLC grade  
H.3  Apparatus  
A liquid chromatography  System equipped with an auto -sampler, a Variable Wavelength Detector (or 
equivalent) and a Column {Phenomenex, 250 x 4.6 mm Luna Phenyl -Hexyl 5μ Reverse Phase (or 
equivalent)}.  
H.4  Operating conditions  
H.4.1 Flow rate: 1.5 ml/min  
H.4.2 Composition: 40 :60 (%, v/v water/acetonitrile)  
H.4.3 Elution: Isocratic  
H.4.4 Oven temperature: 40 ºC  
H.4.5 Wavelength: 240 nm  
H.4.6 Injection Volume: 15 µl  
H.4.7 Stop time: 22 min  
H.4.8 Post time: 1 min  
H.5  Preparation of the standard  
Weigh 20 mg of the pyrethru m standard to the nearest 0.0001 g in a 100 mL volumetric flask and dilute to 
volume with Acetonitrile and label it. Transfer a small portion to a sample vial and label it accordingly.   
16 © UNBS 202 2 – All rights reserved  
 H.6  Sample preparation  
In a 100 ml volumetric flask, weigh 20 mg to the nearest 0.0001 g of the sample to be analyzed and dilute to 
volume with Acetonitrile. Sample this solution using a vial and label it accordingly.  
H.7  Procedure  
After the chromatograph is stable, make a minimum of three injections for the standard sol ution as well as for 
the analyte and average the area counts. The relative Standard Deviation between injections should be within 
2 %. 
H.8  Calculation of the % total pyrethrins (active ingredient)  
The % Total Pyrethrins is calculated as follow:  
% 𝑎𝑐𝑡𝑖𝑣𝑒  𝑖𝑛𝑔𝑟𝑒𝑑𝑖𝑒𝑛𝑡𝑠  = (𝐴𝑣𝑒𝑟𝑎𝑔𝑒  𝑠𝑎𝑚𝑝𝑙𝑒  𝑎𝑟𝑒𝑎  𝑋 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑  𝑋 𝑃𝑢𝑟𝑖𝑡𝑦  𝑜𝑓 𝑡ℎ𝑒 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑  (𝑖𝑛 %)) ÷ 
(𝐴𝑣𝑒𝑟𝑎𝑔𝑒  𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑  𝑎𝑟𝑒𝑎 𝑋 𝑊𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑠𝑎𝑚𝑝𝑙𝑒 .) 
 DUS  2296 -6: 202 2 
© UNBS 202 2 – All rights reserved  17 
 Bibliogra phy 
[1] Product Performance Test Guidelines. OPPTS 810.3700: Insect Repellents to be applied to human 
Skin 
[2]  DEAS 126: 2021 , Petroleum jelly for cosmetic use — Specification  
[3] RS 191: 2019, Refined pyrethrum concentrate — Specification  
 
  DUS  2296 -6: 202 2 
© UNBS 2022 – All rights reserved  19 
 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 testi ng 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 obtai ned from the Director, Uganda 
National Bureau of Standards.  
 
   DUS 2296 -6: 202 2  
 
ICS 71.100.70  
Price based on nn pages  
© UNBS 202 2– All rights reserved