Green Goo, What Is It and Why Is It on My Switches in Gravesend?

During our conversation, they told me they were constantly finding what looked like Fairy Liquid coming out of their light switches and sockets. They had no idea where it was coming from.

I'd seen this before. What they were finding was Green Goo, caused by the chemical breakdown of old PVC cable insulation. I explained what was happening, why simply replacing the switches would not solve the problem, and what needed to be done to make the installation safe.

This is particularly relevant in Gravesend because the town went through a huge amount of housing development between roughly 1965 and 1981. Properties from this period that have never been rewired are more likely to still contain the type of old cable associated with Green Goo.

What is Green Goo?

Green Goo is the result of old PVC cable insulation breaking down over time. Plasticisers within the insulation can react with the copper conductor, producing a sticky green substance that can eventually make its way into electrical accessories such as switches and sockets.

It can look remarkably like washing-up liquid or Fairy Liquid. That's why homeowners often assume something has been spilled or that the switch itself is producing some sort of lubricant.

The affected cable needs investigating because continued deterioration can contribute to electrical faults, overheating and an increased fire risk.

Why replacing the switch does not fix it

This was an important part of the conversation I had with the couple I visited.

They had understandably considered the Green Goo to be a problem with the accessories. Simply replacing a green-stained switch or socket would only deal with what you can see. The old cable behind it would still be breaking down.

I recommended that the affected accessories were wiped clean and that a qualified electrician investigated the installation rather than continuing to replace switches as the goo appeared.

If Green Goo gets onto your skin, wash the affected area thoroughly with soap and water.

What happened during this Gravesend inspection?

The inspection confirmed that the problem was more extensive than a couple of dirty switches. I explained to the customers that the proper remedy was a full rewire, rather than cleaning the accessories and carrying on.

I know the word "rewire" can be daunting, particularly when you have lived in a property for many years and have belongings throughout the house. My customers were understandably worried about the disruption and about what would happen to their home.

I reassured them that we would take care of their property throughout the work. During the rewire, we protected and kept their belongings clean while carrying out the installation.

Once finished, their beautiful home had been restored to its former glory, with brand new wiring and the peace of mind that the electrical installation no longer presented the same danger to them or their visitors.

Could your Gravesend home have the same cable?

If your property dates from the period of major housing development in Gravesend, particularly around 1965 to 1981, and it has not been rewired since, it is worth being aware of Green Goo.

That does not mean every property from this period has the problem. An electrical inspection is the sensible way to establish what condition the wiring and accessories are actually in.

I regularly carry out electrical inspections, and depending on the type and use of a property, an inspection is generally recommended at least every 10 years.

For landlords, an EICR is also an important part of checking the condition of an electrical installation.

What should you do if you find Green Goo?

Don't assume it is simply dirt or something coming from the switch. Wipe the affected accessory clean, avoid unnecessary contact with the substance, and arrange for a qualified electrician to investigate the cause.

Depending on what is found, the work could involve a rewire or partial rewire. An inspection will help establish what is actually required rather than replacing accessories one at a time without addressing the underlying cable.

I have more than 10 years' experience as an electrician, and I take pride in treating other people's properties as I would my own. I keep the work area tidy, take care with customers' belongings and remain contactable throughout the job.

I'm a NICIEC Approved Contractor and work under Part P and the Competent Person Scheme. I've also received an Excellent rating on Trustpilot and have 72 five-star Google reviews.

FAQs

What do I do if I spot Green Goo coming out of my switches?

I recommend wiping the affected accessory clean and arranging for a qualified electrician to investigate promptly. Replacing the switch alone will not deal with old cable insulation that is continuing to break down.

Why is there Fairy Liquid on my light switch?

It may not be Fairy Liquid at all. Green Goo from deteriorating PVC cable insulation can look very similar to washing-up liquid and can appear around switches and sockets.

What is Green Goo?

Green Goo is produced when old PVC cable insulation breaks down and its plasticisers react with the copper conductor. It can indicate deteriorating wiring that needs investigation.

What can be done to fix Green Goo?

I would first inspect the electrical installation to establish the extent of the problem. Where the old cable is affected, the appropriate remedy can be a rewire or partial rewire rather than repeatedly replacing the switches.

Is Green Goo dangerous?

It can indicate deteriorating cable insulation, which can contribute to electrical faults, overheating and fire risk. If you find it, I would recommend getting the installation investigated rather than treating it as cosmetic dirt.

Call me today if you have noticed Green Goo. I'm happy to take a look, explain what I've found and talk you through the options, with no obligation.