Antiseptics and Disinfectants
29.6 Antiseptics and Disinfectants By definition, a disinfectant kills microorganisms.
By definition, an antiseptic slows or stops the growth of organisms but does not kill them.
Antiseptics and disinfectants are used for cleaning wounds and for killing microorganisms in the environment. Some disinfectants are very irritating and actually damage living tissue when applied to wounds. Therefore it is very important to classify disinfectants and antiseptics as to whether they are "irritating" or "non-irritating".
Below is a list of some common disinfectants and antiseptics; what they are used for; and the concentration used.
Common Disinfectants ACRIFLAVINE Non-irritating disinfectant used for cleaning wounds in a concentration of 1:1000.
ALCOHOL
Alcohol may be used on skin or equipment, but should not be used in open wounds. Soak instruments, suture and cotton wool for about 20 minutes in concentrated (70% ethyl alcohol or drinking alcohol).
CHLORHEXIDINE (Nolvasan, Virosan)
Chlorhexidine is one of the safest and most effective antiseptics available. It has very good activity against bacteria, molds, yeasts and viruses. It works rapidly. It is available as a plain solution, and as a scrub solution. The scrub solution contains a detergent and should be rinsed off after use. The plain solution is very good at rinsing and soaking open wounds.
Surgical Prep- 2.0-4.0% Open Wounds- 0.05% Disinfection- 0.5-2.0% Do not use the strong solutions on open wounds.
CHLORINE BLEACH (Sodium Hypochlorite)
Chlorine bleach is readily available and is effective in killing viruses and bacteria. It can be used full strength for disinfection or diluted for use in wounds, but it can damage living tissues.
Open wounds- 0.125% (1/4 strength)
Disinfection- 0.5% (full strength)
Do not use on living tissue if better agents are available. Be careful when handling the solution because it will bleach fabrics and other materials. Do not mix with ammonia or any other cleaning or disinfection agents, as toxic fumes may result.
CRESOL
Cresol compounds are effective in killing bacteria but have less effect on bacterial spores, viruses or fungi. They are primarily used to disinfect non-living surfaces.
Use as directed to clean and disinfect non-living surfaces.
Cresol smells badly. Do not use or store around human food. It is poisonous and should be handled carefully.
DESSICATION
This means "drying out" and it is a very effective way to kill some bacteria and, especially, the immature forms of parasites. Some worm eggs can live a long time (several years) in damp dung and in dark places. However, they can live only a short time if the dung is removed and the area dries out.
FORMALIN
Irritating disinfectant purchased in the market as a 40% solution. Can be used in a foot bath for footrot at a concentration of 2%. Also used as a preservative for tissues as a 10% solution. Can also be mixed as follows and used to clean poultry houses: 40% formalin 35 ml; Potassium Permanganate 17.5 gm for 100 cubic feet.
GENTIAN VIOLET
Non-irritating disinfectant used for cleaning wounds in a 0.5 - 2% solution (5 - 20 gm per liter of water). G.V. is very good to apply to wounds that need to dry out. After cleaning the wound well, apply as needed.
HYDROGEN PEROXIDE
Hydrogen peroxide is a readily available solution usually prepared in a 3% solution. It readily foams and hisses when poured into an open wound. Hydrogen peroxide is very good at flushing out abscesses. It is also toxic to animal tissues and should only be used for initial cleaning and flushing of dirty wounds and abscesses. Repeated use may slow healing.
Use full strength 3% solution on wounds and abscesses.
IODINE
The standard “drug store” iodine tincture is a 2% solution that is painted directly on small cuts and scrapes. A stronger 7% iodine is sometimes used in veterinary medicine as a caustic and is used to treat the umbilical cords of newborn livestock.
Small cuts and scratches- 2% iodine Umbilical cords- 7% iodine Do not confuse the two different iodine solutions. The 7% solution is caustic and should not be used on burns and deep wounds. Keep both solutions away from eyes, and away from flames.
PHENOL
Irritating disinfectant, even in 0.2% solutions. It is used especially for environment cleaning at 1:32 - 1:150.
POTASSIUM PERMANGANATE
Can be irritating in concentrations of 1:100. However, it is non-irritating in concentrations of 1:1000 or 1:5000. It can be used in more dilute solutions for washing wounds; and it can be used in concentrated solutions for cleaning the environment.
SAVLON
Non-irritating disinfectant used for cleaning wounds and for sterilizing instruments. Mix it at a rate of 1:200 for washing wounds. Mix it at a rate of 1:100 with water for instruments. Never soak instruments for more than 30 minutes because it can cause rust and damage. For long term storage of instruments use the following mixture: 4 gm of sodium nitrate; 1 liter of water; and 10 ml of Savlon.
ULTRAVIOLET RAYS (from sun)
Rays are used for cancer treatment. Ultraviolet rays help kill microorganisms in the environment, especially in a dry environment. Sunlight, plus cleaning of dung, etc., is an excellent form of sterilizing the environment (e.g. pasture rotation).
WATER (BOILED)
Used for equipment sterilizing; also use boiled, cooled water to wash wounds.
Common Antiseptics:
ALUM
Non-irritating antiseptic used for cleaning wounds (especially the mouth in FMD). Mouth washing is done with alum-water at a very low concentration (1%) solution.
BORAX
Non-irritating antiseptic used for hot compresses of wounds at a concentration of 2 - 3%.
LIME
Used for environmental cleaning; and for decaying of dead animals.
BORIC ACID
Non-irritating antiseptic used to wash wounds. Especially safe for washing out eyes at a concentration of 1:100. Can be made into an ointment for wounds at 1:40 in Vaseline.