PIC/S publishes a shared Annex 1 interpretation, PI 058-1

By ZY Cleanroom · Updated 2026-10-28 · Sources at the end of the page

What PI 058-1 is

The document runs to 29 pages. A joint working group of WHO, EMA and PIC/S authority experts drafted it. The group began in January 2024. The PIC/S Committee adopted the text on 16 October 2026.

PI 058-1 says plainly that it adds no new GMP requirements. It explains how inspectors should read Annex 1, which came into force on 25 August 2023. It follows an older interpretation paper, PI 032-2, from January 2010.

Answers that touch room design and qualification

Source for the points below is PI 058-1, 28 October 2026, section 4.

Moving materials into grade A or B needs a validated transfer process. Moving materials straight into grade C from an unclassified area is allowed in some cases, if Annex 1 is fully met. Equipment that will be used in a room should be installed before classification. If it runs all the time, it should run during classification.

Maximum limits for particles of 5.0 µm and larger are not a default requirement when classifying grade A, or grade B at rest. Those particles must still be monitored against defined limits in routine use. For requalification, total particle counts at rest and in operation are required. Viable counts are not explicitly required then.

Air speed in unidirectional flow can sit outside the 0.36 to 0.54 m/s guidance range if the contamination control strategy justifies it. Airflow visualisation studies should support that choice.

What a facility owner should check next

Read section 4 of the PDF against your qualification protocols and your contamination control strategy. Check that your airlock transfer steps are validated, and that your classification plan says which equipment is in place and running. Check whether your plan explains how you treat 5.0 µm particles.

PIC/S wrote the paper for inspectors in its member authorities. Ask your national regulator how it will use it. If you are planning a cleanroom, you can send ZY Cleanroom your room list.

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• Contamination control strategy: what the building and air must provide
• Cell and gene therapy cleanroom design: grades, segregation and flows
• Aseptic filling suite layout: grade A and B rooms and flows
• Turnkey cleanroom contractor
• Room list builder

Sources

• PIC/S news, 28 October 2026
• PIC/S PI 058-1, 28 October 2026 (PDF)