HP rp7400 Manual page 74

Other ways to minimize electrostatic discharge are by using specially
grounded mats in front of the computer system or by treating carpeting
with anti-static spray. Anti-static spray is not recommended because it
finds its way into the system intake filter and tends to coat the circuitry.
If spray is used, it should be applied while the system is turned off. Note
that sprays are very temporary and must be reapplied frequently.
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