I have attached a white paper for your review that puts this topic into perspective.
This data seems most relevant in this case, because it
points out how well humidity from 30% and up reduced tribo-charging,
but not good enough for the thin-film applications. Notice
that voltages of up to 1.5 kV are still generated with
ease in an 80% environment! Dropping from 50% to 35% might
be beneficial to prevent corrosion, but still require an
EPA (ESD PROTECTED AREA) with a total ESD protection system.
Download
White Paper (PDF Reader Required)