Sun Microsystems StorageTek StreamLine SL8500, System Assurance Manual

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E24254-01 Chapter 4 Site Preparation 87
Site Preparation
Airborne Contaminants
Control over contaminant levels in a computer room is an extremely important
consideration when evaluating an environment. The impact of contamination
on sensitive electronic hardware is well recognized, but the most harmful
contaminants are often overlooked because they are so small.
Automated Tape Library components and electronics, tape drives, and media
are subject to damage from airborne particulates. The operating environment
must adhere to the requirements of:
• ISO 14644-1 Class 8 environment
For more information refer to the Data Center Site Planning Guide.
For example: Excessive concentrations of certain gasses can accelerate
corrosion and cause failure in electronic components. Gaseous contaminants
are a particular concern in a computer room because of the sensitivity of the
hardware.
The following table lists some recommendations for gaseous limits.
Table 43. Gas Limit Recommendations
Chemical Name Formula ASHRAE OSHA (PEL) ACGIH NIOSH
Acetic Acid CH
3
COOH Not defined 10 ppm Not defined Not defined
Ammonia NH 3500 µg/m
3
350 ppm 25 ppm Not defined
Chlorine Cl 2100 µg/m
3
31 ppm (c) Not defined 0.5 ppm (c)
Hydrogen Chloride HCl Not defined 5 ppm (c) Not defined Not defined
Hydrogen Sulfide H
2
S 50 µg/m
3
320 ppm (c) 10 ppm 10 ppm
Ozone O
3
235 µg/m
3
30.1 ppm Not defined Not defined
Petrol-hydrocarbons C
n
H
n
Not defined 500 ppm 75 ppm 300 ppm
Sulfur Dioxide SO
2
80 µg/m
3
35 ppm 2 ppm 0.5 ppm (c)
Sulfuric Acid H
2
SO
4
Not defined 1 ppm Not defined 1 ppm (c)
PEL: Permissible Exposure Limit

ppm: Parts Per Million
µg/m
3
: Micrograms Per Cubic Meter

(c): ceiling