Up to four 1kg containers of a chemical called 'Silicagel 60A for flash chromatography' were taken from a laboratory environment in the Malone Road area on Thursday at about 11.40am.The substance, in its dry form, is an extremely fine white powder. If inhaled, it has the potential to cause harm to the lungs.The PSNI wants anyone to contact them if they come across the containers, which may have a blue, red or white lids and small white rectangular labels on the front.A statement from the PSNI said: "Police would take this opportunity to again warn members of the public:Do not take controlled drugs.Do not take prescription medication that has not been prescribed for you.Do not mix either with alcohol."The consequences of ignoring this advice are extremely dangerous and potentially life-threatening."The statement continued: "Police would ask anyone who may be aware of the location of these containers of chemicals to contact police on 101."Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111."