Choosing between Food Grade and Industrial Grade STPP is not a matter of price—it's a matter of compliance and safety. While both share the same chemical formula (Na5P3O₁₀), Food Grade STPP enforces strict limits on heavy metals like Arsenic (As ≤ 3ppm) and Lead (Pb ≤ 5ppm), making it safe for seafood, meat, and poultry processing. Industrial Grade STPP has relaxed impurity standards and is intended only for detergents, ceramics, and water treatment. Using the wrong grade can lead to customs rejection, container destruction, and serious health liability. This guide explains how to read a COA, spot fake food-grade certificates, and source the right STPP for your market.