Good question. The answer depends on what type of cleanroom you are entering.
By definition, a cleanroom is:
A room in which the concentration of airborne particles is controlled, and which is constructed and used in a manner to minimize the introduction, generation, and retention of particles inside the room and in which other relevant parameters, e.g temperature, humidity, and pressure are controlled as necessary.
ISO 14644-1 Clause 2.1.1
Every cleanroom is different, depending on the industry and the work being done in the room. Processes done in the same level of cleanroom may therefore require different apparel (e.g. electronics assembly as compared to laboratory analysis).
The basics for determining cleanroom apparel are set out in a USA Federal standard, and an ISO Standard. They are the best sources of information to use in the analysis you need to conduct and document as part of your apparel selection process. A cleanroom requires a highly detailed analysis to determine what is needed in terms of apparel/clothing.
(Learn about 8 Key Cleanroom Protective Clothing Options to Consider).
Cleanrooms are defined by standards in terms of how clean they are. Standards rank cleanrooms from cleanest to dirtiest. The list of garments below, for example, is what is required for the cleanest classification:
Class 1 – ISO 03 (Most Strict/Cleanest)
- Hood
- Bouffant hat
- Coverall
- Intersuit under coverall
- Boot covers
- Goggles
- Facemask
- Gloves
Recommended frequency of change: every entry.
Additional note: make sure all products are labeled class 1-10 compatible.
Compare that to the list for dirtiest:
Class 100,000 – ISO 8 (Least Strict/Clean)
- Bouffant cap
- Frock or lab coat
- Shoe cover
- Face mask (optional)
- Gloves (optional)
Recommended frequency of change: twice a week.
O
ther Considerations
Other cleanroom clothing considerations include:
- Cost
- Wear-ability
- Reusable, yes or no
- Worker acceptance, comfort and serviceability
- Disposal
- Laundry and PPE equipment which could include the need for sanitizing/sterilization
(Learn How to Properly Launder and Clean FR Protective Clothing.)
Check the Standards
Once you define what level of cleanroom you have, or are going to enter, check the standards to determine what type of clothing each level requires. There are excellent sources of information regarding cleanrooms, and it doesn’t hurt to consult manufacturers and suppliers.
(Learn more in A Look at Cleanroom Clothing Requirements.)
The best source of information? The Standards themselves.
For those companies that need to adhere to specific cleanroom design standards, they must understand that cleanrooms can be built and operated to meet different cleanliness classifications, depending on the environmental conditions required for their use. The primary authority for clean room classifications is the International Organization for Standardization or ISO.
ISO 14644-1 classifies a cleanroom based on the size and number of airborne particles per cubic meter of air (see chart above).
Please note that the United States Federal Standard 209E set standards for cleanroom classification. FED-STD-209E was officially cancelled on November 29th, 2001 but it is still widely used. However, the ISO set of Standards is recognized and used worldwide.
One Last Word
Find out what level of cleanroom you have first, then determine what apparel you need, based not only on the level of cleanliness required, but the hazards of the work being done in the room as well. Cleanrooms require a documented, detailed due diligence approach to apparel selection.