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

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

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

Health Risk Very High High Exposure Medium Low Toxicity

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

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

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

“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

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

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

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

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

“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

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

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

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.

SEG Concept Workforce SEG Environmental Agents Workplace

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)

Initial Exposure Rating Inputs QUALITATIVE QUANTITATIVE DATA DATA EXPOSURE ASSESSMENT

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

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

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

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

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

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

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

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