Fundamentals of Industrial Hygiene for Contractors and Technicians

1
Fundamentals of Industrial Hygiene for
Contractors and Technicians

• Prepared by
• Clayton Group Services, Inc. A Bureau Veritas
  Company
• Downers Grove, IL
• 630.795.3200

2
INTRODUCTION

• Basics of Industrial Hygiene
• Anticipation
• Chemical and Physical Hazards
• Heath Hazards and Routes of Entry
• Recognition
• Identifying Potential Heath Hazards
• Evaluation
• Measuring Exposure Concentrations
• Control
• Exposure Control Concepts

3
INTRODUCTION

• Practice Session
• Open Discussion

4
OBJECTIVES

• Understand the Field of IH
• Understand the impact of chemical and physical
  hazards on the short and long term health of
  workers
• Recognize and assess potential for excessive
  exposures
• Audit worksite for exposures

5
INDUSTRIAL HYGIENE

• The goal of an industrial hygiene program is to
  prevent employee exposures to hazardous
  substances.
• Plant health and safety personnel, industrial
  hygienists and contractors are the front line
  persons responsible for meeting this goal.
• Examples of health and safety programs that are
  critical to meeting this goal include
• Hazard Communication
• Hearing Conservation
• Respiratory Protection

6
INDUSTRIAL HYGIENE

• What is an Industrial Hygienist?
• Person having a degree in engineering, chemistry,
  physics, health physics, nursing, medicine, or
  related field, by virtue of special studies,
  training, experience, and/or certification has
  acquired competence in IH.

7
INDUSTRIAL HYGIENE

• Not everything hazardous on the job is a
  chemical.
• Noise
• Radiation
• Vibration
• Exposure to excessive heat or cold.
• Environmental Stressors
• We will use this term to refer to both chemical
  and physical agents.

8
INDUSTRIAL HYGIENE

• Many extremely harmful environmental stressors
  are used in industry without hazard because
  adequate precautions are taken to limit actual
  contact with them to amounts which will not cause
  injury or illness.

9
INDUSTRIAL HYGIENE

• Paracelsus, a Swiss-born physician, chemist and
  alchemist (1493-1541) once said
• All chemicals are poisons, there are none that
  are not. The difference between a cure and a
  poison is the dose

10
TOXICITY VS. HAZARD
It is important that one understand the
distinction between toxicity and hazard.
The ability of a substance to produce an adverse
effect in a biologic system(s).
Toxicity
The potential that a substance will cause an
adverse effect in a given situation or
environment.
Hazard
Based on these definitions, two chemicals can
have the same degree of toxicity, but present
different degrees of hazard.
11
TOXICITY VS. HAZARD

• What is more toxic?
• Mercury
• Sodium chloride (table salt)
• What is more hazardous?
• Putting a thermometer in your mouth.
• Ingesting 2 pounds of sodium chloride

12
INDUSTRIAL HYGIENE

• When evaluating whether an environmental stress
  will be hazardous, it is necessary to know not
  only the toxicity, but also the physical and
  chemical properties, and the manner and quantity
  to be used.
• These factors help determine
• How much enters the body
• Route of entry into the body
• Frequency of exposure
• Duration of exposure

13
HEALTH EFFECTS OF ENVIRONMENTAL STRESSORS
HEALTH HAZARDS
14
HEALTH HAZARDS

• Common Types of Health Hazards
• Carcinogens capable of causing cancer
• Teratogens capable of causing birth defects
• Mutagens capable of producing genetic changes or
  damage
• Irritants produces an irritating effect on
  contact with skin, eyes, nose and/or respiratory
  tract
• Corrosives produces visible or permanent
  destruction of tissue at the site of contact
• Sensitizers can cause an allergic reaction to
  the skin or respiratory track.
• Biological living organism that can cause
  disease.

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HEALTH HAZARDS

• Target Organ Effects - Chemicals that affect
  certain organs more than others
• Hepatotoxins - liver
• Nephrotoxins - kidney
• Neurotoxins - nerves
• Hematopoietic toxins - blood system
• Pulmonary toxins - lungs
• Skin toxins - skin

16
HEALTH HAZARDS

• For environmental stressors to cause harm they
  need to come into contact with the body
• Occupational Routes of Entry
• Inhalation
• Skin contact/skin absorption
• Ingestion
• Injection

17
HEALTH HAZARDS

• Inhalation - Lungs
• Surface area of a tennis court
• Enormous area for chemicals to exert their toxic
  effect
• Gases and vapors pass through the lungs into the
  blood, some more readily than others
• Highly irritating chemicals, such as chlorine,
  will first react with water in the upper airways
• Less irritating chemicals will make it deep into
  the lungs and get absorbed into the blood

18
HEALTH HAZARDS

• Nose Large particles are trapped in mucus and
  hair. They are removed when you blow your nose.
• Air Tubes Particles hit the walls of air tubes
  and are caught in mucus. Thin hair-like fibers
  beat and move the particles up the airways. They
  are then coughed out or swallowed.
• Air Sacs Tiny dust particles are surrounded by
  special white blood cells which move them to
  where they can be coughed out or swallowed.

19
HEALTH HAZARDS

• Inhalation of Evaporated Chemicals
• Evaporation rate increases with rise in air and
  substance temperatures and an increase in wind
  and solar radiation since warmer air can hold
  more moisture.
• In general, organic liquids (benzene, gasoline)
  evaporate at lower temperatures and higher rates
  than water.

20
HEALTH HAZARDS

• Skin Contact
• Natural protective coating of oils acts as
  barrier to chemicals.
• Some chemicals, however, pass through the skin,
  are absorbed into the bloodstream, carried
  throughout the body, and can harm other organs.

21
HEALTH HAZARDS

• Skin Contact
• Benzene, carbon tetrachloride and methyl alcohol
  are easily absorbed.
• Substances will pass more readily through wet or
  damaged skin.
• You can also absorb chemicals through your eyes.

22
HEALTH HAZARDS

• What skin hazard is present on almost every job?

23
Here Comes the Sun

• ABCDs of melanoma

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HEALTH HAZARDS

• Ingestion
• Substances can enter the body through the mouth
  and digestive tract.
• Less common route of entry than respiratory or
  skin contact.
• Mouth contact with contaminated hands, food or
  cigarettes does occur.

25
HEALTH HAZARDS

• Injection
• May inject chemical into your body by a needle
  stick, laceration or puncture the skin on
  contaminated glass or a metal shard.

26
HEALTH HAZARDS

• Dose-Response Relationship
• How a chemical affects your body depends on how
  long you are exposed to it and the concentration
  (amount) of chemical exposure.
• Dose Amount (concentration) x Time (duration)
• Response Effect or reaction caused by dose

27
HEALTH HAZARDS
What do these chemicals have in common?
Answer They are all animal or human carcinogens
or mutagens.
28
HEALTH HAZARDS
Remember that the dose makes the poison.
Holiday Menu
Appetizers Cream of mushroom soup
(hydrazines)Vegetables Baked potato (ethyl
alcohol, caffeic acid) Broccoli (allyl
isothiocyanate) Celery (caffeic acid, furan
derivatives, psoralens)Entrees Roast Turkey
(heterocyclic amines) Cranberry sauce (furan
derivatives)
Bread Rolls with butter (acetaldehyde, benzene,
ethyl alcohol, benzo(a)pyrene,furan derivatives,
furfural) Dessert Apple Pie (acetaldehyde,
caffeic acid, ethyl alchol, methyl eugenol,
quercetin glycosides, safrole)
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ACUTE HEALTH HAZARDS

• Acute Health Hazards - Happen soon after
  exposure, usually of short duration
• Irritant - reversible inflammation at the site of
  contact
• fiberglass insulation, ammonia, acid mists
• Corrosive - a visible destruction by chemical
  action
• Battery acid, some boiler water treatment
  chemicals

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ACUTE HEALTH HAZARDS

• The smaller amount of a substance it takes to
  produce the targeted effect, the more toxic the
  material.
• Rapid action, low dose
• In pharmaceuticals this is known as potency.

31
ACUTE HEALTH HAZARDS

• OSHA defines a toxic agent as
• a. LD50 (oral) -- oral doses in rats ranging
  from 50 to 500 milligrams per kilogram (mg/kg)
• b. LD50 (skin) -- 24-hour skin exposure to
  rabbits ranging from 200 to 1,000 mg/kg
• c. LC50 -- 1-hour inhalation doses to rats
  ranging from 200 to 2,000 parts per million (ppm)
• Examples Ammonia, nitrogen dioxide, ethylene
  oxide

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ACUTE HEALTH HAZARDS

• OSHA Defines a highly toxic agent as
• a. LD50 (oral) -- oral doses in rats of less
  than 50mg/kg
• b. LD50 (skin) -- 24-hour skin exposure to
  rabbits of less than 200 mg/kg
• c. LC50 -- 1-hour inhalation dose to rats of less
  than 200 ppm
• Examples Hydrogen cyanide, mustard gas

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CHRONIC HEALTH HAZARDS

• Chronic health hazards occur from long-term
  exposures - usually of long duration
• Sensitizers - allergies
• Carcinogens - cancers
• Target organ toxins

34
CHRONIC HEALTH HAZARDS

• Examples of chronic exposures and heath effects
• Smoking and lung cancer
• Sun exposure and skin cancer
• Alcohol and liver damage
• Benzene and leukemia
• Sugar and tooth decay

35
Lets Discuss Exposure Limits
36
EXPOSURE LIMITS

• Exposure limits for many chemicals have been
  established.
• A chemical's exposure limit is the concentration
  of that chemical to which nearly all workers may
  be repeatedly exposed, day after day, without
  adverse health effects.

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EXPOSURE LIMITS

• Exposure limits also for physical hazards
• Noise
• Heat Stress
• Cold Stress
• Vibrations
• Ionizing Radiation
• Non-Ionizing Radiation

38
EXPOSURE LIMITS

• Exposure limits for chemicals are commonly
  expressed as
• parts per million (ppm) of a chemical allowed in
  the air, or
• milligrams per cubic meter of chemical allowed in
  the air (mg/m3)
• Exposure above a chemical's exposure limit may
  produce harmful effects on the body.

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(No Transcript)
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EXPOSURE LIMITS

• To give you an idea of how little a ppm is
• 1 mile 5280 feet
• 1 ppm 1/16 of an inch in a mile.

41
EXPOSURE LIMITS

• OSHA Permissible Exposure Limits (PELs) for
  chemicals are enforced by law.
• The American Conference of Governmental
  Industrial Hygienists (ACGIH) has set Threshold
  Limit Values (TLVs).
• TLVs are voluntary exposure limits that may be
  followed but are not enforceable by law.

42
EXPOSURE LIMITS

• PELs and TLVs are usually observed as
  time-weighted-average (TWA) concentrations for
  normal 8-hour workdays.
• In addition to the 8-hour TWA, some chemicals
  have exposure limits of 15 minutes called
  Short-Term Exposure Limits (STELs), and exposure
  limits that should never be exceeded for any
  amount of time, called Ceiling Limits (C).

43
EXPOSURE LIMITS

• Immediately Dangerous to Life and Health (IDLH)
  is the acute respiratory exposure that poses an
  immediate (within 30 minutes) threat to loss of
  life, immediate or delayed irreversible adverse
  effects on health, or acute eye exposure which
  would prevent escape from a hazardous atmosphere.

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EXPOSURE LIMITS
Exposures are really the average concentration
over the time sampled.
45
Back to the Field of Industrial Hygiene
46
INDUSTRIAL HYGIENE
Industrial hygiene is. . .
The science and art devoted to the anticipation,
recognition, evaluation, and control of those
workplace stresses, environmental factors, or
other hazards, which may cause sickness, impaired
health and well-being, or significant discomfort
among workers or among the community.
47
INDUSTRIAL HYGIENE
There are four fundamental elements of industrial
hygiene.
Each of these concepts will be further discussed
throughout this presentation.
48
ANTICIPATION
Hazard anticipation is one of the proactive
components of an industrial hygiene program.

• Review of chemicals (i.e., MSDSs)
• Review of chemical and physical properties
• Review of work practices and work conditions

49
RECOGNITION
Recognition of hazards relates to the
identification of hazards and stressors in the
workplace.
Anticipation
Evaluation
Control
Recognition

• Job Site surveys
• Reviews of past accident reports, audit reports,
  chemical inventories, etc.
• Employee input

50
EVALUATION
Once a hazard has been anticipated and/or
recognized, the degree of exposure to employees
must be determined.
Anticipation
Evaluation
Control
Recognition

• Qualitative exposure evaluations
• Quantitative exposure monitoring

51
CONTROL
There are three primary controls that should be
considered for eliminating hazardous exposures.
Anticipation
Evaluation
Control
Recognition

• Engineering Controls
• Administrative Controls
• PPE

52
ANTICIPATION

• Anticipation requires
• Knowledge of the characteristics of the physical
  state of matter.
• Knowledge of the hazards of environmental
  stressors.
• Knowledge of how chemicals behave
• Knowledge of work practices and processes

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ANTICIPATION

• Physical States of Matter
• Solid
• Liquid
• Gas

54
ANTICIPATION

• Knowledge of the physical state of matter can
  help anticipate its movement in the air near the
  workers Breathing Zone.
• Breathing Zone
• Imaginary globe of two foot radius around the
  head where from which a work breaths in air.

55
ANTICIPATION

• Physical State of Matter
• Gases -
• Fills this space in which it is generated
• Can be toxic, flammable, explosive and/or
  corrosive
• Can be lighter than air
• Can be heavier than air

Gas Model
56
ANTICIPATION

• Physical State of Matter
• Vapors -
• Act like gases
• Source is evaporated liquids
• Can be toxic, flammable, explosive and/or
  corrosive
• Dont confuse vapors with fumes
• Can you identify a vapor generated at the
  worksite?

57
ANTICIPATION

• Gases and Vapors
• Vapor density (V.D.)- the weight of a vapor or
  gas compared to the weight of an equal volume of
  air.
• Can be lighter, heavier, or same density as air
  (air 1)
• Materials lighter than air will have vapor
  densities lt 1.
• Materials heavier than air will have vapor
  densities gt 1.
• Vapor density of gasoline 3 - 4
• Where would you expect the vapors to accumulate?

Q What reference materials can you use to find
the V.D. of a substance?
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ANTICIPATION

• Vapor Density
• Hydrogen Gas 0.07
• Air 1.0
• Gasoline Vapor 3.5

Rises
Sinks
59
ANTICIPATION

• Liquids
• Can evaporate to form toxic, corrosive and/or
  flammable vapors!

60
ANTICIPATION

• Inhalation of Evaporated Chemicals
• Evaporation is the process in which a substance
  changes from a liquid or solid phase to a gaseous
  or vapor phase.
• Some of the factors that affect evaporation
  include air and substance temperatures,
• Wind Speed
• Solar Radiation
• Relative Humidity

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ANTICIPATION

• What can you Anticipate", in general, what will
  happen to the vapors of liquid
• On a hot, sunny day vs. a cold, cloudy day

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ANTICIPATION

• Solids
• Includes powders, smoke, mists, aerosols, fumes
  and dusts.
• Can be toxic and corrosive
• Can be combustible and flammable

63
ANTICIPATION

• If the product is solid, it may be crystalline,
  granular, powdery, etc. If the product is
  liquid, it may be viscous, gelatinous, oily, etc.

64
ANTICIPATION

• Dusts
• Behave like gases
• Smaller particles easily inhaled and stay
  airborne longer.
• Watch for ignition sources

65
ANTICIPATION

• Fumes
• Source is molten or vaporized metals
• Smaller in size than dusts.
• There is no such thing as paint fumes or
  gasoline fumes but you can have welding fumes

66
ANTICIPATION

• Anticipation requires knowledge of the hazards of
  environmental stressors.
• Chemical
• Physical
• Knowledge of the chemical and physical hazards of
  matter can help anticipate how it will come into
  contact and/or interact with the body.

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ANTICIPATION

• Chemical Hazards
• Corrosive
• Irritant
• Sensitizer
• Toxic
• Biohazards Legionella
• Involves the health effect product from exposure
  to a liquid, gas or solid agent
• We covered this in the health hazard section

68
ANTICIPATION

• Physical Hazard of Chemicals
• Radiation
• Thermal
• Ergonomic
• Asphyxiant
• Combustible
• Flammable
• Oxidizers
• May involve the release of energies under certain
  conditions
• May involve interaction with body systems

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ANTICIPATION

• Radioactivity
• Source materials - substances that emit ionizing
  radiation (like plutonium)

70
ANTICIPATION

• Radioactive materials can be found in thickness
  gauges and casting inspection processes
• Radiation spills should only be approached by
  persons trained in radiation hazard recognition

71
ANTICIPATION

• Thermal Hazards
• Molten materials - hot, fire hazard, burns - hot
  work
• Cryogenic liquids (liquid oxygen, liquid
  nitrogen, etc.) - extremely cold, can displace
  air rapidly with uncontrolled release
• Heat Stress and Cold Stress covered later

72
ANTICIPATION

• Liquid nitrogen
• Cryogenic liquid-300 F
• Can cause frostbite on
  contact
• Rapidly expands causing
  oxygen deficient atmosphere
  
  

73
ANTICIPATION

• Asphyxiant
• Two kinds
• Simple and Chemical
• Simple Asphyxiant - displaces air, which contains
  the oxygen we need to live
• carbon dioxide, argon, nitrogen
• Chemical Asphyxiant - replaces oxygen in the
  blood - cells die from lack of oxygen
• carbon monoxide, methylene chloride

74
ANTICIPATION

• Flash Point
• The flash point of a product is the lowest
  temperature at which a sufficient amount of vapor
  is given off to create a mixture with the air
  which is flammable on contact with an open flame
  or spark.

75
ANTICIPATION

• Combustible Liquids
• Flashpoint of at least 100 0 F, but less than
  2000 F
• DOT - flashpoint less than 1400 F
• Examples - diesel fuel, kerosene

76
ANTICIPATION

• Flammable Liquids
• Flashpoint less than 1000 F
• DOT definition less than 1400 F

77
ANTICIPATION

• Fire Triangle
• Need all three sides to have a fire
• Remove any one side - no fire occurs
• Chemical chain reaction - a fourth element?

78
ANTICIPATION

• Some flammable and combustible liquids chemicals
  at a worksite
• Windshield Wiper Fluid (flash point 54 F)
• Gasoline(flash point minus 45F)
• Diesel fuel (flash point 100 F)
• No. 2 fuel oil (flash point 136 F)

79
ANTICIPATION

• Compressed gas cylinders are usually pressurized
  to 2,500 psi (or more).
• Damage to the neck, valves, or cylinder walls can
  result in a rupture and violent release of the
  gas.
• Cylinder can become a rocket.

80
ANTICIPATION

• Explosives - may be formed from mixtures of
  chemicals
• Oxidizers - chemically add oxygen, which
  accelerates certain chemical reactions - like
  fire (examples - oxygen, hydrogen peroxide)
• Pyrophoric Substances - ignites spontaneously in
  air at 1300F or less - like sodium
• Reactive Materials - release energy under
  conditions of shock, pressure or high temperature
  - like nitroglycerine

81
ANTICIPATION

• Water-reactive Chemicals
• Reacts with water to form toxic or reactive gases
• Example calcium carbide and water creates
  acetylene gas (flammable and explosive)
• Acids and water generates heat and hydrogen gas

82
ANTICIPATION

• Chemical Compatibility
• When two or more chemicals can remain in contact
  indefinitely without reaction, they are
  compatible.
• Incompatibility may not always produce a hazard.

83
ANTICIPATION

• Incompatible chemicals can cause
• produce products more hazardous than the original
  materials
• fires
• release hazardous energies
• Sodium hypochlorite (chlorine bleach) is
  incompatible with strong acids. On contact with
  them, it releases highly toxic chlorine vapors.

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ANTICIPATION

• Preventing incompatible chemicals from contact
  with each other is key
• Store like materials together
• Consider
• Storage
• Handling
• Use

85
ANTICIPATION

• Biohazards
• Includes bacteria, viruses, parasites, insects
  and animal droppings
• Bloodborne Pathogens
• Exposure can result in disease transmission

86
ANTICIPATION

• Summary
• Anticipate whether a person may be exposed to an
  environmental stressor based on your knowledge of
  how they behave and interact with the body and
  surrounding environment.

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ANTICIPATION
88
RECOGNITION

• Recognize the potential for worker exposure
• Combine
• Knowledge of the chemical and physical properties
  of chemicals.
• Heath effects
• Physical state of matter
• How chemicals behave
• Knowledge of the work practices and procedures.
• Exposure Assessment
• Qualitative vs. Quantitative exposure evaluation

89
RECOGNITION

• What is Risk?
• Risk is the chance or possibility of an adverse
  outcome.
• We need to evaluate the risks to assess if a
  worker is potentially exposed to an environmental
  stressor over an occupational overexposure limit.
  

90
RECOGNITION
Exposure Assessment

• Stressor Properties
• Exposure Limit
• Corrosive
• Toxicity
• Sensitizer
• Irritant
• Vapor Density
• Physical State of Matter

• Risk Factors
• Quantity Used
• Length of Time Exposed
• Type of Work Performed
• Work Conditions
• Ventilation
• Use in Confined Spaces
• History of Overexposure

Environmental Stressor Properties must be weighed
against the Risks Factors
91
RECOGNITION

• Stressor Properties
• Ask yourself
• Is there an exposure limit?
• If the answer is YES then continue.

92
RECOGNITION

• Stressor Properties
• Ask yourself
• Is there an exposure limit?
• If the answer is NO then your assessment is done
  (or is it?).
• Other SAFETY RELATED hazards may exist but we are
  focusing on overexposures to environmental
  stressors.
• Can you think of other SAFETY RELATED hazards?
• Slip, trips, falls, etc

93
RECOGNITION

• Stressor Properties
• Ask yourself
• If there is an exposure limit. than I must
  assess whether the worker may be exposed over the
  limit using Risk Factors as a guideline.
• Qualitative Exposure Assessment

94
RECOGNITION

• Qualitative Exposure Assessment
• It is an educated guess on whether the worker
  will be exposed over the exposure limit or
  conservatively, ½ the exposure limit (action
  level).

95
RECOGNITION

• Risk Factors
• Ask yourself
• How much chemical will be used?
• How long will they be exposed?
• Will the type of work performed generate airborne
  chemicals?
• Will the work involve exposure to physical
  agents?
• What is the physical state of the chemicals used
  or generated?
• Is there adequate ventilation?
• Will the chemicals be use in Confined Spaces?

96
RECOGNITION

• Risk Factors
• Ask yourself
• How much chemical will be used?
• Total amount, surface area, etc.
• The larger the surface area the more vapors are
  evaporated
• Quantity must be balance against hazardous nature
  of the material
• However Small quantities of highly toxic or
  reactive substances can create significant risk.

97
RECOGNITION

• Risk Factors
• Ask yourself
• How long will they be exposed?
• The shorter the work process the less exposure
  duration.
• However a short amount of exposure to a highly
  toxic or reactive substance can create
  significant risk.

98
RECOGNITION

• Risk Factors
• Ask yourself
• Will the type of work performed generate airborne
  chemicals?
• Are gases used, generated or released?
• Will a liquid generate vapors?
• Will hot works generate fumes?
• Will mechanical actions generate particles?
• If the process does not generate airborne agents
  then there will be no airborne exposure over an
  exposure limit.

99
RECOGNITION

• Risk Factors
• Ask yourself
• Will the work involve exposure to physical
  agents?
• Noise
• Radiation
• Heat
• Cold

100
RECOGNITION

• Risk Factors
• Ask yourself
• What is the physical state of the chemicals used
  or generated?
• Gas
• Will be airborne
• Liquid
• Can evaporate and release vapors
• Large particles (wood chips, granular salt)
• Less likely to become airborne
• Can contain small particles mixed in
• Small particles
• Easily becomes airborne and inhaled

101
RECOGNITION

• Risk Factors
• Ask yourself
• Is there adequate ventilation?
• Local Exhaust Ventilation (LEV)
• Can remove airborne agent at the generation
  source and greatly reduce the airborne
  concentration
• General Ventilation
• Less effective than LEV
• Can reduce airborne concentration by dilution

102
RECOGNITION

• Risk Factors
• Ask yourself
• Is there a history of personnel being overexposed
  during this work task?
• Look at OSHA Logs
• Ask site safety personnel
• Ask workers about past projects with air sampling
• Is there a specific OSHA Regulation where you
  assume overexposure until proven otherwise?
• Lead
• Asbestos
• Others

103
RECOGNITION

• There are times that you can smell odors at
  concentrations many times lower than an exposure
  limit.

104
RECOGNITION

• Your sense of smell has capabilities and
  limitations
• Odor versus toxicity
• benzene sweet, pleasant odor and carcinogen
• skunk brutal and irritant
• Olfactory fatigue
• hydrogen sulfide now you smell it now you
  dont
• Warning properties
• mercaptans added to natural gas to give the
  characteristic odor
• carbon monoxide no odor

105
RECOGNITION
Selected Odor Thresholds
To be used as guidelines only. Are subjective and
differ from person to person.
106
RECOGNITION

• Recognizing Symptoms of Exposure
• Review MSDS to identify sign and symptoms of
  overexposure.
• If your workers experience or report any of the
  listed signs and symptoms of overexposure they
  may be overexposed.

107
RECOGNITION

• Common Symptoms of Acute Exposure
• Feel dizzy while working with solvents
• Nose, lungs and eyes are irritated while working
  with particulates or corrosive chemicals
• Skin rash
• Can you think of others?

108
RECOGNITION
Summary New materials and procedures should be
reviewed prior to being introduced into the work
environment.

• Does the material contain ingredients known to
  be toxic? At what concentrations?
• Does the ingredient have exposure limits?
• How will the material be used?
• Will employees be exposed to the material?
• What are the hazards of the material?
• What types of controls will be needed?

109
RECOGNITION

• Summary
• Your educated and experienced guess will help you
  to
• Determine if an exposure over an occupational
  exposure limit is likely
• If air sampling is required
• If controls are necessary

110
EVALUATION

• Quantitative Exposure Assessment
• Collecting actual measurement of the
  environmental stressor of concern for comparison
  to occupational exposure limits.
• Must be conducted by an experienced Industrial
  Hygienist

111
EVALUATION
If qualitative evaluations are not sufficient,
quantitative exposure monitoring may be necessary

• Determine the stressor that will be measured
  (i.e. a chemical, noise, biological hazard)
• Obtain the sampling and analytical method
• Design the sampling strategy
• Conduct the monitoring
• Analyze and interpret the results
• Determine recommendations for corrective actions
  based on results
• Document the monitoring results

112
EVALUATION
Since it is not possible to monitor everything at
once, priorities need to be established.

• Considerations include
• The level of risk (i.e., the worst first)
• Regulatory requirements
• Signs or symptoms of exposure
• Employee requests for respirators
• History of high exposures
• New materials/process

113
EVALUATION
WHO When selecting personnel to monitor, you
should also look at worst first.
Maximum Risk Employee
The individual who is likely to have the highest
exposure
114
EVALUATION
WHERE When monitoring, a primary consideration
is whether to collect Personal or Area samples.
Personal Sampling
Area Sampling
Air sampling of the contaminant concentration in
the immediate work environment
Air sampling of anindividuals exposure
115
EVALUATION
WHEN Sampling can be representative of a very
short period of time or of a typical work day.
116
EVALUATION
HOW Will the sampling be collected?
117
EVALUATION
HOW Will the sampling be collected?
118
EVALUATION
HOW Will the sampling be collected?
119
EVALUATION
Sampling results below established exposure
limits may require no further action.

• Demonstrate the relative safety of the operation.
• Demonstrate the effectiveness of controls.
• Reinforce effectiveness of safe work practices.
• Demonstrate company/regulatory compliance.

120
EVALUATION
Sampling results above established exposure
limits may indicate the need for corrective
actions.

• Demonstrate the need for more effective
  engineering or PPE controls.
• Demonstrate the potential hazards of an
  operation.
• Reinforce the need for safe work practices.

121
EVALUATION
The results of all exposure monitoring should be
documented and communicated to affected persons.
122
EVALUATION

• Direct-Reading Instruments
• Multi-Gas Detector
• Combustible Gas Meter
• Percent Oxygen
• Carbon Monoxide
• Hydrogen Sulfide

123
EVALUATION
DANGER

• Toxic, Explosive Atmospheres.
• Risk of serious bodily injuries and death.
• You must fully understand how to use and
  calibrate the meter before you attempt to use it.
  
• Read the Operations and Maintenance Manual and
  practice using the instrument before an actual
  emergency or project.

124
EVALUATION

• Combustible Gas Meter
• Determines the concentration of flammable gases
  and vapors to assess the explosive potential and
  risk of working in that atmosphere (Quantitative
  Only)
• Meter typically reads in 0 - 100 of the lower
  explosive limit (LEL)
• Example LEL for ethyl alcohol is 3.3. If the
  meter reads 10, then the concentration is 10 of
  3.3 or .10 x 3.3 0.33
• Or is it really 10 LEL? What is a correction
  factor?)

125
EVALUATION

• Explosive Atmospheres
• EPA Action Guides for Unknown Atmospheres
• 0 - 10 LEL Continue investigation
• 10-25 LEL Continue with caution
• gt 25 LEL LEAVE AREA IMMEDIATELY

126
EVALUATION

• Percent Oxygen in Atmosphere
• Used to identify oxygen-deficient atmospheres
• Meter reads out in percent oxygen, usually 0 -
  25
• Calibrated to ambient oxygen (20.9)
  concentrations in a clean atmosphere
• EPA Action Levels
• lt 19.5 Supplied-air (SCBA) required
• 19.5-25 Continue with caution
• gt 25 LEAVE AREA, INCREASED FIRE HAZARD

127
EVALUATION

• Carbon Monoxide
• Colorless, odorless chemical asphyxiant
• By-product of incomplete combustion
• Propane Forklifts
• 8-hour TWA exposure limits
• PEL 50 ppm
• TLV 25 ppm
• IDLH
• 1200 ppm

128
EVALUATION

• Hydrogen Sulfide
• Colorless gas with a strong odor of rotten eggs
• Often a by-product of decaying organic materials
• Often found in sewers a confined space gas
• Exposure Limit - Ceiling
• OSHA 20 ppm
• TLV 10 ppm
• IDLH 100 ppm

129
EVALUATION

• Detector Tubes
• Direct-reading length of stain indicators
• Can measure airborne concentrations of organic
  and inorganic vapors and gases
• Ethyl alcohol
• Hydrochloric acid
• Hydrogen peroxide

130
EVALUATION

• Process Analyzers - HNU
• In 1974, the first commercial photoionization
  instrument (PID) was introduced by HNU Systems,
  Inc

131
EVALUATION

• PID
• To determine the relative concentrations of air
  contaminants specifically calibrated for the
  instrument
• Will not measure
• Dust
• Fumes
• Solids of any kinds
• Strictly quantitative and not qualitative
• How much but not exactly what it is
• High humidity reduces sensitivity

132
CONTROLS

• Sound Insulation
• Ventilation
• Isolation

Engineering Controls

• Job rotation
• Change work practices
• Material substitution

Administrative Controls

• Eye, face, hand, body, head, foot protection
• Respiratory protection

Personal Protective Equipment
133
CONTROLS
Engineering controls remove or isolate the hazard.

• Design and redesign
• Substitution
• Isolation
• Enclosure
• Ventilation

134
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135
CONTROLS
Administrative controls include the work rules
and procedures that help minimize exposures.

• Written programs
• Standard operating procedures
• Training
• Limited exposure time
• Job rotation
• Medical surveillance

136
CONTROLS
PPE provides a physical barrier between the
hazard and the employee.

• Eye and face protection
• Hearing protection
• Hand and body protection
• Head protection
• Respiratory protection

137
CONTROLS
Other controls to reduce the risk of exposure
include

• Good housekeeping
• Preventive maintenance
• Continuous monitoring devices and alarms
• No eating or drinking at the worksite.
• Personal hygiene

138
SUMMARY

• Why do we need to understand Environmental
  Stressor?
• The physical and chemical properties of hazardous
  materials can predict how they will behave in the
  environment
• How they behave will assist in predicting the
  potential for a worker exposure situation.