Some software might differ from its retail version (if available) and might not include
user manuals or all program functionality.
Particulate contamination
Attention: Airborne particulates (including metal flakes or particles) and reactive
gases acting alone or in combination with other environmental factors such as
humidity or temperature might pose a risk to the storage subsystem that is
described in this document. Risks that are posed by the presence of excessive
particulate levels or concentrations of harmful gases include damage that might
cause the storage subsystem to malfunction or cease functioning altogether. This
specification sets forth limits for particulates and gases that are intended to avoid
such damage. The limits must not be viewed or used as definitive limits, because
numerous other factors, such as temperature or moisture content of the air, can
influence the impact of particulates or environmental corrosives and gaseous
contaminant transfer. In the absence of specific limits that are set forth in this
document, you must implement practices that maintain particulate and gas levels
that are consistent with the protection of human health and safety. If IBM
determines that the levels of particulates or gases in your environment have caused
damage to the storage subsystem, IBM may condition provision of repair or
replacement of storage subsystem or parts on implementation of appropriate
remedial measures to mitigate such environmental contamination. Implementation of
such remedial measures is a customer responsibility.
Table38. Limits for particulates and gases
Contaminant Limits
Particulate vThe room air must be continuously filtered with 40% atmospheric dust
spot efficiency (MERV 9) according toASHRAE Standard 52.21.
vAir that enters a data center must be filtered to 99.97% efficiency or
greater,using high-efficiency particulate air (HEPA) filters that meet
MIL-STD-282.
vThe deliquescent relative humidity of the particulate contamination
must be more than 60%2.
vThe room must be free of conductive contamination such as zinc
whiskers.
Gaseous vCopper: Class G1 as perANSI/ISA 71.04-19853
vSilver: Corrosion rate of less than 300 Å in 30 days
1ASHRAE 52.2-2008 - Method of TestingGeneral Ventilation Air-Cleaning Devices for
Removal Efficiency by Particle Size.Atlanta: American Society of Heating, Refrigerating and
Air-Conditioning Engineers, Inc.
2The deliquescent relative humidity of particulate contamination is the relative humidity at
which the dust absorbs enough water to become wet and promote ionic conduction.
3ANSI/ISA-71.04-1985. Environmental conditions for process measurement and control
systems: Airborne contaminants. Instrument Society of America, Research TrianglePark,
North Carolina, U.S.A.
Documentation format
The publications for this product are in Adobe Portable Document Format (PDF)
and should be compliant with accessibility standards. If you experience difficulties
when you use the PDF files and want to request a Web-based format or accessible
PDF document for a publication, direct your mail to the following address:
Information Development
IBM Corporation
Notices 199