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Green slime from older electric cables

Green exudate seeping from PVC

Issued 4/1996
Reissued 11/2005 and 11/2006

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.

The substance is not water soluble and should be removed from hands using an oil solvent type of cleanser. Methylated spirits is a suitable solvent for cleaning the substance from switch plates etc. Caution: do not use excessive amounts of methylated spirits as it could create a fire hazard. Power to any electrical equipment and sockets must be turned off at the switchboard, and the methylated spirits should be applied using a dampened cloth.

In some cases, such as behind light switches or socket outlets, the amount of exudate can be reduced by forming a drip loop in the cables below the terminal. This must be carried out by a licensed electrical worker only.

Last updated October 31, 2006