Are water purification tablets safe?

Just as an addition:

For treatment and filter, I'd filter first, then treat. For 2 reasons:

• After a while, filters get alive and things start growing.
• Most of the chemical treatments work by oxidation. No use spending the oxidation capacity on stuff that can be oxidized, but could have been filtered out anyways.

posted over 11 years ago

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cbeleites supports Monica‭

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The main concern about iodine tablets is exceeding the recommended daily dose of iodine your body can handle safely. In addition to that, iodine can not kill many of the protozoan cysts. The main concern about chlorine tablets is that they can not kill many of the protozoa. The main concern about the filters is the real size. Most of the viruses are smaller than to be filtered out. But almost all of the cysts and a great deal of bacteria can be filtered out. Boiling water is a good option, but many spores and cysts (like anthrax or Entamoeba hystolitica) can tolerate boiling water. Beside, heavy metals and many other chemical contaminants can not be removed by boiling water or using iodine or chlorine treatment.

posted almost 5 years ago

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Lazgin Zeebaree‭

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If you're worried about the safety of iodine or don't like the terrible taste, you could get some chlorine tablets. They cost about the same, but aren't as easy to find at general sports stores.

posted over 10 years ago

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nife‭

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I currently use a Sawyer Filter without using purification. I carry iodine tablets as a backup. Iodine's been in use for decades, and I don't worry at all about using them when necessary. Ray J. recommends being smart about choosing your water sources, which I am. When I was a kid I drank straight from the streams without any purification or any problems, so perhaps I have some immunities from that. People today are way too worried about water purification, if you ask me. People in some countries survive worse water from their taps than we have from our streams. We also worry too much about chemicals, probably. Water is a chemical, and an extremely dangerous one in pure form.

posted over 11 years ago

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Don Branson‭

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If I am using a water-pump filter. Is it necessary to combine this with a water purification tablet?

As discussed in this answer and at greater length here, the need to treat backcountry water before drinking it is largely a myth. Neither the filter nor the tablets are needed. You're better off focusing your efforts on avoiding the real reason that backpackers are likely to get sick, which is hand-to-mouth contamination. Practice good potty hygiene, and don't share pots with your hiking partners (whose gut flora your body hasn't got a tolerance for).

If you're traveling in the third world, or drinking water that you collected downstream from a poultry farm in Arkansas, that's a different matter. Filters work against protozoan cysts. Tablets kill bacteria and viruses. Another good option to consider is a steripen, which treats water using UV light. It kills cysts, bacteria, and viruses, is more compact than a filter, and is faster than tablets.

Katadyn, a water filter company, suggests doing so.

Katadyn sells tablets, so they have an economic interest in propagating myths about the need for water treatment.

However, this makes me question the safety of putting such chemicals into my drinking water. In general, is it best to just avoid it? Or are there any water purification tablets that are proven safe?

Iodine is a nutrient that your body needs. That's why they iodize salt. So the question is not really whether iodine is bad for you but whether a certain amount is good or bad for you. The lethal dose in humans is a couple of grams, and it kills you by oxidizing proteins. A typical concentration used for purifying drinking water is about 3 mg/liter, so by drinking a liter of water you're getting about a thousandth of the lethal dose. For comparison, a gram of iodized salt has about 0.02 mg of iodine.

posted over 11 years ago

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Ben Crowell‭

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