Potassium Fluoride, 40 Percent (w/v) Aqueous Solution - Spectrum solutions utilize the highest quality raw materials appropriate to your product. Most raw materials meet or exceed the specifications established by the American Chemical Society. Where appropriate, many finished products are traceable to NIST Standard Reference Materials. Manufacturing, quality control testing, and packaging are all performed in Spectrum's own facilities. Record keeping and sample retention of all produced lots ensure product consistency and complete traceability.