bs news by Design 3 (D)
5/9/07
3:55 PM
Page 1
Derek Mowlds e: derek.mowlds@pmg.ie
designing
BUILDING SERVICES an introduction to cleanroom technology Substantial foreign investment by top international companies over a 40-year period has created a significant international pharmaceutical sector in Ireland. Since the late 1950s in particular, foreign direct investment in Ireland has been attracted by low rates of corporate tax and this has contributed significantly to the development of the sector. Other contributory factors are:— — High skill base and third level graduates; — Excellent compliance record (FDA etc); — Access to large European Market; — Presence of top International design firms. In this article we give an overview of the pharmaceutical industry in Ireland and give a brief description of cleanroom technology which is critical to the successful operation of the sector. What is a Cleanroom? A cleanroom is a room in which the concentration of airborne particles is controlled, and which is constructed and used in a manner to minimise the
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introduction, generation, and retention of particles inside the room. Other relevant parameters such as temperature, humidity and pressure are controlled as necessary to meet product, personnel and safety requirements. The only way to control contamination is to control the total environment. Air flow rates and direction, pressurisation, temperature, humidity and specialised filtration all need to be tightly controlled. The sources of these particles also need to be controlled or eliminated whenever possible. There is more to a cleanroom than HEPA filters. Cleanrooms are planned and constructed using strict protocol and methods. They are frequently found in electronics, pharmaceutical, biopharmaceutical, medical device industries and other critical manufacturing environments. Clean areas for the manufacture of sterile products are classified according to the required characteristics of the
environment. Each manufacturing operation requires an appropriate environmental cleanliness level in the operational state in order to minimise the risks of particulate or microbiological contamination of the product or materials being handled (from Annex 6, WHO Technical Report Series, No: 902, 2002). Cleanroom Standards The standard of cleanrooms is defined by the number and size of particles that are permitted per unit volume of air. Previously there were a number of different standards in use around the world, making it difficult to compare cleanrooms in different locations. For this reason an ISO standard has been developed (Table A). The ISO 14644-1 standards specify the decimal logarithm of the number of particles 0.1 µm or larger permitted per cubic metre of air. So, for example, an ISO Class 5 cleanroom has, at most, 105 = 100,000 particles per m3. When stating the classification of a cleanroom using the ISO system, one must specify the occupancy state at a particular
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