Which of the following is used for chemical disinfection of blood spills?

While isopropyl alcohol is a good disinfectant for many surfaces and can be used for skin disinfection, it is less effective on blood spills when compared to bleach. Alcohol may not adequately penetrate or break down the proteins and organic matter found in blood, making it less reliable for thorough disinfection in this context.

Hydrogen peroxide is known for its antiseptic properties and can be used for disinfection; however, it is typically less effective than bleach for blood spills. Its efficacy may vary based on concentration and the type of pathogens present, and it may not achieve the same level of disinfection as bleach in a timely manner.

Formaldehyde is a potent disinfectant and preservative but is not commonly used for cleaning blood spills due to its toxic nature and potential health risks. It is primarily utilized in laboratory settings for specimen preservation rather than in routine disinfection practices for spills.