How Long Do Bath Bombs Last? (Surprising)

  • By: Carl
  • Time to read: 7 min.

Most things have an expiration date, sooner or later. Even things that do not expire might lose some of their potency over time. The same is also true when it comes to things like shower steamers and bath bombs. So, how long do bath bombs last?

Bath bombs last for approximately 6 months. After 6 months bath bombs will begin to lose their fragrance oil due to dehydration and they will even begin to lose their fizz when placed into the water, but they can still be used.

You can attempt to extend this time by keeping the bath bombs fully packaged and stored in a cool and dark place. Let’s take a closer look at this issue.

How Long Can You Store Them?

Like many other products, bath bombs come with an expiry date. Generally, bath bombs last up to a year. However, after the first 6 months, they tend to lose their fizz even though they can still be used safely.

These products go rancid or gather mold due to the addition of ingredients such as flower petals, essential oils, or even oatmeal. The key to keeping these bath products safe and efficient to use is storing them carefully in an environment that is dry and cool.

You must have heard about the shelf life of products, which describes the duration for which a product’s usability is retained when stored carefully.

The shelf life is calculated based on a product’s ingredients that come with the least shelf life. The same rule applies when estimating the shelf life of bath bombs.

Therefore, if you want to know what the shelf life of this bath product is you have to dig deeper into their ingredients’ shelf lives.

Shelf Life Of Ingredients Of A Bath Bomb:

The main ingredients that combine to make this product include citric acid, cornstarch, and baking soda (or sodium bicarbonate). Unraveling each ingredient’s shelf life will help you understand better whether bath bombs expire if unused or not.

  • Citric Acid- Generally, citric acid has a shelf life that extends up to three years (approx.) when placed in dry, cool conditions. This shelf-life remains applicable in case of the product is unopened from its package. After three years, citric acid doesn’t go rancid or even gather mold, but will no longer exhibit any chemical efficiency.
  • Cornstarch- Interestingly, cornstarch has a shelf life that is indefinite (approx.), and remains that way despite being exposed in the open. However, to maintain its efficiency, cornstarch must be placed in a dry, cool environment. Having said that, cornstarch maintains its efficiency and doesn’t generally expire.
  • Baking Soda- The shelf life (opened) of this ingredient is estimated to be six months. This shelf life applies to the unopened packages and includes the optimum air and temperature (dry, cool) conditions where the product is kept for storage. When the six-month mark has passed, sodium bicarbonate will not go bad or gather mold, but will instead no longer have any chemical efficiency.

Here’s a list of the shelf life of additional ingredients that may be used in making a bath bomb:

  • Apricot Kernel Oil- Six months-one year
  • Castor Oil- Up to one year
  • Avocado Oil- up to one year
  • Canola Oil- One-Two years
  • Coffee butter- Up to one year
  • Olive Oil- Up to two years
  • Coconut Oil- Up to one year

Using the information listed above and pairing it with the rule of shelf life, it can be estimated that a bath bomb (basic) has a shelf life of six months because one basic ingredient’s (baking soda) shelf life is six months.

How Should You Store Bath Bombs?

Before learning how to store this product you must know why it is crucial to store it correctly. Careful storage not only ensures that the basic components’ potency is well-preserved but also keeps up the secondary (additional) ingredients’ functionality while minimizing the risk of the growth of mold.

The correct way to store a bath bomb involves keeping this product in a place that is cool, dark, and dry. The contained products must also be stored away from heat sources including hot water pipes, heating vents, sun, underfloor heating, and radiators among others.

Never make the bathroom a place for storing bath bombs, even when they are in packaged condition. A bathroom is a room where heat and moisture prevail regularly, which is exactly what you must avoid for correctly storing this product.

If the product comes with proper packaging, store it in the packaged condition. If the product purchased is ‘naked’ or ‘bare’, place it inside a container that is air-tight the moment you receive it.

Whether bath bombs come unpackaged or packaged, the best way to preserve them is to store these products in air-tight containers. The containers used for storing these products must come with either rubber or silicone seals.

Plastic or glass-based seals are not going to work. Alternatively, you can consider using zip-lock bags for storage, but remove as much air as you can from within the bag before you seal it.

Also, based on your geographical area, consider using a dehumidifier for storing bath bombs.

There are places where humidity level remains high almost all through the year, and if that is the case, opt for a dehumidifier to store these products.

Will Bath Bombs Lose Their Potency?

As mentioned above, the main ingredients used in making bath bombs include natural components like citric acid and baking soda. How to tell if a bath bomb is expired?

You can tell if a bath bomb is expired by checking for a decrease in scent, color fading, loss of fizziness when used, crumbling, or visible mold growth. Store bath bombs in airtight containers to extend their shelf life.

The shelf life of both these ingredients is surprisingly long, but to maintain and preserve their potency, you have to store the product in effectively airtight containers.

The design of a bath bomb is such that when it is exposed to water or moisture, it will produce an ‘acid-base’ reaction. That is the entire purpose for which this product has been created.

It means that if an unused bath bomb is kept exposed to moisture for a long time, it will gradually lose its ‘fizzy impact’ first, and then its overall effectiveness. Such products should be used when they are fresh and fizzy, rather than be kept for a long time in storage.

Will Bath Bombs Expire?

By now it is clear that bath bombs last for a year at maximum. They have a ‘best before date too, within which period these products must be used. Do bath bombs expire?

Bath bombs can lose their fizz and fragrance over time but don’t have a strict expiration date. Store them in a cool, dry place, and use within six months for optimal performance.

What Happens if You Use An Expired Bath Bomb?

Expired bath bombs tend to oxidize and degrade with time. This results in the product being ineffective to give you the desired experience that you would expect of a bath bomb that is freshly made. However, you can still use it and get some of the benefits.

Usually, the best results can be expected when you use a bath bomb within one month of it being manufactured.

Beyond this timeframe, the product will begin to degrade or lose its potency at an exponential rate.

Bath bombs expire, if unused, after six months. However, you can still use a standard product post the expiry date, without causing any harm to your body.

That is because the basic ingredients in the product don’t go bad as they would in the case of food ingredients.

But if a bath bomb is made using additional ingredients like essential oils, chances of it going rancid are high. It may also be harmful when used, so it is best to avoid using such bath bombs if they have been stored for more than a year.

Also, if the bath bomb is discolored or displays mold-growth signs, you should immediately get rid of it. 

Frequently Asked Questions

How long do bath bombs last?

Bath bombs usually have a shelf life of up to one year.

Can bath bombs expire?

Yes, bath bombs can expire. They will lose their potency over time and may become harmful if used after they expire.

How can I store bath bombs to make them last longer?

The best way to store bath bombs is in an airtight container or bag. You can also use a dehumidifier to reduce humidity levels if necessary.

How long do bath bombs last if they are unused?

Unused bath bombs will expire after six months.


In conclusion, bath bombs last for approximately 6 months when stored properly. However, bath bombs can still be used even after they have expired, as the ingredients do not go bad.

Essential oils in bath bombs may go rancid over time, so it is best to avoid using such products if they have been stored for more than a year.

So there you have it – everything you need to know about how long bath bombs last! Be sure to store them in an airtight container or bag and use them within 6 months of manufacture date for the best results.

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