Cleanroom environments are a demanding field of work at the leading edge of technological progress, with fresh challenges continually being encountered. Wherever minimised production tolerances and maximised dependability have to be guaranteed, cleanroom engineering often makes a crucial contribution. The applications range from developing and manufacturing highly integrated semiconductor memory components and micro/mega-chips or compact disk production to assembling precision-engineered drive systems and devices for spacecraft. Keeping harmful germs and particles well away from the production process is particularly important in the chemical and pharmaceutical industries, where sensitive medicines and additives are involved. Moreover the contamination of both neighbouring areas and the environment with particles and germs must also be avoided. Viledon® EPA/ HEPA/ ULPA filters offer effective protection for sensitive products, by arresting almost 100% of the critical particles in the intake and recirculated air flows. To extend the useful lifetime of these EPA/ HEPA/ ULPA filters, Viledon® pocket filters and MaxiPleat or NanoPleat cassette filters are used in the prefiltration stages.