Classification
La classificazione delle camere biancheCleanroom classification
To know if a cleanroom is optimal for your facility you need to understand, based on the industry in which you operate, what standard it must meet. Clean rooms are classified according to the level of cleanliness of the air in them, and based on the amount and size of particles per volume of air there is the class to which the room conforms.
The old Federal Standard 209 was withdrawn in 2001 and officially replaced by ISO-14644-1 in 1999, but it is still widely used.
This standard has classes (from) ISO 1 through ISO 9, starting with ISO 1 which is the “cleanest” class to ISO 9 which is the “dirtiest” class. After ISO 9 are the Unclassified (N.C) environments.
In addition, clean rooms must also comply with regional and industry-specific standards. For example, EU GGMP (ABCD) applies to pharmaceuticals and USP (795, 797 and 800) to compounding pharmacies.
Particle counting
The basis of cleanroom standards is the micrometre, or micron for short (µm), which is the size of the particles to be filtered. As stated earlier, cleanrooms are classified according to air cleanliness, based on the amount and size of particles per volume of air. The following cleanroom classification table shows the maximum concentration limits (particles/m3 of air) for particles equal to and greater than the considered size indicated.
Some classifications do not require testing of certain particle sizes because the respective concentrations are too low or too high to be tested, but they should not be zero.
Air cleanliness is achieved by passing air through HEPA filters. The more often the air passes through these filters, the fewer particles remain in the air in the room. The volume of air filtered in an hour divided by the volume of the room gives the number of air changes per hour.
What ISO does your industry need to take into account?
EN ISO 14644-1
Air cleanliness is achieved by passing air through HEPA filters. The more often the air passes through these filters, the fewer particles remain in the air of the room. The volume of air filtered in one hour divided by the volume of the room gives the number of air changes per hour.Grade A
Environments for higher risk work, for which a ‘laminar flow’ clean air distribution system must be provided (demonstrated and validated)
Grade B
Asepsis preparation and filling environments, complementary for GRADE A.
Grade C/D
For carrying out the less critical stages of manufacture.
Contamination arising from personnel and how to control it
The management of classified, confined, contamination-controlled manufacturing environments, sterile or asepsis areas is influenced by several elements among which the most important are facilities and finishes; air conditioning (HVAC) systems; personnel; clothing; raw materials, product and materials; the manufacturing process; and the state of cleanliness and general hygiene.
Contamination from operators can be of a microbiological and particle type, coming from the oral cavity, nose and upper airways, skin and scalp.
In addition to these main rules to be followed to reduce the contamination of a cleanroom, constant maintenance support is essential.
To control this type of contamination, these standards must be followed
Personnel
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Minimum number of operators present around aseptic operations
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Qualification of dressing by repeated microbiological testing
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High standard of personal hygiene
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Periodic medical check-ups and attention to personnel with diseases (airway, stomach, skin)
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Makeup, personal items or jewellery, food or personal medication not permitted
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Detailed operating procedures for activities to be performed in classified areas, with regulated operations on machines and during aseptic filling
Clothing
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Appropriate and suitable for different operations
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Continuous fibres, fabrics with conductive antistatic threads
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Must not bring contamination to the product
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Comfort for operators, barrier effect
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Clothing sterile, washable and re-sterilizable (steam, radiation)
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Reduced release of particles/fibres e.g., polyester, polyolefins (tywek)
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Intact seams, no tears
Behavior
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Hair and beard must not come out of the hood and mask must cover the face
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Gloves should be closed above the sleeves so that there is no exposed skin
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Disinfect gloves frequently with sterile disinfectant, taking care not to spill the product
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Body position should always be as parallel as possible to the airflow, do not interrupt or create eddies to the flow, do not block the air vents
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Do not interpose yourself or anything between the airflow and the product or contact surfaces
