The meaning of life

The number of industries that are now operating critical and controlled environments continues to increase. This increase is not confined to large multinational companies. In fact, more small companies than ever before, many employing fewer than 50 staff, are building cleanrooms today and planning them for the future. Many of these companies have little or no experience in the operating of cleanrooms and are unclear as to what garments they should be wearing. There are many factors that need to be taken into consideration when making the choice of garments: •Garment changes: In general terms, the number of changes of garments that are required during one week will determine the choice between disposable or reusable garments. Changes are defined as the number of garments that are cleaned and packed for one staff member working in the cleanroom in one week. This is irrespective of the number of staff in the cleanroom. •Visitors: In cleanroom operations that have many visitors it may be too expensive to carry a large number of reusable garments in stock. This can be particularly difficult if the cleanroom requires that all visitors wear garments that are sterile. •Operating conditions: Many companies are moving towards operations in controlled environments, e.g. automotive spray painting. The use of reusable garments in these environments may be impractical because garments will require extended and specialised cleaning. The lifecycle of these garments may also be dramatically reduced, thereby substantially increasing their cost in use. •Personal protection: The handling of certain dry and liquid chemicals, including many pharmaceutical products, may present a risk to the staff working in the cleanroom. Penetration through cleanroom garments of liquids that may be absorbed into the skin can be a serious issue and the choice of garments must take this into consideration. •Operating environment: The choice of garments will be dictated by the level of contamination control required. This may vary from critical environments, e.g. ISO Class 4 or better, through to controlled environments of ISO Class 7 or lower. While it is clear that many companies will have specific requirements that require a bespoke reusable solution, a large proportion are able to take advantage of an "off the shelf" garment solution that may be reusable or disposable. In the past, disposable or "limited life" garments have either been very expensive, with a high technical specification and test data to support, or extremely cheap with no specification and no test data whatsoever. This has made it extremely difficult for companies to decide what disposable garments are compatible with use in their cleanrooms. There are certain key features of disposable cleanroom garments that should be considered when deciding which product should be used: •Particle release: The control of contamination by particulates is important, and garments should be tested to determine their particle release levels. •Durability: All cleanroom garments must be manufactured from materials that will last for at least the required duration of use in the cleanroom. Continuous changing of garments due to failure is an additional cost and is disruptive to production. •Construction: The method of garment construction and way the garment has been sewn is important. Seams must be enclosed to ensure that no contamination is released into the operating environment. This also ensures that they are splash-proof. •Sterility: Where sterile garments are required, the garments must be tested for their post-sterilisation integrity. Many man-made materials degrade substantially after gamma ray sterilisation. •Comfort: A wide range of sizes to ensure user comfort is essential. Staff productivity will be substantially reduced if staff have to wear garments that are incorrectly sized. •Accessories: Different activities in the cleanroom may demand that a range of alternative garment accessories are required. With standard cleanroom coveralls with attached hoods, the relevant accessories would be overboots and, where necessary for extra arm protection, oversleeves. When coveralls with collars are used, hoods should be available.