Cleanroom Classifications / Apparel Recommendation Chart

What are the Cleanroom Classifications and how are they determined?

Current cleanroom classifications are defined by The International Organization for Standardization (ISO). More specifically, ISO 14644-1:2015 specifies the classification of air cleanliness in terms of concentration of airborne particles in cleanrooms and clean zones; and separative devices as defined in ISO 14644‑7.

The International Organization for Standardization (ISO) states that cleanrooms must not exceed a certain particulate count, measured in cubic meters. The amount stipulated for each cleanroom application depends on the class of air cleanliness required.

What is a cleanroom?

A cleanroom is a controlled environment where airborne particulate matter such as dust, microbes, and aerosol particles are filtered out to provide a certain level of cleanliness. This control is achieved by air pressure and filters. Positive pressure keeps new particles from entering the clean area.

Just to put things in perspective…

• The cross section of a human hair is 50 microns
• Dust and bacteria is .5 microns, that is 1/100^th of the size!

The Skin We Shed

• A person sitting still emits 100,000 particles / minute
• Getting up or sitting down causes 2.5 million particles/minute
• Slow walking causes 5 million/minute
• Rapid movement like climbing stairs causes 110 million particles/minute

Cleanroom Classifications

ISO defines nine different cleanroom classifications, ranging from ISO 1 to ISO 9. The most common cleanrooms fall somewhere in the ISO 5 to ISO 8 range.

ISO 4 at any given time has 352 particles in a cubic foot of air and an ISO 8 cleanroom has 3.5 million. A typical room has 35 million particles circulating in the air.

ISO 8 (Class 100,000) Cleanroom – Walls and floors should be non-porous/smooth, and no carpeting or fabric cushioned chairs should be used. Personnel would typically be wearing beard covers, hair nets or bouffant caps, and lab coats. Poly-cellulose, polypropylene, polyester, and cotton cleanroom wipes can be used in these environments.

ISO 7 (Class 10,000) Cleanroom – Walls, floors, and ceilings should be non-porous/smooth and absolutely no linting fabric is permitted. Personnel would typically be wearing beard covers, hair nets or bouffant caps, and lab coats. Shoe covers might also be worn in some environments. Poly-cellulose, polypropylene, polyester, and cotton cleanroom wipes can be used in these environments.

ISO 6 (Class 1,000) Cleanrooms – Walls, floors, and ceilings should be non-porous/smooth and absolutely no linting fabric is permitted. Personnel would typically be wearing beard covers, shoe covers, hair nets, and coveralls. Poly-cellulose, polypropylene, polyester, and cotton cleanroom wipes can be used in these environments.

ISO 5 (Class 100) Cleanrooms – Walls, floors, and ceilings should be non-porous/smooth and absolutely no linting fabric is permitted. Personnel would typically be wearing beard covers, face masks, shoe covers, gloves, hair nets, and coveralls. Gloves used in these environments should be removed from the cardboard box before they are brought in the cleanroom. Gowning is performed outside of the cleanroom. Polyester sealed-edge cleanroom wipes are commonly used in these environments. Certain poly-cellulose and polypropylene cleanroom wipes can also be used in some circumstances.