Dethlac Insecticidal Lacquer is for amateur use against ants, cockroaches, woodlice and other crawling insects. For both indoor and outdoor use in domestic premises. Dethlac has been eliminating insects effectively since 1959; trusted for over 50 years. Dethlac dries to a hard clear film which kills insects within a few hours of coming into contact with treated surfaces. One application remains fully effective for months, even when it rains. You can wash the surface (with or without detergents) and Dethlac will go on killing insects. Dethlac is not designed as a space spray, it is a surface spray (spot, band and crack and crevice treatment) and may be applied to any hard non-porous surface ie. on doors, window frames (not UPVC), skirting boards, shelves, concrete patios etc. It should not be sprayed onto wallpaper, fabrics, furniture or matt surfaces.