Bacterium, Water and Plastic Bottles

Factual Questions
1

I had an interesting conversation with a friend yesterday. As she handed me a bottle of water, instead of just a glass of tap water, she told me that the kids like to take bottles of water to school, and she refuses to ever refill them.

She claimed that the bacteria in the water bred well in the plastic bottles, that you could never re use a plastic bottle because it could not be washed adequately, and that the bacterium in the plastic bottles made kids sick. So, at twenty cents a pop ( pardon the pun ), she gives them- and me- fresh water.

But, how fresh is it? Isn’t she operating under false logic? If the bacterium found in water breeds well in plastic, and she gives me plastic well… I mean. I’m drinking the normal levels of bacterium. If, OTOH, she feels that allowing the bacterium in the mouth that will backwash INTO the bottle to breed will make things worse, I can dig that- but still, how much can there be?

I let my kids re-use those cool Gatorade bottles, the ones with the “sports twist” tops that seal easily and quickly. I wash the bottles out with hot soapy water, and those things are good for a few weeks before they appear to be a bit beat up. Rollerhockey practice and games, man those bottles rock.

Now, take that idea ( of reusing, but only on a limited basis ) and put it against “sports bottles” made for water, etc. People are to re-use THEM relentlessly.

So, what’s her problem? Is she just lazy, and refuses to wash out some bottles by hand? Our villiage water is spectacular, if a bit chlorinated. My Brita pitcher/filter delivers lovely stuff. Or, is she onto something regarding EVER re-using plastic bottles? See, I’d think that the HDPE plastic used in a Gatorade, or water bottle, is LESS succeptable to absorption of bacterium than the softer LDPE bottles used to mold so-called “Sports Bottles”.

I know I’m kind of not focused on a specific question, but I’m asking the scientific minds here to tell me the following things:

  1. Does bacteria grow at a greater rate in plastic than glass?
  2. Does Doris have a point? Should I NEVER re-use those awesomely designed Gatorade bottles, EVEN if I DO hand-wash them out?
  3. Should I abandon plastic and go back to goat skins?

I thank you all in advance for your efforts in solving this dilemma.
And yes, I Google’d it . I got over 30,000 hits. I want to stamp out ignorance, but not at the expense of the next six weeks of my life. I eagerly await the Straight Dope here.

Cartooniverse

2
  1. So what’s wrong with bacteria anyway? Most bacteria are harmless. Certainly any kind of bacteria that are living in your mouth without hurting you aren’t going to hurt you because you inadvertently transferred them to a plastic bottle for a day or two.

The only bacteria that cause disease are disease-causing bacteria of which there are a limited variety. Since most bacteria that cause disease live in diseased people, I’d avoid having diseased people spit in my bottle. As long as you don’t put any bad bacteria in your bottle, there won’t be any bad bacteria in your bottle.

What kind of bacteria is your frient concerned about?

Where does your friend thing the bacteria that she is concerned about are going to come from?

  1. Almost no bacteria “breed” in clean water; they need something to eat. About the only kind of disease-causing bacteria that tend to colonize clean water are Legionella, the kind that cause Legionnaires’ Disease. But they haven’t been associated with drinking water and they are dangerous when inhaled, not when imbibed.

  2. It’s relatively easy to rid a plastic water bottle of disease-causing bacteria because disease-causing bacteria are, in general, not very hardy. Try hot, soapy water.

  3. If reusing platic water bottles is a health hazard, someone better tell the infantry before we invade Iraq because a couple hundred thousand American soldiers are walking around with platic canteens.

3

I can’t answer all your questions authoritatively, but I can tell you this. At my last job, where I was working in a microbiology lab, we once tested the bottled water we were getting delivered. The bacterial counts were horrible - several orders of magnitude higher than we allowed in our products - and there was some nasty stuff in there. IIRC, we managed to isolated and identify E. coli, which indicates fecal contamination. So, just because it’s sold in a bottle doesn’t mean it’s any better than your tap water.

Can bacteria grow in pure water? Not really. At least, not very well. They require nutrients, and while there may be trace amounts of them in the water, there wouldn’t be enough to sustain a whole lot of growth. However, lack of nutrients doesn’t kill them - it just prevents them from making more. So if there was contamination during the bottling process, you could have high levels of bacteria, as we found at my job. I can’t see how the type of container would have any effect.

The one thing with plastics is that they can be harder to clean completely. They tend to attract fats and other hydrophobic molecules. However, even if there are bacteria lurking amongst this film, they can be killed just like any other bacteria - hot soapy water will do it. Or just get yourself an autoclave.

4

See, that’s what I WAS thinkin’. Hot soapy water, vigorous scrubbing with bottle brush, good to go.

So, we’re agreed, she’s insane then?

5

So long as the bottles don’t hafe any interesting curves (I mean, they should be simple cylinders with screw-planes at the top) you should be able to put a bunchj of them standing up in a standard dishwasher and they will be fairly clean after a cycle.
Not sterile, mind you, but pretty close. If your dishwasher has the ability to heat (boil) water, then the combination of oppressive temperature and whatever abilities your detergent has (soap abilities and/or antibiotic abilities and/or chlorine life-blasting-toxic-killing-everything ability) will probably kill everything there.
Somehow, I doubt that there’s a bacteria that will grow in both the human mouth or gut AND in a nutrient-deprived plastic substrate. Or, if there is, that it will be able to grow and divide fast enough to make a human sick once inside the human body.
Granted :slight_smile: you could tinker with genes and make such a thing.

6

“So, we’re agreed, she’s insane then?”

Let’s just say that there is no empirical evidence supporting her theory and that it lacks biological plausibility.

7

I read an article that indicated that plastic cutting boards were (unexpectedly, to the researchers) worse than wooden ones because bacteria (especially salmonella) lived better on the plastic ones. Plastic is a good substrate for bacterial growth. But they also found that a good wash in hot soapy water was fine for either. I still think the answer to the OP is that a good wash will do the job for most dangerous bacteria. I throw ours into the dishwasher and figure that the heat alone will take care of most of it. Heck, you can cook food in there. There are dishwasher recipes on the web.

The clear plastic bottles are not HDPE. HDPE is not usually clear. Milk jugs and soft butter containers are HDPE (recycle number 2).
Polycarbonate and related plastics, and some others are used for clear beverage containers. Reusing plastic bottles, especially HDPE, is probably better than using them for the first time because of the plasiticizers in the bottles. I know from experience that if we put water in a brand new HDPE sample bottle that has not been soaked and rinsed, that it will be toxic to marine inverts. But if we soak the bottles (we use three days soak, with a change of water each day, but we are very careful and that is probably overkill) we have no problem. I don’t think that distilled water and drinking water in the gallon containers from the store are adequately (if at all) cleaned, because we get the same toxicity and sea urchin developmental deformities from those that we get from uncleaned jugs at our lab. We don’t put organisms into straight Distilled water, of course, but we do use distilled water to dilute salt water to the exact text salinities. When our DI unit went down, we tried to make do for a couple days with distilled water from the grocery, and that is when we had the problems.

Bacteria can grow almost anywhere on almost nothing. Anybody who maintains a water distiller for scientific use knows that bacteria growing on the glass in the distilled water is one of the most difficult problems you face in maintaining a very good distilled water supply. But it probably isn’t toxic or disease-causing.

There are a lot of pathogens that we don’t normally call pathogens, that are found in the soil and dirt everywhere, that if you get enough of them in the wrong way will make you sick or kill you. You get things like that flesh-eating bacteria, or columnaris which is everywhere, that are just good bacteria gone bad. So it does pay to be clean.

If you are still concerned at all, give the bottles a rinse or a soak with a dilute bleach solution. That will definately get any pathogens.

8

P.S. - I don’t mean to say that because something is toxic to invertebrates that it is toxic to humans. But there are many who believer that plastics aren’t the best thing for you. We think phthalates are what causes the HDPE toxicity, but we really don’t know, and haven’t done any tests to see.

This web site is one of many that touts the dangers of using plastics as food containers. I think that much of it is overblown, but I still worry about milk for my kids, especially. The fats in the milk probably carry the hydrophobic plasticizers pretty well. http://www.ecologycenter.org/resource_cntr/fact_sheets/plastichealtheffects.html

9

I would think that the complicated hard-to-clean valve on the top of those bottles would be the only possible “hazard.” So, rinse the bottle with dilute bleach then empty it by squirting the cleaning solution through the valve.

Germ-paranoia should be based on reality, and several recent articles point out that the main danger in your environment is your dishrag or kitchen sponge. All kinds of nasty bugs grow on the food and grease trapped in these, and they’re not totally killed by soap and water. Wiping down your kitchen surfaces with a dishrag can widely spread staph and salmonella contamination. The cure is simple: throw sponges or dishrags in the dishwasher or laundry. Or wet the object in question and give it a good steaming in your microwave oven.

SPONGE HARBORS HARMFUL BACTERIA
http://www.health.uab.edu/show.asp?durki=8281

10

No, just a weenie.

11

“There are a lot of pathogens that we don’t normally call pathogens, that are found in the soil and dirt everywhere, that if you get enough of them in the wrong way will make you sick or kill you.”

Drinking them in is the right way. Your gastrointestinal tract is well equipped to deal with almost any bacteria that enter it. The very few that cause disease when imbibed are well recognized and not “found in the soik and dirt everywhere.”

12

I our office there are a couple of water dispensers that deliver water from a very large bottle of - supposedly - pure spring water.

A friend of mine is a keen home brewer, he took a couple of emtied bottles home a convenient receptacles for brewing beer.

But, the yeast kept dieing - it was as if there was something in the plastic of the bottle that kept leaching into the liquid to kill any bugs. Can anybody confirm that this is what is actually going on? If it is, is it safe?

13

Thanks for straightening me out on the whole HDPE thing, fishhead. Well, the twist top nozzle issue DOES bother me, I used hot soapy water, scrubbed around a lot. But not for nothing, I never trust the sports bottles that come with a straw. How do you clean a straw? ( yeah yeah, “very carefully”).

I eschew such mechanisms, but the twist spigots on these Gatorade bottles? They’re perfect to fit into the grilling on the face of a hockey helmet. I shall, henceforth and forthwith, boil them in acitic acid, and then let them soak in a combination of lye and Fels Naptha Soap. By god, THAT’LL kill off the little buggers !!!

Seriously. A mild bleach soak for the bottle tops? Are we agreed that while that may sound like overkill, it will get to where my hot water spray will not?

14

If you really want to see something gross, check out the next unwrapped straw dispenser ( you know, the kind you push down on the bar and out drops a straw?)
Get up close and really inspect that thing, especially where the straw lands. Jeez-oh-Pete That is one witches brew of filth!
I did a google search on the unit in question and I couldn’t come up with much, but you know what I’m talking about. A good place to find tham is at the movie theatre, cheap bastards.
A friend of mine took a swabbing of one, just for the hell of it, and took it back to his lab to grow a culture. He ran up to me , breathless, and said " Man, don’t use those things! They’re toxic!"
Anyone know of a study of this?

15

Smeghead
, no doubt you are aware that bottled water companies must submit a report about the quality of their water. That’s what I read to find out what’s in it. not that I drink it of course, shucks, it costs more than gasoline.

16

You knew she was insane before you posted the op! :smiley:

17

As a Microbiologist, I have tested many a water supply. If you are drinking city water you shouldn’t be having problems with microbial growth. Potable city water has stringent regulations on coliform levels. However, a warning should go with this. My lab tech was having a problem with stinky city water, so I went ahead and tested it. Her water was well above EPA regulations for coliforms/mL. She contacted the city, who tested the water, and of course denied that there was any problem. Her next sample the day following the city testing, turned up clean. The lesson? As my old Micro Prof. used to tell us “if it stinks, don’t eat it.” I know that isn’t a Nuclear Physics type revelation, but you’d be surprised how many folks get sick from obviously bad food. Of course, if you have well water, you’re on your own. You may want to take a sample to a local independent lab and have it tested for total coliform counts. I’ve found that far too many wells are contaminated by fecal coliforms due to the placement of the septic fields.

As for the question. There is no reason for you or your friend to believe that your water bottles are contaminated. I personally refill my plastic bottles (basically because I’m way too cheap). Bacteria do not spontaneously generate. If you have contaminated water, and you put it in a container, quite frankly it doesn’t matter what the container is made of, you’ll STILL have contaminated water. If your water is clean, and you put it in a clean container you have clean water. Once again, this is regardless of container type.

Water isn’t a terribly good growth medium in the first place. Treated water even less so. Clean your bottles regularly (the dishwasher is good, if the plastic can handle the heat), and store it in a cold place and you shouldn’t have any problems. If you do happen to see mold or film, or if the water starts to smell odd, pitch it.

18

Okay.

Used AutoClave from eBay. Check.

Three Dozen Pyrex Lab Bottles with Rubbah Stoppers. Check.

Pipettes to stir Gatorade with. Check.

Genuine Stainless Steel drinking straws, with Scotch_Brite straw inserts for cleansing. Check.

Well, that should about do it. Man, the recyclables bin is full !! :smiley:

Thank you all for the answers and thoughts. Abbysthrnaccent is, as usual, entirely correct. My friend is insane, and I knew it already. However, this particular STRAIN of insanity, well now…