Indoor Residual Spraying

Indoor Residual Spraying (IRS) is the technique of applying a residual deposit of an insecticide onto indoor surfaces where arthropod vectors rest.

The primary goal of IRS is to reduce the lifespan of the vectors and thereby reduce or interrupt disease transmission. The secondary impact is to reduce the density of vectors within the treatment area. Indoor residual spraying is a recognised, proven and cost-effective intervention method for malaria control and it is also commonly used in the management of Leishmaniasis and Chagas disease.

Key assumptions within an effective IRS program:

•             there are a high number of sprayable surfaces within each dwelling

•             the target vectors feed and rest indoors

•             the vectors are susceptible to the insecticide which is being applied

•             a large number of dwellings within the target area can be sprayed (usually minimum of 80 percent coverage required)

Other important considerations within an IRS campaign:

•             the safety of the operator, household residents, and the environment

•             the residual efficacy of the product

•             cost effectiveness (which is also related to residual lifespan)

•             the level of acceptance of the product by the residents (e.g. due to odour or staining)


Product Active ingredient Chemical class IRAC*
Application Rate
Mode of action Duration of effective action
Ficam Bendiocarb Carbamate 1A 100 - 400
Acetyl Cholinesterase inhibitor (reversible) 2 - 6 months
K-Othrine WG Deltamethrin Pyrethroid 3A 20 - 25 Sodium channel modulator 4 - 6 months

Learn more about our two main IRS products via the two links here Ficam and K-Othrine WG.