The black foam is pretty conductive - you should breathe on devices so the humidity in your breath dissipates any static charges on the pins before pressing the pins into the foam - its suddenly discharging these charges that causes current spikes that do the damage.I read in another post that using ESD foam (in the context of protecting ICs from ESD) is "Not as good as a Faraday cage, but it will reduce the possibility of damage."
http://forum.allaboutcircuits.com/t...-for-logic-and-other-esd-sensitive-ics.57154/
If one has an IC inserted in ESD foam and a static event occurs (e.g. the ungrounded person touches a pin on the IC directly and zaps it), how does the ESD foam reduce the possibility of damage when compared to a ESD shielded bag (i.e. a Faraday cage) ?
The pink bags merely "discourage" static. the metalised polyester bags are better - but not as good as the thick black plastic anti static bags.