Originally Posted by raymor

Dihydrogen monoxide for one. Some risks of dihydrogen monoxide:

Death due to accidental inhalation of DHMO, even in small quantities.
Prolonged exposure to solid DHMO causes severe tissue damage.
DHMO is a major component of acid rain
Gaseous DHMO can cause severe burns.
Contributes to soil erosion.
Leads to corrosion and oxidation of many metals.
Contamination of electrical systems often causes short-circuits.
Exposure decreases effectiveness of automobile brakes.
Found in biopsies of pre-cancerous tumors and lesions.
Given to vicious dogs involved in recent deadly attacks.