It is necessary when a cleanroom has just been built, and during its life, to test it to ensure that it is working correctly. The amount and quality of air supplied, the air movement between and within cleanrooms, and the particle and microbiological counts in the cleanroom should be shown to be correct.

The testing of a cleanroom requires skill, and the following certification courses are provided to ensure this. Teaching, and certification is carried out by the CTCB-I , a non profit making board set up originally by the Scottish Society for Contamination Control (S2C2) as an education and training initiative to help fulfil the objectives of S2C2. The Irish Cleanroom Society joined CTCB in 2003 followed by R3Nordic in Scandinavia and more recently VCCN in the Netherlands. The organisation was renamed CTCB-I in 2009 to reflect its increasingly international dimension.