WD-40 COSHH assessment guide

Garages, maintenance teams and workshops use WD-40 aerosols to free seized parts and displace moisture. The sheet's main concerns are an extremely flammable pressurised can, vapours that cause drowsiness, and harm if the liquid gets into the lungs after swallowing.

Taken from the WD-40 Multi-Use Product aerosol safety data sheet from WD-40 Company Limited, revision 18 February 2026. Open the data sheet. Formulas differ between products, so check against the sheet for the product you actually buy. Section 2.1 of this sheet classifies the product H304, but the label list in section 2.2 leaves it out. We show H304 here because section 16 confirms the classification. The sheet is in EU format; we found no GB version.

Hazards on the data sheet

Signal word: Danger.

H222 Extremely flammable aerosol.
H229 Pressurised container: May burst if heated.
H336 May cause drowsiness or dizziness.
H304 May be fatal if swallowed and enters airways.
EUH066 Repeated exposure may cause skin dryness or cracking.

Precautions

P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
P211 Do not spray on an open flame or other ignition source.
P251 Do not pierce or burn, even after use.
P301+P310 IF SWALLOWED: Immediately call a POISON CENTER / doctor.
P331 Do NOT induce vomiting.
P410+P412 Protect from sunlight. Do not expose to temperatures exceeding 50 °C.

Workplace exposure limit

EH40/2005 has no entry for WD-40 itself. It does list carbon dioxide, a component named on the sheet, at 5000 ppm (8-hour) and 15000 ppm (15-minute). The sheet also gives 800 mg/m³ for the hydrocarbon solvent. That is the supplier's calculated figure, not a legal limit.

PPE

Eyes	Tight fitting protective goggles with side protection (EN ISO 16321-1).
Hands	Protective nitrile gloves (EN ISO 374). Minimum layer thickness >= 0,4 mm; permeation time >= 480 minutes. Recommended maximum wearing time is 50% of breakthrough time.
Breathing	Normally not necessary. If the workplace limit value is exceeded: Filter A P3 (EN 14387), code colour brown, white.
Skin	Protective working garments (e.g. safety shoes EN ISO 20345, long-sleeved protective working garments).

First aid

Eyes	Remove contact lenses. Wash thoroughly for several minutes using copious water. Seek medical help if necessary.
Skin	Remove polluted, soaked clothing immediately, wash thoroughly with plenty of water and soap; in case of irritation of the skin (flare), consult a doctor.
Breathed in	Supply person with fresh air. Remove person from danger area. Respiratory arrest - artificial respiration apparatus necessary.
Swallowed	Rinse the mouth thoroughly with water. Consult doctor immediately - keep Data Sheet available. Do not induce vomiting. Danger of aspiration.

Storage, spills and what to keep it away from

Storage	Observe special regulations for aerosols. Keep protected from direct sunlight and temperatures over 50°C. Store in a dry, cool, well ventilated place. Keep out of access to unauthorised individuals. Not to be stored in gangways or stair wells.
Spills	Ensure sufficient ventilation and remove sources of ignition. Avoid inhalation and contact with eyes or skin. Prevent from entering drainage system. Soak up with absorbent material (e.g. universal binding agent, sand, diatomaceous earth) and dispose of according to Section 13.
Keep away from	Avoid contact with strong oxidizing agents.

What your assessment still has to cover

Record how many cans are used in a shift, whether spraying happens in a pit, booth or other enclosed space where vapour builds up, and what ignition sources are nearby: welding, grinding, pilot lights. Note where cans are stored, because the sheet sets a 50°C limit.

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