Transcript Industrial Hygiene - Western Carolina University

Industrial Hygiene
HSCC 300
Readings:
Nims IH
Friend Kohn Chapter 5
Evaluate and Control Hazards
Overview
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Recognition in Industrial Hygiene
Classification of Hazards
Routes of Exposure
Types of Exposures
Types of Air Contaminants
Exposure Limits
Control of Hazards
Walk Through Survey
Industrial Hygiene
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“that science or art devoted to the
anticipation, recognition, evaluation, and
control of those environmental factors or
stresses, arising in or from the
workplace, that may cause sickness,
impaired health and well-being, or
significant discomfort and inefficiency
among workers”
Recognition
Purpose
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Identify potential health hazards in
the workplace
Most critical step
How To Recognize
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Be curious
Ask questions
Know what is used
Know where it is used
Know how it is used
Know who is near it
Apply the IH fundamentals
Classification of Workplace
Hazards
 Biological
 Chemical
 Physical
 Radiological
Biological (biohazards)
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Divided into various classifications – based upon
potential to cause disease
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Divided into types of organisms
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Class I through Class IV
Bacterial Agents
Viral Agents
Rickettsial and Chlamydial Agents
Fungal Agents
Parasitic Agents
Recognition and control is complex and inexact
Physical Hazards
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Radiological
Noise
Thermal
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Heat stress
Cold stress
Vibration
General – sharp objects, fire hazards,
oxygen displacement, explosion hazards
Chemical
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Divided into physical properties:
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Divided into how they get into the body
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Routes of entry
Divided into type of chemical
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Mists, smoke, vapor, gases, fumes,
aerosols
Inorganic – Organic
Natural – Manmade
Divided into Hazard
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Corrosive, Explosive, Reactive, Toxic
Routes of Entry
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Inhalation
Absorption
Ingestion
Injection
Types of Exposure
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Acute
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Chronic
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Short term period between exposure and onset
of symptoms
Long time period between exposure to an agent
and the onset of symptoms
Identify
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Source
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Path
Types of Air Contaminants
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Particulates
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dusts, fumes, mists, and fibers
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non respirable particles
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> 10 m in diameter
respirable particles
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< 10 m in diameter
Types of Air Contaminants
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Fumes
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volatilized solids condenses in cool air
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< 1.0 m in diameter
hot vapor + air (reaction with) = oxide
Mists
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suspended solid droplets
generated by a condensation of liquids from
a vapors to a liquid state
Types of Air Contaminants
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Fibers
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Gases
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solid, slender, elongated structures
length several times the diameter
formless fluids that expand to occupy a
space
Vapors
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liquid changed to vapor, organic solvents
Units of Concentration
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ppm
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mg/m3
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milligrams per cubic meter
mppcf
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parts per million
millions or a particle per cubic foot
f/cc
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fibers per cubic centimeter
Exposure Limits
Air Contaminants
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OSHA
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NIOSH
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Occupational Safety and Health
Administration
National Institute of Occupational Safety and
Health
ACGIH
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American Conference of Governmental
Industrial Hygienists
Exposure Limits
Air Contaminants
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OSHA
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PEL
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NIOSH
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REL
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permissible exposure limit
recommended exposure level
ACGIH
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TLV
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threshold limit value
Exposure Limits
Air Contaminants
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OSHA
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NIOSH
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PEL, STEL, Ceiling
TWA, STEL, Ceiling
ACGIH
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TWA, STEL, Ceiling
Exposure Limits Air Contaminants
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TWA
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STEL
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takes into account variable exposure through a full
shift, 8 hour work day
limit of exposure during a short period, 15 minutes
CEILING
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absolute maximum level of exposure not to be
exceeded
Exposure Limits
Air Contaminants
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Legally enforceable
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OSHA PEL
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OSHA AL (action level)
Air Contaminants
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29 CFR 1910.1000
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Table Z-1
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Table Z-2
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Substances with Limits Preceded by “C” - Ceiling
Values
http://www.osha.gov/pls/oshaweb/owadisp.show_
document?p_table=STANDARDS&p_id=9992
employee’s exposure to Table Z-1 contaminants
shall not exceed exposure limits listed in Z-2 (TWA
and ceiling concentrations)
Table Z-3
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Mineral Dusts
Control of Chemical Hazards Hierarchy
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Engineering Controls
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Administrative Controls
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Exhaust ventilation
Substitution for a less hazardous component
Elimination or reduction of employee exposure
Isolation of hazard
Reducing the amount of time an employee is permitted to be
exposed
Personal Protective Equipment
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Gloves, eye protection, respiratory equipment, etc.
Walk Through Survey Outcome
Competencies
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Recognize potential health problems during
a walk-through survey
Make intelligent evaluations of the severity
of the hazards
Determine requirements for follow-up
investigation or controls.
Identify in depth the health hazards
associated with major industrial substances
Develop problem solving skills involving
chemical hazards
WORKPLACE INVENTORY
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Previous correspondence
Plant contacts ( interview supervisors,
and human relations) to gather
information
General process information
Size of the plant
Potentially hazardous operation/work
areas
WALK THROUGH SURVEY
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Familiarity with the plan processes
Process chemicals and materials
Worker activities
Existing controls of employee exposures
An important part of the process of
protecting workers' health
Failure to recognize a problem at this
time will allow the problem to continue!
DURING WALK THROUGH
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Review the Material Safety Data Sheets
Operation explained by supervisors and
employees
Study process manuals and drawings, if
they are available
Review existing exposure data
DURING WALK THROUGH
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Identify the chemicals and other agents
to which employees could be exposed
Potential source of health hazards
(chemical, physical or biological)
Duration and frequency of the hazard
Employee comments (careful!)
DURING WALK THROUGH
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Determine employees exposed
Observe individual work practices
Understand the routine and work habits
of the employees
Account for the entire range of workday
activities of each exposed employee
DURING WALK THROUGH
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Locations of employees pertinent to the
inspection
Types of engineering controls
Use of personal protective devices
including types of respirators, ear and
eye protection, clothing
COLLECT THIS DATA
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Estimated numbers of employees to be
evaluated at each operation
General mobility of the employees
Indicate stationary or transient work
activities
Duration and frequency of cyclic work
processes
COLLECT THIS DATA
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Description of potential exposures during
each phase of work cycle
Preventive maintenance program for
engineering controls
Employer's occupational health program
Employee break and lunch habits and
location
SAMPLING EQUIPMENT
Consider the type of sampling
that would be appropriate for
the collection of exposure data
during the walk-through
SAMPLING EQUIPMENT
Routine equipment
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Detector tubes
Air sampling pumps
Direct reading instruments
Sound level meter
REASONS TO SAMPLE
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Document compliance with applicable
Federal, State, and local regulations
Investigate employee complaints
Predict the health effects of an exposure
by comparing the sampling results with
occupational exposure limits
REASONS TO SAMPLE
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Determine the effectiveness of
engineering or administrative controls
Determine if any work exposures can be
correlated to observed medical effects
Identify unsatisfactory or unsafe
conditions
REASONS TO SAMPLE
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Establish a baseline profile of employee
exposure levels
Provide a database for future
epidemiological studies
Determine whether a part of a process
(location or time) causes more exposure
Next steps….
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Make intelligent evaluations of the
severity of the hazards
Prioritize
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Hazard vs. low hanging fruit
Determine requirements for follow-up
investigation or controls.
Documentation
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What?
Where?
How long?
Why?