Will Bath Bombs Stain My Tub?

If you have searched for bath bombs online, the chances are that you have come across the horror stories—people reporting bright pink tub stains. Now, bright or multi-colored bathwater is fun; patchy tub stains are not. Yet, some people happily soak in galaxy-style bathwater with no repercussions. Is there any way to know if you will be one of the fortunate or one of the unlucky few?

Discover the ‘secrets’ Professional Bath Bomb Makers use to create luscious bath bombs with this step-by-step guide. You’ll have a priceless reference collection of product recipes with natural ingredients designed to create a relaxing spa atmosphere in your own home.

Bath bombs are designed for use in bathtubs and should not stain them. Stains can occur under some circumstances: high concentrations of colorants, poor bomb manufacturing, pitted bath enamel from age or harsh chemicals, dirty bathtubs (color clings to scum), and not washing the tub after using a bomb.

Bath bombs should not stain bathtubs, but it is undeniable that they sometimes do. So why do some bath bombs cause stains? We give you some possible answers to this question in the article below. We also look at how to avoid bath bomb stains in tubs.

What Are Bath Bombs Made Of?

But first, we need to know what bath bombs are made of, and later on, we’ll understand why some might stain your tub while others don’t. Bath bombs are made of three basic ingredients: sodium bicarbonate (baking soda), citric acid, and cornflour.

Sodium bicarbonate is reported to be soothing for irritated skin. The skin-health benefits of bath bombs are always enhanced through the addition of ingredients such as oils and butter.

The effervescence of fizzing action seen with bath bombs is produced by a reaction between sodium bicarbonate and citric acid. This reaction is triggered by contact with water and yields carbon dioxide gas. The fun and novel experience of bath bombs are enhanced by adding colors, petals, peels, sparkles, etc.

Why Do Some Bath Bombs Stain Tubs?

Many different kinds of colorants are used in bath bombs, including lake, mica, and natural pigments. Bath bombs, especially the vibrant and dark-colored ones, have been known to stain bathtubs. But bath bombs should not be staining your tub, so why do some cause this unpleasant result?

The problem can be the bath bomb itself, how the bath bomb is being used, or the issue may be related to your bathtub.

Bath Bombs Can Stain Tubs When There Is A Problem With The Bath Bomb

Any colored bath bomb contains some form of pigment or colorant. The creators of the bath bombs have to find the balance between intense enough to wow and satisfy clients and yet mild enough not to stain the tub (or the person in the tub!).

Sometimes, the manufacturers can make a miscalculation when it comes to how much colorant to add. The result is a batch that is over-pigmented and may cause stains in the bathtub.

Using handmade bath bombs increases the risk of human error (although they are still a great option). Products from unknown suppliers or suppliers who do not conform to a high level of quality control are also riskier.

Instead, go with a well-known brand. You might still get a bad bath bomb, but you can contact them with evidence of the staining, and you are more likely to receive help in remedying the situation.

Little-known companies that do not have a reputation to uphold might not be as motivated to help. Furthermore, small companies might not be able to help because they are not turning enough profit to cover extras.

Some bath bombs purposefully contain very high concentrations of colorants and therefore are always more likely to stain the enamel of your bathtub. These will be your bright and vivid colors, like bright pink, and your intense dark colors, like navy blue.

Bath Bombs Can Stain Tubs When They Are Not Used Correctly

We are not saying that it is your fault if your bathtub is stained after using a bath bomb. You just need to make sure that you follow the manufacturer’s specifications on when to add the bath bomb, any time limits on how long the colored water can sit in the tub, and what to do after you have used a bath bomb.

As a rule, you should wash your bathtub out after using a bath bomb. If there is a faint tint left on the enamel, you should still be able to get this out with an appropriate cleaner. Think of it like when you use bright cherry lipstick. Your lips can still show traces of the color after you’ve removed it, but it does come off, especially with a good make-up remover.

So, what should you clean your bathtub with after using bath bombs? This depends on what type of colorant was used. If a water-based pigment was used, then most cleaners should work with water. If an oil-based color was used, you would need a cleaner containing a surface-active agent, also known as a surfactant.

Surfactants are special substances that help water and oil to mix. The oily pigment sticking to your bathtub’s enamel will not bind with water alone and so cannot be removed. It will, however, bind to one side of the surfactant molecules. Water attaches to the other side, allowing the oil to be washed off with the water. Dish soap is an excellent and handy surfactant.

If you don’t clean your tub after using a bath bomb, the stain can build up, particularly if you are using the colorful bombs often.

Bath Bombs Can Stain Tubs When There Is An Issue With The Tub Itself

Bathtubs are designed to resist stains. Stains occur when molecules become trapped in pores and indentations on a surface. Bathtubs counter this through their smooth, non-porous coating.

The non-porous coating of old bathtubs can be compromised. Over the years, these tubs have worn down, and the underlying porous surface is exposed. There may also be noticeable or undiscernible scratches and imperfections on which the bath bomb colorants can be snagged. This leads to a stained look.

Some abrasive cleaning products can strip the non-porous coating of even new bathtubs, so you need to be careful what products you use to clean your tub.

Feel your bathtub. The surface should feel smooth like glass. If you can feel any kind of texture, the issue may be a worn coating. If this is the case, then scrubbing may only probe to be partially effective in removing the bath bomb stain.

You might want to consider refinishing your tub (you don’t have to buy a new one!). If the stain occurred because it was time to revamp your bathtub anyway, save yourself some time and get it re-surfaced. This might cost you a bit, but it is an investment. You will also love how your newly finished bathtub feels, making future bath bomb baths more enjoyable.

There is another bath-related alternative to why bath bombs can look like they stain the tub, and this one is much easier to solve. If you do not clean your bathtub out often, soap and the impurities in the water can accumulate inside your tub, which can trap colorant molecules from bath bombs and result in a stained look.

This ‘scum’ may not be overtly visible, but you may be able to feel it, and in this case, it is not the tub itself that is stained but rather the layer of residue covering it. A good scrub with an appropriate cleaner should do the trick. But ensure the cleaner you use is not too harsh, or it may strip the surface of the bathtub.  

How To Prevent Bath Bomb Stains In Your Tub

  • Use color-free or neutral to light-colored bath bombs. These can still make your bath-time experience fresh and fun, especially if you get those with a hidden flower petal center.
  • Clean your bathtub before and after use.
  • Buy bath bombs from a reputable supplier.  
  • Limit how often you have a bath bomb bath and also limit the duration.
  • Ensure that your bathtub is correctly surfaced.


Most bathtubs are designed with a non-porous surface that resists staining, and bath bombs are designed specifically for use in tubs and therefore should not be causing discoloration. If the finish on the bathtub has been compromised, or if there is a build-up of scum, the pigments of bath bombs can become trapped in these imperfections and textures.

Sometimes, the bath bombs are too heavily pigmented, and this can leave a mark on the finish of a tub, but it should come off with the right cleaner. Careful notice should be paid to the right way to use the bath bomb to ensure that unwanted staining does not result from a mistake.

If you are really worried about a bath bomb staining your tub, avoid those with vibrant or dark colors. Stick to the light and neutral hues; these have their own value, even if they don’t create colorful bath art, not the least of which is peace of mind.

Recent Posts