The term ‘contact cleaner’ is not necessarily obvious to everyone. Just what is contact cleaner? Simply put, contact cleaners are typically aerosols filled with compressed air and a cleaning agent that evaporates. A number of cleaning agents can be used; however, isopropyl alcohol is perhaps the most widely used chemical agent for this purpose. The purpose of using an electrical contact cleaner is to perform cleaning of electrical components so that they can function properly for an extended period.

Whether it is oil, grease, corrosion, or a food substance that contaminates an electrical or electronic component, a contact cleaner can be used to effectively dislodge all of these foreign elements so that the components can be put back into place, in their original condition. Contact cleaners are available under several brands, which means that they are available in different qualities and specifications.

Better understand contact cleaners: Definitions:

What is a contact?

We talk about contact when two parts made of metals (or materials) conductors of electricity are connected to pass the current. An electrical outlet constitutes a ‘contact’. And when we speak of ‘contact’ it means an ‘electrical connection’ or the socket itself.

What is Dielectric strength?

Dielectric resistance measures the ability of a material or a liquid to withstand an electric current before reaching its breakdown voltage. Once the breakdown voltage has been reached, the material can no longer withstand (nor insulate) the electric current.

WD-40® Specialist Contact Cleaner has a dielectric strength of 33,800 volts.

The reason why dielectric strength remains an important factor in the case of WD-40 Specialist Contact Cleaner is when equipment or devices are energised before the contact cleaner has completely evaporated. In these cases, the dielectric strength ensures that ‘breakdown’ cannot occur.

Drying time:

There is a balance between degreasing power and drying time. You cannot have both strong cleaning power and rapid drying. A contact cleaner must be less ‘aggressive’ (low degreasing power) to avoid damaging sensitive electronic components.

Kb value:

The Kauri-Butanol value is an international standard that measures the cleaning power of hydrocarbon solvents. A higher Kb value means that the solvent is more aggressive in its ability to dissolve certain materials.

Kb 10’s-20’s = mild solvent

Kb> 100’s = powerful (or very aggressive) solvent

A cleaning solvent with a high Kb value (> 100) is too aggressive for sensitive materials. These solvents are so aggressive that they can accidentally damage certain materials such as plastics, soft metals, and rubber. They are therefore potentially dangerous for electrical circuits.

NSF accreditation:

NSF accreditation is a minimum requirement that allows the authorisation of approved industrial products in many industry sectors. It opens the door to many possibilities. Certification protects food, water, consumer products and the environment.

WD-40 Specialist Contact Cleaner: Features & Benefits

What is a contact cleaner and how do I use it?

Our WD-40 Specialist Contact Cleaner is fast-acting, non-conductive and non-corrosive that is suitable to use on all sensitive electrical components. It provides excellent cleaning performance, with minimal fuss, and removes dirt, dust, condensation, and flux residue with ease and without damaging sensitive electrical/electronic components. In addition, it prolongs the life of electrical equipment and is compatible with all plastics, rubbers and metals.

Unlike some contact cleaners on the market, WD-40 Specialist Contact Cleaner leaves no residue or deposits that could build up and possibly cause problems, such as a short circuit.

Its Kb value is 62.3 KbV, so it is considered neither as a mild solvent, nor as an aggressive solvent and is therefore a good compromise for cleaning electrical components efficiently, without risk of damaging them.

It is NSF-K2 certified. It therefore falls into the category of cleaners for electrical equipment: “use permitted as a solvent for cleaning of instruments and electronic devices which do not tolerate aqueous cleaning solutions in and around food processing areas, provided that the cleaning product is not intended to come into direct contact with food. Before using this product, all food products and packaging must be removed from the work area and placed under protection. ”

Practical and simple to use, it has a Smart Straw applicator, meaning you have two ways to spray. Use the flip up straw for hard-to-reach areas, such as inside chains, locks or rollers, then flip it down to use the wide-angle spray eye for larger area coverage on surfaces. Whichever way you need to spray, you can rely on the clever 360° valve to work efficiently at every angle, even upside.

How to use Contact Cleaner?

  1. Turn off the power and allow hot surfaces to cool.
  2. Make sure all stored power is drained from the system.
  3. Shake the aerosol well.
  4. Hold the aerosol 15-20cm away from the surface and spray directly onto the electronic component or circuit board.
  5. Tilt the surface during cleaning to release any excess cleaner.
  6. Let the product dry completely and ventilate the system thoroughly before restoring power.

Example of uses of a cleaner for electrical contacts

Below are some examples of uses according to the sectors:


  • Electrical components and printed circuit boards
  • Fuses and switches
  • Alarms and signalling systems


  • Circuit breakers
  • Heating and air conditioning control panels
  • Male and female sockets
  • Fuse boxes
  • Connectors for gates, roller shutters, etc.
  • Boiler electronic boards


  • Battery terminals
  • Parking sensors
  • Switches or printed circuit boards
  • 12V socket or USB socket
  • Electrical contacts for rear lights and trailer sockets


  • Battery contacts for remote control
  • Audio sockets and jacks
  • Alarms and detectors
  • Fuses and switches

With that, you should have all the information you need on what contact cleaners are and how they can be applied. In many cases, it might be just the cleaner you need for your electrical project. For more in-depth knowledge, check out our full guide on How to Use Contact Cleaners!