Final answer:
The concentration of phenol required to kill vegetative bacteria varies and must be determined relative to phenol using the phenol coefficient. Phenols have been historically effective as disinfectants, but due to their toxicity, safer alternatives are preferred. The efficacy of these compounds typically requires rigorous testing to confirm their disinfecting ability in various settings.
Step-by-step explanation:
The concentration of phenol needed to kill most vegetative bacteria is not provided in a single value since it varies depending on the specific species and environmental conditions. However, it is known that phenolic compounds like cresols and o-phenylphenol have been effective in controlling microbial growth. Additionally, the effectiveness of these compounds can be compared to phenol using the phenol coefficient, with a coefficient greater than 1.0 indicating a more effective disinfectant than phenol itself.
For example, hexachlorophene has been used effectively against gram-positive bacteria and can cause neurological problems if used inappropriately. Considering the toxicity to humans and the severe side effects of phenol, safer alternatives which have lower systemic toxicity are often utilized in both hospital settings for handwashing and as general disinfectants.
Testing for the efficacy of disinfectants is critical in maintaining appropriate protocols to control microbial growth in clinical settings, ensuring the protection of healthcare settings and the public.