Water by Another Name Is Still the Same
RUMOR
Cups and containers made with polystyrene (PS) plastic leach toxic dihydrogen monoxide.
STATUS
Busted!
ORIGINS
Dihydrogen monoxide pranks have been around for years, appearing in student projects, e-mail hoaxes and a number of silly websites. (See examples: Dihydrogen Monoxide Research Division; Coalition to Ban Dihydrogen Monoxide.) The offshoot involving polystyrene arose when someone failed to recognize a hoax website for what it was. Fortunately, this version of the prank was fairly short lived.
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WHAT YOU SHOULD KNOW
All dihydrogen monoxide pranks share two things in common: (1) they are generally based in fact, and (2) they neglect to mention that “dihydrogen monoxide” is just another name for water.
(Think about it. “Dihydrogen” indicates two hydrogen atoms, or “H2.” “Monoxide” refers to a single oxygen atom, or “O.” Put them together, and you get H2O.)
If you reread the above spoof, you’ll see that the information is generally factual. For instance, dihydrogen monoxide is a real chemical compound, also known as water. Under very extreme conditions, water can cause drowning, hypothermia and other dangers. And water is used in the manufacture of polystyrene. But using water in the manufacturing process does not pose a health risk to consumers. (Now that you’re in on the prank, this should be fairly obvious.)
So, how did the particular myth about the dangers of dihydrogen monoxide in polystyrene get started? In March 2004, someone came across a dihydrogen monoxide hoax on the Internet, and without first verifying the information with an authoritative source, incorporated the bit about polystyrene into a proposed city council ordinance. Fortunately, the facts came to light and the proposal was withdrawn.
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MORE RESOURCES AND INFORMATION
- Dihydrogen Monoxide: Unrecognized Killer
Junkscience.com - Local Officials Almost Fall for H20 Hoax
MSNBC
Other MythBusting Websites
- Drowning in Dihydrogen Monoxide
BreakTheChain.org - Dihydrogen Monoxide
Snopes.com - Safety Warning: Dihydrogen Monoxide (DHMO)
Urban Legends and Folklore




Dihydrogen monoxide is colorless, odorless, tasteless, and kills uncounted thousands of people every year. Most of these deaths are caused by accidental inhalation of DHMO, but the dangers of dihydrogen monoxide do not end there. Prolonged exposure to its solid form causes severe tissue damage. Symptoms of DHMO ingestion can include excessive sweating and urination, and possibly a bloated feeling, nausea, vomiting and body electrolyte imbalance. For those who have become dependent, DHMO withdrawal means certain death.

Before you send. Spare your friends the unnecessary concern. Don’t leave yourself open to potential embarrassment. Always verify an Internet scare with an authoritative source before spreading the word. Learn more about how to research a rumor.