The essentials in 30 seconds
Contact cleaner is a non-conductive solvent spray that removes dust, dirt, oil, flux residue and condensation from electrical contacts and components and evaporates without leaving residue. WD-40 Specialist's directions: isolate all power, let hot surfaces cool and drain any stored power, shake the can, spray from 15 to 20 cm, let the excess run off, then let it dry completely and ventilate before restoring power. CRC's sheet says never spray it on energised equipment or circuits, to put out flames, pilot lights and heaters first and to test on sensitive plastics, adhesive-mounted or stressed parts. The WD-40 Specialist safety data sheet classifies it as an extremely flammable aerosol that can cause skin and serious eye irritation and drowsiness or dizziness, so use it with ventilation, gloves and eye protection.
- It cleans; it is not a lubricant.
- It does not repair worn, burnt or loose contacts.
What is electrical contact cleaner?
| Question | Answer |
|---|---|
| What it removes | Dust, dirt, oil, flux residue, fingerprints and condensation that cause poor contact, current leakage or corrosion |
| Where to use it | Switches, controls, connectors, plugs and sockets on equipment, relays, circuit boards, sensors, printers, tape heads |
| Conductive? | No: both WD-40 Specialist and CRC describe it as non-conductive |
| Residue | Evaporates completely, leaving no residue |
| Materials | WD-40 says plastics, rubber and metal; CRC says most rubbers, plastics and coatings, testing sensitive plastics first |
| Hazard | Extremely flammable aerosol (WD-40 Specialist SDS) |
How to clean electrical contacts
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01
Isolate the power
Unplug the device or switch off its supply. Let hot surfaces cool and, as WD-40 says, make sure any stored power has drained.
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02
Remove ignition sources
Put out any flames, pilot lights and heaters nearby, as CRC instructs, and do not smoke.
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03
Ventilate
Open windows or work outdoors, because flammable vapours can build up, especially inside closed equipment.
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04
Test first
Try a small area on sensitive plastics, glued or stressed parts.
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05
Spray
Shake the can, hold it 15 to 20 cm away and spray the contacts. Use the straw for tight spots.
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06
Let it run off
Tilt the part so the excess drains away.
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07
Dry and vent
Wait until it is completely dry and the vapours have gone before restoring power.
What the safety data sheet warns about
The WD-40 Specialist Contact Cleaner safety data sheet (version 17, October 2026) lists these hazards and precautions:
- H222 / H229: extremely flammable aerosol; pressurised container that may burst if heated.
- H315 / H319: causes skin irritation and serious eye irritation.
- H336: may cause drowsiness or dizziness.
- H411: toxic to aquatic life with long-lasting effects, so do not pour it away or spray it outdoors near drains.
- Precautions: keep away from heat, sparks and flames; do not spray on a flame; do not pierce or burn the can, even when empty; avoid breathing the spray; wear protective gloves and eye protection; protect from sunlight and do not expose to temperatures above 50 °C.
Its solvents include propan-2-ol (isopropyl alcohol) and light hydrocarbons, according to the same sheet.
What contact cleaner will not fix
- Burnt, pitted or loose contacts: CRC's sheet says oxide and carbon deposits need an abrasive, with the cleaner used to rinse. A burnt switch or a loose connection needs replacing or repairing, not spraying.
- Lubrication: contact cleaner evaporates; CRC suggests re-lubricating with a separate product if the part needs it.
- Faults in the mains wiring: scorch marks, a burning smell, buzzing or a socket that gets hot are jobs for an electrician.
Electrical contact cleaner: frequently asked questions
What is electrical contact cleaner used for?
Removing dust, oil, flux residue and moisture from switches, connectors, controls and circuit boards to restore good contact.
Can I spray contact cleaner on live electronics?
No. Isolate all power first, and only restore it once the product is completely dry and the vapours have cleared.
Is contact cleaner safe on plastic?
On most plastics, rubbers and coatings, but test sensitive plastics, glued or stressed parts first.
Is contact cleaner flammable?
Yes. The WD-40 Specialist safety data sheet classifies it as an extremely flammable aerosol.
Does contact cleaner leave a residue?
No. It is designed to evaporate completely without residue.
Is contact cleaner the same as WD-40 Multi-Use?
WD-40 Specialist Contact Cleaner is a separate product, sold as a fast-drying, non-conductive cleaner for electrical components.
Sources
Manufacturer sources, checked on 2 November 2026 (02/11/2026).
- WD-40 UK · Specialist Fast Drying Contact Cleaner ↗Non-conductive; removes dirt, dust, oil, condensation and flux residue; dries before powering up; circuit boards, switches, printers, tape heads; plastics, rubber and metal; Smart Straw and 360° valve. Read in the browser.
- WD-40 Specialist Contact Cleaner · Technical data sheet (PDF) ↗Directions: isolate all power, let hot surfaces cool, drain stored power, shake, spray from 15 to 20 cm, tilt to run off, dry completely and vent before restoring power; check with the manufacturer of precision instruments; classed as extremely flammable.
- WD-40 Specialist Fast Drying Contact Cleaner · Safety data sheet, version 0017 of 19 October 2026 (PDF) ↗H222, H229, H315, H319, H336, H411 and precautionary statements; propan-2-ol and hydrocarbon solvents. Linked from the WD-40 UK product page.
- CRC Industries Europe · Contact Cleaner technical data sheet, ref. 10151 (PDF) ↗Non-conductive, evaporates without residue; relays, switches, connectors, plugs and sockets, circuit boards; safe on most rubbers, plastics and coatings, test sensitive, adhesive-mounted or stressed parts; do not spray on energised equipment; put out flames, pilot lights and heaters; ventilation; dry thoroughly before reactivating; abrasive for oxide and carbon deposits; re-lubricate if needed.
Contacts still faulty after cleaning?
A burnt, loose or overheating switch or socket needs repair, not more spray: call a qualified electrician.