Api-bioxal has been approved by the Veterinary Medicines Directorate and is a fully registered oxalic acid product.  It has an OA concentration of 4.2% giving maximum (95%) efficacy when used in a broodless colony. Application: trickle 5ml into the seam of each brood frame occupied by bees. 50 ml is enough for one colony. You need to bring a container or administer with a Trickle-2 bottle or 50ml Syringe.