1. Using A Comprehensive Exposure Assessment Strategy to Assess Workplace Health Risks
Elizabeth L. Pullen, CIH
APOSHO 26 & Australasian
Safety Conference 2011

2. What is Industrial Hygiene?
Industrial hygiene is a process for managing the health risks associated with workplace exposures to chemical, physical, and biological agents

3. 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

4. Health Risk
Very
High
High
Exposure
Medium
Low
Toxicity

5. Comprehensive Strategy
Why?
Exposures occur whether we’re 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

6. 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

7. Hazardous Materials Management and Procurement
Exposure Assessment is the Core Activity
Hazardous Materials Management and Procurement
Exposure Monitoring
Personal Protective Equipment
Medical Surveillance
Hearing Conservation
Exposure
Risk
Assessment
& Management
(ERAM)
Education And Training
Engineering Controls
Hazard Communication
Work Practice Controls
Compliance
Administrative Controls
Epidemiology
Environmental

8. “A Strategy for Assessing and Managing Occupational Exposures”,
AIHA’s Exposure Risk
Assessment & Management Strategy
Start
Basic Characterization
Exposure Assessment
Uncertain
Implement Controls
Reassessment
Further Information Gathering
Unacceptable Exposure
Acceptable Exposure
“A Strategy for Assessing and Managing Occupational Exposures”,
3rd edition

9. Exposure Assessment Strategy
Reflects iterative “continuous improvement cycle” or real-world assessment programs
Assessment include a combination of qualitative and quantitative information

10. Exposure Assessment The process of: defining exposure profiles and
judging the acceptability
of workplace exposures to environmental agents

11. 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

12. Exposure Assessment Strategy
Control measures
Ventilation, Enclosures, PPE
Re-assessment
Communication and documentation
Implementation

13. “A Strategy for Assessing and Managing Occupational Exposures”,
AIHA’s Exposure Risk
Assessment & Management Strategy
Start
Basic Characterization
Exposure Assessment
Uncertain
Implement Controls
Reassessment
Further Information Gathering
Unacceptable Exposure
Acceptable Exposure
“A Strategy for Assessing and Managing Occupational Exposures”,
3rd edition

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

15. 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

16. 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.

17. SEG Concept
Workforce
SEG
Environmental
Agents
Workplace

18. 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)

19. Initial Exposure Rating Inputs
QUALITATIVE
QUANTITATIVE
DATA
DATA
EXPOSURE ASSESSMENT

20. 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

21. Exposure Rating (ER) Rating % OEL Description 4 >100
Poorly controlled 3
50 – 100
Controlled 2
10 – 50
Well controlled 1
<10
Highly controlled
Choice of schemes should depend on how OELs are defined and applied.
AIHce 2009 – PDC #706 21

22. Exposure Assessment Exposure assessment is a judgment
Acceptable health risk
Uncertain health risk
Unacceptable health risk

23. SEG Exposure Control Category Follow-up
Exposure Rating**
Recommended Follow Up
/ Exposure Control
0 (<1% of OEL)
no action
1 (<10% of OEL)
general HazCom
2 (10-50% of OEL)
+ chemical specific HazCom
3 (50-100% of OEL)
+ exposure surveillance, medical surveillance, work practices
4 (>100% 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
We can use our Qualitative or Quantitative Judgments to quickly drive controls.
** - Decision statistic = 95th percentile

24. Delivering Value
Risk based prioritization and management of IH programs
Material substitution
Engineering controls
Work practice controls
Personal protective equipment
Medical surveillance

25. 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!
Start
Basic Characterization
Exposure Assessment
Uncertain
Control
Reassessment
Further Information Gathering
Unacceptable Exposure
Acceptable Exposure

26. 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 can’t do it all at once, so start the process and build on it

27. Further Information References:
“A Strategy for Assessing and Managing Occupational Exposures”, 3rd edition, AIHA Press
AIHA Exposure Assessment Strategies Committee