Reference number  
DRS 406: 2019  
© RSB 2019  
 
 
 RWANDA 
STANDARD  DRS 
406 
 
First edition  
2019 -mm-dd 
 
Pesticide — Terminology  
 
  DRS 406: 2019  
©RSB 2019  - 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 2019  
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 
prior written permission from R SB. 
Requests for permission to reprodu ce this document should be addressed to : 
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E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw   
ePortal: www.portal.rsb.gov.rw   DRS 406: 2019  
iii                ©RSB 2019  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Term inology  ................................ ................................ ................................ ................................ ...........  1 
 DRS 406: 2019  
©RSB 2019  - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepared  by Technical Committees and approved by Rwanda 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 standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards 
adop ted by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and 
gazettment as Rwanda Standards.  
DRS 406 was prepared by Technical Committee RSB/TC 024, Chemicals and consumer Products . 
In the preparation of this standard, reference was made to the following standard:  
ES 693: Pesticides – Terminology  
The assistance de rived from the above source is hereby acknowledged with thanks.  
Committee membership  
The following organizations were represented on the Technical Committee on  Chemicals and Consumer 
Products (RSB/TC 024) in the preparation of this standard.  
Star Construction and Consultancy (SCC) Ltd  
University of Rwanda/College of Science and Technology (UR/CST)  
HORIZON/SOPYRWA Ltd  
University of Rwanda/College of Education  
AGR OPY Ltd  
Rwanda  Standards Board  (RSB) – Secretariat  
  DRS 406: 2019  
1                ©RSB 2019  - All rights reserved  
 Pesticides  — Terminology   
1 Scope   
This Draft Rwanda Standard defines the fundamental terms used in pesticides and related products.  
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 doc ument.  For dated references, only the edition  cited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies.  
There are no normative references in this  document . 
3 Term inology  
3.1 
abrasiveness  
measure of wear of a surface by moving solids  
3.2 
acaricide  
chemical used for killing mites and thicks (acarina) as distinct from insects  
3.3 
acarina  
mites and ticks  
3.4 
acid equivalent  
the total organic acid content expressed in terms of the active acid  
3.5 
active ingredient  
the biologically active part of the pesticide formulation   
©RSB 2019  - All rights reserved                  2 
 3.6 
additive  
any substance added to the active ingredient to improve its performance  
3.7 
adjuvant  
see formulant  
3.8 
aerosol  
a dispersion of liquid particles, the majority of which are between 0.1 and 0.5 µm diameter, in air or other gas.  
3.9 
aerosol dispensers  
a device which dispenses an aerosol  
3.10 
agglomerate (see also granule, pellet, rod, tablet)  
particles bound firmly together (see lump)  
NOTE 1 : This covers coated or impregnated or particles.  
3.11 
aggregate  
particles adhering loosely together (see lump)  
3.12 
arboricide  
a chemical for killing trees and shrubs  
3.13 
avicide  
a chemical for killing birds  DRS 406: 2019  
3                ©RSB 2019  - All rights reserved  
 3.14 
bactericide  
a chemical for killing bacteria  
3.15 
batch  
the material produced in a single series of operations by a non -continuous process  
3.16 
biological compatibility  
a mixture of chemicals (formulations) which, under defined conditions, retains the activity claimed for each 
separately and does not have any unwan ted biological effect when used.  
3.17 
blend  
a homogeneous mixture of two or more batches  
3.18 
bridging  
formulation of arches of keyed, or jammed material, impending the flow of particles  
3.19 
brush killer  
a chemical for killing brush wood  
3.20 
bulk density  
see density  
3.21 
carrier or filler  
an inert formulant added to facilitate uniform distribution of a formulation when used   
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 3.22 
chemical compatibility  
no appreciable unwanted chemical reaction between one chemical and/or formulation and another  
3.23 
chlorosis  
reduction in green chlorophyll content resulting in yellowing of leaves  
3.24 
classification of powders  
separation of the particles of a powder based on physical characteristics  
3.25 
compatible chemicals  
chemicals (including formulations, etc; not e 2) which are chemically , physically and biologically compatible  
NOTE 2:  Corrosion of the containers by a product and/or the container affecting the product adversely are special 
aspects of incompatibility.  
3.26 
compatibility agent  
a substance which impro ves compatibility  
3.27 
contact herbicide  
a herbicide toxic to the treated parts of the plant  
3.28 
cream (of emulsions)  
any creamy layer that separates at the top or bottom of an emulsion  
3.29 
defoliant  
a chemical which causes leaf fall  DRS 406: 2019  
5                ©RSB 2019  - All rights reserved  
 3.30 
density  
the mass of substance occupying unit volume at a stated temperature (note 3)  
NOTE 3:  When reporting the density of a solid or liquid the units of mass and volume used must all be explicitly stated, 
e.g. grams per millilitre at t ºC (d). Unless otherwise stated  density shall refer to mass in grams per millilitre at 20 ºC. 
3.31 
density, bulk (of a powder)  
density determined under stated conditions of free pouring  
3.32 
density, tap (of a powder)  
density determined under compaction caused by tapping without additio nal pressure  
3.33 
desiccant (of crops)  
a chemical for dehydrating foliage of plants  
3.34 
dispersible powder  
a powder intended for dispersion in a liquid  
3.35 
water dispersible powder  
a fine powder for dispersing in water  
3.36 
oil dispersible powder  
a fine powder for dispersing in oil  
3.37 
dispersibility  
the ease with which a substance is dispersed uniformly in a fluid   
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 3.38 
dormant spray  
a spray applied to dormant plants  
3.39 
dressing seed  
the process of treating seeds with pesticides  
3.40 
dust  
a fine powder, usually airborne, which can settle  
3.41 
dust concentrate  
a powder intended for further formulation before use as a dustable powder  
3.42 
dustable powder fine (note 6)  
a powder of particles smaller than 45 µm in diameter intended for dry application  
3.43 
coarse (note 4)  
a powder of particles betwees 45 and 90 µm diameter intended for dry application  
NOTE 4:  It is proposed that, in normal cases of materials of mixed particle sizes, the classification should refer to the 
major proportion by weight falli ng within the specified size range.  
3.44 
emulsifiable concentrate  
a solution which forms an emulsion on mixing with water  
3.45 
emulsion  
the mixture of water and a liquid in which the liquid is dispersed in water  DRS 406: 2019  
7                ©RSB 2019  - All rights reserved  
 3.46 
invert emulsion  
an emulsion of water in  oil 
3.47 
epinasty  
curling of leaves downwards  
3.48 
eradicant  
a pesticide which will eradicate pests  
3.49 
extractable acids  
total organic acids extractable from a formulation (note 5)  
NOTE 5:  After conversion, where necessary, of a salt, amine, ester, etc,  to the parent acids.  
3.50 
filler  
see carrier  
3.51 
fines  
solid particles smaller than a specified size  
3.52 
flammable  
readily ignitable. See highly flammable liquid  
3.53 
flammable liquid  
a liquid of flash point of 21 ºC or more bur less than 55 ºC (note 6)   
©RSB 2019  - All rights reserved                  8 
 NOTE 6:  An EC Directive on Classification and labelling of Dangerous Substances, which includes a number of pure 
substances marketed as pesticides, has been adopted. There is also a Directive in draft on labelling of pesticide 
formulations. In both these documents the definitions of highly flammable and flammable liquids are those given above.  
3.54 
flash point  
the lowest temperature at which a material forms a flammable vapour/air mixture under standards conditions  
3.55 
flocculation  
joining together of par ticles in suspension  
3.56 
flowability of solids  
ability to flow under stated conditions  
3.57 
formulant  
any added material in a formulation other than the biologically active ingredients (s)  
3.58 
formulation  
active ingredient(s) plus formulant(s)  
3.59 
friab ility of solids  
the crumbling properties of solids  
3.60 
fumigant  
a material volatilized in air for the control of pests and/or diseases  
3.61 
fungicide  
a chemical for killing fungal spores and/or mycelium  DRS 406: 2019  
9                ©RSB 2019  - All rights reserved  
 3.62 
fungistat  
a chemical which inhibits the growth of fungi without killing them  
3.63 
granules  
agglomerates, or coated or impregnated lumps, or particles defined by size  
3.64 
grindability  
the ease with which a material may be broken down by mechanical means  
3.65 
grit 
hard non -friable particles present in a  material  
3.66 
plant growth regulator  
a chemical for regulating plant growth  
3.67 
haulm killer  
a chemical for killing off plant tops to facilitate harvest  
3.68 
herbicide  
a chemical for killing weeds  
3.69 
highly flammable liquid  
a liquid of flash point less  than 21 ºC (note 7). See also flammable liquid  
NOTE 7:  An EC Directive on classification and Labelling of Dangerous Substances, which includes a number of pure 
substances marketed as pesticides, has been adopted. There is also a Directive in draft on labelling of pesticide 
formulations. In both these documents the definitions of highly flammable liquids are those given above.   
©RSB 2019  - All rights reserved                  10 
 3.70 
Incompatible substances  
substances whose useful properties are adversely affected when mixed together (see compatible subst ances)  
3.71 
inflammable  
synonym for flammable (cf)  
3.72 
insecticide  
a chemical for killing insects  
3.73 
Invert emulsion  
see emulsion  
3.74 
LD50 
the lethal dosage that kills 50% of the test organisms  
3.75 
lump  
mass of solid matter without regular shape  
3.76 
molluscicide  
a chemical for killing slugs and snails  
3.77 
nematicide  
a chemical for killing nematodes, e.g.: eelworms  DRS 406: 2019  
11                ©RSB 2019  - All rights reserved  
 3.78 
non-flammable  
not readily ignitable, e.g. with a flash point over 55 ºC 
3.79 
oversize  
particle s of a solid material larger than a specified size  
3.80 
ovicide  
a chemical for killing eggs  
3.81 
pellet  
an agglomerate which is approximately spherical, avoid or cylindrical with no dimension less than 2 mm  
3.82 
pest 
any animal (or) plant causing harm or damage to man, his animals, or his pl ants 
3.83 
pesticide  
a chemical for killing pests  
3.84 
physical compatibility  
a mixture of chemicals (including formulations) which under defined conditions, has satisfactory physical 
properties for the intended use  
3.85 
phytotoxicity  
chemical damage to a p lant  
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 3.86 
post-emergence  herbicide  
a selective herbicide applied after the crop emerges  
3.87 
powder (note 8)  
solid particles  up to 250 µm in diameter (not an agglomerate q.v)  
NOTE 8:  It is proposed that, in normal cases of materials of mixed particle sizes, the classification should refer to the 
major proportion by weight falling within the specified size range.  
3.88 
pour point  
the minimum temperature at which a material will flow under specified conditions  
3.89 
pre-emergence herbicide  
a selective herb icide applied after the crop is sown but before it emerges  
3.90 
prill 
a spherical solidified droplet formed by rapid cooling of an anhydrous molten mixture  
3.91 
protectant  
a substance which protects the surface of an organism against infection or infestati on 
3.92 
rain fastness  
the proportion of a pesticide residue remaining on a treated surface after exposure to a specified spray of 
water  
3.93 
repeat treatment  
a treatment which follows an identical treatment on the same site  DRS 406: 2019  
13                ©RSB 2019  - All rights reserved  
 3.94 
rod 
a cylindrical agglomerate, minimum diameter 1.5 mm, length greater than its diameter  
3.95 
run-off 
the quantity of spray which runs off a unit area of plant surface  
3.96 
sedimentation  
fall of particles in a continuous medium  
3.97 
seed dressing  
see dressing seed  
3.98 
seed treatment ( formerly seed dressing cf)  
the process of coating or impregnating seeds with a pesticide  
3.99 
Sequential treatment  
a treatment followed by any other on the same site (c/f repeat treatment)  
3.100  
sieving  
separation of particles in accordance  with their size by sieves  
3.101  
size distribution  
the distribution of the particles of a solid material amongst a given series of size ranges   
©RSB 2019  - All rights reserved                  14 
 3.102  
size fraction  
portion of a material between two given size limits expressed in terms of weight, volume, or numerical 
frequency  
3.103  
size range  
lower and upper limits in size of a solid  
3.104  
smoke  
a visible cloud of airborne  particles (1 to 5 µm) which is generated by combustion or heat  
3.105  
soil-acting herbicide  
a herbicide applied to the soil to control weeds  
3.106  
soil sterilant  
a pesticide applied to the soil to kill soil flora and fauna  
3.107  
solution  
a single phase liquid system (note 9)  
NOTE 9:  This is fully miscible with water when intended for aqueous dilution.  
3.108  
spray  
to apply a liquid in the form of droplets suspended in air  
3.109  
coarse spray  
a dispersion of drops of mass volume diameter (note 10) over 500 µm DRS 406: 2019  
15                ©RSB 2019  - All rights reserved  
 NOTE 10:  Mass volume diameter (m.v.d) has been used in preference to mass median diameter (m.m.d.). The diference 
will be negligible un less evaporation is significant, but in practice it is the m.v.d. which is measured.  
3.110  
medium spray  
a dispersion of drops of 200 to 500 µm mass volume diameter  
3.111  
fine spray  
a dis persion of drops 100 to 200 µm mass volume diameter  
3.112  
very fine spray  
a dispersion of drops 30 to 100 µm mass volume diameter  
3.113  
aerosol  
a dispersion of drops below 30 µm mass volume diameter  
3.114  
spray concentrate  
an undiluted preparation  
Terms (note 11) Bushes and trees l/ha  
(litre oer hectar)  Ground crops l/ha  
(litre per hectar)  
High volume spray  More than 1000  More than 700  
Medium volume spray  500 to 1000  200 to 700  
Low volume spray  200 to 500  50 to 200  
Very low volume spray  20 to 200  5 to 50  
Ultra low volume spray  Less than 20  Less than 5  
 
NOTE 11:  These definitions are based on suggestions originally made by Dr. Johnstone of the Ministry of Overseas 
Development, Centre for Over Seas Pest Research and Subsequently modified by EPPO (European Plant Protection 
organization). Only a rough guideline can b e given since the exact volume necessary in particular crops depends on 
growth stage and development, as well as the specific properties of the pesticide being applied and the application 
equipment available. The volume may be exceeded in certain cases.   
©RSB 2019  - All rights reserved                  16 
 3.115 
sticker  
a material, which increase the retention of a product, applied to a surface  
3.116  
surfactant  
a material for reducing inter -facial tension  
3.117  
suspensibility  
the amount of solid, which retains suspended after a given time in a column of a specified liquid, of stated 
height, under specified conditions (note 12)  
NOTE 12:  It is expressed as a percentage of the amount of active ingredient (and /or carrier) in the original suspension.  
3.118  
suspension concentrate  
a stable suspension of active ing redients in a fluid intended for dilution before use)  
3.119  
synergist  
a chemical with relatively low biological activity which significantly increases the biological activity of another 
active ingredient  
3.120  
systematic (pesticide)  
a (pesticide, etc.) whi ch, when applied to an organism, moves internally within it to produce the desired 
activity. (see translocated herbicides)  
NOTE 13:  Other terms can be used in stead of pesticide, e.g., fungicide.  
3.121  
tablets  
agglomerates of uniform shape and dimensions, u sually circular, with either flat or curved faces, the distance 
between faces being less than the diameter  DRS 406: 2019  
17                ©RSB 2019  - All rights reserved  
 3.122  
tank mix  
the mixing by the operator of chemicals (and/or formulations) in the spray tank  
3.123  
Tape density  
see density  
3.124  
technical material  
the unformulated active ingredient  
3.125  
tolerance  
permitted limits of variation from a given value  
3.126  
total herbicide  
a herbicide used in such a way as to kill all vegetation  
3.127  
translocated herbicide  
a herbicide which, when absorbed by a p lant, moves within it (see systemic pesticide)  
3.128  
undersize  
particles smaller than a specified size  
3.129  
water -soluble powder  
a powder readily soluble in water at the recommended concentration for use  
NOTE 14:  There may be a small amount of insoluble m aterial.   
©RSB 2019  - All rights reserved                  18 
 3.130  
wettable powder  
see dispersible powder  
3.131  
wetter or wetting agent  
a chemical which improves wetting properties of a chemical or formulation  
 
  DRS 406: 2019  
ICS 65.100.01  
 
 
©RSB 2019  - All right s reserved