Role of Cleanrooms in Sterility Testing

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The Importance of Cleanrooms in Sterility Testing

Sterility testing is a cornerstone of quality control and safety for certain drugs, biologics, and medical devices. Sterility testing ensures the absence of viable microorganisms. In sterility testing the presence of a single contaminant in a study can have massive implications. Therefore environmental controls are of utmost importance to study integrity.

Since both people and the environment are replete with natural “flora,” or microbial contaminants, sterility testing in a cleanroom and isolator or laminar flow cabinet helps ensure reliable test results.

What is a Cleanroom?

A cleanroom is a highly controlled environment engineered to limit the presence of particles and microorganisms. Cleanrooms operate under strict guidelines that classify the number and size of particles allowed within the space. These classifications are outlined in the ISO 14644 Series, which defines “Cleanrooms and associated controlled environments.”

When you hear the term “ISO Class,” it refers to the particle concentration on a logarithmic (10-fold) scale. For example:

  • ISO Class 1: The strictest classification, with the lowest allowable particle levels.
  • ISO Class 9: Equivalent to normal room air.

The table below shows particle allowances by cleanroom class:

Key design elements of cleanrooms ensure their efficiency:

  • Airflow Control: To prevent swirling and particle redistribution, cleanrooms with stricter classifications (ISO 5 or cleaner) utilize a unidirectional airflow pattern, where air enters and exits in the same direction.
  • Filtration Systems: High-Efficiency Particulate Air (HEPA) or Ultra-Low Penetration Air (ULPA) filters capture up to 99.99% of particles, maintaining the required cleanliness.

At Microchem Laboratory, our cleanroom meets ISO 7 classification requirements, and our laminar flow hood achieves ISO 5 standards. This dual approach, coupled with the skill of our highly trained microbiologists, ensures precision and compliance in sterility testing.

Why are Cleanrooms Essential in Sterility Testing?

  1. Preventing Contamination

    • Sterility testing requires an environment free from contaminants like dust, microorganisms, and particles. Cleanrooms provide this controlled space, ensuring external factors do not compromise test results.
    • The controlled airflow design prevents particle redistribution, essential for maintaining sterile conditions.
  2. Maintaining Accurate Test Results

    • A clean environment ensures that sterility test outcomes reflect the actual condition of the product being evaluated, without interference from external contaminants.
    • This is critical for industries where product safety and efficacy are paramount, such as pharmaceuticals and medical devices.

Key Features of Cleanrooms for Sterility Testing

  • Air Filtration Systems
    • HEPA and ULPA filters ensure a high level of air cleanliness by removing particles as small as 0.1 microns.
    • Cleanrooms with ISO 5 classifications use unidirectional airflow to maintain uniform particle removal.
  • Strict Environmental Controls
    • Factors like temperature, humidity, and pressure are carefully regulated to prevent conditions that might promote microbial growth.
    • Differential pressure systems prevent contaminants from entering critical areas.
  • Specialized Design
    • Floors, walls, and ceilings are constructed from smooth, non-porous materials that prevent particle accumulation and are easy to clean.
    • Laminar flow hoods in cleanrooms, such as those at Microchem Laboratory, provide localized areas of ISO 5 cleanliness for highly sensitive tasks.
  • Personnel Protocols
    • Personnel entering cleanrooms must wear protective gear, including sterile suits, gloves, masks, and shoe covers, to minimize contamination risks.
    • Movement is restricted, and procedures are designed to maintain a sterile workflow.


Working with Microchem for Sterility Testing

Cleanrooms are the cornerstone of sterility testing, offering controlled environments that ensure precision, compliance, and safety. By preventing contamination, maintaining strict ISO standards, and enabling accurate results, cleanrooms support the production of safe and reliable products across industries. At Microchem Laboratory, our cleanroom facilities exemplify these principles, meeting ISO 7 and ISO 5 standards to provide exceptional sterility testing services.

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Role of Cleanrooms in Sterility Testing

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