From the Material Safety Data Sheet. AU
I suppose this applies to musicians too...

SKIN
If solids or aerosol mists are deposited upon the skin:
- Flush skin and hair with running water (and soap if available).
- Remove any adhering solids with industrial skin cleansing cream.
- DO NOT use solvents.
- Seek medical attention in the event of irritation
SAFETY
Do not breathe gas/fumes/vapour/spray.
Wear eye/face protection.
Use only in well ventilated areas.
Keep container in a well ventilated place.
Keep container tightly closed.
Take off immediately all contaminated clothing.
In case of contact with eyes, rinse with plenty of water and contact Doctor or
Poisons Information Centre.
If you feel unwell contact Doctor or Poisons Information Centre. (Show the label
if possible).
From WD-40 facts:
What surfaces or materials are OK to use WD-40 on?
WD-40 can be used on just about everything. It is safe for metal, rubber, wood and plastic. WD-40 can be applied to painted metal surfaces without harming the paint. Polycarbonate and clear polystyrene plastic are among the few surfaces on which to avoid using a petroleum-based product like WD-40.
What does WD-40 contain?
While the ingredients in WD-40 are secret, we can tell you what WD-40 does NOT contain. WD-40 does not contain silicone, kerosene, water, wax, graphite, chlorofluorocarbons (CFCs), or any known cancer-causing agents.
I suppose this applies to musicians too...

SKIN
If solids or aerosol mists are deposited upon the skin:
- Flush skin and hair with running water (and soap if available).
- Remove any adhering solids with industrial skin cleansing cream.
- DO NOT use solvents.
- Seek medical attention in the event of irritation
SAFETY
Do not breathe gas/fumes/vapour/spray.
Wear eye/face protection.
Use only in well ventilated areas.
Keep container in a well ventilated place.
Keep container tightly closed.
Take off immediately all contaminated clothing.
In case of contact with eyes, rinse with plenty of water and contact Doctor or
Poisons Information Centre.
If you feel unwell contact Doctor or Poisons Information Centre. (Show the label
if possible).
From WD-40 facts:
What surfaces or materials are OK to use WD-40 on?
WD-40 can be used on just about everything. It is safe for metal, rubber, wood and plastic. WD-40 can be applied to painted metal surfaces without harming the paint. Polycarbonate and clear polystyrene plastic are among the few surfaces on which to avoid using a petroleum-based product like WD-40.
What does WD-40 contain?
While the ingredients in WD-40 are secret, we can tell you what WD-40 does NOT contain. WD-40 does not contain silicone, kerosene, water, wax, graphite, chlorofluorocarbons (CFCs), or any known cancer-causing agents.