Hydrogen peroxide (H2O2) acts immediately as a disinfectant. There is no residual effect, as H2O2 rapidly breaks down into O2 (oxygen) and H2 (water). This is one of the positive benefits of H2O2 disinfection, as no residues or deposits left behind on disinfected surfaces. As cleaning must occur each day, long-term residual effects of disinfectants are often superfluous in hygiene settings. Moreover, if residues persist and product builds up on surfaces, over time such deposits may decrease the effectiveness of cleaning, and in particular the ability to remove microbial biofilms.