When sourcing CMS, the most critical parameter is the Degree of Substitution (DS), which typically ranges from 0.2 to 0.5; a higher DS generally improves water solubility and stability. For the oil drilling industry, ensure the product meets API RP 13B standards for fluid loss control. In the pharmaceutical sector, CMS is used as a disintegrant (Sodium Starch Glycolate), requiring strict adherence to USP/EP pharmacopeia grades. For textile and paper applications, focus on viscosity stability (measured in mPa.s) and purity levels to ensure consistent bonding and sizing performance.