Using A Comprehensive Exposure Assessment Strategy to Assess Workplace Health Risks

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Using A Comprehensive Exposure Assessment
Strategy to Assess Workplace Health Risks

• Elizabeth L. Pullen, CIH
• APOSHO 26 Australasian
• Safety Conference 2011

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What is Industrial Hygiene?

• Industrial hygiene is a process for managing the
  health risks associated with workplace exposures
  to chemical, physical, and biological agents

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What is the process for managing workplace
exposures?

• Assess and prioritize ALL exposures into
  exposure control categories to focus resources
  on highest risks.
• Differentiate acceptable from unacceptable
  exposures
• Control unacceptable exposures

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Health Risk
Very
High
High
Exposure
Medium
Low
Toxicity
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Comprehensive Strategy

• Why?
• Exposures occur whether were there or not!
• A comprehensive strategy best manages risk and
  resources
• Comprehensive strategy
• Directed at assessing all exposures for all
  workers on all days
• Transparent system provides foundation for
  feedback into Professional Judgment.
• Helps prevent occupational illnesses

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Outcomes of Comprehensive Exposure Assessment
Management

• An assessment of the potential health risks faced
  by all workers
• Assurance that exposure controls are properly
  identified and utilized
• Demonstration of compliance with government and
  exposure guidelines
• The establishment of a historical record of
  exposure for all records
• Efficient and effective allocation of time and
  resources

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Exposure Assessment is the Core Activity
Hazardous Materials Management and Procurement
Exposure Monitoring
Personal Protective Equipment
Hearing Conservation
Medical Surveillance
Exposure Risk Assessment Management (ERAM)
Engineering Controls
Education And Training
Hazard Communication
Work Practice Controls
Compliance
Administrative Controls
Epidemiology
Environmental
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AIHAs Exposure Risk Assessment Management
Strategy
A Strategy for Assessing and Managing
Occupational Exposures, 3rd edition
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Exposure Assessment Strategy

• Reflects iterative continuous improvement cycle
  or real-world assessment programs
• Assessment include a combination of qualitative
  and quantitative information

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Exposure Assessment

• The process of
• defining exposure profiles
• and
• judging the acceptability
• of workplace exposures to environmental agents

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Exposure Assessment Strategy 7 Steps

• Basic Characterization
• Exposure Assessment
• Define similar exposure groups (SEGs)
• Define the exposure profile
• Judge acceptability of the profile for each SEG
• Further information gathering

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Exposure Assessment Strategy

• Control measures
• Ventilation, Enclosures, PPE
• Re-assessment
• Communication and documentation
• Implementation

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AIHAs Exposure Risk Assessment Management
Strategy
A Strategy for Assessing and Managing
Occupational Exposures, 3rd edition
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Basic Characterization

• Collect and organize information on the
• Workplace
• Processes, equipment, controls
• Workforce
• Jobs, tasks, personnel, shiftwork
• Environmental Agents
• Chemical, physical, biological, radiological

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Exposure Assessment
Establish Similar Exposure Groups
Define Exposure Profile
Select/Define OELs
Compare
Exposure Profile and its Uncertainty
OEL and its Uncertainty
Acceptable
Uncertain
Unacceptable
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Similar Exposure Group

• SEG a group of employees having
• the same general exposure profile because of the
  similarity and frequency of the tasks they
  perform,
• the similarity of the materials and processes
  with which they work,
• and the similarity in the way they perform the
  tasks.

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SEG Concept
Workforce
SEG
Workplace
Environmental Agents
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Establishing Exposure Limits

• Occupational Exposure Limits (OELs)
• Different Sources
• Regulatory OEL
• Authoritative OEL
• Internal OEL
• Working OEL
• Different Endpoints
• Local, Systemic, Acute, Chronic
• Averaging Time
• STEL, Ceiling, TWA, Excursion
• Inhalation, Dermal (REACH DNEL)

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Initial Exposure Rating Inputs
QUALITATIVE
QUANTITATIVE
DATA
DATA
EXPOSURE ASSESSMENT
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Initial Exposure Assessments

• May use worst-case assumption and then compare
  the overestimate to the OEL, which will account
  for the uncertainty
• May separate out acceptable and unacceptable
  exposures, to focus on uncertain exposures

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Exposure Rating (ER)
Rating OEL Description
4 gt100 Poorly controlled
3 50 100 Controlled
2 10 50 Well controlled
1 lt10 Highly controlled
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Exposure Assessment

• Exposure assessment is a judgment
• Acceptable health risk
• Uncertain health risk
• Unacceptable health risk

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SEG Exposure Control Category Follow-up
Exposure Rating Recommended Follow Up / Exposure Control
0 (lt1 of OEL) no action
1 (lt10 of OEL) general HazCom
2 (10-50 of OEL) chemical specific HazCom
3 (50-100 of OEL) exposure surveillance, medical surveillance, work practices
4 (gt100 of OEL) respirators engineering controls, work practice controls
5 (Multiples of OEL e.g., based on respirator APFs) immediate engineering controls or process shutdown, validate respirator selection
- Decision statistic 95th percentile
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Delivering Value

• Risk based prioritization and
  management of IH programs
• Material substitution
• Engineering controls
• Work practice controls
• Personal protective equipment
• Medical surveillance

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Exposure Assessments

• This is a cyclical process
• Initial assessment is usually based more on
  judgment and less on quantitative data
• It may have a higher degree of uncertainty
• Note Spreadsheets are good tools for managing
  Basic Characterization and Initial Exposure
  Assessments!

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Continuous Improvement

• Make opportunities to verify and refine
  initial exposure assessments
• Each re-evaluation will build upon
  information collected and documented
  in past assessments
• We cant do it all at once, so start the process
  and build on it

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Further Information

• References
• A Strategy for Assessing and Managing
  Occupational Exposures, 3rd edition, AIHA Press
• AIHA Exposure Assessment Strategies Committee
• www.aiha.org