Should I be worried about blue on my copper gas pipe in a couple of places? The pipe was fitted around 18 months ago and held in place next to the wall with some plastic brackets. Basically I've had a lot of problems with damp to that wall (which to my knowledge has been rectified). But the blue on the pipe seems to have been caused by where the plastic bracket screw has rusted off the wall, rather than something else such as flux. Hope this makes sense. Anyhow should I be worried about this?