Fact Check

Is Dihydrogen Monoxide Dangerous?

The dihydrogen monoxide hoax shows that even the most innocuous of substances can be made to sound like a dangerous threat to human life.

Published Jun 22, 1999

Updated Apr 1, 2013
A water faucet image for a story about dihydrogen monoxide. (Shutterstock/Jakub Zak)
A water faucet image for a story about dihydrogen monoxide. (Image Via Shutterstock/Jakub Zak)
Dihydrogen monoxide is a dangerous chemical that should be banned.

On April Fool's Day in 2013, a pair of Florida disc jockeys got themselves into a bit of hot water with station management for prankishly warning their listeners that "dihydrogen monoxide" — another name for that life-giving substance we identify as H2O, or more commonly, "water" — was coming out of local residents' taps:

The radio station's joke involved that “dihydrogen monoxide” was coming out of county residents' taps.The joke immediately got the attention of Patty DiPiero from Lee County Utilities. She said Lee County residents began calling the utility saying they heard on the station that county water was unsafe and should not be used for drinking, showering or for any use.

DiPiero stressed in an email to media outlets that the utility was not having any issues with the water supply and the water is safe to use.

However, some people believed the hoax, at least for a short time.

One woman wrote in saying she worked in the food service industry and was trying to figure out how to serve customers and prepare food without requiring water.

Lee County residents were far from the first people to fall for this venerable jape. Back in September 2007, for example, news media reported that a New Zealand MP was tricked by a letter from a constituent asking her to raise the issue of "dihydrogen monoxide" (DHMO):

National MP Jacqui Dean has been caught out by a long-running hoax that seeks to trick gullible MPs into calling for a ban on "dihydrogen monoxide" — or water. A letter, signed by Ms Dean and sent to Associate Health Minister Jim Anderton, the minister in charge of drug policy, asked if the Expert Advisory Committee on Drugs had a view on banning the "drug".

Mr Anderton yesterday took the opportunity to rub Ms Dean's nose in the embarrassing blunder.

He said dihydrogen monoxide "may have been described to her as colourless, odourless, tasteless and causing the death of uncounted thousands of people every year, and withdrawal from which, for those who become dependent on it, means certain death.

"I had to respond that the experts had no intention of doing so."

In 1997, Nathan Zohner, a 14-year-old student at Eagle Rock Junior High School in Idaho Falls, made the news when he based his science fair project on a warning similar to the one reproduced in the "Example" box above. Zohner's project, titled "How Gullible Are We?", involved presenting that warning about "the dangers of dihydrogen monoxide" to fifty ninth-grade students and asking them what (if anything) should be done about the chemical:

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.Dihydrogen monoxide:

  • is also known as hydroxl acid, and is the major component of acid rain.
  • contributes to the "greenhouse effect."
  • may cause severe burns.
  • contributes to the erosion of our natural landscape.
  • accelerates corrosion and rusting of many metals.
  • may cause electrical failures and decreased effectiveness of automobile brakes.
  • has been found in excised tumors of terminal cancer patients.

Contamination is reaching epidemic proportions!

Quantities of dihydrogen monoxide have been found in almost every stream, lake, and reservoir in America today. But the pollution is global, and the contaminant has even been found in Antarctic ice. DHMO has caused millions of dollars of property damage in the midwest, and recently California.

Despite the danger, dihydrogen monoxide is often used:

  • as an industrial solvent and coolant.
  • in nuclear power plants.
  • in the production of styrofoam.
  • as a fire retardant.
  • in many forms of cruel animal research.
  • in the distribution of pesticides. Even after washing, produce remains contaminated by this chemical.
  • as an additive in certain "junk-foods" and other food products.

Companies dump waste DHMO into rivers and the ocean, and nothing can be done to stop them because this practice is still legal. The impact on wildlife is extreme, and we cannot afford to ignore it any longer!

The American government has refused to ban the production, distribution, or use of this damaging chemical due to its "importance to the economic health of this nation." In fact, the navy and other military organizations are conducting experiments with DHMO, and designing multi-billion dollar devices to control and utilize it during warfare situations. Hundreds of military research facilities receive tons of it through a highly sophisticated underground distribution network. Many store large quantities for later use.

Forty-three students favored banning DHMO, six were undecided, and only one correctly recognized that 'dihydrogen monoxide' was actually plain old water. Zohner's analysis of the results he obtained won him first prize in the Greater Idaho Falls Science Fair; garnered him scads of attention from newspapers, magazines, radio and TV stations, universities, and congresspeople; and prompted the usual round of outcries about how our ignorant citizenry doesn't read critically and can be easily misled.

Even back then Nathan Zohner's project wasn't original, as spoof petitions about dihydrogen monoxide and other innocuous "dangers" had been circulating for years, and Nathan based his project on a bogus report that was already making the rounds of the Internet. Moreover, his target audience was ninth-graders, a group highly susceptible to allowing peer pressure to overwhelm critical thinking. Thrust any piece of paper at the average high school student with a suggestion about what the "correct" response to it should be, and peer pressure pretty much assures you'll get the answer you're looking for. Someone that age isn't very likely to read a friend's petition calling for the banning of whale hunting and critically evaluate the socio-economic and environmental impact of such a regulation; instead, he's probably going to say to himself, "This issue is obviously important to my friend, and he must have some good reasons for circulating the petition, so I'll sign it."

That said, this example does aptly demonstrate the kind of fallacious reasoning that's thrust at us every day under the guise of "important information": how with a little effort, even the most innocuous of substances can be made to sound like a dangerous threat to human life.

In March 2004 the California municipality of Aliso Viejo (a suburb in Orange County) came within a cat's whisker of falling for this hoax after a paralegal there convinced city officials of the danger posed by this chemical. The leg-pull got so far as a vote's having been scheduled for the City Council on a proposed law that would have banned the use of foam containers at city-sponsored events because (among other things) they were made with DHMO, a substance that could "threaten human health and safety."


Braun, Michael.   "April Fools Prank Foes Awry, Gator Country Deejays Suspended."     [Bonita] News-Press.   1 April 2013.

Glassman, James K.   "Dihydrogen Monoxide: A Killer."     The Denver Post.   22 October 1997   (p. B7).

Ridley, Matt.   "Acid Test: Dihydrogen Monoxide: Now There's a Real Killer."     The Daily Telegraph.   15 September 1997   (p. 20).

Roddy, Dennis B.   "Internet-Inspired Prank Lands 4 Teens in Hot Water."     Pittsburgh Post-Gazette.   19 April 1997   (p. A1).

Associated Press.   "Sophomore's Project Makes People Think."     St. Louis Post-Dispatch.   2 November 1997   (p. E4).

Associated Press.   "SoCal City Falls Victim to Internet Hoax."     The [San Jose] Mercury.   14 March 2004.

stuff.co.nz.   "National MP Falls Victim to Water Hoax."


Update [15 March 2004]: This article has been updated to include Aliso Viejo.

Update [16 September 2007]: This article has been updated to add information about New Zealand

Update [02 April 2013]: This article has been updated with information about Florida disc jockey.

David Mikkelson founded the site now known as snopes.com back in 1994.

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