Polyanionic Cellulose is a polymer derivative of Cellulose with a high degree of purity. It is regarded as a premium product because of its typical higher carboxymethyl substitution and the presence of less residual NaCl than that of technical-grade Carboxymethylcellulose (CMC). However, PAC still contains a considerable amount of NaCl. It is a water-based drilling fluid used for varying purposes in fluid environments. Its molecular structure is similar to that of CMC, but it is considered to be better than CMC. It also has low water loss properties.