CLEANING AND DISINFECTION

Soil

Organic matter that is making a surface unclean or dirty

Cleaning

is the removal of dirt and organic substances (ie, soil), such as fat and protein particles from surfaces of walls, floors, tools and equipment; the process prevents accumulation of organic residues which may decompose, support the growth of disease-causing organisms, or produce toxins

Cleaning agents

are compounds that modify the nature of water so that it may efficiently penetrate, dislodge and carry away surface contamination

Sanitization

a process that reduces the number of disease-causing organisms that may be present on a surface (such as equipment and utensils) after cleaning

Sanitizing agent

Reduces the number of bacterial contaminants to safe levels, as may be judged by public health requirements

Disinfection

The destruction of all vegetative forms of microorganisms

Spores are not destroyed

Disinfecting agent

A chemical that kills vegetative forms (but not resistant spores) of bacteria, and/or inactivates viruses

Sterilization

The destruction of all infective and reproductive forms of all microorganisms (bacteria, fungi, viruses, etc)

Cleaning

The removal of dirt and organic substances from surfaces of walls, floors, tools, and equipment

Detergents

These contain surfactants that reduce surface tension between the soil and the surface, allowing the detergent to penetrate quickly and soften the soil

Degreasers - Alkaline

These are solvents that contain a grease-dissolving agent; they work well in areas where grease has been burned on (eg, stove-tops)

Acidic Cleaners

These remove mineral deposits and other soils that cannot be removed by alkaline cleaners (eg, used to remove scale from ware-washing machines)

Abrasive Cleaners

Used to remove heavy accumulations of soil found in small areas; the abrasive action is provided by small mineral or metal particles, fine steel wool, copper, or nylon particles (eg, Comet, Vim); these sometimes disinfect

Prewash

The removal of gross food particles before applying the cleaning solution; this may be accomplished by flushing the equipment surface with cold or warm water under moderate pressure; very hot water or steam should not be used because it may make cleaning more difficult

Washing

The application of the cleaning compound; effectiveness and economy of the method generally dictate its use

Soaking

Immersion in a cleaning solution; the solution should be hot (125°F), and the equipment permitted to soak for 15–30 minutes before being manually or mechanically scrubbed; method of washing

Spray method

Spraying cleaning solution on the surface using a fixed or portable spraying unit with either hot water or steam; method of washing

Clean-in-place systems (CIP)

An automated cleaning system generally used with permanent-welded pipeline systems; fluid turbulence in the pipeline is considered the major source of energy required for soil removal; method of washing

Foaming

utilizes a concentrated blend of surfactant developed to be added
to highly concentrated solution of either alkaline or acid cleaners; it produces a stable, copious foam when applied with a foam generator; the foam clings to the surface to be cleaned, which increases contact time of the liquid with the soil, and prevents rapid drying and runoff of the liquid cleaner, thereby improving cleaning; method of washing

Jelling

utilizes a concentrated powdered-jelling agent which is dissolved in hot water to form a viscous gel; the desired cleaning product is dissolved in the hot gel and the resulting jelled acid or alkaline detergent is sprayed on the surface to be cleaned; the jelled cleaner will hold a thin film on the surface for 10 minutes or longer to attack the soil; soil and gel are removed with a pressure warm water rinse; method of washing

Abrasive cleaning

abrasive type powders and pastes are used for removing difficult soil; complete rinsing is necessary and care should be taken to avoid scratching stainless steel surfaces; scouring pads should not be used on food-contact surfaces because small metal pieces from the pads may serve as focal points for corrosion or may be picked up in the food; method of washing

Rinsing

the removal of all traces of the cleaning solution with clean potable water

Sanitization and/or Disinfecting

to kill invisible soils (ie, microorganisms) that may cause spoilage, animal disease or foodborne disease

Heat

use of hot water or steam to treat food-contact surfaces or food equipment

Chemicals

there are a wide variety of known chemicals whose properties destroy or inhibit the growth of microorganisms; many of these chemicals, however, are NOT suitable for use on food-contact surfaces because they may corrode, stain, or leave a film on the surface

Others may be highly toxic or too expensive for practical use; the most commonly used chemical sanitizers include chlorine, iodophores, quaternary ammonium, carboxylic acid, and peroxy compounds

Hot water (heat sanitization)

A non-selective, effective sanitizing method for food contact surfaces that kills
Concentration of the Sanitizer

Temperature of Solution

All of the common sanitizers increase in activity as the solution temperature increases; this is partly based on the principle that chemical reactions in general are speeded up by raising the temperature; however, a higher temperature also generally lowers surface tension, increases pH, decreases viscosity, and effects other changes which may enhance its germicidal action; it should be noted that chlorine compounds are more corrosive at high temperatures, and iodine tends to sublime at temperatures above 120°F; factor influencing efficiency of chemical sanitizers

pH of Solution

The pH of the solution exerts a very pronounced influence on most sanitizers; quaternary compounds present a varied reaction to pH depending on the type of organisms being destroyed; chlorine and iodophores generally decrease in effectiveness with an increase in pH; factor influencing efficiency of chemical sanitizers

Time of Exposure

Sufficient time must be allowed for whatever chemical reactions that occur to destroy the microorganism; the required time will not only depend on the preceding factors, but on microorganism populations and the populations of cells having varied susceptibility to the sanitizer due to cell age, spore formation, and other physiological factors of the microorganisms; factor influencing efficiency of chemical sanitizers

Disinfection process

this is done after thorough cleaning of facilities; disinfectants are applied onto thoroughly cleaned surfaces

microbes by protein coagulation, though spores may survive; requires ≥171°F (77°C) for 5 minutes when pumped or 30 seconds when immersed; the microbicidal action is thought to be the coagulation of some protein molecules in the cell

Steam (heat sanitization)

an excellent agent for treating food equipment; treatment on heavily contaminated surfaces may cake on the organic residues and prevent lethal heat to penetrate to the microorganism; steam flow in cabinets should be maintained long enough to keep the thermometer reading above 171°F (77°C) for at least 15 minutes or above 200°F for at least 5 minutes; when used on assembled equipment, the temperature should be maintained at 200°F for at least 5 minutes as checked at the outlet end of the assembled equipment

Chlorine (chemical sanitization)

and its compounds combine indiscriminately with any and all
protein and protoplasm; the mode of bactericidal action is thought to be the reaction of chlorine with certain oxidizable groups in vital enzyme systems

Iodophores (chemical sanitization)

are soluble complexes of iodine combined usually
with non-ionic surface-active agents, loosely bound

Quaternary Ammonium Compounds (chemical sanitization)

are synthetic surface-action agents; the most common ones are the cationic detergents which are poor detergents, but excellent germicides; in these compounds, the organic radical is the cation and the anion is usually chlorine; the mechanisms of germicidal action is not completely understood, but is associated with enzyme inhibition and leakage of cell constituents

Carboxylic Acid (chemical sanitization)

In the 1980’s, a new category of acid sanitizers was developed; the carboxylic acid sanitizers are also called fatty acid sanitizers; they combine an acidulant, such as phosphoric acid or citric acid with a fatty acid such as octanoic acid; they have the dual function of providing an acid rinse to remove mineral films and kill microorganisms; they have good broad-spectrum activity and, because of their low foaming characteristics, are very good for CIP applications

Peroxy Compounds (chemical sanitization)

Combining hydrogen peroxide with short chain organic acids such as acetic acid makes these sanitizers; the resulting peracid is an excellent broad-spectrum sanitizer with the added benefit of providing an acidified rinse to remove mineral films; a big advantage is their ability to kill microorganisms at temperatures as low as 40 degrees F, which can be important on the dairy farm in certain regions of the country in the winter

Contact Time

In order for a chemical to react with microorganisms, the cleaned item must have intimate contact with the sanitizer; factor influencing efficiency of chemical sanitizers

Selectivity of the Sanitizer

Certain sanitizers are non-selective in their ability to destroy a wide variety of microorganisms; while others demonstrate a degree of selectivity; chlorine is relatively non-selective; however both iodophors and quaternary compounds have a selectivity which may limit their application; factor influencing efficiency of chemical sanitizers

Concentration of the sanitizer

the more concentrated a

sanitizer, the more rapid and certain its actions. Increases in

concentration are usually related to exponential increases in

effectiveness until a certain point, when it accomplishes less noticeable

effectiveness

Temperature of Solution

all of the common sanitizers increase in

activity as the solution temperature increases. This is partly based on

the principle that chemical reactions in general, are speeded up by

raising the temperature. However, a higher temperature also generally

lowers surface tension, increases pH, decreases viscosity, and effects

other changes which may enhance its germicidal action. It should be

noted that chlorine compounds are more corrosive at high

temperatures, and iodine tends to sublime at temperatures above 120oF.

pH of Solution

The pH of the solution exerts a very pronounced

influence on most sanitizers. Quaternary compounds present a varied

reaction to pH depending on the type of organisms being destroyed.

Chlorine and iodophores generally decrease in effectiveness with an

increase in pH

Time of Exposure

sufficient time must be allowed for whatever

chemical reactions that occur to destroy the microorganism. The

required time will not only depend on the preceding factors, but on

microorganism populations and the populations of cells having varied

susceptibility to the sanitizer due to cell age, spore formation, and

other physiological factors of the microorganisms

Disinfection

The destruction of all vegetative forms of

microorganisms present on the surface of thoroughly cleaned

equipment and facilities; Spores are not killed