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Chemistry of Cleaning ©2006 Basic Custodial Technician Program
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Objectives Chemical safety Two basic types of soil
Seven basic types of cleaning agents Processes involved in soil removal Three physical characteristics of cleaning agents Acidity or alkalinity determining the strength of cleaning agents How to work dilution ratio problems Non-chemical factors that affect cleaning chemistry Method of germ growth, reproduction and control Types of disinfectants ©2006 Basic Custodial Technician Program
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Introduction Cleaning and maintenance chemicals are among the most important items you will use in custodial work. ©2006 Basic Custodial Technician Program
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Most Widely – Used Chemicals for General Daily Cleaning
Bowl cleaners Carpet spotters Disinfectants Floor-finish restorers and spray buffs General-purpose cleaners Glass cleaners Hand soaps Wood and metal polishes ©2006 Basic Custodial Technician Program
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Chemical Safety Prevent serious injury with these basic rules:
Training Labels and Documents Flammability Personal Protection Chemical Mixing It’s the Law! ©2006 Basic Custodial Technician Program
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Training on chemical safety
Labels and documents provide essential safety information Flammability – Check the flash point on the label! Make sure ventilation is adequate and don’t use products near open flames Personal Protection includes gloves, safety goggles/face shields, aprons and respirators when you use toxic products or strong acid or alkaline chemicals Chemical Mixing – Never combine chemicals! It’s the Law! – Follow safety practices set up by government agencies and your employer ©2006 Basic Custodial Technician Program
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Personal Protection Use proper protective devices selected to fit the job Know the limitations of the clothing you wear Wide assortment of clothing available: Gloves to protect against chemical hazards, burns, cuts and shock Gloves and wristlets made of leather, wire mesh, canvas, hand pads ©2006 Basic Custodial Technician Program
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Mixing Chemicals Mix your own cleaner/disinfectant solution? NEVER mix a chemical cleaner and disinfectant to make your own cleaner/disinfectant solution CUSTODIANS ARE NOT CHEMISTS ©2006 Basic Custodial Technician Program
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Discussion Questions What is a MSDS?
Material Safety Data Sheet – provides important safety information regarding chemicals What is a “flash point”? The temperature at which a chemical will catch fire Identify 4 types of PPE. Gloves Safety goggles or face shields Aprons Respirators ©2006 Basic Custodial Technician Program
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Oily, Sticky Soil Greases and Oils Animal Vegetable Mineral Synthetic
Two Types of Soil Loose, Dry Soil Dust Any surface not cleaned in 12 hours will have dust on it Oily, Sticky Soil Greases and Oils Animal Vegetable Mineral Synthetic It’s oily because of Hydrocarbons – chemical compounds composed of two elements: Hydrogen and Carbon ©2006 Basic Custodial Technician Program
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Discussion Questions Identify the two types of soil
Loose, dry soil and oily, sticky soil Why is it important to remove loose, dry soil as soon as possible? To prevent it from becoming oily, sticky soil What two elements form the chemical compound that makes greases and oils feel slick? Hydrogen and carbon - hydrocarbon ©2006 Basic Custodial Technician Program
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Cleaning Agents Products that act on surfaces to remove dirt and soil
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Seven basic types of cleaning agents
Water Natural Soap Synthetic Detergents Solvent Cleaners Acid Cleaners Alkaline Cleaners Abrasive Cleaners ©2006 Basic Custodial Technician Program
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Water Water is the oldest cleaning agent, but alone it cannot remove grease and oil, because it cannot penetrate and wet the surface under the grease and oil ©2006 Basic Custodial Technician Program
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Water Softeners Soft Water = < 200 PPM
Chemicals that remove the salts that make water hard Soft Water = < 200 PPM Moderately Hard Water = 200 – 400 PPM Hard Water = > 400 PPM PPM = Parts Per Million of Calcium Carbonate ©2006 Basic Custodial Technician Program
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Natural Soap Second-oldest cleaning agent
Alkalis plus animal or vegetable fats and oils ©2006 Basic Custodial Technician Program
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Synthetic Detergents/Surfactants
Man-Made Cleaning Agents A combination of chemicals that can replace natural soaps Provide the wetting and cleaning action of soaps without causing any film or buildup. ©2006 Basic Custodial Technician Program
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Solvent Cleaners Dissolve, emulsify, suspend greasy, oily types of dirt such as automotive grease, heavy-duty grease, engine oils, fingerprints, body fats and varnish Examples of solvent cleaners: Pine Oil Ethyl alcohol Butyl cellosolve D-limonene Isopropyl alcohol Kerosene Benzene Methyl Chloride Caution: Wear protective gloves and goggles or face shields ©2006 Basic Custodial Technician Program
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Acid Cleaners NO Never use Hydrofluoric acid on leaded glass
Remove mineral deposits and rust stains left by water NO Never use Hydrofluoric acid on leaded glass Never use Sulfuric acid or strong phosphoric acid on metal YES Use under rims of urinals and toilets, on porcelain, vitreous china glass, cement machinery, Plexiglas®, on some types of quarry and ceramic tile and metals ©2006 Basic Custodial Technician Program
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Alkaline Cleaners Neutralize and remove soil that contain acids
Abrasive Cleaners Detergent components plus scouring materials such as silica dust of volcanic dust Caution: Wear protective gloves and goggles or face shields ©2006 Basic Custodial Technician Program
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Discussion Questions What is the oldest cleaning agent? Water
What makes water hard? Calcium and magnesium What is the second oldest cleaning agent? Natural soaps What is the disadvantage to natural soaps? Natural soaps react to hard water to form a film that remains on the surface being cleaned ©2006 Basic Custodial Technician Program
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Discussion Questions What is a synthetic detergent?
Man-made cleaning agent Name three examples of solvents Pine oil, ethyl alcohol, butyl cellosolve, D-limonene, isopropyl alcohol, kerosene, benzene or methyl chloride. What kinds of hazards must you watch for when using cleaning solvents? They can damage some surfaces They are usually flammable Some have vapors that attack skin or lungs ©2006 Basic Custodial Technician Program
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Discussion Questions Where would you use an acid cleaner?
On mineral deposits or rust stains left by water on a surface such as flushing rims under toilets, urinals or showers In what three forms are abrasive cleaners available? Lotions Pastes Powders ©2006 Basic Custodial Technician Program
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Processes involved in soil removal and Three physical characteristics of cleaning agents
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Soil Removal ©2006 Basic Custodial Technician Program
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Physical Cleaning Actions
Penetration Suspension Viscosity ©2006 Basic Custodial Technician Program
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Discussion Questions The detergency process consists of how many chemical actions? Four Name the four detergency processes Wetting action Emulsifying action Dispersing action Adsorption action ©2006 Basic Custodial Technician Program
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Discussion Questions How do you reduce the surface tension of water?
You add a cleaning agent to make the water "wetter" Name the three physical characteristics of cleaning agents Penetration Suspension Viscosity ©2006 Basic Custodial Technician Program
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Acidity or alkalinity determining the strength of cleaning agents
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The pH Scale ©2006 Basic Custodial Technician Program
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Discussion Questions On a pH scale, how many times stronger is 6 than 7? 10 times stronger On a pH scale, how many times stronger is 10 than 8? 100 times stronger On a pH scale, how many times stronger is 0 than 7? 10 million times stronger (10,000,000) ©2006 Basic Custodial Technician Program
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How to work dilution ratio problems
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Ratios 1 cup = 8 ounces 1 pint = 16 ounces 1 quart = 32 ounces 1 gallon = 128 ounces ©2006 Basic Custodial Technician Program
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Ratio Mixture with Water
1 to 4 (1:4) 1 to 8 (1:8) 1 to 10 (1:10) 1 to 12 (1:12) 1 to 16 (1:16) 1 to 20 (1:20) 1 to 26 (1:26) 1 to 30 (1:30) 1 to 40 (1:40) 1 to 64 (1:64) 1 to 128 (1:128) 1 to 200 (1:200) 1 to 256 (1:256) Mixture with Water 32 oz. chemical per gallon water 16 oz. per gallon 13 oz. per gallon 11 oz. per gallon 8 oz. per gallon 6 oz. per gallon 5 oz. per gallon 4 oz. per gallon 3 oz. per gallon 2 oz. per gallon 1 oz. per gallon 2/3 oz. per gallon 1/2 oz. per gallon ©2006 Basic Custodial Technician Program
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Discussion Questions Using a dilution ratio of 1:3, how many ounces of chemical should be added to 1 gallon of water? 32 ounces of chemical Using a dilution ratio of 1:15, how many ounces of chemical should be added to 1 gallon of water? 8 ounces of chemical Using a dilution ratio of 1:63, how many ounces of chemical should be added to 1 gallon of water? 2 ounces of chemical ©2006 Basic Custodial Technician Program
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Discussion Questions Using a dilution ratio of 1:256, how many ounces of chemical should be added to 1 gallon of water? .5 ounces of chemical Why is the proper dilution of cleaning agents important? To achieve the proper balance of chemicals in proportion to the water for creating a cleaning solution to be used on the desired surface without adverse effects ©2006 Basic Custodial Technician Program
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Other Cleaning Factors
Aside from choosing the proper chemicals and diluting them for cleaning, there are other factors to consider. ©2006 Basic Custodial Technician Program
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Cleaning Chemistry Factors that Affect Cleaning Chemistry:
Water Temperature Contact Time Mechanical Action ©2006 Basic Custodial Technician Program
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Discussion Questions What are the three factors that affect cleaning chemistry? Water temperature Contact time Mechanical action Why would you increase the water temperature when cleaning? In general, increasing the water temperature increases the chemical reaction ©2006 Basic Custodial Technician Program
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Discussion Questions Why should you not use extremely hot water with a general purpose cleaner to mop floors that are coated with floor finish? The finish will be softened and removed by this process Why is contact time important? Usually the longer the cleaner is in contact with the surface, the greater the chemical reaction and the better it will clean ©2006 Basic Custodial Technician Program
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Discussion Questions List the four methods of mechanical action
Agitation with a brush Water pressure Abrasive pads Vacuum suction or manual pressure ©2006 Basic Custodial Technician Program
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Disinfection One of your most important jobs as a custodian is to kill germs or stop their growth before they make people sick ©2006 Basic Custodial Technician Program
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Disinfection & Killing Germs
One of your most important jobs as a custodian is to kill germs or stop their growth before they make people sick. Germs = Microorganisms “Too small to see with the human eye” A microscope is needed to see GERMS ©2006 Basic Custodial Technician Program
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Ideal Germ Conditions Ideal temperature for germ growth is 95 to 100 degrees Fahrenheit Germs reproduce by dividing themselves in two every 20 minutes One germ can multiply into 64 billion germs in 12 hours ©2006 Basic Custodial Technician Program
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Germ Reproduction Rate
Typical germ growth rate in optimum conditions Time N° of bacteria 1 20 mins 2 2 hours 64 6 hours 262,144 8 hours 16,777,216 ©2006 Basic Custodial Technician Program
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Discussion Questions What are germs? Germs are microorganisms
What are the two types of germs? Non-pathogenic and pathogenic What type of germs causes disease? Pathogenic germs What conditions are needed for germs to multiply? Food, moisture, darkness and heat ©2006 Basic Custodial Technician Program
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Discussion Questions At what temperature do germs grow fastest?
95 to 100 degrees Fahrenheit Under ideal conditions, how often will germs multiply? Once every 20 minutes What are the three methods of reducing or controlling germs? Sanitization Disinfection Sterilization ©2006 Basic Custodial Technician Program
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Discussion Questions Which of the three processes of controlling germs is the least effective? Sanitization Which process kills 99 percent of germs on a given surface? Sterilization ©2006 Basic Custodial Technician Program
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Seven types of disinfectants
Natural Pine Oil Iodine Iodophors Hypochlorites Natural Phenols Synthetic Phenols Quaternary Ammonium Compounds ©2006 Basic Custodial Technician Program
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Natural Pine Oil Positive Negative
80% oil 20% water Will effectively kill germs Is very expensive at this dilution ratio BUT ©2006 Basic Custodial Technician Program
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Iodine Positive Negative Very powerful. Broad kill range
Stains surfaces, corrodes metals. Use under controlled conditions BUT ©2006 Basic Custodial Technician Program
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Discoloration. Less effective for oily soils. Not for general use
Iodophor Positive Negative Cleaner and disinfectant. Color change if disinfectant is weak. Effective in food service areas due to low toxicity Discoloration. Less effective for oily soils. Not for general use BUT ©2006 Basic Custodial Technician Program
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Powerful germ killer (Household bleach)
Hypochlorites Positive Negative Powerful germ killer (Household bleach) Works only on clean surfaces, corrodes metals, dulls tile, damages grout, will oxidize or burn any material BUT ©2006 Basic Custodial Technician Program
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Natural Phenols Positive Negative Made from carbolic acid
Poisonous to humans. Corrodes metal. Unpleasant odor BUT ©2006 Basic Custodial Technician Program
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Synthetic Phenols Positive Negative
Widely used germ killer. Broad kill range Poisonous. Will burn skin and irritate eyes. Fumes can damage lungs BUT Synthetic phenols can be used to make cleaner/disinfectants. They will work with some detergents, but not with all. ©2006 Basic Custodial Technician Program
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Quaternary Ammonium Compounds
Positive Negative Not poisonous. No odor. Will not burn. Good germ killer. Powerful. Less corrosive than phenols. Can be used in food processing areas Will not kill Tuberculosis. The more soil, the more kill power is reduced. Hard water slows kill power BUT ©2006 Basic Custodial Technician Program
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Dilution Rule: More is not always better
Proper Disinfection Dilution Rule: More is not always better Too much water makes the cleaning solution too weak, and it will not kill germs Not enough water will make the cleaning solution too strong and potentially dangerous ©2006 Basic Custodial Technician Program
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Discussion Questions Name the seven types of disinfectants
Natural pine oil Iodine Iodophor Hypochlorite Natural phenols Synthetic phenols Quaternary ammonium compounds ©2006 Basic Custodial Technician Program
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Discussion Questions What are the main disadvantages of using natural pine oil as a disinfectant? It is very weak and has a low kill rate. This makes it expensive due to the dilution ratio of 80 percent pine oil to 20 percent water Which disinfectants have a broad range of kill, including tuberculosis germs? Synthetic phenols or iodine ©2006 Basic Custodial Technician Program
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Discussion Questions Which disinfectant is commonly referred to as household bleach? Hypochlorite What is the main disadvantage of quaternary ammonium compounds? They will not kill tuberculosis Why is it important to not use too strong a disinfectant solution on coated floors? The disinfectant solution will damage the floor finish ©2006 Basic Custodial Technician Program
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Vocabulary Detergency processes Dilute Disease Disinfectant Dispersing action Flash point Germicide Germs Hydrocarbon Hypochlorite Iodine lodophor Microorganisms Pathogenic germs Penetration Pine oil Quaternary ammonium compounds Safety Sanitization Solvent cleaners Sterilization Synthetic Synthetic detergents Surface tension Suspension Virus Viscosity Wetting agent ©2006 Basic Custodial Technician Program
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Review Questions Name two types of soil
List seven types of common cleaning agents List the four detergency cleaning agents Name the three physical characteristics of cleaning agents Describe acidity and alkalinity List three factors that affect cleaning chemistry What are the three methods of germ control? List seven types of disinfectants and disinfectant cleaners ©2006 Basic Custodial Technician Program
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Review Questions Name the equipment for cleaning restrooms/showers
Name the supplies for cleaning restrooms/showers Name the materials for cleaning restrooms/showers Identify the recommended procedures for cleaning restrooms and showers ©2006 Basic Custodial Technician Program
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