DISINFECTANTS

A disinfectant is a chemical agent, which destroys or inhibits growth of pathogenic microorganisms in the non-sporing or vegetative state.

Disinfectants do not necessarily kill all organisms but reduce them to a level, which does not harm health or the quality of perishable goods.

Disinfectants are applied to inanimate objects and materials such as instruments and surfaces to control and prevent infection.

They may also be used to disinfect skin and other tissues,are called as  

ANTISEPTICS  

An antiseptic is a type of disinfectant, which destroys or inhibits growth of micro-organisms on living tissues without causing injurious effects when applied to surfaces of the body or to exposed tissues.

Some antiseptics are applied to the unbroken skin or mucous membranes, to burns and to open wounds to prevent sepsis by removing or excluding microbes from these areas.

Example :-  Iodine has been modified for use as an antiseptic.

1.   The iodophore, polyvidone-iodine , is effective against bacteria, fungi, viruses, protozoa, cysts and spores and significantly reduces surgical wound infections.

2.   The solution of polyvidone-iodine releases iodine on contact with the skin.

3.   Chlorhexidine  has  a  wide  spectrum of bactericidal and  bacteriostatic  activity and  is effective against both Grampositive and Gram-negative bacteria although it is less effective against some species of Pseudomonas and Proteus and relatively inactive against mycobacteria.

Types of Disinfectants

1.   Air disinfectants

2.   Alcohols

3.   Aldehydes

4.   Oxidizing agents

5.   Peroxy and peroxo acids

6.   Phenolics

7.   Quaternary ammonium compounds

8.   Inorganic compounds

9.   Terpenes

10. Other- non- chemical or herbal agents. 

Air disinfectants

Chemical substance  capable  of disinfecting  microorganism suspended (flooting) in air, use to control aseptic like laboratory.

Alcohols

Ethyl or isopropyl at a concentration of 50-70% are used for some surfaces where a rapid evaporation of the chemical and leaving no residue may be important, such as on laboratory equipment, etc.

Alcohols are low in sporocidal activity and must remain wet on the surface for several minutes to achieve any reasonable disinfection.

Additionally, high-concentration mixtures of 80% ethanol+5%isopropanol are required to effectively inactivate  lipid-enveloped viruses such as HIV, hepatitis B, hepatitis C.