What Is Trisodium Phosphate (TSP)?

Pros and Cons, Cleaning With TSP, and Safety Tips

By
Lee Wallender
Lee Wallender
Lee Wallender

Lee has over two decades of hands-on experience remodeling, fixing, and improving homes, and has been providing home improvement advice for over 13 years.

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Updated on 03/27/24
Reviewed by
Deane Biermeier
Deane Biermeier
Reviewed by Deane Biermeier
Deane Biermeier is an expert contractor with nearly 30 years of experience in all types of home repair, maintenance, and remodeling. He is a certified lead carpenter and also holds a certification from the EPA. Deane is a member of The Spruce's Home Improvement Review Board.
Learn more about The Spruce's Review Board
Fact checked by
Jillian Dara
Jillian Dara
Fact checked by Jillian Dara
Jillian is a freelance journalist with 10 years of editorial experience in the lifestyle genre. She is a writer and fact checker for TripSavvy, as well as a fact-checker for The Spruce.
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In This Article
Project Overview
  • Working Time: 15 mins
  • Total Time: 20 - 30 mins
  • Skill Level: Beginner
  • Estimated Cost: $5 to $10

Trisodium phosphate, or TSP, could be the heavy-duty cleaner you need for projects around the home, such as painting or cleaning soot from chimneys and cleaning mildew and mold behind refrigerators and kitchen sinks. As for areas around the country that have banned TSP, a substitute that works nearly as well is available.

Trisodium Phosphate

The Spruce / Lee Wallender

What Is Trisodium Phosphate (TSP)?

Trisodium phosphate, commonly called TSP, is a packaged, blended cleaning product consisting of 75 to 80 percent trisodium phosphate and 20 to 25 percent sodium carbonate.

TSP is typically inexpensive and comes in the form of an odorless dry powder that must be thoroughly mixed into hot water to form a mostly clear solution, though slightly cloudy. Applied to surfaces with sponges or scrub brushes, TSP is an effective, heavy-duty cleaner for problem areas around the house that may be sooty, greasy, or dirty, such as walls or cabinets in need of painting.

Though bans on phosphates are in effect in many communities, TSP is still legal in many areas. It's often favored by contractors and painters to ensure that the surface will be clean, dust-free, and able to accept the paint. However, phosphate-free substitutes to TSP are also available nearly everywhere.

Pros

  • Inexpensive

  • Readily available in states that do allow its sale

  • Excellent cleaner for heavy-duty dirt and stains, especially grease

  • Can be mixed stronger or weaker, as needed

  • Long shelf life if kept dry

  • TSP substitutes are available

Cons

  • Not available in some states due to TSP bans

  • Will clump if it is not kept dry or free of humid conditions

  • Will stain some surfaces if precaution is not taken

  • Can irritate the eyes and skin

  • Can damage glass and mirrors and darken aluminum

  • Requires extreme care when using

Personal Safety and Environmental Considerations

Trisodium phosphate is a safe cleaner if you use it properly. Trisodium phosphate is harmful and toxic if used incorrectly because it can cause eye and skin irritation and is harmful if swallowed. TSP requires care when you work with it. Always use eye protection and waterproof gloves when handling or cleaning with TSP. Also wear full skin protection, including long sleeves and long pants. Safety precautions apply to both dry and mixed or diluted forms of TSP. Keep TSP away from glossy surfaces.

TSP is known to harm vegetation and grass according to product safety data sheets. Since 2010, states around the country have increasingly started to ban household cleaning products that contain phosphates as this chemical has been linked to water-fouling and toxic algae growth that can deplete oxygen levels in the water and kill aquatic wildlife and aquatic plants.

Trisodium Phosphate Alternatives

Due to bans on TSP, as well as general concerns about the environment, some manufacturers offer TSP substitutes and you can also find your own.

Free of phosphates, these substitutes usually come in fluid form for easier mixing with water and work comparable to TSP. Safe for cleaning aluminum, these solutions will not harm vegetation if you are using them for outdoor cleaning. Another benefit of these phosphate-free cleaners over TSP is that they do not require rinsing after they have been applied to the surface. Here's a list of alternatives to TSP:

  • Borax: Though TSP and borax are not the same, they can both be used to clean and cut through surface grease.
  • Dawn: You can use the original blue Dawn dish detergent instead of TSP to cut through surface grease.
  • Pressure-washing: This is another alternative to cleaning outside surfaces without TSP. With sufficient and well-calibrated water pressure, it is possible to clean tough areas with only the pressure of the water.

What You'll Need

Equipment / Tools

  • Sponge
  • Bucket
  • Latex or nitrile gloves
  • Eye protection

Materials

  • Trisodium phosphate (TSP)
  • Hot water

Instructions

How to Clean With Trisodium Phosphate (TSP)

  1. Prepare Yourself and Work Area

    Wear eye protection, long sleeves, and waterproof gloves. Use plastic sheeting to protect areas of the home that are not being cleaned with the TSP.

  2. Mix TSP Solution

    The correct trisodium phosphate formula is a mix of 1/2 cup of TSP per 2 gallons of water for heavy-duty cleaning or 1/4 cup of TSP per 2 gallons of water for household cleaning. Make sure that the water is hot, as this allows the TSP to become soluble. Thus, wearing gloves not only helps to protect the skin but it allows you to handle hotter water than you could manage with bare hands.

  3. Soak and Squeeze

    With gloves on, soak the sponge in the water. Hold the sponge over the bucket and thoroughly squeeze it dry. A damp sponge is better than a wet sponge, since the wet sponge may leave tracks from drops of water.

  4. Clean Surface With TSP

    Clean the surface from the bottom upward. Move the sponge in broad strokes to remove the worst of the debris. Again soak the sponge in the TSP solution and squeeze out, the more frequent, the better.

  5. Rinse Surface Thoroughly

    Rinse the cleaned area with cool water. Because TSP begins as a dry, white powder, it often can conclude as a dry, white powder on the surface after the water has dried.

    To combat this, make sure that you rinse the surfaces with a new sponge and a bucket that has been thoroughly rinsed out or even a new bucket of clean water.

  6. Clean Surface Again With TSP

    For difficult areas, a second cleaning with TSP is required. Mix up another bucket with fresh, warm water and TSP and clean with this new solution. Rinse with a fresh bucket of cool water.

Tips For Cleaning With Trisodium Phosphate (TSP)

  • If you're not accustomed to rinsing surfaces after washing them down with a cleaning solution, this step is absolutely necessary with TSP. It will always leave a white film behind if not rinsed.
  • For problem surfaces or for mold and mildew, add some chlorine bleach to the TSP mix.
  • When you first mix up the TSP solution, it should have a cloudy, milky appearance but it should not be solid white.
  • Be especially careful of using TSP around glass, mirrors, and porcelain or ceramic tile. The mild acids in the TSP can etch the surface.

What to Clean With TSP

  • Walls, ceiling, trim, and other woodwork before painting
  • Mold and mildew from decks
  • House siding
  • Soot on chimney mantels
  • Greasy stains and unidentifiable stains
  • Lead paint dust
  • Beams or joists in crawlspace
  • Mold in the home, before mold remediation
  • Kitchen walls near cook areas before painting
  • Behind refrigerators
  • Bathroom ceilings before painting

Tip

TSP is often used to de-gloss painted surfaces that need another coat of paint. Just be sure to thoroughly rinse the TSP with fresh water and wipe it down with a tack cloth.

What Not to Clean With TSP

Though TSP can be used for a wide variety of surfaces, it cannot be used for all surfaces.

  • TSP can darken or stain some materials, and it can etch glass and mirrors.
  • Keep TSP away from aluminum, as well as other metals, when the TSP solution is at its hottest.
  • Paints that have a glossy sheen may lose their sheen if they come into contact with TSP.
  • Hardwoods like oak and mahogany may darken if they are cleaned with TSP.

If you have any concerns about whether or not to use TSP on a particular surface, test a small amount in an inconspicuous area first, or use a substitute cleanser.

TSP Bans and Availability

TSP has long been the go-to cleaning product for most home improvement-related projects. However, dishwasher and laundry detergents containing phosphates are banned in many states, and the movement toward banning phosphates includes TSP in many states. For retailers offering TSP in states with bans, the penalty can be high, as a few major home centers have already experienced.

FAQ
  • What is tridosium phosphate used for in food?

    TSP is sometimes used as an additive in processed foods, functioning as a thickener, acidity regulator, and emulsifier, among other potential purposes.

  • Why is trisodium phosphate in toothpaste?

    The addition of trisodium phosphate in toothpaste is meant to assist in protecting tooth enamel.

  • Is trisodium phosphate dangerous for cats and dogs?

    Yes, trisodium phosphate can be dangerous if ingested, as it is extremely corrosive.

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. PubChem Compound Summary for CID 24243, Trisodium phosphate. National Center for Biotechnology Information, PubChem, 2005

  2. The Unintended Consequences of Household Phosphate Bars. Iowa State University

  3. Phosphorus. EPA.

  4. Unintended Consequences of Household Phosphate Bans. Iowa State University.

  5. Safety Data Sheet, TSP. University of Florida.