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close this bookVector and Pest Control in Refugee Situations (United Nations High Commissioner for Refugees (UNHCR) / Alto Comisionado de Naciones Unidas para los Refugiados (ACNUR), 1997, 124 p.)
View the document(introduction...)
View the documentPreface
View the document1. Introduction
View the document2. Factors influencing the spread of vectors in refugee camps
View the document3. Arthropods of medical importance
Open this folder and view contents4. Mosquitos
Open this folder and view contents5. Non-biting flies
Open this folder and view contents6. Lice
Open this folder and view contents7. Fleas
Open this folder and view contents8. Bed bugs
Open this folder and view contents9. Human scabies mites
Open this folder and view contents10. Ticks
Open this folder and view contents11. Other arthropods of medical importance
Open this folder and view contents12. Snails hosts of schistosomes
Open this folder and view contents13. Commensal rodents
Open this folder and view contents14. Organisation of a control programme
Open this folder and view contents15. Pesticides
Open this folder and view contents16. Safe use of insecticides
View the documentGlossary
View the documentBibliographic selection
View the documentAnnex 1. Some arthropods and their importance to health
View the documentAnnex 2. Morphological characteristics of some arthropods of medical importance
View the documentAnnex 3. Reporting form for spraying operations
View the documentAnnex 4. Calculation of the quantity of solution and insecticide for use in treatments
View the documentAnnex 5. Determination of the insecticide concentration for use in a sprayer
View the documentAnnex 6. Preparation of a solution from an insecticide formulation
View the documentAnnex 7. Preparation of a solution from an emulsifiable concentrate
View the documentAnnex 8. Calculation of the quantity and dilution of insecticide for use in impregnation of fabrics
View the documentAnnex 9. Calculation of the quantity of molluscicide for use in a waterway

Annex 6. Preparation of a solution from an insecticide formulation

In order to prepare a suspension or a solution from a given formulation of a pesticide in wettable powder or emulsifiable concentrate form, the following formula must be applied:

where

X = quantity of formulation necessary
A = desired concentration
B = desired quantity of solution
C = concentration of a.i. in the formulation
D = 1 if X and B are expressed in kg or litres; D=8.33 if X and B are expressed in pounds or US gallons and D=10 if X and B are expressed in pounds or imperial (UK) gallons.

Example:

To obtain 100 litres of a 2.5% solution from an insecticide formulation containing 50% a.i.:

Therefore 5 kg or 5 litres of insecticide formulation have to be mixed with 100 litres of water to obtain the solution at the concentration required for filling the pumps.

N.B. When using powders for suspensions, the powder should be put into a receptacle with a little water, and mixed to obtain a paste. This paste should then be thinned by adding small quantities of water until the desired volume is attained and the resulting mixture poured through a filter into the tank.