Agriculture Reference
In-Depth Information
Figure 4.3
Bulk container showing labels indicating an emulsifiable concen-
trate with a flammable carrier solution.
Emulsifiable concentrates are not abrasive and won't separate when the
sprayer isn't running. The solvents in emulsifiable concentrates may cause
rubber hoses, gaskets, and pump parts to deteriorate rapidly unless they are
made of neoprene rubber or more resistant materials.
2.
Wettable Powders
Wettable powders (WP or W) are finely divided, relatively insoluble pow-
ders. The active ingredients are combined with a dry diluent (inert carrier) such
as clay, talc, or silica and with wetting agents (surfactants) and/or dispersing
agents. Without the wetting agent, the powder would float when added to wa-
ter, and the two would be almost impossible to mix. The formulated product
normally contains 15% to 95% active ingredient; usually 25% or more. Wet-
table powders form a suspension rather than a true solution when added to wa-
ter or liquid fertilizer. Therefore, constant and vigorous agitation is needed in
the spray tank to maintain the suspension because the wettable powder sepa-
rates quickly when the sprayer is turned off.
