Vinegar has a MSDS sheet. You can read the whole document here:

Part of that MSDS sheet says:

SKIN CONTACT: Contact may cause mild injury and burns from vinegars of 11% acetic acid and greater. Dilute solutions may cause dermatitis in some individuals.

EYE CONTACT: May cause severe burns and permanent corneal injury from concentrated vinegars. May be followed by blindness. High vapor concentrations may result in conjunctivitis.

INGESTION: Concentrated vinegars may cause pain, irritation and burns in mouth, gullet and stomach.


SPECIAL FIRE FIGHTING PROCEDURES: Water may be used to dilute spills and reduce flammability.
UNUSUAL FIRE AND EXPLOSION HAZARDS: Toxic gasses and vapors may be released in a fire involving concentrated vinegar.

I hope you don't mind if I just stick to ranch salad dressing!