Science, Tech, Math › Science Preventing, Treating Stings From Jellyfish and Portuguese Man-of-War Common Household Chemistry Comes to the Rescue Share Flipboard Email Print Mataya / Getty Images Science Chemistry Medical Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated November 19, 2019 You can apply common household chemistry to treat jellyfish and Portuguese man-of-war stings. Here's a look at how to tell these marine animals apart and how the chemistry of treating the stings differs, depending on what stung you. Key Takeaways: Jellyfish and Portuguese Man-of-War Stings A jellyfish can sting you even if it's dead.Vinegar, ammonia, meat tenderizer, or heat can inactivate the toxin in jellyfish venom. However, if there is a risk a sting is from a Portuguese man-of-war, using a chemical can cause all of the stinging cells to fire at once and worsen the injury.Another method of treating a sting is to lift off the tentacle (using a credit card or seashell) and rinse the area with water.An antihistamine can help reduce allergic responses. Hydrocortisone can relieve inflammation. An over-the-counter pain reliever can help reduce pain. Don't Make the Sting Worse Do you know what to do if you or someone you're with finds a jellyfish or is stung by one? You should know the answer to these questions before you go to the beach, since an encounter with a jellyfish can be a painful or possibly lethal experience. As a matter of practical chemistry, your biggest risk from a jellyfish or Portuguese man-of-war sting may come from improper first aid intended to deal with the venom. What Should You Do If You See a Jellyfish? Best Answer: Leave it alone. If it's in the water, get away from it. If it's on the beach and you need to walk around it, walk above it (on the dune side) rather than below it (surfside), since it may be trailing tentacles. Keep in mind a jellyfish does not need to be alive in order to sting you. Detached tentacles are capable of stinging and releasing venom for several weeks. Other Answer: It depends on what kind of jellyfish it is. We realize if it looks like floating jelly, it's considered a "jellyfish," but there are different types of jellyfish and animals that look like jellyfish but are something else entirely. Not all jellyfish can hurt you. Some jellyfish are either nonvenomous or else their stinging cells can't penetrate your skin. What do you do when you see one of these? If you are a kid, you'll probably pick it up and throw it at another kid (unless it's alive, then be kind and let it be). Most parts of the world have nonvenomous jellyfish. They tend to be easy to spot. The ones you don't see present the biggest threat. Many jellyfish are transparent (but glow under a black light). You probably won't see them in the water, so if you are stung, you won't know exactly what got you. If you see a jellyfish and don't know what type it is, treat it like a venomous species and get away from it. How Do I Treat a Jellyfish Sting? Answer: If you know the victim is allergic to insect stings, seek medical attention immediately. People who are allergic to bees and wasps may experience a dangerous allergic reaction to a jellyfish sting. Otherwise, act quickly and calmly to remove the tentacles, stop the stinging, and deactivate any toxin. Here is where people get confused because the best steps to take depend on what type of animal caused the sting. Use these good basic strategies, especially if you don't know what caused the sting: Get out of the water. It's easier to deal with the sting on land, and it also takes drowning out of the equation.Rinse the affected area with seawater. Do not use freshwater. Freshwater will cause any stinging cells that haven't fired (called nematocysts) to do so and release their venom, possibly worsening the situation. Do not rub sand on the area for the same reason.If you see any tentacles, carefully lift them off the skin and remove them with a stick, shell, credit card, or towel (just not your bare hand). They will stick to swimwear, so use caution touching clothing.Keep an eye on the victim. If you see any signs of an allergic reaction, call 911 immediately. Symptoms could include difficulty breathing, nausea, or dizziness. Some redness and swelling is normal, but if it spreads outward from the sting or if you see hives on other parts of the body, that could indicate an allergic response. If you suspect a reaction, do not hesitate to seek medical attention.Now, if you are sure the sting is from a jellyfish and not a Portuguese man-of-war (not a true jellyfish) or any other animal, you can use chemistry to your advantage to inactivate the toxin, which is a protein. (Technically, the venom tends to be a mixture of polypeptides and proteins including catecholamines, histamine, hyaluronidase, fibrinolysin, kinins, phospholipases, and assorted toxins). How do you inactivate proteins? You can change the temperature or acidity by applying heat or an acid or base, such as vinegar or baking soda or diluted ammonia, or even an enzyme, such as the papain found in papaya and meat tenderizer. However, chemicals may cause the stinging cells to fire, which is bad news for someone allergic to jellyfish toxin or anyone stung by a Portuguese man-of-war. If you do not know what caused the sting, or if you suspect it is from a Portuguese man-of-war, do not apply freshwater or any chemical. Your best course of action is to apply heat to the affected area since it penetrates the skin and inactivates the toxin without causing more venom to be injected. Also, heat quickly helps alleviate the pain of the sting. Hot seawater is great, but if you don't have that handy, use any warmed object.Some people carry aloe vera gel, Benadryl (diphenhydramine) cream, or hydrocortisone cream. We're not sure how effective the aloe is, but Benadryl is an antihistamine, which may help limit an allergic response to the sting. Hydrocortisone can help reduce inflammation. If you seek medical attention and used Benadryl or hydrocortisone, be sure to alert the medical professionals. Acetaminophen, aspirin, or ibuprofen are commonly used to relieve pain.