Check the listing for details. True Colloidal Copper NanoParticles (CuNPs): 25 ppm - 500 mL in Plastic. Condition: New. Listed at 24.90 USD. True Colloidal Copper (25 ppm) - 99.99+% purity - 500 mL (16.9 Fl Oz) in a clear glass bottle Non-toxic CAS # 7440-50-8 Volume: 500 mL, 16.9 Fl Oz 25 ppm 25 mg/L 99.99+% purity (metals assay) Color: Tan Ingredients: pure distilled water, 99.99+% pure Copper nanoparticles pH: Acidic Flammability: Non-flammable Odor: None Reactivity: None Container: Clear glass bottle with black phenolic cap Shelf life: 2+ years Made in the USA Protect from freezing The shelf life of this true colloidal Copper can be several years unopened. The average nanoparticle size is 2 Copper atoms with about 0.28 nanometers in size. There is no true colloidal Copper product with smaller Copper nanoparticles as we have inspected them all. No (0.00%) chemicals are found in this product - only 99.99+% pure Copper nanoparticles colloidally suspended in pure distilled water. No other ingredients - especially no preservatives or stabilizers as found in other colloidal Copper products. PLEASE DO NOT ALLOW THIS PRODUCT TO FREEZE! If allowed to freeze, all of the Copper nanoparticles will no longer be colloidally suspended and afterward the colloidal suspension may collapse resulting in a loss of color as the Copper nanoparticles will have fallen to the bottom of the bottle, leaving only clear water. WARNING: Avoid contact with this product if allergic to Copper; allergic reactions to Copper are extremely rare.