Jellyfish release venomous nematocysts or stingers that attach to the skin and an effective method to deactivate the venom is to use acetic acid or white vinegar.
A study published in The Medical Journal of Australia revealed that after removing tentacles left behind by a jellyfish, dousing the affected area with acetic acid, which is present in regular vinegar, could relieve pain and stop the release of more venom. Do not use your hands to remove the tentacles.
Vinegar can be poured directly onto the sting or use a paper towel or cloth soaked in vinegar to apply onto the skin for thirty minutes.
However, experts do not recommend the use of vinegar on Portuguese man-of-war, a type of jellyfish that looks like a Portuguese battleship with a sail.
Source: “Old Wives’ Tale? Urine as Jellyfish Sting Remedy Vinegar Works Best, Doctors Say” ABC NEWS, 6 August 2006; Peter J Fenner and John A Williamson “Worldwide deaths and severe envenomation from jellyfish stings” Medical Journal of Australia (1996) 165:658
Chapter: Vinegar :: 30 August 2007