Potable Aqua Drinking Water Germicidal Tablets

What is Potable Aqua®?

Potable Aqua® is an iodine based tablet used to treat water and make it bacteriologically suitable for drinking. Each Potable Aqua tablet contains a proprietary compound called TGHP that incorporates 8 milligrams of germicidal iodine into each tablet of Potable Aqua.

How does Potable Aqua® work?

Dissolving Potable Aqua® tablets in water releases iodine from the TGHP compound. Two forms of iodine are released when Potable Aqua tablets are added to water, free iodine (I2) and hypoiodous acid (HIO). Both I2 and HIO are effective germicidal compounds that work by penetrating the cell wall of a microorganism, thereby rendering it inactive. Potable Aqua tablets also contain a buffering agent that brings the pH of the water to a slightly acidic level to optimize the disinfecting properties of the iodine. This mixture provides adequate disinfection of most waters.

How many Potable Aqua® tablets are needed to treat 1 quart (1 liter) of water?

In accordance with the product labeling, two (2) Potable Aqua® tablets are required to treat 1 quart (1 liter) of water.

How quickly does Potable Aqua® work?

Although the exact time required for Potable Aqua® to inactivate target microorganisms may vary slightly depending upon conditions such as water temperature and level of contamination in the water, the product labeling calls for a 30-minute waiting period before drinking water treated with Potable Aqua® tablets. This 30-minute wait period ensures adequate time for Potable Aqua to inactivate target organisms and make water bacteriologically suitable for drinking.

I don’t understand why I have shake my water container to cause leaking 5 minutes after adding Potable Aqua® tablets - can’t I just cap tightly right after adding the tablets to my water, wait 30 minutes and then drink?

No, you should not deviate from the directions in the Potable Aqua® labeling. Because microorganisms on the lip of your container or in the container lid can recontaminate treated water, it is necessary that they too be disinfected. To do so, loosely cap your water container after addition of the Potable Aqua tablets in accordance with the product labeling. Wait five minutes then shake the container briskly so that a small amount of solution seeps out to rinse the screw threads. This will help to disinfect the container lid as well as the lip of the container to prevent any possible recontamination of the water being treated. Tighten the cap and wait 30 minutes before drinking.

What is the shelf life of Potable Aqua® Tablets?

Unopened bottles of Potable Aqua® tablets, when stored at room temperature should remain effective up to four years. Because exposure to heat, humidity, moisture, and air will reduce the effectiveness, it is recommended that once opened, a bottle of Potable Aqua not be kept for more than one year. In order to maximize effectiveness, keep the bottle cap tightly sealed.

Does Potable Aqua® have an expiration date?

No, Potable Aqua® tablets are not required to have an expiration date. However, the Potable Aqua label does include a Lot Number that provides information regarding when the product was manufactured and, therefore, how old it is.

How do I read the Lot Number on the Potable Aqua® label?

The lot number is a five or six digit number, for example: 4 03 27. The first digit(s) represent the month of manufacture, the next two digits represent a two-digit year and the last digits represent a batch number for that month and year. Using the example above, the product was manufactured the 4th month of the year 2003 and was the 27th batch of product made. An unopened bottle of Potable Aqua® held under normal storage conditions should remain effective for at least four years from the date of manufacture and once opened, for at least a year if tightly capped.

Is there any way to visually assess the quality of Potable Aqua® Tablets?

Check the Potable Aqua® tablets appearance to assess any potential issues related to product quality or effectiveness. If the tablets are gray or dark brown in color, there is no indication their effectiveness may be compromised. However, if the tablets are light green or yellow, they are probably no longer effective. Potable Aqua tablets are very sensitive to moisture. Take care that moisture does not get inside the Potable Aqua bottle.

What are the advantages of using Potable Aqua® Tablets?

Potable Aqua® has long been considered one of the best germicidal tablets for drinking water on the market. Potable Aqua was developed by the U.S. Military during World War II and is still used by the military today , along with various relief organizations, mission groups and outdoor enthusiasts throughout the world.

Potable Aqua provides an accurate dose, and is effective over extreme conditions such as cloudy water, low temperatures, and extreme pH. It is simple to use, foolproof, and time-efficient.


Will Potable Aqua® remove chemical contaminants or particulate matter from my water?

No, Potable Aqua® does not neutralize or remove chemical contaminants, nor does it eliminate particulates from water. Potable Aqua may be used in conjunction with a water filter. It is effective against bacteria, viruses, and many cysts such as giardia lamblia. Potable Aqua is not effective against cryptosporidium cysts.

What if I don’t like the iodine taste caused by Potable Aqua®?

While iodine may impart a “taste” to the water, this is easily removed by adding PA Plus after the 30-minute disinfection period. PA Plus rapidly and effectively takes away the taste and odor of iodine as explained more fully below. (See Potable Aqua® with PA Plus)

Can Potable Aqua® tablets be repackaged in a different container?

No, repackaging Potable Aqua® tablets is not recommended. Potable Aqua tablets are manufactured under highly controlled temperature and humidity conditions that minimize exposure to the atmosphere. The tablets are very hygroscopic (i.e. have the ability to attract moisture), which causes them to degrade quickly if exposed to moisture or high humidity. Potable Aqua is manufactured to strict specifications and is tested to assure it meets those requirements throughout the manufacturing and packaging process. Even the wadding inside the bottle (which prevents the tablets from getting crushed or crumbling) is a special moisture resistant material. Once a tablet is handled or is outside of its original container, its effectiveness can no longer be assured. To ensure optimal shelf life and effectiveness, storage in original container is recommended with cap tightly sealed.

Is it OK to eat Potable Aqua® tablets?

No, Potable Aqua® is not meant to be ingested or taken whole without being diluted in water. Potable Aqua is only to be used in accordance with the label directions. Using this product in a manner inconsistent with its labeling is a violation of federal law. Potable Aqua is intended only for the emergency disinfection of water and should not be used in any other way.

What organisms are iodine effective against?

Iodine, in the concentration released by Potable Aqua®, has been found to kill the following organisms:

  • Escherichia coli
  • Vibrio cholerae
  • Salmonella typhosa
  • Salmonella typhimurium
  • Salmonella paratyphi
  • Shigella dysenteriae
  • Shigella flexneri
  • Shigella sonnei
  • Aerobacter aerogenes
  • Klebsiella terrigena
  • Streptococcus faecalis
  • Leptospira icterohaemmorrhagiae
  • Infectious hepatitis
  • Poliomyelitis
  • Entamoeba histolytica (amoebic dysentery)
  • Giardia lamblia (Giardiasis)
  • Schistosome cercariae (aka Bilharzia)