Four quick and crucial facts about cleanrooms
1. What is a cleanroom?
According to the ISO14644-1 (International Standards Organisation), a cleanroom is a room where the number of airborne particles is controlled and classified and which is designed, constructed and operated in a manner to control the introduction, generation and retention of particles inside the room. In other words, cleanrooms are rooms in which environments are controlled for critical activities.
2. How to determine cleanroom class?
Cleanroom classes are categorized by the number of airborne particles allowed in each room. The less airborne particles present, the cleaner the room. Levels of cleanroom are expressed in terms of an ISO Class, which represents maximum allowable concentrations of particles in a unit volume of air. 
Table 1 – ISO Classes of air cleanliness by particle concentration
a. All concentrations in the table are cumulative. e.g. for ISO Class 5, the 10,200 particles shown at 0.3 µm include all particles equal to and greater than this size.
b. These concentrations will lead to large air sample volumes for classification. A sequential sampling procedure may be applied; (see  page 33).
c. Concentration limits are not applicable in this region of the table due to very high particle concentration.
d. Sampling and statistical limitations for particles in low concentrations make classification inappropriate.
e. Sample collection limitations for both particles in low concentrations and sizes greater than 1 µm make classification at this particle size inappropriate, due to potential particle losses in the sampling system.
f. In order to specify this particle size in association with ISO Class 5, the macroparticle descriptor M may be adapted and used in conjunction with at least one other particle size. (see  page 26)
g. This class is only applicable for the in-operation state.
3. What is a cleanroom used for?
Cleanroom environments are highly controlled. The main function of these extremely clean areas is to help manage and mitigate particle contamination generated by people, products and processes. In Life Sciences, cleanrooms are used to produce injectables like vaccines, ingestible like tablets as well as implantable like pacemakers. In short, industries which make pharmaceuticals, medical devices and other biotech products will use a cleanroom as a critical component in their day-to-day working environment.
4. How to control contamination in a cleanroom?
Humans are by far the biggest source of contamination in any cleanroom. Our every movement generates particles. The goal is to always ensure that we do not unnecessarily introduce particles into a cleanroom environment. A large part in controlling particles in environments is through the proper selection of consumables used by personnel working in the cleanroom. Every piece of PPE (Personal Protective Equipment) used must be selected to ensure it minimises the ingress of particles into the Cleanroom. In fact, the EU GMP Annex 1: Manufacture of Sterile Medicinal Products outlines the criteria necessary for the consideration and selection of Cleanroom PPE depending on the classification of the environment 
Isofield’s range of PPE consumables are compatible for both ISO Class 4 or ISO Class 5 cleanrooms. Technical reports are available to confirm the cleanliness of our products and are available upon request.
 “Cleanrooms and associated controlled environments – Part 1: Classification of air cleanliness by particle concentration.” <https://zoser.com.co/wp-content/uploads/2015/10/ISO%2014644-1%20Version%202015.pdf> Accessed July 2, 2021