Hexanoic acid and copper/brass - toxicity?

We have a sensor made of brass through which we are flowing organic solvent vapours mixed with air, typically hexane and various alcohols. After a year or so the interior is covered in a greenish-black slime. The smell is definitely that of hexanoic acid, so I am assuming much of the deposit will be the copper salts of the various acids.


Is there likely to be any significant toxicity with the probable compounds that may require special cleaning procedures? 


