is my tap water safe to drink?

[porina]

A quick note on units, ppm = mg/l and ppb = ug/l. 1000ppb = 1ppm. Be careful when comparing between different reports.

 

Lead has always been a concern. In parts of the UK there are still lead pipes in active use, and sitting water in them can elevate levels. Water companies in those areas put additives (some kind of phosphate) to prevent the water from picking up the lead from the pipes.

 

Actually, same could be said of copper. Water sitting in copper pipes will pick up detectable quantities of it. As an experiment I used an aquarium grade copper test kit, and my "clean" sample (flushed from cold tap) was visibly lower than my "contaminated" sample which sat for a period in my water system. I wouldn't trust the kit enough to say what levels they were, but it was detectable.

 

I think at a basic level, you could fit a carbon filter to the water system. This removes many things like chlorine (but not necessarily effective on chloramine unless they're designed for it) and heavy metals, but you have to remember to replace them regularly to remain effective. Reverse osmosis is the next level and will remove various % of things in water. It depends on the specific item how well it gets removed. For example, most things will be removed at 95% or better, but nitrate can be 80% or lower. To give it an extra polish, you can put a de-ionisation resin stage after it, but this is probably overkill for drinking water. It will obviously add more cost and complexity.

[IAnthonyFX]

5 hours ago, spartaman64 said:

thats only if you drink like gallons of water in a short time

No, it starts drawing important salts of nutrients away from you first. Then it can start making your cells explode. You won't die with a couple of ml but I do not know how much it takes either. I have only used Nanopure water in labs with microorganisms so I can't event extrapolate it to humans. 

[leadeater]

22 minutes ago, IAnthonyFX said:

No, it starts drawing important salts of nutrients away from you first. Then it can start making your cells explode. You won't die with a couple of ml but I do not know how much it takes either. I have only used Nanopure water in labs with microorganisms so I can't event extrapolate it to humans. 

In a general sense yes drinking lab deionized/demineralized water is not safe but it's typically not for those reasons. The real question is whether the water used is potable or not before the demineralization of that water. If it was non potable before then it is still non potable after so still not safe to drink. Potable or not since the water is demineralized drinking it has very little value to your body.

 

Quote

While the process of removing the mineral ions from water doesn't necessarily make it unsafe to drink, it's important to keep in mind that deionization only removes the ions. Other contaminants, including bacteria and viruses, are not removed in this process. DI water is often produced from water that has already been processed by other water filtering technologies, including reverse osmosis, which removes many of the contaminants that a DI system does not. In addition, if the water originates from a municipal source, it has already been treated with chlorine or another disinfectant and should not contain dangerous bacteria or other pathogens.

Lab water is for lab work, not for drinking.

[captain_to_fire]

3 minutes ago, leadeater said:

Lab water is for lab work, not for drinking.

It depends. Back when I was working in a pharmaceutical company we have a dedicated water filtration setup that does fractional distillation, carbon filtration, deionization and even UV sterilization used for preparation of reagents and final rinsing of glasswares but the water is potable so we drank the cleanest water possible and it tastes a bit bitter.

[porina]

23 minutes ago, IAnthonyFX said:

No, it starts drawing important salts of nutrients away from you first. Then it can start making your cells explode. You won't die with a couple of ml but I do not know how much it takes either. I have only used Nanopure water in labs with microorganisms so I can't event extrapolate it to humans. 

I've always wondered about these claims. How pure does water have to be to be dangerous? I'm not convinced that "pure" water is different enough from "very soft" water to be biologically significant, at least in terms of osmotic pressure and the consequential effects from that.

 

BTW I routinely "manufacture" RO+DI water at home for fishkeeping use. I can't say how pure it is, but its conductivity is less than 1ppm NaCl equivalent.

2 minutes ago, leadeater said:

Potable or not since the water is demineralized drinking it has very little value to your body.

It should still have value purely as a water source. Any dietary beneficial mineral content could be seen as a bonus. Again, people in soft water areas will gain very little from their water also, and it would have to come from other parts of their diet.

[leadeater]

5 minutes ago, captain_to_fire said:

It depends. Back when I was working in a pharmaceutical company we have a dedicated water filtration setup that does fractional distillation, carbon filtration, deionization and even UV sterilization used for preparation of reagents and final rinsing of glasswares but the water is potable so we drank the cleanest water possible and it tastes a bit bitter.

Yep, it's just that a lot of lab water is deionized solely for not interfering with chemical reactions, it being drinkable isn't required. As long as the water is classified as potable all good, drink up just don't dry drown in it .

 

Edit:

Also reason why I brought up lab water is because that's why DI water exists... not for drinking water purity. If stupid people want to pay extra for it go for it.

[captain_to_fire]

27 minutes ago, IAnthonyFX said:

No, it starts drawing important salts of nutrients away from you first. Then it can start making your cells explode. You won't die with a couple of ml but I do not know how much it takes either. I have only used Nanopure water in labs with microorganisms so I can't event extrapolate it to humans. 

Just so you know, even purified water with trace minerals won't be classified as "isotonic (0.9% ^w/_v NaCl solution)" so chugging too much water can still result to bursting of cells. Also, drinking water doesn't automatically lead to something harmful. The human body is capable of regulating itself including water in the body which is a part of homeostatic balance. http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr_pre_2011/homeostasis/waterbalrev1.shtml

4 minutes ago, leadeater said:

As long as the water is classified as potable all good, drink up just don't dry drown in it .

I once tried to make coffee using our lab's deionized water and expensive spring water. It tastes the same. 

[spartaman64]

49 minutes ago, porina said:

I've always wondered about these claims. How pure does water have to be to be dangerous? I'm not convinced that "pure" water is different enough from "very soft" water to be biologically significant, at least in terms of osmotic pressure and the consequential effects from that.

 

BTW I routinely "manufacture" RO+DI water at home for fishkeeping use. I can't say how pure it is, but its conductivity is less than 1ppm NaCl equivalent.

It should still have value purely as a water source. Any dietary beneficial mineral content could be seen as a bonus. Again, people in soft water areas will gain very little from their water also, and it would have to come from other parts of their diet.

i think you literally have to drink gallons of it in a few minutes or something. ive drank a jug of deionized water before and im still alive. its probably not good if you only drink di water over a long period of time

[porina]

49 minutes ago, spartaman64 said:

i think you literally have to drink gallons of it in a few minutes or something. ive drank a jug of deionized water before and im still alive. its probably not good if you only drink di water over a long period of time

I'd argue drinking a few gallons of otherwise normally safe water in a short amount of time isn't going to be good for you either. The lack of minerals I think is a minor part. Water supply mineral content varies with local geography. It may be a nice little extra supplement but as long as you get your requirements from other food sources, I don't see that as being significant.

[vanished]

5 hours ago, porina said:

I'd argue drinking a few gallons of otherwise normally safe water in a short amount of time isn't going to be good for you either. The lack of minerals I think is a minor part. Water supply mineral content varies with local geography. It may be a nice little extra supplement but as long as you get your requirements from other food sources, I don't see that as being significant.

Yeah people forget this but there's actually an LD50 for water