A Critical Quality Attribute (or CQA) is an attribute chosen for a product that ensures that it is of the desired quality. For example a product could have a CQA for the pH, Particle size, endotoxin content, sterility etc.. CQAs must be rigorously defined and then monitored as part of Continuous Process Verification as per FDA/other governing body requirements. Manufacture parameters that directly impact CQAs are Critical Process Parameter.