Hi Brett
I have seen this goo oozing from electrical PVC control cables from the 80's. This is what I have found on the subject. I like how they put the cancer bit at the end!
"The Electrical Safety Office has investigated the possible safety issues of a green oily substance exuded by some thermoplastic insulated and sheathed cables. The results were that:
- The affected cables are V60 and V75 type PVC insulated and sheathed cables.
- The substance is a plasticiser used in the manufacture of the cable.
-The release of the substance is initiated and exacerbated by high ambient temperatures such as can be found in ceiling spaces and in hotter climates.
- The substance is not conductive and therefore not liable to electrical tracking.
- The presence of the substance will not alter the flame propagation characteristics of the cable.
- The presence of the substance does not necessitate replacement of the cable.
-Cables should be assessed for replacement only when insulation tests reveal failure or when cracking of the insulation becomes apparent.
- The green exudate is mildly toxic and can cause burning and irritation, especially to mucous membranes such as in the eyes, nose and mouth.
- There has been no epidemiological link established with cancer in humans."