What People Wonder About Water

We're getting so used to use-by dates that sometimes we hesitate to make decisions without them. For example, when has an unopened bottle of water hung around too long?  Other questions come to mind: Where does bottled water come from? Which is better, bottled water or tap (municipal)? Is it okay to reuse a bottle of water by refilling it with tap water?  What water precautions do scientists recommend to travelers?  Is a plastic water bottle a good toy for a dog? Let's see what water facts we can learn and what fake facts (erroneous myths) we can unlearn.

WHEN DOES AN UNOPENED  BOTTLE OF WATER BECOME TOO OLD TO DRINK?

I'll answer this one with a true story and a scientist's opinion.  The story first.  Recently, my tranquil marriage was disrupted by a water fight.  Not one that got my spouse and me wet.  Just a debate about 12 bottles of water that were lined up in our breezeway, where they had been standing at attention for years (some number of years between a few, several, and too many). My husband had received them as a prize from Costco after he agreed to take out a new credit card. He lined them up neatly and promptly forgot about them.

One hot summer day, I announced to my spouse that I was discarding all 12 bottles. There was, of course, no expiration date to guide us. If we drank them, would we expire? My husband leaped, though not very high, to their defense:  "Why? What could happen to sealed bottled water?"  

"I'm not sure," I admitted.  "Maybe it could start to taste like plastic? Maybe bacteria could sneak in?"  After continuing this heated dispute awhile, we voted to save our marriage by compromising. We used the beverage in the bottles to water our roses. The flowers thrived.

But afterward, food scientist Dr. Joe Regenstein, a member of our site's Advisory Board, sent an email in response to our question about this issue. He seemed to side with my husband when he wrote as follows: "I believe bottled water doesn't expire, so I would assume it would remain drinkable.  Considering the quality of modern plastics, I doubt that there would be any leaching of flavor compounds.  I would recommend taking an initial sip.  If you detect an off-flavor, discard it but don't expect it to taste bad. If it tastes okay, it should also be microbially safe." 

 Sorry, Dr. Regenstein. I'm never brave enough to sample a food or beverage I don't trust. I don't enjoy anxiety. Anyway, I had already watered the flowers with said water before receiving your response.  I conclude that your short answer to the initial question (in boldface caps above) is "Never."

Two other scientists who serve on the Shelf Life Advice Advisory Board weighed in on this question.  Food process engineer Dr. Timothy Bowser, offered this comment:  "Potable water does not expire! It does not contain food ingredients that might grow old or nutrients to support the growth of microorganisms.  Unfortunately, any plastic bottle that holds water can deteriorate.  The bottle may either leach bad-tasting chemicals into the water, or it may leak.  The water probably won't be toxic, but it may taste foul."  

Food scientist Dr. CatherineCutteragreed that, in general, sealed bottled water is pretty safe, but it can degrade over time and develop quality or safety issues.  Plastic water bottles are not completely impermeable. Plastic can also cause the water to develop off-flavors. Well, our flowers didn't mind all that.

WHICH IS HEALTHIER--TAP WATER OR BOTTLED WATER?

I won't bother quoting all my sources. Everything I read online says that, in general, in the U.S., tap and bottled water are about the same in terms of safety and quality. 

A Mayo Clinic article entitled "Is tap water as safe as bottled water?" states, "Tap water and bottled water are generally comparable in terms of safety."  Bottled water is regulated by the Food and Drug Administration (FDA);  tap water is regulated by the Environmental Protection Agency (EPA). Bu the standards for ensuring safety are quite similar. Water might be obtained from a lake, river, aquifer, or some other source.  Since the EPA doesn't regulate private wells, if your tap water comes from that source, you should test your water for contaminants at least annually and more often if necessary.  

The FDA has good procedures for keeping our supply of bottled water safety.  These include protecting bottled water from contaminants such as bacteria and harmful chemicals and testing bottled water to be sure it is meeting the standards set. But standards for water safety need to be more stringent for some people, for example, those undergoing chemotherapy, people with HIV/AIDS, and those who have received transplants. Additional precautions, such as boiling tap water before drinking it, may be needed for some individuals.

Choosing bottled or tap water may not exactly be an either/or decision.  According to Reader's Digest (its article entitled "Bottled Water Vs. Tap Water: Rethink What You Drink"), most people don't realize that, while some bottled water comes from "sparkling springs and other pristine sources, more than 25 percent of it comes from a municipal supply." In other words, it's tap water.   Bottlers are not required to print the source of their water on the bottle. However, if you go to the company website, you'd probably find that information.

ONCE A BOTTLE OF WATER IS OPENED IS IT MORE LIKELY TO GET CONTAMINATED?  IS CARBONATED WATER SAFER?

Dr. Cutter says that after a water bottle is opened, in time, it will get contaminated. Carbonated water is more antimicrobial, so that's what she asks for when traveling.  

WHY IS EVERYONE BUYING BOTTLED WATER?

You're correct, dear questioner. Virtually everyone is doing it.  Although drinking tap water costs us almost nothing, sales of bottled water are huge. In 2012, worldwide sales were about 200 billion liters; projections for 2017, were about 391.  Mexico has the highest per capita consumption of bottled water at about 64.5 gallons.  In the U.S., bottled water holds the second largest share of the beverage market It's even ahead of milk and beer. The only beverage that Americans drink more of than bottled water is soda. Some experts are convinced that bottled water is 2,000 times  more expensive than tap, according to "Bottled Water Statistics: 23 Outrageous Facts." Still, the average person living in the U.S. drinks about 31.8 gallons of bottled water a year.  

Some folks buy bottled water because they're convinced it tastes better and/or is healthier, 

I suspect that most buy these bottles for the same reason I do-- for convenience--to carry in a purse, pocket, lunch bag, or backpack, or to stick in the car holder. An 8-12 oz. bottle is relatively lightweight (compared to a metal reusable water bottle) and disposable when you're finished with it.  Just remember that the environment is suffering for your convenience (and mine). 

Does bottled water taste better than tap?  I doubt that I could tell them apart.  Have someone give you a taste test.  See if you can identify which glass contains bottled water and which holds water directly from your tap. (Make sure both samples are refrigerated to the same temperature before doing the test.)

IS IT SAFE TO REUSE AN EMPTY PLASTIC  WATER BOTTLE?

When Shelf Life Advice was in its infancy, some 10  years ago,  the answer was "No." Why not?

Here's what we quoted from the University of Nebraska Cooperative Extension: "The bottles in which water is sold are meant for one-time use. They are hard to clean and dry and are not intended for multiple cleanings.  In fact, they may not hold up if washed in the dishwasher or very hot running water, the kind of cleansing needed to remove lipstick and germs."

 I can only tell you that I'd have a lot fewer living relatives and friends if reusing water bottles were a menace. My daughter and I both reuse bottles.  My friend Nadine advised me to save money by going through airport security with an empty water bottle and refilling it after I cleared security, and,  ever since,  I've been avoiding paying the airport $2.75 or so for a bottle of water.

Dr. Regensteinsays, "I generally pour out the water and rinse the bottle once if I've left it hanging around.  In my home, we probably have some bottles that have been refilled and reused over a couple hundred times.  Don't be afraid of tap water.  This whole bottled water craze is getting out of control and harming the environment."

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Food process engineer Dr. Timothy Bowser offered this advice:  "I frequently reuse water bottles when traveling internationally.  I carry a First-Need water filter (model XLE, available at https://generalecology.com/category/portable)  that makes filling bottles with a screw top easy and convenient.  

"I wouldn't bother with a dishwasher since the narrow neck of most bottles makes it difficult for wash and rinse water to enter and leave the bottle.  Also, the hot sterilization cycle of some dishwashers could melt the bottle.  I prefer to wash narrow-mouth water bottles by hand or just recycle them when they become dirty.  Remember to use clean, potable water for bottle washing."

A third member of our Advisory Board,  food scientist Dr. Catherine Cutter, supplied additional suggestions: water bottles can be hand-washed with warm, soapy water, sanitized with a mild agent such as vinegar or diluted lemon juice, and then rinsed well.  They can also be washed in the dishwasher, but glass ones may shatter.  

CAN I DRINK WATER FROM UNOPENED BOTTLES  THAT HAVE BEEN SITTING IN MY HOT  CAR FOR DAYS?

Both Dr. Bowser and Dr. Regensteinagree that hot water is better than no water if you're desperate for a drink.  It may not taste great, but it's not likely to hurt you.  Here's Dr. Bowser's comment: "A lot depends upon how thirsty I am and the availability of water!  Ideally, I would cool a bottle of hot water down and then taste it before drinking.  If any off-flavors were present, I would discard it. If nothing else was available, I would (and have in the past)  certainly drink it--even if hot. " 

IF I DRINK FROM A WATER BOTTLE, WILL I CONTAMINATE  THE REST OF THE WATER IT CONTAINS?

Dr. Rosensteinresponded thusly: "Once you drink from a bottle, the water will have some microbial content.  But because the saliva has only a little content, the bugs cannot really grow.  Additionally, it is your own oral bacteria  that's in the bottle if anything."

WHAT ABOUT THE WATER IN MY KEURIG?  HOW OFTEN DO I NEED TO CHANGE  IT?

Dr. Bowser's response: "I recommend replacing all the water in a Keurig reservoir whenever it hasn't been used for about 7-10 days. There shouldn't be any danger of using 'old' water left in your Keurig since the water is clean and protected. The water is also heated during the brewing process, which is a food safety step. However, for the best flavor, I prefer to brew coffee with fresh water."

MY DOG LOVES TO CHEW ON AN EMPTY PLASTIC WATER BOTTLE.  IS THAT A SAFE TOY FOR A DOG?

Someone asked this very question on the website Quora Digest.  The answer, obviously, was "NO!" Allow your dog to do that, and you'll probably wind up with a huge bill from your vet.  Buy the dog a toy made for safe chewing.

SOURCES:

Shelf Life Advicescientists who contributed:

Timothy J. Bowser, Ph.D., Oklahoma State University, Dept. of Biosystems and Agricultural Engineering

Catherine Nettles Cutter, Ph.D., Pennsylvania State University, Department of Food Science 

Joe Regenstein, Ph.D., Cornell University, Dept. of Food Science 

mayoclinic.org   "Is tap water as safe as bottled water?"

https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/tap-vs-bottled-water/faq-20058017

reader's digest.com  "Bottled water VS. tap water: Rethink what you drink" 

https://www.rd.com/health/diet-weight-loss/rethink-what-you-drink/

creditdonkey.com  "Bottled Water Statistics: 23 Outrageous Facts"

 https://www.creditdonkey.com/bottled-water-statistics.html

quora.com"Is it OK for my dog to chew on plastic water bottles?"

https://www.quora.com/Is-it-OK-for-my-dog-to-chew-on-plastic-water-bottles