WAPI – What Is It and Why Do You Need One

WAPI stands for Water Pasteurization Indicator. This little device is one that every prepper and survivalist should have in their gear. It will save time and fuel when you need to boil water so that you have safe water to drink.

Why Is Pasteurization Important?

You need safe water to drink. And because you will easily get dehydrated if you don’t have water to drink, having clean water in any situation, especially an emergency situation, is very important.

Contrary to what many people believe, it is not necessary to boil water to make it safe to drink. Also contrary to what many people believe, it is usually not necessary to distill water to make it safe to drink. Heating water to 65 C (149 F) for 6 minutes, or to a higher temperature for a shorter time, will kill all germs, viruses, and parasites. This process is called pasteurization and its use for milk is well known though milk requires slightly different time-temperature combinations. One obvious problem that arises with pasteurization is the question of how to tell when and if the water has reached the right temperature.


A WAPI provides an easy solution for anyone trying to pasteurize water for drinking.

Pasteurization occurs at 149F

How Does a WAPI Work?

A WAPI is simply a small polycarbonate tube that contains a special wax. A washer or metal weight on the small device keeps the WAPi submerged as it is placed inside a pot of water that is being heated. As the water reaches the point of pasteurization, the wax at the top of the tube melts and moves to the bottom of the tube. Once all the wax is melted and at the bottom of the tube, the water is sufficiently pasteurized and ready to drink.

A WAPI can be reused over and over again. The only thing to remember is that you have to wait 30 minutes between each use. After it cools, you can pull the WAPI through the thin stainless steel wire to turn it over.

Using a WAPI Saves Fuel

Boiling water takes a lot of fuel. So whether you are heating water over a propane stove or over a wood fire out in the forest, spending the extra fuel to get water to boil when it isn’t necessary is not smart. Using a WAPI takes the guessing game out of trying to figure out the temperature or having to carry around a thermometer as an extra piece of gear.

In the pics below, I put 4 cups of water in a pot on medium heat on my stove. The wax in the WAPI was fully melted at the 6:48 mark. The CDC recommends that you boil water for 1 minute after it comes to a “rolling boil.” The WAPI was melted way before this. See the pic below.

How to Use a WAPI

  • Pre-filter the water you are going to use. Use a coffee filter, crude water filter with grass, sand, rocks, charcoal, or even a t-shirt to filter out the “nasties” when you are in the wild.
  • Place your water in a pot above a fire.
  • Center your WAPI in the pot, with the weight closes to the WAPI
  • Heat the water until the wax on the top of the WAPI melts to the bottom.
  • Take out the WAPI, let the water cool and drink.
WAPI Package
WAPI's have a small profile.
WAPI’s have a very small profile. They are perfect to save space in your bag!
WAPI in the center of a pot.
A WAPI should be placed right in the middle of the pot
WAPI fully melted in a pot.
The WAPI was fully melted at the 6:48 mark, way before a rolling boil.
WAPI drying off
Dry off the WAPI, pull the metal string through and it is ready to pasteurize more water after 30 minutes.

You can purchase WAPI’s on Amazon in single packs or packs of 5. Single packs run $9.99 while the 5 packs, enough for every member of your family, run under $35.

WAPI’s for a Good Cause

If you are wanting to support a great cause, WAPIs for the World distributes WAPIs all around the world to people who don’t have a clean water source. You can support this ministry by purchasing WAPIs from them directly. 1 WAPI for $2 or 50 for $100! For more information on how you can help support this cause, visit their website – WAPIs for the World. Or if you would like to make a purchase, email Margo – CLICK HERE.

A WAPI in Preparedness

For the self-reliant mind, water is always a topic of discussion. Many preppers have multiple ways to filter and purify water. Having a WAPI is another inexpensive tool in the toolbox when it comes to having safe water. If you don’t have one, consider getting one soon!


5 thoughts on “WAPI – What Is It and Why Do You Need One”

  1. Zulu-36

    I would say that having a WAPI is nice and saves heating time, fuel, and cooling time when pasteurizing water for consumption. But, if you don’t have one, or a cooking thermometer, letting the water come to a simple low boil is a handy reference to make sure it’s been heated enough.

    I remember when I was younger, all of the advice about boiling the water for five minutes, even ten minutes, didn’t make sense to me. However, more recently some sources say just let it get to boiling and that’s enough.

    1. The advice about getting your water to a rolling boil is still out there.

      If I was in a survival scenario and didn’t have a wapi, I would want to make sure I was super safe. 🙂

  2. Dick Daignault

    Good info, wasn’t familiar w WAPI. I agree that we will want to min our use of resources, i.e. propane, cooking time, etc and it ENSURES, and important necessity, clean water. The devil will most certainly be in the details, those nasty bugs are small and everywhere, again, good info. Thnx again, stay safe out there, and God Bless.
    dickie in VT

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