For industrial applications like celluloid, PVC plastics, and paint, a purity level of 96% or higher is generally sufficient. However, for pharmaceutical or medicinal use, you must ensure the product meets USP (United States Pharmacopeia), BP (British Pharmacopeia), or CP (Chinese Pharmacopeia) standards, typically requiring a purity of 98% to 99%. Key parameters include melting point (174°C - 179°C), optical rotation, and non-volatile matter content (less than 0.05%) to ensure chemical stability and safety.