the filling mandrel unit is lifted off, and the head mold hermetically seals the container. Simultaneously, the head contour is formed by vacuum. In the last step, the mold opens and the finished container leaves the mold. One process cycle takes a few seconds. The process speed and thus process output largely depends upon the BFS container size and the BFS machinery dimensioning. For instance, in the early 2000s, Rommelag's 3012, 305, and 4010 M machines had outputs of approximately 4000, 8000, or 20,000 containers per hour. These machines have been succeeded by the Rommelag 312, 321, 360, 364 and 460 machines with output ranges of up to 35,000 containers per hour. Sterility requirements The BFS processes is an aseptic filling process, which produces sterile products and thus needs to be sterile. Aseptic BFS machines must be designed in a way that prevents extraneous contamination. Thus, rotary-type BFS machines are placed in classified areas same as shuttle-type BFS machines (open parison), which have a cleanroom shroud grade-A-compliant provided with sterilised air and kept under overpressure. Automatic SIP programs are used to sterilise the BFS equipment and this avoids human interventions. Due to automatic start up and filling processes BFS machines require no human interaction during the actual BFS process. However, certain adjustments or interventions need to be carried out by personnel. Both particle and microbiological contamination monitoring are required in a BFS machine environment, as well as routine CIP/SIP processes. BFS machines are typically fitted with several different sterilising air filtration systems for the buffer air, support parison air and air shroud grade A air (if needed for shuttle machines, e. g. open parison type ones). Typically, the air is sterilised by filtration systems that have automatic filter integrity testing installed (i. e. automatic water intrusion or particle testing). The air systems are typically integrated into the SIP cycle of the BFS machine. BFS material The materials used in BFS packaging are usually polyolefins, mainly polyethylene (LDPE or HDPE), and polypropylene (PP). These materials are robust and inert to ensure sterility and tightness during the product's shelf life. Diffusion tendencies can be reduced by using virgin polymers, but diffusion cannot be prevented entirely. This is due to the nature of polyolefins and their additives, if present. Several polyethylene suppliers have developed special EP or USP grade resin for BFS containers. Permeation into BFS containers and water loss may be an