Green Goo!

[mike2790]

Hello fellow sparky's.
I came across something on a job the other day which i think warrants me starting up my very first thread.
The job i was doing was to swap all accessories in a property for some lovely expensive polished brass ones. Problem was, when i took the switches and sockets off i would say at least 50% of them had "Green Goo". Basically the terminals in the original accessories looked like they were filled with a luminous green slime. I did the job and the customer has paid but upon researching the green goo afterwards online and consulting a snags and solutions booklet, i found out that this is a health hazard and it is recommended that the circuits affected are treated as hazardous and are re-wired (all the cable work in my particular case is sound and has been tested by me). I was just wondering if anyone has ever come across this and if so, what did you do about it because all i did was clean the conductors off? i have found this link if this helps Subcategory - 1. MV & LV Cables & Accessories - Voltimum UK - Electrical Installation Products and Contracting

Cheers guys.

 

[telectrix]

the link says it all. clean ends off for a temporary solution, advise customer to have a REWIRE..

 

[robsparky1975]

the green goo is apparently toxic,i have had it all over my hands before,and done the same as you researched,rewire time for them.

 

[gnselectricals]

found it on a couple of jobs ive been on, & as i have the habit of putting my terminal driver in my mouth when im busy i can tell you that it tastes like *****

 

[Sintra]

Found this about it.

Green gunge is most prevalent in cables made between 1965 and 1971. The
gunge is degraded di-isoctyl phthalate and is the result of the reaction
between the plasticisor in the insulation and the copper. Between 1965 and
1971 the temprature performance of PVC was uprated by the inclusion of an
anti-oxidant in to the PVC. An unappreciated side effect was that the
anti-oxident encouraged the production of exudate.
Evidence suggests that that high ambient temperatures accelarate the
process. The exudate is of low flammability and low toxicity. Although
unsightly it does not reduce the electrical integity of the conductor or the
insulation.

See also the draft BCA statement (April 2001) below: -

1) PVC
PVC comes in two main grades, plasticised and unplasticised PVC.
Unplasticised PVC (UPVC) is used for example in double glazing window frames
where a rigid material is required.
The PVC used for manufacture of cables is a plasticised PVC that conforms to
the relevant British Standard for the cable type in question.

2) Ageing effects
As a cable ages; (at temperatures above normal ambient), the elongation to
break decreases (also the Insulation Resistance increases). The life
expectancy of a cable is arbitrarily considered to be when the elongation to
break of the PVC is 50%.
A lower elongation to break value could be considered suitable especially
for a fixed wiring cable. Therefore, providing the cable is not subject to
movement or when moved due to inspection of socket outlet or the like, the
PVC does not crack, a much lower value of elongation to break is considered
by some as suitable.

3) Greening
Greening is the appearance of a wet green substance that is a product of an
adverse reaction between certain types of plasticiser and the copper
conductors. This greening, which is a rare occurrence, can happen either
after a long period of time for some cables, or if the cable has been
severely overheated.
The plasticiser itself is a clear oily liquid that is non conductive. The
green substance is a combination of copper oxide and plasticiser which may
become conductive under certain adverse conditions.

4) Action if Greening is found
Therefore whenever this green substance is found at socket outlets etc.
initially it should be removed and the terminations cleaned (gloves should
be used) otherwise it is possible that tracking/overheating may occur. It is
strongly recommended that rewiring should be carried out as soon as
possible.

If further information is required, the original cable manufacturer should
be contacted​

 

[nickblake]

Yes theres been a thread on this before Sintra post just about covers it all heres a link To the ESC an article about it in a switched on magazine http://www.esc.org.uk/fileadmin/user_upload/documents/public/switched_on/SwitchedOn-Issue-19.pdf

 

[DH Electrical]

Hi from what you are saying i would ask was the T&E solid or the older stranded? it is defo breakdown of the plastisizer in cable which was found in certain cables manufacturers several years ago?
DH

 

[nickblake]

Hello fellow sparky's.
I came across something on a job the other day which i think warrants me starting up my very first thread.
The job i was doing was to swap all accessories in a property for some lovely expensive polished brass ones. Problem was, when i took the switches and sockets off i would say at least 50% of them had "Green Goo". Basically the terminals in the original accessories looked like they were filled with a luminous green slime. I did the job and the customer has paid but upon researching the green goo afterwards online and consulting a snags and solutions booklet, i found out that this is a health hazard and it is recommended that the circuits affected are treated as hazardous and are re-wired (all the cable work in my particular case is sound and has been tested by me). I was just wondering if anyone has ever come across this and if so, what did you do about it because all i did was clean the conductors off? i have found this link if this helps Subcategory - 1. MV & LV Cables & Accessories - Voltimum UK - Electrical Installation Products and Contracting

Cheers guys.

Bad news is mate that the installation will require a full rewire you cant clean it off and as been mentioned in other posts its due to the plasticiser used in the manufacture of the cables that has caused this , over time the cable will deterioate so be safe and advise a rewire

 

[AlanWirral]

Who you gonna call!!????...............................

Sorry couldn't resist Nice info there sintra..

 

[mike2790]

the t&e was in quite good nick otherwise, its solid core cable and it all bells through with high IR. its the first time ive ever seen it and a few other sparky i know wanted to come and look because they hadnt seen it either. cheers fellers for the info, i'll advise the rewire, which should be fun.

 

[brucelee]

IET had it in the wiring matters magazine last month as above rewire

 

[MarkieSparkie]

Green Goo happens when cables are operated near their maximum conductor operating temperature, the green colouring is caused by the chemical reaction of PVC plasticiser on hot copper. It can also happen at lower temperatures in colourless, grey or black forms depending on the insulation chemistry, when the PVC insulation comes into contact with polystyrene (tiles & wall membrane for example), solid insulation foams (Cellotex and similar), expanding foam (Everbuild expanding foam & similar) and construction fillers (solvent version of Gripfill & similar).

 

[barnyparker]

Hi
I've just noticed green gunk in plug socket and wire about a metre before when moving a plug socket. Also in another bedroom, from what I've read the wire needs to be replaced, but how urgent is it.

Thanks

Steve

 

[Strima]

4) Action if Greening is found

Therefore whenever this green substance is found at socket outlets etc.
initially it should be removed and the terminations cleaned (gloves should
be used) otherwise it is possible that tracking/overheating may occur. It is
strongly recommended that rewiring should be carried out as soon as
possible. ​

​

Hi
I've just noticed green gunk in plug socket and wire about a metre before when moving a plug socket. Also in another bedroom, from what I've read the wire needs to be replaced, but how urgent is it.

Thanks

Steve

Highlighted bit from Sintras post.

 

[Crosswire]

"The exudate is of low flammability and low toxicity. Although
unsightly it does not reduce the electrical integrity of the conductor or the
insulation."

I'm confused.

If this is true, then why an automatic rewire without an IR test?