Which type of disinfectant is not recommended for use in salons in any form?

Formalin is not recommended for use in salons due to its strong toxicity and potential health risks associated with its use. It is a solution of formaldehyde in water and is known to be a potent irritant, and prolonged exposure can cause serious health issues, including respiratory problems and skin irritation. In addition to its health risks, formalin can also produce harmful fumes that can affect both clients and technicians working in enclosed spaces.

In contrast, other disinfectants listed, such as bleach, alcohol, and hydrogen peroxide, can be effective when used appropriately, but they also come with specific guidelines and concentrations that must be followed to ensure safety and efficacy. Bleach can be corrosive and must be diluted correctly, alcohol is effective but can evaporate quickly, and hydrogen peroxide must be stored properly to maintain its effectiveness. Thus, formalin stands out as an option that poses higher risks and is discouraged in salon environments.