MT 15 - Suspensibility of wettable powders in water


Content Handbook F


Outline of method

A suspension of known concentration in Standard Water or distilled water is prepared, placed in a prescribed measuring cylinder at a constant temperature,and allowed to remain undisturbed for the specified time. The top 9/10ths are drawn off and the content of active ingredient in the bottom 1/10th determined, so allowing the content of the top 9/10th to be calculated.



The method is suitable for suspensions containing up to 1% active ingredient but is not necessarily suitable for suspensions of higher concentrations.

15.2 AID (Aid for International Development Programme) method

This method has been successfully used with (i) 75% DDT wettable powders and (ii) malathion wettable powders, at a concentration of 5 g per 100 ml.