Common disinfectants used in chiller tanks and dipping stations at poultry processing plants are not effective against Salmonella in its biofilm state, caution Tereza Chylkova and colleagues at the University of California–Davis. 
Salmonella biofilms aren’t as pathogenic as free-floating Salmonella particles but, nevertheless, are significant contributors to contamination in food processing plants. However, there’s no established way to measure the sensitivity of biofilms to specific disinfectants.
Consequently, the researchers tested the effectiveness of disinfectants used by commercial poultry companies against Salmonella biofilms.
 Chylkova T, et al. Susceptibility of Salmonella Biofilm and Planktonic Bacteria to Common Disinfectant Agents Used in Poultry Processing. J Food Protection. 2017 July;80(7):1072-1079.