Considered one of the most porous substances in existence, activated charcoal is used in a variety of applications all over the world.
In the survival world, you’ll see activated charcoal used in applications like water filtration and first aid to draw toxins out of the body. It’s a handy substance to have in any survival kit.
Don’t get activated charcoal confused with regular charcoal which is the stuff you buy from the store in briquettes for your barbecue. There is a big difference and they should not be used interchangeably.
People often wonder if there is a shelf life associated with activated charcoal as it is extremely absorbent. So does it ever go bad?
No, activated charcoal does not have an expiration date. However, it’s all about how you store your activated charcoal that dictates how long it is effective.
Since it is highly absorbent you can’t just have it out in the open for extended periods without it losing effectiveness.
Making activated charcoal is an involved process that involves high heat and other chemicals but can be done in a survival situation for certain things. First, let’s look a little more in-depth at activated charcoal and its uses.
As was said above there is a difference between charcoal and activated charcoal. The similarities are that both are devoid of moisture and other organic elements using high heat to burn organic matter. Wood is a great example of something you would use to make charcoal.
Activated charcoal is treated at high heat but then further treated with calcium chloride and an even higher heat to create even more absorbent pores. The activated charcoal can then be ground up and used for things like water filtration.
It’s such a unique byproduct of heat in that it is filled with tiny pores. Once something gets trapped in those pores they are essentially stuck because of how deep they are.
If the substance passing through is made up of negative ions then the positive ions of the activated charcoal will absorb and hang on to it.
If you’re filtering tap water, chlorine is an excellent example of a substance that would bind to the activated charcoal and stay behind while your water is filtered.
Not everything will bind to your activated charcoal or some substances will bind weakly. Metals and caustic compounds (acids) are good examples of things that activated charcoal can not absorb.
Methane is a gas that charcoal cannot absorb because its molecular makeup is similar, as methane is just hydrogen and carbon.
Keep in mind that ingesting activated charcoal as part of your diet could have a detrimental effect on your health. Inside your body, it can start working to absorb medications that you are taking as well as some minerals that your body would use.
You can see how activated charcoal is made here.
When you make any form of charcoal you are destroying everything but the carbon left behind. That means it has no organic material inside of it that could decompose and cause it to break down.
That won’t happen unless an organic material is added to it. Even then it is an inhospitable environment for most bacteria so it wouldn’t be much of a host.
With this kind of thinking you can see that by keeping the charcoal dry and in a sealed environment you can keep extending that shelf life indefinitely.
Since it is so absorbent, keeping it out in the open might eventually decrease its effectiveness but if that’s the case then you can always use it to fuel a fire in your backyard or on a camping trip.
Getting your activated charcoal wet can potentially cause an issue if you don’t dry it out quickly.
Water is an excellent vessel for bacterial growth and once it’s in the pores then it’s pretty much game over for that charcoal.
There are products out there where companies have sprayed the charcoal with chemicals that stop it from absorbing water.
If you want to store it over the long term then a mylar bag would be best to keep the air and moisture out. Some people keep it in a watertight plastic tote in their basement or cellar.
Due to the nature of its extreme absorbency and high heat generation, activated charcoal makes its special properties useful in a variety of applications.
You can grind up activated charcoal and use it as a water filter as long as you have something to use as a filter with it.
Some people use handkerchiefs or cheesecloth if they have it handy.
Not only will it filter out debris and sediment, but the absorbent qualities of the charcoal will get rid of herbicides, pesticides, and water-borne viruses.
Some say baking soda is the best odor absorber but you’d be surprised at the power of activated charcoal.
Because of its extreme porosity, odors tend to get trapped and held very easily. You could try and put some activated charcoal in a used hockey bag or laundry hamper to test out its effects.
Furthermore, activated charcoal is used in the construction of gas mask filters for its ability to filter out toxic elements that could harm the wearer.
Oftentimes hunters and paddlers will use activated charcoal under their eyes to reduce the amount of glare that they get.
Paddlers will use it since they are out on the highly reflective water and hunters so they can maintain the line of sight even in bright conditions.
Those who practice military tactics in the woods find that charcoal rubbed on your face will throw off the eyes of someone who is tracking you as they are focused on finding the semblance of a human face.
This is a popular item among survivalists as it’s essentially a portable fire. Pieces of charcoal that have cooled down can be transported and used for the next fire.
Once you have a small fire started the charcoal can be heated and it’ll keep hot for hours afterward.
Having a little stash of charcoal can be an excellent way to create a portable barbecue as the heat coming off of it is concentrated and can last a long time.
With a potentially unlimited shelf life and a multitude of uses, activated charcoal is a must-have in any household or backpack.
If it gets wet then it is pretty much unusable for anything but water filtration until it dries out.
Making it yourself can be a tedious process but it’s possible if you have a fire and some calcium chloride. Otherwise activated charcoal is readily available in many outlets both online and in person.
Perrin is an adventure guide and naturalist currently living a nomadic life in the Canadian wilderness. His education and expertise is in wilderness survival and wildlife tracking. He enjoys teaching people about the outdoors and has managed large groups on expeditions.
With several accredited certifications, including being a wilderness first responder and a leave no trace expert, Perrin believes it is important for all of us to reconnect with the natural world.