The outer black layer is made from virgin premium quality l.l.d.p.e. The inner white layer of the tank, made from titanium di oxide, is safe and hygienic as any dirt in it is clearly visible. Both the layers of the tank are made from food grade quality material. The weight of the tank is equal to the weight of l.l.d.p.e. Material used. No fillers are used while manufacturing the tank. This gives the tank superior wall thickness that ensures no bulging of the tank.