Overview from Wikipedia (H/T Raymond)

Dihydrogen monoxide:

• is also known as hydroxyl 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

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.

Material Safety Data Sheet from ChemSafe

Even worse is the contribution of DHMO to the climate crisis

Conclusion: Stop obsessing over Carbon Dioxide, and Ban Dihydrogen Monoxide Now!