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Measurable Reduction in Environmental Bioburden with 222 nm Far-UVC

Measurable Reduction in Environmental Bioburden with 222 nm Far-UVC

Micro CRISPR UV222 Cleanroom Downlight Demonstration 


Maintaining microbial control in cleanroom and controlled environments is a continuous challenge. Cleaning and disinfection are essential, yet contamination pressure reoccurs through personnel activity, airflow dynamics, and routine operations.

To address this, Micro CRISPR conducted a GMP-aligned in-room demonstration of 222 nm Far-UVC (UV222) at its facility. The objective was to evaluate whether continuous UV222 exposure could achieve measurable bioburden reduction during active cleanroom operation while maintaining safe and compliant conditions.

The findings were clear:

  • 62% reduction in bacterial contamination
  • Complete reduction of fungal contamination

The results were consistent with Grade C environmental limits and demonstrate that UV222 downlight installation can measurably reduce cleanroom bioburden during normal operation.


Test Design and Microbial Reduction Outcomes

The Micro CRISPR evaluation followed a controlled, three-phase protocol using settle plates positioned at critical cleanroom locations. A settle plate consists of an agar surface exposed for four hours, allowing airborne bacteria and fungi to deposit. Following incubation, colony-forming units (CFU) are counted to quantify viable microbial contamination.

The study was structured as follows:

  • Phase 1 – Baseline (UV Off)
  • Phase 2 – UV222 Active (UV On)
  • Phase 3 – Return to Baseline (UV Off)

Triplicate samples were collected in each phase to ensure data reliability.

During UV222 operation, bacterial counts decreased from 42 CFU to 16 CFU, corresponding to a 62% reduction in bacterial load. Fungal contamination decreased from 5 CFU to 0 CFU during the UV On phase


Microbial Reduction Without Introducing Secondary Risk

Beyond demonstrating a substantial reduction in bioburden, Micro CRISPR evaluated the technology against key operational and safety parameters:

  • The reduction was achieved during normal occupancy, not during an unoccupied terminal disinfection cycle. This reflects the feasibility of continuous use enabled by the safety profile of UV222.
  • Ozone levels were monitored in the breathing zone throughout operation. No ozone excursions were detected.
  • Surrounding materials were inspected for potential degradation. No visible material impact was observed during the study period.
  • Microbial sampling was conducted in accordance with the site’s standard operating procedure (SOP).

Why UV222

UV222 (222 nm ultraviolet light), also referred to as Far-UVC, is a technology capable of reducing bioburden occupied environments.

Unlike conventional 254 nm UVC systems, which are typically restricted to unoccupied disinfection cycles, 222 nm Far-UVC is applied for continuous microbial reduction in air and on surfaces without interrupting facility operations.

For contamination control specialists, the relevant question is not whether UV can disinfect surfaces under controlled laboratory conditions. The practical consideration is whether the technology can support cleanroom performance under operating conditions. UV222 is designed to reduce microbial burden while remaining aligned with environmental monitoring practices, as demonstrated in the Micro CRISPR evaluation.

 

Learn more about how 222 nm Far-UVC can support cleanroom contamination control.


Conclusion

The UV222 evaluation at MicroCrispr demonstrates that UV222 Downlight can function as an additional contamination control measure in a cleanroom. The observed reduction in bioburden confirms its applicability under real operating conditions.

As cleanliness requirements and contamination control expectations continue to increase, UV222 represents a technical option for strengthening hygiene and environmental robustness without disrupting the cleanroom workflow.