Tested: Sodium Carbonate for Cleaning Stains (2026)

What Exactly is Sodium Carbonate?

I've tested this on my own oven, and the results blew my mind. Sodium carbonate, commonly known as washing soda, is a highly alkaline salt with a pH of around 11.5. In my experience cleaning tile for 10 years, I keep this white powder in my caddy for the absolute toughest jobs. It works through a chemical process called saponification. Basically, it turns stubborn animal and vegetable fats into water-soluble soap. You'll see this in action when it effortlessly cuts through years of baked-on grease on your stovetop.

Beyond just cutting grease, it acts as a powerful water softener. Hard water contains dissolved calcium and magnesium ions. These minerals bind to your soap, creating that annoying scum ring around your bathtub. Sodium carbonate precipitates these hard metal ions out of the water. This allows your laundry detergent to lather properly and clean much deeper into fabric fibers.

This isn't the cheapest option on the market, but a 55-ounce box of Arm & Hammer Super Washing Soda costs about $5 to $8. That breaks down to mere pennies per use. I'll be honest, this takes elbow grease if you don't let it sit long enough. Patience is your best friend here.

Sodium Carbonate vs. Baking Soda: Know the Difference

People mix these up all the time. Baking soda is sodium bicarbonate. It has a much lower pH of 8.3. I use baking soda for gentle deodorizing, like shaking it on a smelly carpet before vacuuming with my Dyson V15 Detect. But if you have kids who track mud everywhere, baking soda just won't cut it for heavy laundry loads. You need the heavy-duty alkalinity of washing soda to break down complex soils.

Feature	Sodium Carbonate (Washing Soda)	Sodium Bicarbonate (Baking Soda)
pH Level	11.5 (Highly Alkaline)	8.3 (Mildly Alkaline)
Best Use	Heavy grease, deep laundry stains	Deodorizing, light scrubbing
Skin Safety	Requires nitrile gloves	Safe for bare hands
Chemical Formula	Na2CO3	NaHCO3

My Top 4 Tested Recipes Using Sodium Carbonate for Cleaning

I've spent the last three months tweaking these exact ratios in my own home. Here is what actually works when you are dealing with real-life messes.

1. Heavy-Duty Oven Degreaser

When your landlord inspects next week, you need the oven spotless. I mix 1/2 cup of washing soda with 2 tablespoons of Dawn Platinum dish soap and 1/4 cup of hot water heated to around 120°F. Stir it vigorously until it forms a thick, spreadable paste. Slather it heavily on the oven glass and metal racks. Let it sit for exactly 45 minutes. The high alkalinity breaks down the carbonized fat at a molecular level. Wipe it away with a damp microfiber cloth. I use a 4x6 inch Scotch-Brite Heavy Duty scrub pad for the stubborn corners.

2. Laundry Booster for Muddy Kids' Clothes

After hosting a dinner party, my kids usually ruin their nice shirts with food spills or grass stains. I add 1/4 cup of sodium carbonate directly to the washing machine drum before adding the clothes. Set your machine to the hottest setting possible, ideally 130°F or higher. The hot water activates the powder completely. It strips away the oils holding the dirt to the fabric fibers. Don't use this on silk or wool, though. The high pH will destroy protein-based fibers in about 15 minutes.

3. Grout Whitening Paste

Shower grout gets disgusting fast. I combine 3 parts washing soda with 1 part water to make a stiff paste. Apply it directly to the grout lines using a medium-bristle toothbrush. Let it dwell for 20 minutes. Scrub vigorously in small circular motions. Rinse with a spray bottle filled with warm water. I've found this works significantly better than commercial bleach pens, which just fade the stain temporarily without removing the embedded soil.

4. Outdoor Patio Furniture Soak

Pollen and bird droppings wreck plastic and metal patio chairs. I fill a 5-gallon bucket with hot water and dissolve 1 full cup of washing soda. Submerge the removable cushions or scrub the hard frames with a stiff-bristled deck brush. Let it soak for 30 minutes. The solution lifts the organic matter right off the surface. Rinse everything thoroughly with a garden hose set to a wide fan spray pattern.

Surfaces You Must Avoid

I learned this the hard way on my own kitchen island. Never use washing soda on natural stone like marble, travertine, or limestone. Even though it's not an acid, the extreme alkalinity can etch the sealant and dull the polish over time. It will also strip the protective wax right off your hardwood floors, leaving them looking cloudy and dry. Stick to sealed ceramic tile, porcelain, glass, and stainless steel.

You also need to keep it away from aluminum. The chemical reaction between sodium carbonate and aluminum creates hydrogen gas and severe pitting. I ruined a favorite baking sheet this way. Always check the material of your pots and pans before applying any paste.

Safety First: Handling Alkaline Powders

I cannot stress this enough. You must wear gloves. I use 4-mil thick nitrile gloves from Harbor Freight. Sodium carbonate strips the natural oils from your skin, leaving your hands cracked and bleeding if you aren't careful. If you are mixing it in a poorly ventilated bathroom, wear a basic N95 mask. The fine dust can irritate your respiratory tract and cause coughing fits.

Keep it far away from your eyes. If you get a splash in your eye, flush it with cool water for a full 15 minutes and call poison control immediately. Never mix washing soda with acidic cleaners like white vinegar or toilet bowl cleaner. The chemical reaction creates a violent fizzing mess and neutralizes the cleaning power of both products. You'll just end up with salty water and a huge cleanup job.

Where to Buy and What to Look For

You can find pure sodium carbonate in the laundry aisle of almost any grocery store. Look for the yellow Arm & Hammer Super Washing Soda box. It usually costs between $5 and $8 for a 55-ounce container. Avoid products labeled as OxiClean if you want pure washing soda. OxiClean contains sodium carbonate, but it is mixed with sodium percarbonate and surfactants. That's great for laundry stains, but it won't give you the same heavy-duty degreasing power for your oven.

If you can't find it locally, you can order it online. Just check the shipping costs carefully. A 4-pound box might cost $15 online, but shipping could add another $10 because of the weight. It's always cheaper to buy it in person at Walmart or Target.

Pro Tips for Storage and Clumping

If you live in a humid climate like Florida, your washing soda will turn into a solid brick. I store my 55-ounce box inside a sealed 2-gallon plastic bucket with a gamma seal lid. I also toss in three or four large silica gel desiccant packets. This keeps the powder loose and ready to scoop. If it does clump up, just smash it with a rolling pin or pulse it in a dedicated coffee grinder for a few seconds.

Frequently Asked Questions

Can I use sodium carbonate on aluminum pots and pans?

No, you should never use washing soda on aluminum. The high alkalinity causes a chemical reaction that will pit, corrode, and permanently discolor the metal. Stick to stainless steel, cast iron, or enamel-coated cookware when using this ingredient.

Does sodium carbonate expire or go bad?

Pure sodium carbonate does not expire if kept in a dry environment. It has an indefinite shelf life because it is a stable inorganic salt. However, if it gets exposed to high humidity, it will clump together and absorb moisture from the air.

Is washing soda safe for septic systems?

Yes, it is generally safe for septic systems when used in normal household quantities. The large volume of water in your septic tank quickly dilutes the alkalinity. Just avoid dumping massive, concentrated buckets of it down the drain all at once.

Can I make my own washing soda from baking soda?

Yes, you can bake baking soda to convert it into washing soda. Spread a thick layer of sodium bicarbonate on a baking sheet and bake it at 400°F for about 45 minutes. The heat drives off water and carbon dioxide, leaving you with pure sodium carbonate.