Final answer:
Increasing the strength of chemical sanitizers may lead to the development of resistant bacterial strains, rendering the sanitizer less effective. The issue of resistance is particularly noted with triclosan-based sanitizers. Environmental concerns also drive the development of phosphate-free detergents.
Step-by-step explanation:
Increasing the strength of chemical sanitizer may leave resistant bacterial strains. Using sanitizers, specifically those containing triclosan, at higher concentrations can lead to the development of bacteria that can withstand its effects. Such bacteria, like Salmonella enterica, undergo genetic changes that enable them to survive, making the sanitizer less effective.
This resistance to triclosan arises from alterations to a single gene associated with the bacterial fatty acid-synthesis pathway. Additionally, while phosphates in detergents can be effective, they result in environmental harm through eutrophication, prompting bans on their use and research into alternatives like phosphate-free detergents.