A friend of mine says his workplace has had a hot water heater broken for over a month. The company refuses to fix it. My friend claims hot water should be provided in the rest rooms and clean up areas for personal cleaning. The boss man says that the cleaning and sanitization comes from the soap, and that water temperature is for comfort only.
Can the company really ignore the lack of hot water and is a warmer water temperature really just a convenience item when it comes to washing your face and hands?
Unless one’s hands are REALLY grimey, cold water should do fine for hand washing.
Personal cleaning? Does this company have showers? Or do you mean like tupperware containers for lunch or something.
Cold water should be fine for dishwashing and cleaning hands, but hot water would be better.
I believe the reason why hot water is better is because it imparts thermal energy to the dirt and soap. the detergent molecules are moving more vigoriously and thus are more likely to capture some dirt molecules into their little micelle of hygeinc doom.
Sounds like scientific reasoning, so let’s see how big this difference might be: How much greater is the thermal enegy in 40[sup]o[/sup]C water, compared with 10[sup]o[/sup]C? As the thermal energy is proportional to the absolute temperature, that is easily seen by comparing 313K and 283K, which is about 10%. Clearly not enough to make much of a difference.
Much more likelly.
But I believe that there’s another effect as well. The solubility of most solids (as opposed to gasses!) increases with increasing temperature. Unfortunatelly I have no data on the solubility of grime versus temperature, but if any dopers have such tables, please post them!
It’s also worth noting that the viscosity of water decreases noticably as the temperature increases. I don’t think this effect is great enough to cause any measurable difference when washing up though.
No, don’t tell him anything. Clearly, he wouldn’t listen anyway.
Tell your local health inspector.
Or the nearest office of OSHA.
Or your Union Steward.
Or the local TV station’s Investigative Reporter (especially during sweeps week).
Or even try telling your boss’s boss (and mention how embarrassing it would be for the company if “somebody” were to tell all these other people).
But the rate and amount of energy transferrence is related to the temperature differential. Given that 10C water is likely to be colder than the detergent, it will cool things down while the 40C water will heat things up.