Re-boiling water

Not heard of that, but I know that you cannot use reboiled water to make baby formula.

...

Further, consumers are advised to empty the water in the thermal pots regularly and fill in fresh water to start boiling anew, instead of adding water and reboiling the contents repeatedly. This is because there may be in the water chemical impurities which may accumulate and become concentrated over time through repeated boiling.

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http://www.consumer.org.hk/website/ws_en/news/press_releases/p320.html

The problem is not the water itself it is the pipes that carry all the gunk to your tap

roger52 is right; we don't know where the WHO tests their water, but it gets delivered to our homes through a variety of pipes. Its very common for water to be contaminated in transport rather than from the source, so filtering and boiling are, at least, no harm. I use an inline filter on my faucet (from TaiKoo: $400) that has a filter pore space of .1micrometers. Thats small enough to filter giardia, something that I've heard is a problem on the south side.


Boiling water kills any bacteria that makes it through the filter (at this pore size, it would be because of bad seals in the filter), but it does nothing to remove the heavy metals. Those accumululate in the pot, but you would need to boil ALL the pot dry, then refillthe pot to nearly double your heavy metal content. You get that same HM content by just drinking two potfuls of water, so I think a regular rinsing of the pot is sufficient. I sure wouldn't treat water that has been boiled twice or three times as something poisionous...just don't do it all the time.