What is Sodium phosphate tribasic dodecahydrate?

Sodium phosphate tribasic dodecahydrate (SPTD)is an effective cleaning agent, but using it could be risky for your health and the environment. Learn when cleaning with it is probably safe—and when you should have a Plan B. SPTD is a white, dry powder commonly used as a cleaning agent. It consists of a mix of SPTD and sodium carbonate, typically in a 4:1 or 3:1 ratio. It's inexpensive to purchase and can cut through heavy-duty grease, film, and dirt very easily.

Sodium phosphate tribasic dodecahydrate is water soluble, and is mixed with hot water to create a potent cleaning solution. The solution can be used for cutting through soot, grease, dirt, and other nasty messes. It can also prepare previously painted surfaces like walls or cabinets for a fresh coat of paint, which is why it’s been a go-to for painters and contractors for many years. Despite its affordability and usefulness, Sodium phosphate tribasic dodecahydrate isn’t universally loved. Sodium phosphate tribasic dodecahydrate contains phosphates, and these substances are illegal in dishwashing and laundry detergents in most areas throughout the U.S. Studies have linked them to algae that release harmful toxins that affect human and animal health. Where legal, however, SPTD and substitutes are still readily available.

Synthesis of Sodium phosphate tribasic dodecahydrate

A solution of 52.2 g (0.1 mol) of tributylhexadecyl-phosphonium bromide in 1000 ml of toluene was introduced into a 5 1 stainless-steel pressure reactor and pre-heated to 60° C. 62 g (2 mol) of yellow phosphorus were added, the mixture was cooled to -10° C. with vigorous stirring, and 252 g (2 mol) of dimethyl sulfate were then metered in. The mixture was then warmed to 20° C., and 500 g of 40% aqueous sodium hydroxide solution were metered in over the course of 4 hours, during which the temperature was held at 20° C. Over the course of a further hour, 300 g of water were added, the mixture was then stirred for a further hour, and the reactor was subsequently decompressed via combustion. Two homogeneous liquid phases were obtained, which were separated and analyzed. [00043] The aqueous phase (weight: 930 g) contained 54.6 mol % of methylphosphonous acid, 17.9 mol % of phosphorous acid, 19.7 mol % of hypophosphorous acid, 2.8 mol % of dimethylphosphinic acid in the form of their sodium salts and 3 mol % of dimethyldiphosphine. The acids can be obtained from the salts prepared in Example 1 in a known manner, for example by ion exchange.[1]

Cleaning With Sodium phosphate tribasic dodecahydrate

Cleaning with Sodium phosphate tribasic dodecahydrate is fairly straightforward, but it’s important to take precautions. You’ll need plastic sheeting, a bucket, two sponges, a pair of safety glasses, a pair of chemical-resistant gloves, a respirator, long sleeves and pants, as well as hot water. Sodium phosphate tribasic dodecahydrate is an irritant and can cause itching on exposed skin or airways, so it's best to cover up. Cover anything in the area that you don't intend to clean with plastic sheeting. This also includes nonporous surfaces like glass and tile. Mix Sodium phosphate tribasic dodecahydrate with hot water in the bucket. Adjust the ratio as necessary. For a heavy-duty mess or stain, mix ? cup of SPTD with 1 gallon of water. For general-purpose use, like cleaning cabinets before painting, mix ? cup of Sodium phosphate tribasic dodecahydrate with 2 gallons of water. Mix it until the solution is clear. While wearing all of the proper PPE listed above, soak the sponge in the SPTD solution. Lift the sponge out of the solution and let it drain into the bucket for a few seconds and then squeeze the sponge until it is damp rather than saturated. Starting at the bottom of the stained or soiled area, scrub the sponge back and forth across the surface. Frequently dip the sponge back in the bucket, let it drain, and squeeze excess liquid out while cleaning. Continue cleaning the entire surface.[2]

Once clean, rinse the bucket well with cold water to remove any residual Sodium phosphate tribasic dodecahydrate. Then, fill the bucket with cold water and rinse the surface with a clean sponge soaked in cold water. This is an important step: Sodium phosphate tribasic dodecahydrate users must rinse the surface with fresh water to prevent SPTD from creating a white film over the surface. Sodium phosphate tribasic dodecahydrate is truly a multipurpose cleaner. Mixed in different ratios, it can clean a variety of surfaces safely, even if there are hard-to-remove stains present. DIYers can feel confident using SPTD in the following ways: Cleaning stains on concrete driveways, walkways, and walls; Preparing painted surfaces for paint or stripping paint from masonry (as in the case of a paint spill, perhaps); Removing tough grease from a variety of surfaces in the kitchen or workshop; Cleaning creosote and soot from fireplaces. Sodium phosphate tribasic dodecahydrate can also be helpful when removing mold and mildew from surfaces like siding, decks, or even interior walls. Mixing a bit of bleach into the solution gives it a bit more cleaning power, but, with the added bleach, users should be even more careful to wear the proper protective gear.

What Not to Clean with Sodium phosphate tribasic dodecahydrate

Despite its multipurpose nature, there are surfaces with which Sodium phosphate tribasic dodecahydrate should not make contact. DIYers should not clean glass surfaces like mirrors and ceramic tiles with SPTD, because the solution's acidity could etch the glass surface, and it can also eat away at the grout between the tiles. Avoid using SPTD on metal surfaces, particularly aluminum. The solution can darken and corrode metals, leaving them looking dull and pitted.[3]

Avoid using Sodium phosphate tribasic dodecahydrate on hardwoods like oak and maple, because it will darken wood after cleaning with it. One final point about painted surfaces: SPTD is ideal for preparing surfaces for a new coat of paint. However, it will also remove the shininess, or sheen, from glossy painted surfaces, so it's not a good idea to use it for general cleaning.

Sodium phosphate tribasic dodecahydrate Alternatives

If the disadvantages of using Sodium phosphate tribasic dodecahydrate give you pause and you'd like to explore other options, consider this eco-friendly SPTD substitute: borax. Also known as sodium borate, borax is a naturally occurring mineral compound that will clean many of the same surfaces Sodium phosphate tribasic dodecahydrate has been used on for years, including mold- and mildew-stained areas, all without causing damage to nearby plants. (See it in use in our tutorial for homemade deck cleaner.) The good news is that you can usually find this powerful antimicrobial cleaning agent right in your grocery store's cleaning aisle. Another substitute that is generally considered to be eco-friendly is Simple Green. This product cleans and cuts grease well (maybe slightly less effectively than SPTD. It has a distinct smell that some folks may not enjoy, but it's generally safe for just about any surface in the home and doesn’t have the same ill effects on waterways as Sodium phosphate tribasic dodecahydrate.

But, for folks looking for something a bit stronger, it might be worth checking out Klean Strip Sodium phosphate tribasic dodecahydrate No-Rinse Substitute. This product can remove grease, mildew, and food stains, but it is an irritant and proper PPE should be worn when handling (gloves, respiratory, and safety glasses)

References

[1] CLARIANT PRODUKTE DEUTSCHLAND - US6806383, 2004, B1

[2] Pradip, Kulkarni, R.A., Moudgil, B.M. (1991). "SELECTIVE FLOCCULATION OF KAOLINITE FROM MIXTURES WITH TRIBASIC CALCIUM-PHOSPHATE USING HYDROLYZED POLYACRYLAMIDES". International Journal of Mineral Processing, 32(3-4), pp.259-270.

[3] Xi, Z.Q.; Yang, D.R. and Que, D.L. (2003). "Texturization of monocrystalline silicon with tribasic sodium phosphate". Solar Energy Materials and Solar Cells, 77(3), pp.255-263.