Particulate contaminationAttention: Airborne particulates (including metal flakes or particles) and reactivegases acting alone or in combination with other environmental factors such ashumidity or temperature might pose a risk to the server that is described in thisdocument. Risks that are posed by the presence of excessive particulate levels orconcentrations of harmful gases include damage that might cause the server tomalfunction or cease functioning altogether. This specification sets forth limits forparticulates and gases that are intended to avoid such damage. The limits must notbe viewed or used as definitive limits, because numerous other factors, such astemperature or moisture content of the air, can influence the impact of particulatesor environmental corrosives and gaseous contaminant transfer. In the absence ofspecific limits that are set forth in this document, you must implement practices thatmaintain particulate and gas levels that are consistent with the protection of humanhealth and safety. If IBM determines that the levels of particulates or gases in yourenvironment have caused damage to the server, IBM may condition provision ofrepair or replacement of servers or parts on implementation of appropriate remedialmeasures to mitigate such environmental contamination. Implementation of suchremedial measures is a customer responsibility.Table 9. Limits for particulates and gasesContaminant LimitsParticulate v The room air must be continuously filtered with 40% atmospheric dustspot efficiency (MERV 9) according to ASHRAE Standard 52.21.v Air that enters a data center must be filtered to 99.97% efficiency orgreater, using high-efficiency particulate air (HEPA) filters that meetMIL-STD-282.v The deliquescent relative humidity of the particulate contaminationmust be more than 60%2.v The room must be free of conductive contamination such as zincwhiskers.Gaseous v Copper: Class G1 as per ANSI/ISA 71.04-19853v Silver: Corrosion rate of less than 300 Å in 30 days1 ASHRAE 52.2-2008 - Method of Testing General Ventilation Air-Cleaning Devices forRemoval Efficiency by Particle Size. Atlanta: American Society of Heating, Refrigerating andAir-Conditioning Engineers, Inc.2 The deliquescent relative humidity of particulate contamination is the relative humidity atwhich the dust absorbs enough water to become wet and promote ionic conduction.3 ANSI/ISA-71.04-1985. Environmental conditions for process measurement and controlsystems: Airborne contaminants. Instrument Society of America, Research Triangle Park,North Carolina, U.S.A.Documentation formatThe publications for this product are in Adobe Portable Document Format (PDF)and should be compliant with accessibility standards. If you experience difficultieswhen you use the PDF files and want to request a web-based format or accessiblePDF document for a publication, direct your mail to the following address:Information DevelopmentIBM Corporation205/A0153039 E. Cornwallis RoadP.O. Box 12195Research Triangle Park, North Carolina 27709-2195Appendix B. Notices 77