The Rentokil wasp nest powder is for use on wasp nests around the home and garden. It kills wasps in the nest using the acutely toxic insecticide Bendiocarb and is effective within 24 hours.
If wasps do nest around your home using such a nest killer is necessary for your safety, as wasps are easily aggravated and can be dangerous to those who have a reaction to their stings.
The powder is best deployed on to the nest using a tube, be careful not to inhale or touch the powder yourself. The powder is highly toxic to wasps and you will see immediate effects.