Susan Ripple, MS, CIH, Fellow Global Manager – Industrial Hygiene The Dow Chemical Company Midland, MI Occupational Exposure Banding and Exposure Risk Management
Topics for Discussion • Value of Occupational Exposure Bands (OEB) to supplement other authoritative OELs • Value of OEBs to the industrial hygiene process (ERAM) • OEB Framework • Exposure Risk Assessment & Management (ERAM)
Question! • How many of you are familiar with the AIHA “Exposure Assessment Strategies” for performing “qualitative exposure assessment”?
“Bread and Butter” of Industrial Hygiene • Traditional IH Definition: • Anticipate • Recognize • Evaluate • Control Hazard Assessment Risk Assessment (Qualitative or Quantitative) Risk Management
ERAM – What is it?
General Definition of Exposure Risk Assessment and Management (ERAM) • “ERAM is a concise framework to help illustrate the core skills of the industrial hygiene profession. Taken at a high level, ERAM is the anticipation, recognition, evaluation and control of chemical, physical and biological hazards to prevent illness and injury in workers, customers and communities.” • It is the science of understanding and managing human exposure risks.
Strengthen our CORE, Expand our Impact • ERAM is the core competency of IH. Owning the science of ERAM both strengthens our CORE and expands our market opportunities. • ERAM is an important skill set needed for parts of… • Sustainability • Product Stewardship • EHS Management • When we are viewed as being ERAM experts, these Allied Professions will put a higher value on our services. This creates greater need for internal and external IH Consultants
ERAM Discipline Under the Umbrella of Public Health IH Expert Level of ERAM Expertise IH Generalist EHS Generalist Affiliated Professionals
Hypothetical Amount of “ERAM Expertise” for each job type…. (illustration only) IH Expert IH Generalist EHS Generalist Affiliated Professionals
Exposure Management (Controls & Programs) Exposure risk assessment knowledge gaps HAZARD Assessment EXPOSURE Assessment <2000 OELs <2% REACH Chemicals with OELs Occupational Exposure Bands (OEBs) & Exposure Limits (OELs) Exposure Risk Assessment (modeling, monitoring, analogy) Courtesy of Elizabeth Pullen and ERAM Working Group Occupational Health Hazard Criteria & Process IH Expertise Understanding Exposure & Controls ~21,000,000 commercial-available chemicals; >107,000 REACH “Exposure Gap”
Scope of challenge to “design-out” chemical hazards • ~21,000,000 commercially available chemicals • 107,067 REACH* registrations (1-3-11) for >1000 tons production volume or those of high concern • But…only ~ 500 PELs, ~ 650 RELs, ~ 125 WEELs, ~ 650 TLVs *REACH – Registration, Evaluation, Authorization, and Restriction of Chemicals
Scope of challenge to “design-out” chemical hazards • ~21,000,000 commercially available chemicals • 107,067 REACH* registrations (1-3-11) for >1000 tons production volume or those of high concern • But…only ~ 500 PELs, ~ 650 RELs, ~ 125 WEELs, ~ 650 TLVs Missed Opportunity for ERAM *REACH – Registration, Evaluation, Authorization, and Restriction of Chemicals
The Gap . . . . . . . . . . • Hygienists prefer the more official peer-reviewed Traditional OELs, But . . . . . . . .
“You can’t always get what you want, but if you try some times you might find, you’ll get what you need” – Mick Jaeger
. . . . . . . . . . . • Occupational Exposure Bandingprovides a mechanism for the evaluation of hazard and risk to offset the misconceptions by employers and workers that a substance must be non-toxic if there is not an OEL! MIHS
‘Occupational Exposure’ vs. ‘Control’ Banding • “Hazard banding is simply the first step in the control banding process” Susan D. Ripple. The Synergist: October 2009 • “Occupational Exposure Bands” are a more appropriate description of Hazard Grouping or Hazard Banding Donna Heidel and Susan Ripple. The Synergist: April 2012 BOHS OEL-Setting Plenary
Hazard Bands = Occupational Exposure Bands (OEBs) • OEBs for a chemical provide a range of acceptable exposure levels based on expert evaluation of the dose-response relationships provided through animal testing.
OEBs simply highlight the concept of this model
Objective of “OEBs” • Develop the framework to systematically evaluate occupational hazards of chemicals without authoritative OELs (PELs, RELs, TLVs, etc.) and communicate the hazards in terms of occupational exposure bands (OEBs).
Value of Occupational Exposure Banding • Facilitates more rapid evaluation of health risk & provides guidance for many materials without OELs • Highlights areas where data are missing (highlights uncertainties) • Identifies hazards to be evaluated for elimination or substitution • Aligned with GHS for hazard communication • Supports the definition of OEL-ranges for families of materials
Project plan • Establish minimum viable dataset, including data quality requirements • Establish process and decision logic • Validate data endpoints and band cut points, process, and decision logic • Identify data sources • Develop NIOSH guidance • Educate stakeholders
Criteria • Criteria include qualitative, semi-quantitative, and quantitative data for each toxicological endpoint • Acute toxicity • Skin corrosion/irritation • Serious eye damage/eye irritation • Respiratory and skin sensitization • Germ cell mutagenicity • Carcinogenicity • Specific target organ toxicity, both single and repeated exposure • Reproductive toxicity
OSHA GHS Link • OEB toxicological endpoints are aligned with GHS classification and labeling system* • Important goal is to relate potency of each toxicological hazard-banding endpoint to GHS hazard statements and categories, when possible • Data quality is also considered
Now – A Little “Detail” to Give You Confidence in the OEB Process! MIHS
Overview of “Tier Approach” to OEBs Tier 1a—Qualitative Use GHS Hazard Phrases to identify chemicals with potential for irreversible health effects at relatively low doses (Band D-E) or remain at default Band C A B C D E Tier 1b—Semi-quantitative Use GHS Hazard Categories to assign chemicals into Bands D or E or remain at default Band C Tier 2—Quantitative Determine point of departure, factoring data availability, hierarchy, and quality to support assigning chemicals into Bands A, B, or C Tier 3—Weight of Evidence Involves integration of all available data and determining the degree of conviction of the outcome.
Framework for Decision Logic • Tier 1 a & b: GHS hazard code or statement from SDS or the preferred GHS database (Annex VI, REACH, GESTIS, etc.). Hazard category will further define Bands D and E • User: H&S generalist; may overestimate risk • Warning – negative results vs. absence of data • Tier 2: quantitative data from authoritative sources • User: skilled industrial hygienist • Tier 3: toxicological weight of evidence – determine the critical study from which a scientifically sound point of departure (POD) can be determined • User: toxicologist or experienced industrial hygienist
Tier 1 a & b Identify Bands D-E from Default Band C Chemical for OEB Need to define Band D vs. E? Remain at Band D-E no yes Authoritative OEL available? No OEB necessary yes no Review available Hazard categories Health statements available? no Band C default assigned yes E Hazard categories? yes D or E statement? Assign Band E no Band C default assigned no yes D Hazard categories? Tier 2 processto determine Band A or B yes Assign Band D Band D-E assigned
Tier I “D” vs. “E” • Using GHS hazard statements or codes (qualitative hazard banding), for most criteria, cannot separate the “D” from the “E” bands • Acute toxicity H codes: H300, H330, H310 • Sensitization H code: H334 • Germ cell mutagenicity: H340 • Carcinogenicity: H350 • Toxic to reproduction:H360f, H360d, or H360fd • STOT(RE): H372 • Using the GHS hazard category and/or a Tier II process will be required to separate D from E
Tier 1 Example 1-bromopropane • TIER 1a • Signal word: danger • H360FD: May damage fertility or the unborn child (D or E) • OSHA-GHS: Presumed human reproductive toxicant • H373: May cause damage to organs through prolonged or repeated exposure (STOT-RE-2) • H319: Causes serious eye irritation • H335: May cause respiratory irritation • H315: Causes skin irritation • H336: May cause drowsiness or dizziness TIER 1a outcome: Band D-E • TIER 1b • Hazard Category Repro 1B Tier 1b outcome: Band D: (1-10 ppm) • TLV: 10 ppm
Tier 2 (quantitative) • OEB based on point of departure (POD) at which adverse effects are observed • LD50 (oral and dermal) or LC50 (inhalation) for acute toxicity data; • RD50 (in mice) for sensory irritation; • Irritation threshold (mice, rats or human volunteers) for irritation; • NOAEL, BMDL or LOAEL for target organ systemic toxicity, developmental/reproductive toxicity; and • CSFs, IUR, TD05/TC05, NSRLs (CalEPA Prop 65) of tumorigenic doses for carcinogenicity (still being investigated)
Tier 2 Can Band A or B be considered? Tier 1 Process results in Band C Data insufficient for OEB, “C” default band Does TDS exceed threshold for minimum, quality dataset? no yes Endpoint PODs from authoritative reviews Establish OEB Score data quality and relevance TDS reflects the availability of qualitative info and/or quantitative data for each endpoint under consideration. Endpoint scores include data relevance and quality factors. TDS is the sum of the endpoint scores. Establish Total Determinant Score (TDS)
Validate • Criteria endpoints and band cut points • Process • Decision logic • Modify based on validation results
Work in progress • Finalize criteria for each band, including weight of evidence and dose-response considerations • Develop process, decision logic, and algorithms • Validate process and tools • Develop stakeholder education materials and guidance document • Identify data sources
Expected project outputs • NIOSH guidance • Overall process, including the decision logic • Tools to facilitate finding and evaluating hazard data and assign chemicals to hazard bands • Education materials for H&S professionals, managers, and workers
Occupational Exposure Bands = OEBs DRAFT MIHS
Limitations of HHB . . . . . • Hazard Bands are screening level hazard groups, often based on limited data. • One of the critical limitations to the use of Hazard Banding has been the lack of standardization of hazard phrases in MSDSs and the lack of expertise to translate those phrases into hazard groups by non-toxicologists. MIHS
More Limitations . . . • Since Hazard Banding is a preliminary attempt to categorize the relative hazards of the substance to assist OEHS personnel to assign the right controls such as ventilation and PPE, lack of the ability to categorize the hazards can seem insurmountable. MIHS
Even More Limitations . . . . . • But, where this data exists, it is helpful to compare the relative hazard risk to other more well characterized substances. • Another concern is when a substance is a solid particle or aerosol, the same dilemma exists as often exists for setting an OEL since there is rarely sufficient inhalation toxicology data for these substances. MIHS
Effective and Efficient Exposure Risk Assessment and Management “Most Effective” SUSTAINABILITY of CONTROL CERTAINTY of EXPOSURE JUDGMENT AVAILABILITY of TOXICOLOGICAL DATA Least Effective
Contact: Susan Ripple, MS, CIH Manager Industrial Hygiene Expertise Center The Dow Chemical Co. Midland, MI firstname.lastname@example.org MIHS