several hemostatic bandages that are commercially available function by tightly sealing a wound so that hemostasis can occur before excessive blood loss takes place . hemostatic bandages which seal a wound but which do not actually speed the coagulation mechanism include chitosan and chitin - based bandages . hemostatic gauzes based on chemically modified cellulose are also commercially available . these bandages and gauzes , used in combination with various inorganic materials such as zeolite , silica , and / or diatomaceous earth powder show a synergistic effect . it has been found that the inorganic material activates the contact coagulation mechanism while the biopolymer component binds the wound and prevents excessive blood loss .