What does ISO Class 5 or ISO Class 7 mean for a contractor working in a cleanroom?
ISO 14644-1:2015 classifies cleanrooms by the maximum airborne particle concentration. ISO Class 5 allows 3,520 particles of 0.5 µm or larger per cubic metre; ISO Class 7 allows 352,000; ISO Class 8 allows 3,520,000. For a contractor, a lower class number means stricter gowning, material entry, tool cleaning and work methods. Construction inside or next to a classified area must not push particle counts above the class limits.
From the RRD Field Guide, checked against the sources cited in Working in Live Premises: Construction in Occupied Offices, Malls, Fabs, Hospitals and Places of Worship. General information, not advice for your project.
The fuller picture
Construction in occupied premises in Singapore is controlled less by one statute than by layered duties: the WSH Act duty to protect everyone on the premises, landlord and MCST house rules on hours and permits, fire safety management for hot works and alarm isolation, licensed electrical and plumbing workers for shutdowns, and sector standards such as ISO 14644 cleanroom classes or hospital infection control risk assessments.
More questions on this topic
- Can fit-out works be done during office hours in an occupied building?
- Who approves fire alarm isolation during renovation works?
- What is a hot work permit and when is it needed?
- What is an infection control risk assessment for hospital works?
- Who must carry out electrical isolation and reconnection during a shutdown?
- How should works in a temple, church or mosque be scheduled?
- Do I need to tell tenants or residents before works start?