1. Chemistry of Cleaning
©2006 Basic Custodial Technician Program

2. 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
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3. Introduction
Cleaning and maintenance chemicals are among the most important items you will use in custodial work.
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4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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
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12. Cleaning Agents Products that act on surfaces to remove dirt and soil
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13. Seven basic types of cleaning agents
Water
Natural Soap
Synthetic Detergents
Solvent Cleaners
Acid Cleaners
Alkaline Cleaners
Abrasive Cleaners
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14. 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
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15. 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
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16. Natural Soap Second-oldest cleaning agent
Alkalis plus animal or vegetable fats and oils
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17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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
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24. Processes involved in soil removal and Three physical characteristics of cleaning agents
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25. Soil Removal
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26. ©2006 Basic Custodial Technician Program

27. ©2006 Basic Custodial Technician Program

28. Physical Cleaning Actions
Penetration
Suspension
Viscosity
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29. 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

30. 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

31. Acidity or alkalinity determining the strength of cleaning agents
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32. The pH Scale
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33. 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)
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34. How to work dilution ratio problems
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35. Ratios
1 cup = 8 ounces 1 pint = 16 ounces 1 quart = 32 ounces 1 gallon = 128 ounces
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36. 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

37. 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

38. 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

39. Other Cleaning Factors
Aside from choosing the proper chemicals and diluting them for cleaning, there are other factors to consider.
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40. Cleaning Chemistry Factors that Affect Cleaning Chemistry:
Water Temperature
Contact Time
Mechanical Action
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41. 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

42. 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

43. Discussion Questions List the four methods of mechanical action
Agitation with a brush
Water pressure
Abrasive pads
Vacuum suction or manual pressure
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44. Disinfection
One of your most important jobs as a custodian is to kill germs or stop their growth before they make people sick
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45. 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

46. 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
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47. 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

48. 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

49. 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

50. 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
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51. Seven types of disinfectants
Natural Pine Oil
Iodine
Iodophors
Hypochlorites
Natural Phenols
Synthetic Phenols
Quaternary Ammonium Compounds
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52. Natural Pine Oil Positive Negative
80% oil 20% water Will effectively kill germs
Is very expensive at this dilution ratio
BUT
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53. Iodine Positive Negative Very powerful. Broad kill range
Stains surfaces, corrodes metals. Use under controlled conditions
BUT
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54. 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

55. 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
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56. Natural Phenols Positive Negative Made from carbolic acid
Poisonous to humans. Corrodes metal. Unpleasant odor
BUT
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57. 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

58. 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

59. 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

60. 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

61. 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

62. 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

63. 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

64. 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

65. 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