RADIATION STERILISATION - A CONTRACT STERILISER'S VIEW

摘要

It is appropriate during meetings such as this to consider recent changes that have taken place in relation to radiation sterilisation and the developing trends that are likely to affect our operations in the near future. Since operators of contract sterilisation plants are a major world contributor to the volume of material processed as well as being actively involved in the development of the technology their perspectives for the future are relevant to the industry as a whole. Radiation processing is based on two characteristics of high energy radiations namely their ability to kill micro-organisms and their ability to modify polymer structure. Sterilisation using gamma or electron beam radiation is obviously associated with the former characteristic. Contract radiation plants are particularly prominent in the application of radiation processing, accounting for approx. 33% of gamma plants world wide and over 50% of installed Cobalt 60. Amongst contract radiation plants Globally sterilisation will account for some 70-80% of gamma plant revenues with 20-30% being associated with other microbiological control activities. Individual plants however will show significant variation. Total volumes of sterile product generated by contract gamma plants are estimated at approx 1.5-2.O m3 per annum. Chemical modification generally forms a small proportion of their activity in value or volume terms although the high dosages generally required for polymer modification may result in a larger proportion of process time. Non-sterilisation irradiation services based on microbiological control are provided for a variety of industries particularly pharmaceutical raw material, food packaging and pharmaceutical packaging and food itself. Contract electron beam plants find their activity split between polymer modification and sterilisation as a result of the capability of the plant being operated. The more powerful 10 MeV machines are being predominantly used for sterilisation activities whilst machines of 5 MeV and below are directed towards polymer modification.