TSP - The Down & Dirty

Should I use TSP to clean my furniture before painting? In the painting community there can be a fair bit of controversy surrounding TSP cleaners and their continued usage when there are so many highly regarded alternatives in today's market.


TSP stands for Trisodium Phosphate and it is a popular and commonly recommended surface preparation cleaner for painting. TSP can be purchased as a powder that you dissolve in water or as a ready to use spray. There are various trisodium phosphate cleaners available that are marketed under other names as well - these will list trisodium phosphate as one of their main ingredients.

For more than half a century, TSP has been used as a heavy duty cleaning agent. TSP was once a popular ingredient in a variety of soaps, laundry detergents and other consumer-grade cleaning solutions. The versatility and low cost of manufacturing TSP made it an obvious ingredient choice. Trisodium phosphate is still sold and used for cleaning, however, in most household cleaning products phosphates are no longer a significant ingredient. The overall popularity of TSP has diminished due to awareness of its harmful effects on the environment. Phosphates aren't "toxic" to the environment in the way that you may think. They do not poison wildlife but rather they cause water quality problems by creating nutrient pollution. Phosphates enter our water systems, enriching them with unnatural levels of minerals and nutrients, this in turn creates favorable conditions for the formation of harmful algal blooms. These algal blooms prevent light and oxygen from entering the water killing off important organisms and throwing off the balance of the ecosystem.


So the obvious question becomes: If phosphates are not being commonly used in products anymore, should we still be using TSP for prepping furniture? Below I have further explained the purpose of TSP as it relates to painting, as well as proper handling instructions for using it safely so you can make an informed decision on whether or not you choose to use it as a cleaner.

Safe TSP Handling

TSP is a heavy duty cleaner. If used incorrectly, TSP can cause skin irritation and even burns.

  • Avoid direct contact between TSP and bare skin - wear rubber gloves and long sleeves when working with trisodium phosphate. If skin contact occurs, wash thoroughly with soap and water.

  • Protect your eyes from potential exposure to TSP by wearing safety goggles. It is not uncommon to splash a bucket of cleaning solution in your face when washing walls or even furniture. If eye contact occurs, flush with clean water for at least 15 minutes and seek medical attention.


Protecting Surfaces You Aren’t Painting

When you are using trisodium phosphate cleaners, it is important to protect other surfaces from splashes. Painted surfaces, finished wood (such as hardwood flooring), and metals (furniture hardware) can be discolored or de-glossed by TSP. Be sure to cover or mask off anything you don’t want damaged.