Title: Fundamentals of Industrial Hygiene for Contractors and Technicians
1Fundamentals of Industrial Hygiene for
Contractors and Technicians
- Prepared by
- Clayton Group Services, Inc. A Bureau Veritas
Company - Downers Grove, IL
- 630.795.3200
2INTRODUCTION
- 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
3INTRODUCTION
- Practice Session
- Open Discussion
4OBJECTIVES
- 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
5INDUSTRIAL 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
6INDUSTRIAL 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.
7INDUSTRIAL 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.
8INDUSTRIAL 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.
9INDUSTRIAL 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
10TOXICITY 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.
11TOXICITY 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
12INDUSTRIAL 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
13HEALTH EFFECTS OF ENVIRONMENTAL STRESSORS
HEALTH HAZARDS
14HEALTH 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.
15HEALTH 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
16HEALTH 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
17HEALTH 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
18HEALTH 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.
19HEALTH 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.
20HEALTH 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.
21HEALTH 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.
22HEALTH HAZARDS
- What skin hazard is present on almost every job?
23Here Comes the Sun
24HEALTH 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.
25HEALTH HAZARDS
- Injection
- May inject chemical into your body by a needle
stick, laceration or puncture the skin on
contaminated glass or a metal shard.
26HEALTH 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
27HEALTH HAZARDS
What do these chemicals have in common?
Answer They are all animal or human carcinogens
or mutagens.
28HEALTH 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)
29ACUTE 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
30ACUTE 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.
31ACUTE 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
32ACUTE 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
33CHRONIC HEALTH HAZARDS
- Chronic health hazards occur from long-term
exposures - usually of long duration - Sensitizers - allergies
- Carcinogens - cancers
- Target organ toxins
34CHRONIC 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
35Lets Discuss Exposure Limits
36EXPOSURE 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.
37EXPOSURE LIMITS
- Exposure limits also for physical hazards
- Noise
- Heat Stress
- Cold Stress
- Vibrations
- Ionizing Radiation
- Non-Ionizing Radiation
38EXPOSURE 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.
39(No Transcript)
40EXPOSURE 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.
41EXPOSURE 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.
42EXPOSURE 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).
43EXPOSURE 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.
44EXPOSURE LIMITS
Exposures are really the average concentration
over the time sampled.
45Back to the Field of Industrial Hygiene
46INDUSTRIAL 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.
47INDUSTRIAL HYGIENE
There are four fundamental elements of industrial
hygiene.
Each of these concepts will be further discussed
throughout this presentation.
48ANTICIPATION
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
49RECOGNITION
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
50EVALUATION
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
51CONTROL
There are three primary controls that should be
considered for eliminating hazardous exposures.
Anticipation
Evaluation
Control
Recognition
- Engineering Controls
- Administrative Controls
- PPE
52ANTICIPATION
- 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
53ANTICIPATION
- Physical States of Matter
- Solid
- Liquid
- Gas
54ANTICIPATION
- 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.
55ANTICIPATION
- 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
56ANTICIPATION
- 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?
57ANTICIPATION
- 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?
58ANTICIPATION
- Vapor Density
- Hydrogen Gas 0.07
- Air 1.0
- Gasoline Vapor 3.5
Rises
Sinks
59ANTICIPATION
- Liquids
- Can evaporate to form toxic, corrosive and/or
flammable vapors!
60ANTICIPATION
- 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
61ANTICIPATION
- What can you Anticipate", in general, what will
happen to the vapors of liquid - On a hot, sunny day vs. a cold, cloudy day
62ANTICIPATION
- Solids
- Includes powders, smoke, mists, aerosols, fumes
and dusts. - Can be toxic and corrosive
- Can be combustible and flammable
63ANTICIPATION
- If the product is solid, it may be crystalline,
granular, powdery, etc. If the product is
liquid, it may be viscous, gelatinous, oily, etc.
64ANTICIPATION
- Dusts
- Behave like gases
- Smaller particles easily inhaled and stay
airborne longer. - Watch for ignition sources
65ANTICIPATION
- 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
66ANTICIPATION
- 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.
67ANTICIPATION
- 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
68ANTICIPATION
- 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
69ANTICIPATION
- Radioactivity
- Source materials - substances that emit ionizing
radiation (like plutonium)
70ANTICIPATION
- 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
71ANTICIPATION
- 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
72ANTICIPATION
- Liquid nitrogen
- Cryogenic liquid-300 F
- Can cause frostbite on
contact - Rapidly expands causing
oxygen deficient atmosphere
73ANTICIPATION
- 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
74ANTICIPATION
- 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.
75ANTICIPATION
- Combustible Liquids
- Flashpoint of at least 100 0 F, but less than
2000 F - DOT - flashpoint less than 1400 F
- Examples - diesel fuel, kerosene
76ANTICIPATION
- Flammable Liquids
- Flashpoint less than 1000 F
- DOT definition less than 1400 F
77ANTICIPATION
- Fire Triangle
- Need all three sides to have a fire
- Remove any one side - no fire occurs
- Chemical chain reaction - a fourth element?
78ANTICIPATION
- 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)
79ANTICIPATION
- 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.
80ANTICIPATION
- 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
81ANTICIPATION
- 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
82ANTICIPATION
- Chemical Compatibility
- When two or more chemicals can remain in contact
indefinitely without reaction, they are
compatible. - Incompatibility may not always produce a hazard.
83ANTICIPATION
- 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.
84ANTICIPATION
- Preventing incompatible chemicals from contact
with each other is key - Store like materials together
- Consider
- Storage
- Handling
- Use
85ANTICIPATION
- Biohazards
- Includes bacteria, viruses, parasites, insects
and animal droppings - Bloodborne Pathogens
- Exposure can result in disease transmission
86ANTICIPATION
- 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.
87ANTICIPATION
88RECOGNITION
- 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
89RECOGNITION
- 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.
90RECOGNITION
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
91RECOGNITION
- Stressor Properties
- Ask yourself
- Is there an exposure limit?
- If the answer is YES then continue.
92RECOGNITION
- 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
93RECOGNITION
- 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
94RECOGNITION
- 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).
95RECOGNITION
- 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?
96RECOGNITION
- 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.
97RECOGNITION
- 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.
98RECOGNITION
- 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.
99RECOGNITION
- Risk Factors
- Ask yourself
- Will the work involve exposure to physical
agents? - Noise
- Radiation
- Heat
- Cold
100RECOGNITION
- 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
101RECOGNITION
- 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
102RECOGNITION
- 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
103RECOGNITION
- There are times that you can smell odors at
concentrations many times lower than an exposure
limit.
104RECOGNITION
- 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
105RECOGNITION
Selected Odor Thresholds
To be used as guidelines only. Are subjective and
differ from person to person.
106RECOGNITION
- 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.
107RECOGNITION
- 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?
108RECOGNITION
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?
109RECOGNITION
- 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
110EVALUATION
- 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
111EVALUATION
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
112EVALUATION
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
113EVALUATION
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
114EVALUATION
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
115EVALUATION
WHEN Sampling can be representative of a very
short period of time or of a typical work day.
116EVALUATION
HOW Will the sampling be collected?
117EVALUATION
HOW Will the sampling be collected?
118EVALUATION
HOW Will the sampling be collected?
119EVALUATION
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.
120EVALUATION
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.
121EVALUATION
The results of all exposure monitoring should be
documented and communicated to affected persons.
122EVALUATION
- Direct-Reading Instruments
- Multi-Gas Detector
- Combustible Gas Meter
- Percent Oxygen
- Carbon Monoxide
- Hydrogen Sulfide
123EVALUATION
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.
124EVALUATION
- 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?)
125EVALUATION
- 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
126EVALUATION
- 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
127EVALUATION
- 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
128EVALUATION
- 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
129EVALUATION
- 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
130EVALUATION
- Process Analyzers - HNU
- In 1974, the first commercial photoionization
instrument (PID) was introduced by HNU Systems,
Inc
131EVALUATION
- 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
132CONTROLS
- 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
133CONTROLS
Engineering controls remove or isolate the hazard.
- Design and redesign
- Substitution
- Isolation
- Enclosure
- Ventilation
134(No Transcript)
135CONTROLS
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
136CONTROLS
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
137CONTROLS
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
138SUMMARY
- 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.