Lilly pioneers system for decontamination

Safety management at Eli Lilly, Kinsale, Republic of Ireland, have pioneered the development of a new system for containment and prevention of cross contamination during the manufacture of pharmaceutical powders.

The Lilly facility is a bulk manufacturing plant predominantly producing human health medicines on a large scale, although ingredients for some animal healthcare products are also manufactured. The Kinsale products are shipped to finishing plants around the world where they are converted into final dosage forms such as pills, capsules or injectables. The processes at the plant are designed to be fully contained. However, there are occasions when planned breaks in containment have to be carried out and the new system is designed to cater for these circumstances.

Purpose designed "fog cart" The concept is based on the use of a purpose-designed "fog cart", enabling the operator to be covered by an exceptionally fine fog of water on exit from a critical area. Any residues on the surfaces of the disposable Personal Protection Equipment (PPE) worn by the operator are dampened down and gently encapsulated, so that the PPE can be safely discarded, with virtually no risk of transferring dust traces beyond their proper confines. For process rooms not equipped with permanent decontamination showers, the new system is said to offer a practical alternative that can be set up without disruption and provide high levels of containment and safety at a fraction of the cost of a fixed shower installation. A fleet of 19 fog carts came into full operation in November 2002, which is the result of collaboration between Lilly Kinsale's containment technologist Tony O'Connell – who identified the need and came up with the original concept and design – and spray technology specialist, Spraying Systems, which designed and manufactured the equipment. Certain locations within the production floors are fitted with fixed PPE decontamination showers. For space and operational reasons, with production organised in small discrete areas, this is not practical everywhere. In some locations with no shower, spray mist lances were used to reinforce containment measures, but these had limitations as they required both a water supply and a second operator. Moreover, says Tony O'Connell, the heavy mist they generated tended to leave the floor wet and potentially slippery. Using components supplied by Spraying Systems, a prototype fog cart was designed, built and tested by O'Connell at the site. Spraying Systems was then invited to look at the prototype and to supply a factory build unit. The result of this collaboration was a purpose made fog shower for self-operation by a single person. The cart carries its own supply of water in a removable stainless steel pressure pot. Compressed air from the plant system is split into two separately regulated streams – supplying pressure to move liquid to the spray nozzles and to atomise it at the nozzle. Key components are the two Spraying Systems AirJet Fogger nozzles which produce a flow-adjustable dry fog, able to dampen surfaces without wetting them.

Simple for operator to use Before first use, safety staff set air and liquid pressures. Once this has been carried out, the user needs only to connect the cart to plant air, adjust spray height if necessary, lay down some adsorbent matting, then start the spray and turn around gently in the fog for two minutes – time enough to cover all surfaces of the PPE. Spraying Systems says it is important to remember that this system is designed to encapsulate any dust on the PPE – thus making it safe for the user to remove and dispose of safely – not to wash it. With its low working pressure and flow rate, the 19 litre pressure pot holds enough water to give more than 2 hours fogging. When it needs filling, or when the whole shower assembly has to be removed from a red room, it is said to be easily washed down using a trigger jet spray gun built in to the cart. According to Tony O'Connell, the great advantage of the new fog cart system is its flexibility. "It lets us set up a buffer zone for effective decontamination almost anywhere, using existing space and with no provision for plumbing," he says. "We just mark out on the floor a small, dedicated area next to the exit in each room and station a fog cart there." Another benefit is self-operation by the user. "It's more convenient and easier to validate. And the fogging process itself is quicker." Personal safety is also improved, he believes, because the specialised nozzles give more efficient coverage, while the fog is very light so the floor stays relatively dry.