Check the listing for details. True Colloidal Silver NanoParticles (AgNPs): 200 ppm - 250 mL in Plastic. Condition: New. Listed at 44.90 USD. True Colloidal Silver (200 ppm) - 99.99+% purity - 250 mL (8.45 Fl Oz) in a clear plastic bottle Non-toxic CAS # 7440-22-4 Volume: 250 mL, 8.45 Fl Oz 200 ppm 200 mg/L 99.99+% purity (metals assay) Color: Black Ingredients: pure distilled water, 99.99+% pure Silver nanoparticles pH: Acidic Flammability: Non-flammable Odor: None Reactivity: None Container: Clear plastic bottle with black phenolic cap Shelf life: 2+ years Made in the USA Protect from freezing The shelf life of this true colloidal Silver can be several years unopened. The average nanoparticle size is 2 Silver atoms with about 0.28 nanometers in size. There is no true colloidal Silver product with smaller Silver nanoparticles as we have inspected them all. No (0.00%) chemicals are found in this product - only 99.99+% pure Silver nanoparticles colloidally suspended in pure distilled water. No other ingredients - especially no preservatives or stabilizers as found in other colloidal Silver products. PLEASE DO NOT ALLOW THIS PRODUCT TO FREEZE! If allowed to freeze, all of the Silver nanoparticles will no longer be colloidally suspended and afterward the colloidal suspension may collapse resulting in a loss of color as the Silver nanoparticles will have fallen to the bottom of the bottle, leaving only clear water. WARNING: Avoid contact with this product if allergic to Silver.