When sourcing chitosan in bulk, the most critical parameters are the Degree of Deacetylation (DAC) and Molecular Weight. For industrial or agricultural use, a DAC of 85% or higher is standard, while medical or food-grade applications often require >95%. Additionally, you must verify the viscosity (measured in mPa.s), as it determines the product's solubility and film-forming properties. Ensure the ash content is below 1% for high-purity requirements and check the particle size (mesh) to ensure it matches your production machinery.