ICS 65.100.10  
 
Reference number  
DRS 465 -2: 2021  
© RSB 2021  
  
 RWANDA 
STANDARD  DRS 
465-2 
 
First edition  
2021 -mm-dd 
 
Pyrethrum -based insecticides  — 
Specification  — 
Part 2:  
Grease (GS) for direct application  
   
DRS 465 -2: 2021  
©RSB 2021  - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2021  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
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Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw   DRS 465 -2: 2021  
iii                ©RSB 2021  - All rights reserved  
 Contents  Page 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Requirements  ................................ ................................ ................................ ................................ .........  2 
4.1 General requirements  ................................ ................................ ................................ ...........................  2 
4.2 Specific requirements  ................................ ................................ ................................ ...........................  2 
5 Packaging and labelling ................................ ................................ ................................ ........................  2 
5.1 Pack aging  ................................ ................................ ................................ ................................ ...............  2 
5.2 Labelling  ................................ ................................ ................................ ................................ ...............  23 
6 Sampling  ................................ ................................ ................................ ................................ ................  3 
Annex  A (normative)  Det ermination of total pyrethrins  ................................ ................................ ................  4 
A.1 General  ................................ ................................ ................................ ................................ ...................  4 
A.2 Reagents  ................................ ................................ ................................ ................................ ................  4 
A.3 Apparatus  ................................ ................................ ................................ ................................ ...............  4 
A.4 Operating condit ions ................................ ................................ ................................ ............................  4 
A.5 Preparation of the standard  ................................ ................................ ................................ .................  5 
A.6 Sample preparation  ................................ ................................ ................................ ...............................  5 
A.7 Procedure  ................................ ................................ ................................ ................................ ...............  5 
A.8 Calculation  ................................ ................................ ................................ ................................ .............  5 
Annex  B (normative)  Determination of pH value  ................................ ................................ ...........................  6 
B.1 Outline of the method  ................................ ................................ ................................ ...........................  6 
B.2 Reagents  ................................ ................................ ................................ ................................ ................  6 
B.3 Apparatus  ................................ ................................ ................................ ................................ ...............  6 
B.4 Procedure  ................................ ................................ ................................ ................................ ...............  6 
B.5 pH of aqueous dispersion  ................................ ................................ ................................ ....................  6 
Annex  C (normative)  Determination of melting point  ................................ ................................ ....................  7 
Annex  D (normative)  Determination of sulphated ash  ................................ ................................ ..................  8 
D.1 Reagents  ................................ ................................ ................................ ................................ ................  8 
D.2 Procedure  ................................ ................................ ................................ ................................ ...............  8 
D.3 Calculation  ................................ ................................ ................................ ................................ .............  8 
Annex  E (normative)  Determination of sulphur and sulphides  ................................ ................................ .... 9 
E.1 Principle  ................................ ................................ ................................ ................................ .................  9 
E.2 Apparatus and materials  ................................ ................................ ................................ ......................  9 
E.3 Procedure  ................................ ................................ ................................ ................................ ...............  9 
E.4 Results  ................................ ................................ ................................ ................................ ....................  9 
Annex  F (normative)  Determination of stability  ................................ ................................ ...........................  10 
F.1 Apparatus  ................................ ................................ ................................ ................................ .............  10 
F.2 Procedure  ................................ ................................ ................................ ................................ .............  10 
F.3 Evaluation  ................................ ................................ ................................ ................................ ............  10 
 DRS 465 -2: 2021  
©RSB 2021  - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of sta ndards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards 
adopted by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and 
gazettment as Rwanda Standards.  
DRS 465-2 was prepared by Technical Committee RSB/TC 007, Agrochemicals.  
DRS  465 consists of the following parts, under the general title Pyrethrums -based insecticides — 
Specification : 
 Part 1: Dusting powders (DP)  
 Part 2: Grease (GS)  
Part 3:  Emulsions (Oil in wat er, EW)  
Committee membership  
The following organizations were represented on the Technical Committee on Agrochemicals  (RSB/TC 007)  in 
the preparation of this standard.  
University of Rwanda/College of Sciences and Technology (UR/CST)  
University of Rwanda/College of Education (UR/CE)  
Rwanda Forensic Laboratory (RFL)  
Ministry of Environment (MoE)  
Standards for Sustainability (SfS)  
AGROPY Ltd  
Rwanda Inspectorate, Competition and Consumer Protection Authority (RICA)  
Rwanda Agriculture and Animal Resourc es Development Board (RAB)  
Rwanda  Standards Board  (RSB) – Secretariat  DRS 465 -2: 2021  
v                ©RSB 2021  - All rights reserved  
 Introduction   
A paragraph.  
 
 DRS 465 -2: 2021  
1                ©RSB 2021  - All rights reserved  
 Pyrethrum -based Insecticides — Specification  — Part 2: Grease (GS) for 
direct application  
1 Scope   
This Draft Rwanda Standard prescribes the requirements, sampling and test methods for pyrethrum -based 
grease insecticides for direct application used in animal  protection to control insect pests, including ticks, lice 
and mites.  
2 Normative references   
The following documents are 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 document (including any amendments) applies.  
RS 406 , Pesticides  — Terminology  
RS 191 , Refined pyrethrum concentrate — Specification  
RS 40 5, Pesticides  — Sampling  
3 Terms and definitions   
For the purposes of this standard, the terms and definitions given in RS 406 and the following apply.  
3.1 
pyrethrum  
genus of several Old World plants now classified as Chrysanthemum or Tanacetum (e.g., C. coccineum) 
which are cultivated as ornamentals for their showy flowers heads  
3.2 
pyrethrum concentrate  
extract of the flowers of the plant, Chrysanthemum cinerariaefolium  
3.3 
pyrethrins  
the six naturally occurring isomers that are esters of pyrethric acid and chrysenthemic acid viz: pyrethrin -I, 
pyrethrin -II, cinerin -I, cinerin -II, jasmolin -I, jasmolin -II; having insecticidal property and are extracted from the 
flower of Chrysanthemum cinerariaefolium.   
©RSB 2021  - All rights reserved                  2 
 3.4 
grease (GS)  
very viscous formulation based on oil o r fat 
4 Requirements  
4.1 General requirements  
4.1.1  The product shall consist of a homogeneous mixture of pyrethrum extract, complying with RS 191, 
together with inert carriers such as petrolatum grease and any other necessary formulant.  
4.1.2  The product may co ntain one or more synthetic pyrethroid, but the formulation shall be approved by 
the Competent Authority.  
4.1.3  The product shall be in form of soft, homogenous unctuous mass.  
4.2 Specific requirements  
The product shall comply with specific requirements given in table 1 when tested according to the method 
prescribed therein.  
Table 1 – Specific requirements for pyrethrum -based grease insecticides for direct application  
S/N Parameters  Requirements  Test methods  
i.  Total pyrethrins content, % by mass  0.10 – 2.0 Annex A  
ii.  pH range  5 – 7  Annex B  
iii.  Melting point, °C 45 – 60  Annex C  
iv.  Sulphated ash, % by mass, max.  0.10 Annex D  
v.  Sulphur and sulphide  To pass test  Annex E  
vi.  Stability  To pass test  Annex F  
5 Packaging and labelling  
5.1 Packaging  
5.1.1  The product shall be packaged in a well closed container that will preserve its original characteristics.  
5.1.2  The packaging material shall protect the contents from adventitious contamination under handling 
and storage conditions.  
5.2 Labelling  
The containers shall be closed and  shall bear legibly and indelibly the following information in any of the three 
languages officially accepted in the Republic of Rwanda namely: Kinyarwanda, English and French.  
a) Name of the product;  DRS 465 -2: 2021  
3                ©RSB 2021  - All rights reserved  
 b) Name and address of the manufacturer;  
c) Manufacture and expi ry dates;  
d) Batch number;  
e) Active ingredient (s) contents;  
f) Storage conditions;  
g) Instructions for use;  
h) Precautions and warnings; and  
i) Country of origin.  
6 Sampling  
Representative samples of the product shall be drawn as prescribed in RS 405.  
  
©RSB 2021  - All rights reserved                  4 
 Annex  A 
(normative)  
 
Determination of total pyrethrins  
A.1 General  
The active ingredients in pyrethrum 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 Pyre thrins I).  
A.2 Reagents  
World pyrethrum standard, 50%  
Acetonitrile, HPLC grade  
Water, HPLC grade  
A.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)}.  
A.4 Operating conditions  
Flow rate:    1.5 ml/min  
Composition:    40:60 (%, v/v water/acetonitrile  
Elution:     isocratic  
Oven temperature:  40 °C 
Wavelength:    240 nm  
Injection volume:   15 µl 
Stop time:    22 min  
Post time:    1 min  DRS 465 -2: 2021  
5                ©RSB 2021  - All rights reserved  
 A.5 Preparation of the standard  
Weigh 20 mg of the pyrethrum 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 accordingl y. 
A.6 Sample preparation  
In a 100 ml volumetric flask, weigh 20 mg to the nearest 0.0001 g of the sample to be analysed and dilute to 
volume with Acetonitrile. Sample this solution using a vial and label it accordingly.  
A.7 Procedure  
After the chromatograph is st able, make a minimum of three injections for the standard solution as well as for 
the analyte and average the area counts. The relative Standard Deviation between injections should be within 
2 %. 
A.8 Calculation  
The total pyrethrins is calculated as follow:  
 total pyrethrins ,% m/m=𝐴𝑣𝑒𝑟𝑎𝑔𝑒  𝑠𝑎𝑚𝑝𝑙𝑒  𝑎𝑟𝑒𝑎  𝑋 𝑤𝑒𝑖𝑔 ℎ𝑡 𝑜𝑓 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 ∗𝑃𝑢𝑟𝑖𝑡𝑦  𝑜𝑓 𝑡ℎ𝑒 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑  (𝑖𝑛 %)
𝐴𝑣𝑒𝑟𝑎𝑔𝑒  𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑  𝑎𝑟𝑒𝑎 ∗𝑊𝑒𝑖𝑔 ℎ𝑡 𝑜𝑓 𝑠𝑎𝑚𝑝𝑙𝑒 
 
   
©RSB 2021  - All rights reserved                  6 
 Annex  B 
(normative)  
 
Determination of pH valu e 
B.1 Outline of the method  
The pH value of a liquid is determined by means of pH meter and a glass electrode.  
B.2 Reagents  
B.2.1  Potassium hydrogen phthalate (COOH -C6H4-COOK) 0.05 mol/l (0.05M) – Dissolve 10.21 g in 
freshly boiled distilled water and make up to 1 000 ml. do no keep the solution for longer than one month.  
B.2.2  Disodium tetraborate (Na 2B4O7.10H 2O 0.05M  – Dissolve 19.07 g in freshly boiled distilled water 
and make up to 1000 ml. do no keep the solution for longer than one month.  
B.2.3  Water  – Freshly boiled and cooled distilled water of pH 5.5 to 7.0  
B.3 Apparatus  
B.3.1  pH meter  
B.3.2  Glass electrode and reference electrode  
B.4 Procedure  
Operate the pH meter and electrode system in accordance with the manufacturer’s instructions. Standardize 
the met er and electrodes with the 0.05M phthalate (pH 4.00) when an acid solution is being measured or 
0.05M borate when an alkaline solution is being measured (see Table B1). The reading should not differ by 
more than 0.02 pH units from the original value at whi ch the apparatus was standardized. If the difference is 
greater than 0.05, then repeat the measurements.  
Table B1 – pH values of 
0.05M disodium 
tetraborateTemperature, 
°C 10 15 20 25 30 
pH 9.32 9.28 9.22 9.18 9.14 
B.5 pH of aqueous dispersion  
weigh 1 g of sample, transfer to the measuring cylinder containing water (about 50 ml), make up to 100 ml 
with water, and shake vigorously for 1 min. allow any suspension to settle for 1 min and then measure the pH 
of the supernatant liquid . DRS 465 -2: 2021  
7                ©RSB 2021  - All rights reserved  
 Annex  C 
(normative)  
 
Determination  of melting point  
C.1 Heat a quantity of the sample on a water bath while stirring until it reaches a temperature of 90 °C to 92 
°C. Cool the molten sample to a temperature of 8 °C to 10 °C above the expected melting point. Chill the bulb 
of a thermometer (range 1 °C to 100 °C) to 5 °C, wipe it dry and while it is still cold, dip it into the molten 
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 i t for 5 min into a water bath having a temperature not 
higher than 16 °C.  
C.2 Fix the thermometer prepared in 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 2 °C per minute up to 30 °C, then change the rate of rise to 1 °C per min and note the 
temperature 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 the three as the melting point. If the variation in three determinations is more than 1 °C, make 
two additional determinations and take the average of five.   
©RSB 2021  - All rights reserved                  8 
 Annex  D 
(normative)  
 
Determination of sulphated ash  
D.1 Reagents  
Dilute sulphuric acid, approximately 5 N  
D.2 Procedure  
Heat a porcelain or silica dish of 50 mL to 100 mL capacity to redness; cool in a desiccator and weigh. Place  
about 20 g of t he sample, accurately weighed, in the dish. Heat the dish gently by means of a Bunsen burner  
until the oil can be ignited at the surface. Remove the burner and allow the oil to burn completely, taking care  
that all the free carbon on the sides of the dish is completely burnt. Heat the residue with a strong flame or in a  
muffle furnace until all the carbonaceous matter has disappeared. Cool the dish; add a few drops of dilute  
sulphuric acid; heat gently to drive off the acid and then heat strongly. Cool the dish again in the desiccator  
and weigh it. Repeat the heating, cooling and weighing until constant mass is obtained.  
D.3 Calculation  
The sulphated ash content shall be calculated as follows  
Sulphated ash, % by mass  = 𝑀2− 𝑀1  
𝑀×100 
where  
M1 is the mass in g  of the residue, and  
M2 is the mass in g of the sample taken for the test . DRS 465 -2: 2021  
9                ©RSB 2021  - All rights reserved  
 Annex  E 
(normative)  
 
Determination of sulphur and sulphides  
E.1 Principle  
The presence of sulphur and sulphides in oils is qualitatively determined using copper strips.  
E.2 Apparatus and material s 
E.2.1  Copper strips, 1 cm in width and freshly polished  
E.2.2  Analytical balance, well calibrated and maintained  
E.2.3  Thermostatically controlled water bath, capable of maintaining a temperature of 95 °C  
E.2.4  Stop watch  
E.3 Procedure  
Weigh approximately 50  g of the sample in a beaker and place on a water -bath maintained at temperature of 
95 °C. Place a strip of copper in the sample so that it is partially immersed in it and allow to remain for 10 min.  
E.4 Results  
The sample 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.   
©RSB 2021  - All rights reserved                  10 
 Annex  F 
(normative)  
 
Determination of stability  
F.1 Apparatus  
Ultra violet lamp, with emission at 360 mm  
F.2 Procedure  
Place 50 mL of the material in a  100-ml glass beaker. Turn on the ultra violet lamp and expose the samples at 
a distance of 12 cm - 14 cm below the lamp for 6 h. After the specified time, remove the sample, cool to room 
temperature and compare for any change in odour or colour. The same volume of material shall be employed 
for all tests so that comparison is ensured on a reproducible basis.  
NOTE — The output of the ultra violet lamp diminishes with time in service. A log of number of hours of the 
lamp in use should be maintained. The lamp  is to be replaced after the specified hours of service, as 
recommended by the lamp manufacturer.  
F.3 Evaluation  
Evaluation is done by comparing the test material against an unexposed specimen from the same sample.  DRS 465 -2: 2021  
11                ©RSB 2021  - All rights reserved  
 Bibliography  
[1] ES 757(First edition), Pesti cides — Determination of pH value , 2002  
[2] RS EAS 847 -22, Cosmetics — Analytical methods — Part 22: Determination of sulphur and sulphides 
in oils  
[3] RS EAS 342, Pomades and solid brilliantines — Specification  
 
 DRS 465 -2: 2021  
 
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