Medela pump kits available in my hospital are packaged sterile. I feel comfortable using them with no further innitial treatment. Those available in my community (purchased outside of hospital) are packaged as "clean". It is difficult as a practitioner outside of hospital to obtain the sterile kits and they are more expenisve. In the case of the "clean" kit, I feel the instructions to boil first are best followed. In the case of the sterile kit I feel perfectly comfortable telling the mom the innitial boiling step called for in the instructions can be disregarded. Note the same instruction manual comes in both types of kit packages. Carla (hospital based LC, in Maryland)