Presented By N.E.M
TOPICS: Disinfecting Flow-Through Areas (C.I.P.) Surface Disinfecting, Area Disinfecting,
of Working Environment
The most important principle concerning disinfecting/disinfection is that a dirty surface can not be sanitary. The sanitiser cannot come into contact with bacteria trapped in and under soil.
The undisturbed growth of microorganism under ideal conditions is shown below. One bacterium under perfect conditions could produce one billion bacteria in ten hours. Clean and sanitary conditions are critical for product quality.
|30 minutes 2 cells|
|60 minutes 4 cells|
|90 minutes 8 cells|
|2 hours 16 cells|
|11 hours 10 million cells|
|0 minutes 1 virus|
|30 minutes 200 virus|
|60 minutes 400,000 virus|
|1.5 hours 8 million virus|
|2.0 hours 1.6 billion virus|
|2.5 hours 320 billion virus|
Characteristics of disinfectants
Active chlorine has been in use for many years as a disinfectant in the food industry because of its broad bactericidal spectrum and economic advantage. The active chlorine carrier has taken several forms with the liquid types based on inorganic chlorine compounds, such as sodium hypochlorites and the powder form based on organic chlorine compounds, such as the dichloroisocyanurate group.
Most often the bactericidal effect of active chlorine is best in a neutral or weakly acidic condition (pH 5 to pH 7), but the chlorinated alkaline cleaners also have an excellent bactericidal effect against all groups of microbes. Many tests, according to various methods, have proved that chlorine renders a very fast kill on viruses, bacteria, yeasts, and molds. The activity against spore forming bacteria is slightly slower.
The question of the corrosiveness of hypochlorite solutions on metals such as stainless steel and aluminum is still a matter of intense discussion, resulting in certain reservations regarding chlorine-based products.
Chlorine Sanitisers Have These Additional Advantages:
The rule of thumb is that if chlorine is used as a sanitiser prior to production, the equipment should be used within one hour after the disinfecting procedure.
Sanitisers based on hydrogen peroxide are most suitable for use in the dairy industry. This is attributed to its non-contaminating residues of water and oxygen. It has been used in the pharmaceutical and food processing industry for the aseptic packaging area. UHT milk in Europe is heated to 100oC with a 25 - 50% concentration of hydrogen peroxide and a short contact time. There is complete microbial destruction, including the destruction of Bacillus spores.
The Following Denote Advantages And Disadvantages Of Different Types Of Sanitisers:
Acidic iodine-based sanitisers have a universal killing effect on all types of microbes. The amount of active ingredients to achieve the same killing power is lower in iodophors than in active chlorine-based products. Usually by increasing the temperature of the disinfecting solution, the killing time is reduced, and this is true for the iodine type products as well. Iodine will gas off at temperatures of 39oC-49oC and the loss of the iodine is high.
This and the possibilities of corrosion make it standard practice to use iodophors at room temperature.
50-100 ppm available chlorine should be employed for disinfecting large equipment and utensils and 200 ppm for spraying applications of large equipment.
The contact time for effective sanitation should be long enough to produce complete kill of bacteria, usually 10 seconds or longer.
Acid Anionic disinfectants:
100 - 200 ppm
Quaternary Ammonium Compound (Quat)
For disinfecting of equipment a 200 ppm solution is sufficient to reduce bacterial counts with a one minute exposure.
Peroxyacetic Acid ( PAA ):
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