Water heated by sunlight….Harmful?

Which is harmful and what kind of harm is expected.

1)Water is heated by direct sunlight.

2)Water inside a covered tank is heated by sunlight.

[quote=“signode, post:, topic:”]

Which is harmful and what kind of harm is expected.

1)Water is heated by direct sunlight.

2)Water inside a covered tank is heated by sunlight.

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I don’t think its harmful as it kills the germs so its beneficial :D

Dont think its harmful

Its a tricky question because if you read on mineral water bottles and cans they say keep it away from direct rays of sunlight

[quote=“highway, post:4, topic:14540”]

Its a tricky question because if you read on mineral water bottles and cans they say keep it away from direct rays of sunlight

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That is because the material of the PET bottle melts and mixes with mineral water or beverage.

^ Point taken...

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[quote=", post:7, topic:14540"]

Melting point of plastic bottle is not so low. I have seen a guy on Discover channel boiling water in pet plastic bottles over flame (keeping them 1 or 1.5 feet above from flame). Moreover, mineral water or carbonated water bottles are supplied via trucks in extremely hot weather and these can tolerate 50+ degree centigrade of temperature. People also use plastic tanks placed on roofs, water gets extremely hot in them but they tolerate the high temperature.

If someone wants to heat water in sunlight, preferably use stainless steel utensil. But plastic bottle can also be used.

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Ahmed Talal

Melting is a general and usually understandable term by everyone, but now I will dig all the chemistry behind it.

Plastics are of zillion types and all are hydrocarbon products, basically derived from petroleum and fossil remains. PET is PolyEthylene Terephthalate, it is a universally accepted fact that taste of water or beverage is changed when it is stored in a PET bottle especially on high ambient temperature.

[quote=", post:, topic:"]
Acetaldehyde, which is found in trace amounts in PET bottles after production, affects the taste of the water content especially when the bottles are exposed to elevated heat. Tests show the presence of a slight fruity taste from a PET bottle which was stored at 490 (120F) for 72 hours. A similar taste was also observed from a year-old bottle stored at ambient temperature. The intensity of the taste varies among PET resins.
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Source: http://www.packagingconsultancy.com/polyethylene-terephthlate-water-bottles.html

That is the reason why mineral water/beverage manufacturers put this clear cut instruction “Don’t expose to direct sunlight or heat”

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[quote=", post:9, topic:14540"]

Longer period is not a day or two but many days or weeks or months… You must consider the ‘‘duration’’. A short duration of few hours or few days is not enough for PET bottle to get itself decomposed. You must have seen delivery vehicles carrying bottles from factories in extremely hot noons. So, what is your take on it?

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Put a mineral water bottle in your car tomorrow noon for two hours on the dashboard and then try to drink this water, you will know the difference even after you have cooled it down to ambient temperature.

Buy two regular glass bottles of Shezan, open one bottle and pour all of the beverage into an empty plastic / PET bottle. Now put this PET bottle + other glass bottle of Shezan together in the car for 2-3 hours. Taste both of them, you will feel glass bottle beverage just hot but no change in taste while the same beverage in PET bottle when tasted, will tell you how wrong you could be :)

PET bottles transported on open trucks in direct sunlight is not a recommended procedure which you are quoting as an example to prove your point. They are basically doing wrong.

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Lets back to my question. B)

I've seen UN videos about how they are helping the poor in Africa get safe drinking water by placing transparent plastic water bottles the sun for a few hours; so it should be relatively safe.

You can get very detailed information about it here http://en.wikipedia.org/wiki/Solar_water_disinfection

I don't think water inside a covered tank would be affected much by the sun at all.

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[quote=", post:11, topic:14540"]

Now, you are arguing needlessly just to prove nothing. The whole world drinks bottled beverages bottled in plastic bottles without noticing if these have slight taste difference or not.

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The whole world also agrees that PET bottle changes the taste of beverages and this process gets accelerated with higher ambient temperature.

Taste sense is different from person to person.

Now let’s get back to original topic.

[quote=“signode, post:12, topic:14540”]

Lets back to my question. B)

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I assume you mean usage of such water for drinking.

Sunlight does no harm at all, it is actually benificial. It is the type of container which can do little / more harm to water when temperature gets higher.

I can clearly tell taste difference in tap water if overhead tank is a plastic type rather than a concrete / cemented tank.

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[quote=", post:17, topic:14540"]

There is no point in it. I have good sense of taste but I do not feel it.

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Is there any point in “I have good sense of taste but I do not feel it” ?

Taste, liking, disliking, choice are different amongst humans. If you don’t feel something, why forcing others not to feel it as well ?

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