TS 11605 EN ISO 14644-1 Cleanrooms and associated controlled environments Part 1 - Classification of air cleanliness
The standard for cleanrooms and associated controlled environments has been prepared to control airborne particle contamination and ensure that contamination remains within the acceptable limits for sensitive activities.
Industries benefiting from the control of airborne contamination include space, microelectronics, pharmaceuticals, medical devices, food, and healthcare, among others.
TS 11605 EN ISO 14644-1 defines the limits of ISO classification used for describing the cleanliness of the air in cleanrooms and controlled environments. In addition to determining the concentration of airborne particles, it also describes the standard testing methods.
The TS 11605 EN ISO 14644-1 standard provides a particle size range designed for the classification purposes to set particle concentration limits. It also provides standard protocols for the determination and design of cleanliness levels based on the concentration of particles outside this defined particle size range.
TS 11605 EN ISO 14644-1 is part of a series of standards related to cleanrooms and contamination control.
When designing, defining, using, and controlling cleanrooms and other controlled environments, the factor of being free from airborne particles must be considered, alongside many other factors, as detailed in other sections of the international standards prepared by ISO/TC 209.
In certain cases, additional methods and restrictions may be set by the competent regulatory authorities.
In such cases, suitable adaptations of standard testing procedures may be required.
The TS 11605 EN ISO 14644-1 standard covers the classification of cleanliness in cleanrooms and controlled environments specifically according to airborne particle concentration. The classification considers only cumulative distribution populations of particles with a size range of 0.1 µm to 5 µm. The classification does not cover the classification of particle populations outside the size range of 0.1 µm to 5 µm.
Very small particles (smaller than 0.1 µm) and macro particles (larger than 5 µm) concentrations may be used to determine their quantities with U and M descriptors, respectively.
The TS 11605 EN ISO 14644-1 standard does not specify the physical, chemical, radiological, or permeable structures of airborne particles. Due to the increase in size distribution, the final distribution of particle concentration is naturally unpredictable and typically changes over time.
Cleanroom: A room where the entry of particles, their formation, and retention are minimized, and where the concentration of airborne particles and other related parameters, such as temperature, humidity, and pressure, are controlled as necessary.
DEMONSTRATING COMPLIANCE
Customer: By performing agreed-upon testing processes between the customer and the supplier, providing the documentation that includes results and test conditions, compliance with the specified air cleanliness (ISO class) is confirmed by the customer.
Tests: Cleanroom analysis must be performed to demonstrate compliance. If no consensus is reached on any method or no method is defined, a reference method may be used, along with an alternative method that provides comparable clarity. Tests to demonstrate compliance must be carried out using calibrated instruments.
TS EN ISO 14644-2 CLEANROOMS AND ASSOCIATED CONTROLLED ENVIRONMENTS - PART 2: TESTING AND MONITORING CONDITIONS FOR CONTINUED COMPLIANCE WITH ISO 14644-1
The TS EN ISO 14644-2 standard provides a process to ensure continued compliance with ISO 14644-1 and defines the minimum conditions for testing and monitoring. Specific conditions related to the operations of the facility, risk assessment of the installation, and their usage must be carefully considered in any testing plan.
Cleanrooms and associated controlled environments ensure the control of airborne particles at appropriate levels for activities sensitive to contamination. Products and processes benefiting from air contamination control include aerospace, microelectronics, pharmaceuticals, medical devices, healthcare, food, and others. In addition to air particle cleanliness, many factors must be considered in the design, specification, operation, control, and monitoring of cleanrooms and other controlled environments. Regulatory bodies may impose additional policies and restrictions in some cases.
In such cases, appropriate adaptations of the standard testing procedures may be necessary.
The TS EN ISO 14644-2 standard specifies the periodic testing requirements and conditions for verifying continuous compliance with the cleanliness level classification of cleanrooms and controlled environments as described in ISO 14644-1.
The standard also provides additional optional tests at the discretion of the user. The TS EN ISO 14644-2 standard further outlines the conditions for monitoring to ensure continued compliance with the cleanliness level classification of airborne particles.
Revalidation of Adequacy: Based on the facility classification, a set of tests must be conducted to demonstrate compliance with ISO 14644-1. Verifying pre-test conditions is also included.
Testing: A procedure carried out according to a defined method to determine the performance of a facility or one of its elements. Likely tests for an operational cleanroom are as follows:
• Airborne particle measurement from predefined points based on cleanroom condition • Microbiological measurement from the same points (Total bacteria, Fungi-Yeast) • Microbiological test samples from the hands of operational personnel (Total coliforms, E. coli, S. aureus) • Microbiological test samples from floor surfaces at entry points, cleanroom interiors, and material entry sections (Total bacteria, Total coliforms, E. coli) • Microbiological test samples from surfaces in the cleanroom that are in contact with the product (equipment, material boxes, etc.) (Total bacteria, Total coliforms, E. coli)
Monitoring: Observational activities through measurements and analyses carried out according to a defined method and plan to provide evidence about the performance of a facility.
Periodic Times for Cleanroom Measurements and Analysis:
• Continuous: Ongoing updates as they occur. • Frequently: Updates occurring within intervals of no more than 60 minutes during operation. • 6 months: Updates occurring at average intervals not exceeding 183 days during operational use. No interval should exceed 190 days. • 12 months: Updates occurring at average intervals not exceeding 366 days during operational use. No interval should exceed 400 days. • 24 months: Updates occurring at average intervals not exceeding 731 days during operational use. No interval should exceed 800 days.
Demonstrating Continued Compliance: Continuous compliance with the specified air cleanliness (ISO class) for the facility is verified by conducting defined tests and documenting the results. Monitoring data can serve as an indicator of the facility's status and can be used to determine the frequency of the tests.
Tests for Continued Compliance: The maximum time interval between these tests to demonstrate continued compliance with the defined ISO class is provided below.
< ISO Class 5 every 6 months (Particulate) every month (Air Microbiology)
< ISO Class 5 every 12 months (Particulate) every 3 months (Air Microbiology)