Water is a most interesting substance. It forms the basis of life as we know it and can be used for cooking, cleaning, swimming or dumping on your younger brother.
Aside from dumping it on my brothers, one of the properties of water which I’ve always found interesting is that it’s composed of Hydrogen and Oxygen. Combine them and they form water; but separate them and they burn – leaving water as the only residue.
Given the tendency of its constituent elements to combine in a flash of flame, water seems an unlikely choice for extinguishing a fire, and yet that’s exactly what you use in most cases. (The most common exceptions being, of course, grease and electrical fires.)
The reason it’s safe to use water on most fires is that once they’re combined, the Hydrogen and Oxygen atoms form a bond which requires a great deal of energy to break. In order for a fire to split water molecules back into individual atoms, the fire would have to be around 6,000 degrees Fahrenheit. By comparison, the water in your water heater is generally only 140 degrees or so. Nowhere near the temperature required for the gases to dissociate and burn.
Knowing all that, perhaps I’m being something of an alarmist. But I can’t help thinking it might be cause for concern when midway through a load of laundry, smoke starts coming out of the washing machine.