Final answer:
Chlorhexidine shows the greatest resistance to degradation by chlorine among scale inhibitors, due to its persistent antiseptic effect and its ability to remain effective in the presence of chlorine.
Step-by-step explanation:
When analyzing the resistance of scale inhibitors to degradation by chlorine, it is evident that chlorhexidine demonstrates a significant degree of stability and efficacy. Chlorhexidine belongs to a class of compounds known as bisbiguanides, recognized for their antiseptic properties. According to research, while chlorhexidine can be bacteriostatic at lower concentrations, it is bactericidal at higher concentrations and effectively disrupts cell membranes. Most importantly, as it relates to chlorine resistance, chlorhexidine is known for its persistent effect which implies greater resistance to degradation by chlorine compared to other tested agents.
Notably, chlorhexidine's broad-spectrum activity does not extend to Pseudomonas aeruginosa which may develop resistance with repeated exposure. Nonetheless, for the scope of the question regarding chlorine resistance, chlorhexidine stands out. This is particularly relevant in clinical settings where long-lasting antimicrobial activity is vital and the impact of chlorine degradation on antiseptic performance must be minimized.