ISO 14644-1 Class 8 – The Data Centre Cleaning Standard.
The international standard for cleanrooms, clean zones and controlled environments. Data halls, server rooms, comms rooms, MERs and SERs are controlled environments.
ISO 14644-1 defines the international standard for air cleanliness by particle concentration in controlled environments — including data halls, server rooms, comms rooms, MERs and SERs.
This is now recognised as best practice for IT environments across the UK. Major OEMs such as NVIDIA, Cisco and Dell-EMC increasingly require their equipment to operate in environments meeting ISO 14644-1:2022 Class 8. If these requirements aren’t met, equipment warranties may be void in the event of dust-related damage.
A Data Centre Cleaning Standard of ISO 14644-1:2022 Class 8, plus all accessible surfaces free from dust, is the UK’s accepted best practice.
The yardstick is particles per cubic metre of air — typically measured at 0.5 µm to 5 µm.
ISO Class
0.5 µm particles / m³
Environment type
ISO Class 1
10
Semiconductor cleanroom
ISO Class 5
3,520
Surgical suite / Pharma
ISO Class 8
3,520,000
Data Centre / Server Room
Class 1 is the most stringent (microchip fabrication). Class 8 defines the cleanliness level appropriate for mission-critical IT environments. Some specifiers still call this a “5 Micron Clean” or “Clinical Standard” — Class 8 is the correct modern classification.
Classification of air cleanliness
Particle size and concentration limits defined by ISO 14644-1:2022 — the current standard, replacing the withdrawn 2015 edition.
Testing & validation
ISO 14644-3 procedures for particulate measurement using a calibrated Solair 5100+ counter.
Design & maintenance
Guidelines for how controlled environments should be constructed and maintained between cleans.
Certificate of Conformity
Full validation report and 12-month certificate - audit-ready documentation on every clean.
ASHRAE’s 2011 Gaseous and Particulate Contamination Guidelines confirm ISO 14644-1 Class 8 is the most effective way to prevent particulate-related failures.
- Blocks server airflow and raises operating temperatures.
- Wears out cooling fans and rotating parts.
- Creates electrical shorts (static) and corrosion via ionic migration.
- Causes unexplained downtime and hardware failure.