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Ajax vs. Comet: Which Powder Cleaners Are Better?

Ajax and Comet powder cleaners are highly-effective, versatile, and cheap.

But what’s the difference between the two? Is one powder cleaner better than the other?

In this comparison of Ajax vs. Comet, I answer these questions so you can make an informed decision about which brand to buy. 

You’ll learn how they differ in ingredients, efficacy, safety, price, and more.

Let’s get started!

Use the links below to navigate the comparison:

Product Offerings

Before comparing Ajax vs. Comet powder cleaners, let’s review each brand’s complete product line.

If you prefer simplicity, Ajax makes your purchasing decision easy: it only offers its original powder cleaner and dish soap. Let’s take a quick look at each.

Ajax Powder Cleanser: Ajax powder cleaner only comes in one scent and formula, so the only difference is the container size. You can purchase this product in 14 oz, 21 oz, or 28 oz sizes.

Ajax Powder Cleanser
Ajax Powder Cleanser

Ajax Dish Soap: Ajax dish soap comes in several formulas and six different scents. The options include Ajax Ultra Vinegar +, Ajax Ultra Super Degreaser, Triple Action, Bleach Alternative, and + Charcoal, and the fragrances include lime, citrus, grapefruit, lemon, orange, and citrus berry splash.

Comet offers more powder cleaners and several other cleaning-related products such as sprays (multi-surface and bath) and eraser pads. Here’s an overview of Comet’s lineup.

Comet Powder Cleaners: The company’s powder cleaners come in several scents, including pine, lavender, and lemon. In addition to the regular strength option, Comet powder cleaners come in 2X and Ultra formulas, which are more potent than the original cleaner and can handle tougher messes.

Comet Powder Cleanser
Comet Powder Cleanser

Comet Bath Sprays: Comet Ultra Bathroom spray kills 99.9% of germs and comes in three scents: regular, lavender, and lemon. You can purchase this spray in a 32 oz or 17 oz size, and there is also a foaming spray option.

Comet Multipurpose Sprays: Comet’s lineup of multipurpose sprays includes multi-surface cleaners, concentrated bleach, specialty bathroom and kitchen sprays, antibacterial spray, foam bath spray, and glass cleaner with ammonia. The scents and exact size options for each spray vary by product.

Comet Eraser Pads: Comet’s eraser pads can be compared to Mr. Clean’s Magic Eraser. They’re sold in packs of either 2 or 4.

Comet Soft Cleaners: Comet’s Soft Cleansers category includes two cleaning creams that are gentler and safer to use than some of the commonly used, more abrasive cleaners. These creams come in the regular strength formula or the Ultra formula.


Both Ajax and Comet use similar ingredients in their powder cleaners, with just a few variations. The basic formula for both includes the following:

  • Calcium carbonate: An abrasive material used as a scrubbing or scouring agent
  • Sodium carbonate: A softener, which helps to remove hard water or similar stains
  • Trichloroisocyanuric acid: A bleaching agent and disinfectant
  • Dyes
  • Fragrance

The main variation is the surfactant used by Ajax and Comet.

Ajax’s formula utilizes sodium dodecyl benzene sulfonate as its primary surfactant, while Comet uses alkylbenzene sulfonic acid.

There are no significant differences between these two surfactants; both have the same purpose (lift and remove dirt/stains).


As with many cleaners, Ajax and Comet come with a few warnings and safety concerns.

The best place to learn about cleaning products’ health and environmental safety is the Environmental Working Group’s (EWG) website, which lists, describes, and rates hundreds of brands.

EWG Safety Ratings
EWG Safety Ratings

According to the EWG, Ajax contains chemicals with moderate concern for asthma/respiratory complications and poses a moderate risk to aquatic life (if the product comes into contact with waterways).

EWG also mentions Ajax poses “some concern” regarding allergy risk and carcinogenic compound exposure.

Comet also has several concerns. The EWG warns that this cleaner carries a “serious” environmental concern level and poses a moderate risk for asthma and respiratory problems. 

Regarding allergies, developmental/reproductive risks, and carcinogen risks, the EWG flagged “some concern” with Comet.

Ajax and Comet both carry an “F” rating with this organization.

As a general rule, all powder cleaners contain harsh chemicals, so exercise caution when using them.

According to the product labels, proper use includes gloves, eye protection, and ventilation. Never use these cleaners in unventilated spaces, and don’t discard or use them near waterways.

Read the Ajax and Comet safety data sheets to learn more.

How to Use

Usage directions for both Ajax and Comet are identical. Here are the basic steps:

  1. Put on gloves, open windows, and observe other safety precautions before use.
  2. Dampen the surface to be cleaned with plain water.
  3. Sprinkle the powder cleaner onto the surface, then let it sit for about 15 seconds.
  4. Use a damp sponge or cloth to rub the powder into the dirty surface, forming a thin paste.
  5. Rinse the surface completely and allow it to dry.

Ajax specifically warns against using its powder cleaner on silver, painted surfaces, fabrics, or plexiglass. Refrain from using Comet on these materials, too. 

If you are cleaning a delicate surface, such as imitation marble or chrome fixtures, test the cleaner on a small, inconspicuous area before using it on the rest of the surface. Always refer to the instructions on the product’s label before use.

Test Results

Now that you know what Comet and Ajax offer, how the ingredients differ, and how to use the powder cleaners, it’s time to answer the most critical question: which works better?

To find out, I tested each brand’s powder cleaners on three different surfaces.

First, I tested both cleaners on a porcelain-coated cast iron bathtub. The tub has texture on the floor to prevent slips, but that texture also collects dirt.

I used Ajax powder cleaner on the left side of the tub and Comet in the middle. I left a gap between the two, so you can see the contrast between the areas I cleaned and the area left dirty.

Testing Ajax powder versus Comet powder to clean a bathtub

Within 30 seconds, Ajax removed the dirt completely. Comet also got the job done, but it took about a minute longer and much more effort. 

Bathtub after cleaning it with Ajax powder cleanser
Bathtub after cleaning it with Ajax powder cleanser

Next, I tested both products on the bottom of a stained stainless steel pan.

Stainless steel pan before cleaning it with Comet and Ajax
Stainless steel pan before cleaning it with Comet and Ajax

I cleaned the right side of the pan with Ajax and the left side with Comet. Like the previous test, Ajax cleaned the surface with ease while Comet required more time and effort.

Stainless steel pan after cleaning the left side with Comet and right side with Ajax
Stainless steel pan after cleaning the left side with Comet and right side with Ajax

I tested Ajax and Comet on another stainless steel pan with significant stains from burnt oil.

Heavily stained stainless steel pan before cleaning it with Comet and Ajax

Again, Ajax was more effective than Comet.

Stainless steel pan after cleaning the right side with Ajax
Stainless steel pan after cleaning the right side with Ajax
Heavily stained stainless steel pan after cleaning the left side with Comet and right side with Ajax
Heavily stained stainless steel pan after cleaning the left side with Comet and right side with Ajax

However, both products struggled to completely remove the discoloration on the sides; I had to soak it overnight to remove those stains.

Note: I’ve tested several other brands, and Bar Keepers Friend was the most effective stainless steel cookware cleaner. Check out this comparison of Comet vs. Bar Keepers Friend to see the test results.

Finally, I tested Comet vs. Ajax on grout lines that hadn’t been cleaned in over a year. Both products were equally effective, unlike the other two tests where Ajax showed superior cleaning power.

Both cleaners contain abrasive particles in the formulas to loosen dirt and stains, but the particles in Comet are larger. After adding water to Comet powder, you can see the green granules.

Granules inside Comet powder
Granules inside Comet powder

Ajax’s granules are much smaller and less noticeable, even when you look closely.

Keep that in mind when cleaning soft surfaces like plastic or vinyl. Those granules, especially Comet’s larger granules, can scratch surfaces.

Overall, Comet and Ajax both got the job done. Although Ajax was slightly more effective in my porcelain and stainless steel tests, Comet wasn’t far behind. Since both brands use nearly the same ingredients, these results weren’t a surprise.


Ajax and Comet are inexpensive enough that price shouldn’t be a deciding factor.

When comparing prices between retailers or product options, make sure to calculate the difference based on the price per ounce (rather than per bottle).

This price chart gives an overview of how much Ajax and Comet cost.

Prices pulled from the Amazon Product Advertising API on:

FAQs About Ajax and Comet

Here are answers to the most commonly asked questions about Ajax and Comet powder cleaners.

What surfaces can you clean with Ajax and Comet powder cleaners? 

Powder cleaners like Ajax and Comet can clean pots and pans, countertops, bathroom tiles, porcelain, and outdoor furniture. That said, both cleaners contain abrasive particles that can scratch delicate surfaces — exercise caution. 

What surfaces cannot be cleaned with Ajax and Comet powder cleaners? 

Don’t use powder cleaners on natural stone surfaces (such as granite or marble), plexiglass, precious metals, stainless steel, or any surface that has recently been cleaned with bleach. Never mix powder cleaners with bleach or ammonia.

Are Ajax and Comet powder cleaners septic tank-safe? 

Yes, both cleaners are septic-safe when used as recommended. 

Are Ajax and Comet powder cleaners disinfectants? 

Ajax and Comet powder cleaners are not disinfectants. Comet’s Bathroom Spray and Classic Antibacterial Spray are EPA registered disinfectants. Ajax doesn’t offer any disinfectants.

Do Ajax and Comet contain bleach? 

The original formulas made by Comet and Ajax did not contain bleach, but now most of their powders do. The products that contain bleach have “with bleach” clearly marked on the label. 

Can you mix Ajax and Comet with bleach? What about vinegar? 

Never mix Ajax or Comet with bleach. Doing so can cause a dangerous chemical reaction. It’s also best to avoid mixing these cleaners with vinegar. Essentially, avoid mixing them with anything besides water.  

Are Ajax and Comet toxic?

As previously noted, the EWG gives both Ajax and Comet “F” ratings for environmental and health safety. Read the instructions carefully and take precautions when using these cleaners. 

Can you dilute Ajax and Comet powder cleaners in water?

Since these cleaners are already used in conjunction with water, you can adjust the strength simply by moderating the powder to water ratio. 

Where can you buy Ajax and Comet products? 

Both Ajax and Comet are available at all major retailers where cleaning products are sold. You can purchase these cleaners at Amazon (link to Comet and Ajax), Target, Walmart, and most grocery stores.

Bottom Line: Should You Use Ajax or Comet?

As you’ve learned throughout this article, Ajax and Comet powder cleaners are nearly identical.

They’re both effective, easy to use, easy to find, and cheap. The powder cleaners are made of the same ingredients, except for the surfactants.

Based on my tests, Ajax does a better job scrubbing dirt from porcelain-coated bathtubs and discoloration from stainless steel cookware, but the difference in performance was minimal.

Bottom line — if you’re looking for a powerful and versatile powder cleaner from a trusted brand, Ajax and Comet both fit the bill.

The most notable downside of Comet and Ajax is they both contain harsh ingredients that earn them an “F” rating from the EWG. 

If you’re looking for more natural cleaners that are safer for your health and the environment, consider brands like Seventh Generation, Method, Mrs. Meyers, or ECOS.

Another excellent alternative to Comet and Ajax is Bon Ami. Bon Ami is a powder cleaner that’s been around since the 1800s.

 It performs similarly to Comet and Ajax, but it’s made with non-toxic and biodegradable ingredients and earns an “A” rating from the EWG.

If you’re ready to buy or just want to learn more, Comet and Ajax are available on Amazon.

Andrew Palermo Founder of Prudent Reviews

Andrew Palermo - About the Author

Andrew is the Founder and Editor-in-Chief of Prudent Reviews. He began his career in marketing, managing campaigns for dozens of Fortune 500 brands. In 2018, Andrew founded Prudent Reviews and has since reviewed 600+ products. When he’s not testing the latest cookware, kitchen knives, and appliances, he’s spending time with his family, cooking, and doing house projects. Connect with Andrew via emailLinkedIn, or the Prudent Reviews YouTube channel.

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