Question

Choose the odd one out of the following terms given and name the category to which the others belong
Formalin, iodine, DDT, lime

Answer 1

Hint: Various compounds are used to disinfect objects, kill pathogens and prevent infection.

Complete answer:
Iodine is the only antiseptic of all compounds. So, the answer is Iodine. Whereas formalin, DDT and lime are disinfectants.

Additional information:
- An antiseptic is a chemical that is appropriate to be applied on the skin or body to kill germs.
- They prevent the growth or kill germs or microbes.
- They are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction.
- Commonly used antiseptics are benzoic acid, dettol, iodine, boric acid, etc.

Disinfectants are strong chemicals used for destroying germs and microbes from surfaces, spots and places.
- They are strong and are not applied on the human body.
- Disinfection does not kill all microbes, mainly highly resistant bacterial spores; it is less effective than sterilization, which is a physical or chemical process that kills all types of microbes or pathogens.
- Commonly used disinfectants are phenol, lime, formalin, DDT, bordeaux, etc.

Note: Antiseptic and disinfectants work with help of following mechanism of actions;
1. Oxidation of protoplasm of pathogen
2. Denaturation of microbial protein and disruption of its cell membrane
3. Increasing permeability of the microbial cell membrane