... -7)[EPA Substance Registry System]50-81-7(EPA Substance) Safety Data[Hazard Codes ]Xn[Risk Statements ]R20/21/22:Harmful by ... .R36/37/38:Irritating to eyes, respiratory system and skin .[Safety Statements ]S24/25:Avoid contact with skin and eyes .S36 ... not available; however, L-ASCORBIC ACID is probably combustible. Material Safety Data Sheet(MSDS)[msds information]L-Threo-2,3,4,5,6 ...