Chemistry of Cleaning Handout
CHEMICAL SAFETY
Prevent serious injury with these basic rules:
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.
Chemistry of Cleaning Handout
TYPES OF SOIL
To effectively remove soil, you must understand:
1. Types of soil
2. Elements that make up soil
Two Types of Soil
Loose, Dry Soil
Dust
Any surface
not cleaned in
12 hours will have
dust on it.
Oily, Sticky Soil
Greases & Oils
Animal
Vegetable
Mineral
Synthetic
It’s oily because of
hydrocarbons
chemical compounds
composed of two elements:
hydrogen and carbon
Chemistry of Cleaning Handout
GREASE & OIL
ON MANY BUILDING SURFACES & FURNISHINGS
COME FROM MANY SOURCES
Chemistry of Cleaning Handout
CLEANING AGENTS
Products that act on surfaces to remove dirt and soil.
COMMON TYPES OF CLEANING AGENTS
Water
Natural Soaps
Synthetic Detergents
Solvent Cleaners
Acid Cleaners
Alkaline Cleaners
Abrasive Cleaners
Chemistry of Cleaning Handout
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 film.
Soft Water = <200 PPM
Moderately Hard Water = 200-400 PPM
Hard Water = > 400 PPM
PPM= Parts Per Million of Calcium Carbonate
Water Softeners: Chemicals that remove the salts
that make water hard.
Chemistry of Cleaning Handout
CLEANING AGENTS
Natural Soaps:
Alkalis and animal or vegetable fats and oils.
Synthetic Detergents:
Man-made cleaning agents. A combination of
chemicals that can replace natural soaps.
Solvent Cleaners:
Dissolve, emulsify and suspend greasy, oily types of
dirt such as automotive grease, heavy-duty grease,
engine oils, fingerprints, body fats and varnish.
Examples of solvent cleaners:
o Kerosene
o Benzene
o Methyl Chloride
o Pine Oil
o Alcohol
Caution: Wear personal protective equipment
such as gloves and goggles or face shields.
Chemistry of Cleaning Handout
CLEANING AGENTS
Abrasive Cleaners:
Detergent components and scouring materials such
as silica dust or volcanic dust.
Acid Cleaners:
Remove mineral deposits and rust stains left by
water.
NO
YES
NEVER USE
hydroflouric acid on
leaded glass.
USE
under rims of urinals
and toilets, on porcelain,
vitreous china glass,
cement machinery,
plexiglass, on some
types of quarry and
ceramic tile and metals.
NEVER USE
sulfuric acid or strong
phosphoric acid on
metal.
Caution: Wear personal protective equipment
such as gloves and goggles or face shields.
SOIL REMOVAL
Chemistry of Cleaning Handout
SURFACE TENSION: Water stands in drops on dirty
surfaces.
WETTING ACTION: Making dirt wetter (water gets under the dirt).
EMULSIFICATION: Chemical action that enables water
to break oil into small particles, and then keeps the
particles suspended in the solution.
DISPERSING ACTION: Dirt is broken up into smaller
particles and spread apart.
ADSORPTION ACTION: Dirt and oil attract or cling to the
cleaning solution.
Chemistry of Cleaning Handout
pH Scale
Degree
of Acidity
& Alkalinity
Hydrochloric Acid
0
Descaler
1
Rust Remover
2
Vinegar
3
4
5
Boric Acid
7
General
Purpose Detergent
Window Cleaner
Dust Treatment
Hand Soap
Wood Polish
Ammonia
Degreaser
TSP
Floor Stripper
8
CAUSTIC SODA (LYE)
1 to 4
1 to 8
1 to 10
1 to 12
1 to 16
1 to 20
1 to 26
1 to 30
1 to 40
1 to 64
1 to 128
1 to 200
1 to 256
INCREASING
ACIDITY
1000 Times
stronger than water
6
PURE WATER
Ratio
10 Million times
stronger than water
NEUTRAL
9
10
11
12
1000 Times
stronger than water
INCREASING
ALKALINITY
13
14
Mixture with Water
32 oz. (1qt) per gallon
16 oz. (1 pint) per gallon
13 oz. per gallon
11 oz. per gallon
8 oz. (1 cup)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
½ oz. per gallon
Chemistry of Cleaning Handout
Factors that Affect Cleaning Chemistry:
Water Temperature, Contact Time and
Mechanical Action.
WATER TEMPERATURE
CONTACT TIME
MECHANICAL ACTION
Chemistry of Cleaning Handout
KILLING GERMS
Germs = Microorganisms
Germs are “TOO SMALL to SEE with the human
eye.”
A microscope is needed to see GERMS.
Chemistry of Cleaning Handout
GERM GROWTH AND REPRODUCTION
And so on and so forth.
FROM 1 to 64 BILLION GERMS
In just 12 Hours!!!!!
Chemistry of Cleaning Handout
MIXING CHEMICALS
Mix your own cleaner/disinfectant solution?
mix a chemical cleaner and disinfectant to make your
own cleaner/disinfectant solution.
CUSTODIANS ARE NOT CHEMISTS.
Chemistry of Cleaning Handout
SAFETY HAZARDS
PERSONAL PROTECTION
Arm and Hand Protection
o Use proper protective devices selected to fit the job.
o Know the limitations of the clothing you wear.
o Wide assortments of clothing are available:
o Gloves to protect against
chemical hazards, burns,
cuts and shock.
o Gloves and wristlets made of
leather, wire, mesh or canvas
and hand pads.
Eye and Face Protection
o Required by OSHA where there is a reasonable
probability of preventable injury when such protective
equipment is used.
o 60% of eye injuries happen when
workers are not wearing eye
protection because it was
not normally used or
required on the job.
Chemistry of Cleaning Handout
DISINFECTANTS
Natural
Pine Oil
Positive
Negative
80% oil
20% water
Will effectively kill germs.
However, it is very
expensive at this
dilution ratio.
Iodine
Positive
Negative
Very powerful.
Broad kill range.
Iodine stains surfaces and
corrodes metals. Use under
controlled conditions.
Chemistry of Cleaning Handout
Iodophor
Positive
Negative
Cleaner and disinfectant. Color
change occurs if disinfectant is
weak. Effective in food service
areas due to low toxicity.
Causes discoloration and is less
effective for oily soils. Not for
general use.
Hypochlorites
Positive
Negative
Powerful germ killer, found in
household bleach.
Works only on clean surfaces,
corrodes metals, dulls tile,
damages grout, will oxidize or
burn any material.
CAUTION: Dry hypochlorite can cause a flash fire if
used with oil or soap!
Chemistry of Cleaning Handout
Natural
Phenols
Positive
Negative
Made from carbolic acid.
Poisonous to humans.
Corrodes metal. Has an
unpleasant odor.
Synthetic
Phenols
Positive
Negative
Widely used germ killer with a
broad kill range.
Poisonous. Will burn skin and
irritate eyes. Fumes can
damage lungs.
Synthetic phenols can be used to make cleaner/disinfectants.
They will work with some detergents, but not with all.
Chemistry of Cleaning Handout
Quaternary
Ammonium
Compounds
Positive
Negative
Not poisonous, no odor, will
not burn. Good germ kill.
Powerful, less corrosive than
phenols and can be used in
food processing areas.
Will not kill Tuberculosis. The
more soil, the more the kill
power is reduced. Hard water
slows the kill power.
Chemistry of Cleaning Handout
PROPER DISINFECTION
Dilution Rule: More is not always better.
Too much water
makes the cleaning
solution weak, and it
will not kill germs.
Not enough water
will make the cleaning solution too
strong and potentially dangerous.