D recommended air changes per hour ach.
Iso 8 clean room guidelines.
Usually manufacturers will define an airborne particulate concentration standard class such as iso 14644 1 iso 8 at rest outline gowning and a pressure cascade regime defining a clean corridor design or a dirty corridor design.
In theory for an entire room to reach iso 6 air cleanliness you need to enter the cleanroom via an iso 8 ante room then go through an iso 7 to finally get into the iso 6 as shown in the image.
Considerations for iso class 8 cleanrooms.
Maximum allowable concentrations by cleanroom class.
Class 100 000 associated eu gmp grade.
A cleanroom must have less than 35 200 000 particles 0 5 micron per cubic meter and 20 hepa filtered air changes per hour.
5 48 typically measured micron sizes.
Information on iso 14644 1 2015 class 8 cleanroom classification.
Classification of air cleanliness by chemical.
Federal standard 209e equivalent.
Iso clean room classifications are rated according to how much of a particulate of a specific size exists per cubic meter within a given enclosure see second chart.
Clean room classifications are based on an eight class rating system with an iso class 1 cleanroom being rated the most particle free and iso class 8 allowing the most particles.
In reality however you can reach an iso 6 clean room with 1 recommendation is 2 airlock.
By comparison a typical office space would be 5 10 times more dirty.
Iso 14644 7 2004 part 7.