Introduction to Disinfectants

The dictionary definition of a disinfectant is an antimicrobial agent which kills or inactivates dangerous/harmful micro-organisms.

Disinfectants can sometimes be mixed up with sanitisers which are substances that reduce the number of microorganisms to a safe level but do not completely destroy all of them.

The main physiological difference between a disinfectant and a sanitiser is that at a specified dilution a disinfectant must be able to kill more micro-organisms than that of a sanitiser.

One thing that most sanitisers and disinfectants are unable to do are sterilise which would be to cause complete destruction of all microorganisms. In this case an autoclave would be used.

The problem that disinfectants have is that 光觸媒殺菌 many are toxic and harmful to humans and animals so it is recommended that they are always treated with extreme care. Many modern household disinfectants contain a substance called bitrex which is a very bitter tasting liquid. The idea of including this is to discourage the ingestion of the disinfectant by children and animals.

Any disinfectant that is used indoors should: (this includes home, hospitals, dental surgeries) never be mixed with other cleaning products because chemical reactions can occur, producing harmful gases. There have been numerous recorded incidents of people mixing bleach with other household products and falling unconscious from the gases released.

Depending on what it is you want to disinfect influences your choice of disinfectant. Some disinfectants can destroy a wide range of microorganisms whilst others will only kill a small range of germs.

Common Disinfectants
There are many different types of disinfectant available of different jobs and purposes.

Common alcohols like ethanol and isopropano alcohol are used for their disinfectant properties; they are also used frequently in medical situations as an antiseptic. It is common for these two alcohols to be used directly on the skin – their advantage over other disinfectants is that they are non corrosive however they do pose a fire risk so should always be used with care.

Oxidising Agents
Oxidising agents like bleach act by breaking cell membrane of an organism causing it to die. Sodium hypochloride (household bleach) is an oxidising agent.

Other oxidising agents include:

1. Chloramine is used in drinking water treatment.
2. Hydrogen peroxide is used in hospitals to disinfect surfaces, it is again a preferred disinfectant because it causes few allergic reactions.
3. Iodine is used in the poultry industry; it is mixed in with water added to birds drinking water.
4. Potassium permanganate (KMnO4) is a red crystalline powder when added to water is changes the waters colour. It is commonly used in disinfecting aquariums and ponds.

Medical Disinfectants
Medical disinfectants vary depending on the situation but 2 common disinfectants found in hospitals ward and surgeries across the UK are:

1. Hibiscrub is a preoperative surgical hand scrub found in hospitals and used for both disinfectant and its antiseptic properties.
2. Ebiox Trionic Spray is an alcohol free multisurface cleaner proven to kill a wide range of micro-organisms including MRSA and E-coli.