Barium Sulfate (BaSO4) (98.5% Purity 0.31 micron CAS:7727-43-7)

NOT FOR HUMAN CONSUMPTION

Note: the loonie in the small photo is just for size reference (not included).

For those thinking about climate change, or for those who want very white paint, it would seem that Barium sulfate could be quite helpful. It is not generally considered a hazardous substance (under normal conditions) and has many applications, including:

1. Heat-reflecting white paint. Barium sulfate is highly reflective of a broad spectrum of light, including visible light (such that it appears very white when used as a white pigment for paints), plus infrared and ultraviolet. Recently, researchers have successfully explored using it as an ingredient in paint that reflects greater than 98% of all solar radiation, thus cooling surfaces to which it has been applied (the YouTube video below inspired our interest).
2. Radiocontrast agent. Barium sulfate in suspension is often used medically as a radiocontrast agent for X-ray imaging and other diagnostic procedures (OURS IS NOT FOR HUMAN CONSUMPTION).
   
3. Pyrotechnics (a niche use): Barium compounds emit a characteristic green light at high temperatures.

Detailed specifications from our supplier are at the bottom (for those interested). We sought the best available for making heat-reflecting white paint from our supplier (the manufacturer) and imported it directly by sea to keep costs low. It is a very fine powder (D50 of 0.31 μm). Solid Barium Sulfate is quite dense at ~4.5 grams/ml, but this powder is a bit less than 1 gram/ml (it varies a bit depending on settling). We deliberately try to avoid compacting it, because compacting will only make life harder for all involved.

We are presently offering 3 sizes:

(1) Standard Size: 2kg of Barium Sulfate

Your Barium Sulfate will be contained in an air-tight 0.6-gallon (~2.27 litres) Screw Top Pail.

The Screw Top Pail is vacuum-tight (with a neoprene gasket) and is designed to quickly open and reseal for easy access. It is 7.39" high (with Lid), 7" wide (Top of Lid), 46 Mil thick, BPA free, made of FDA-compliant resins, for Storage temperatures of -29° to 43° C (-20° to 110° F), and carries a UN Rating of 1H2/Y4/S.

(2) Large Size: 5kg of Barium Sulfate

Your Barium Sulfate will be contained in an air-tight 1.25-gallon (~4.73 litres) Screw Top Pail.

The Screw Top Pail is vacuum-tight (with a neoprene gasket) and is designed to quickly open and reseal for easy access. It is 9.14" high (with Lid), 9" wide (Top of Lid), 62 Mil thick, BPA free, made of FDA-compliant resins, for Storage temperatures of -29° to 43° C (-20° to 110° F), and carries a UN Rating of 1H2/Y6/S.

(3) Small Size: 375 grams of Barium Sulfate

Your Barium Sulfate will be contained in a 500 ml bottle with a child-resistant lid. The bottle is 5.75" high (with Lid), and 3" in diameter.

Ideal Paint-to-Barium Sulfate Ratio

It seems the ideal Paint-to-Barium Sulfate ratio is close to 60/40. More paint tends to yield better durability, whereas more Barium Sulfate yields better reflectivity.

For those who like to go fast, and want to use up all materials with no waste, I'd convince myself that the right ratio is 2kg of Barium Sulfate (the amount we can fit in our Standard Size pail), to whatever your standard size of paint is locally (though probably large size in Australia). The choice of paint is yours, but you most likely want white acrylic paint. We've shown the ratios you get in the chart below for various locations. For those who want to stay close to 60 Paint / 40 Barium Sulfate, or go higher Barium Sulfate, you probably need our Large Size, and will have some leftovers, for another project.

MIXTURES OF PAINT AND BARIUM SULFATE

Rationale and Implementation

We are quite intrigued by its application as a heat-reflecting paint to save energy and cost, such as the following rather inspirational video:

Detailed Specifications

For those interested, below are some detailed specs from our supplier: