Hoax/Claim: Dihydrogen monoxide is dangerous and should be banned.
Dihydrogen monoxide also known as water, H2O is "colorless, odorless, and tasteless" chemical compound that is essential to all organisms in our ecosystem. The human body is composed of 60% water and the human brain is composed of 70% water.
This article claims that dihydrogen monoxide killed thousands of people each year. Majority of those accidental deaths are cause by inhalation of the water in liquid state. In the solid state, water is also known as "ice" which can cause tissue damage. Dihydrogen monoxide is a major component of acid rain, contributes to global warming, greenhouse effect, can cause severe burns in its gaseous state, and much more.
All these statements are true and scientifically proven. All the claims against dihydrogen monoxide are true. Every year there are thousands of accidents where water is the main perpetrator, water cause many death by inhalation or drowning, it is a major component in not just acid rain but rain, and so much more. Hence, this claim is replicatable and there were extraordinary evidence proving this statement.
This hoax may have such a high impact on the readers due to the somatic marker theory. The somatic marker theory proposes that we use our "gut reactions" to help us determine how we should react. Dihydrogen monoxide sounds like very complicated word which sounds similar to the word carbon monoxide. Carbon monoxide is also a colorless, odorless, and tasteless compound if ingested, can cause death. Hence these characteristics should not be correlated and labeled as harmful compounds because dihydrogen monoxide is the key component of our biological composition and our survival.
Link to Hoax Article:
http://www.snopes.com/science/dhmo.asp
It would be good to expand more on your theory of why people fall for this hoax more. That section was good.