CHMM CHMM Risk Assessment and Hazard Analysis 2 — Questions and Answers
Question 1: In Fault Tree Analysis (FTA), what does a 'top event' represent?
- The most frequent minor incident
- The undesired event whose causes are being analyzed (Correct answer)
- The root cause at the base of the tree
- The safeguard that prevents failure
Correct answer: The undesired event whose causes are being analyzed
The top event in an FTA is the undesired outcome (such as a toxic release) from which the analyst works downward to identify contributing causes.
Question 2: OSHA's Process Safety Management (PSM) standard (29 CFR 1910.119) applies to processes containing threshold quantities of which types of substances?
- Radioactive materials only
- Highly hazardous chemicals including flammables and toxics (Correct answer)
- Any chemical exceeding 55 gallons on-site
- Chemicals listed on the RCRA F-list only
Correct answer: Highly hazardous chemicals including flammables and toxics
PSM applies to processes with threshold quantities of highly hazardous chemicals—substances with toxic, flammable, reactive, or explosive properties—listed in Appendix A.
Question 3: Which consequence modeling tool is commonly used to estimate the dispersion of a toxic gas release in the atmosphere?
- CAMEO/ALOHA (Correct answer)
- CHEMTREC database
- RCRA Waste Analysis Plan
- EPA ECHO database
Correct answer: CAMEO/ALOHA
ALOHA (Areal Locations of Hazardous Atmospheres), part of the CAMEO suite, models toxic and flammable gas dispersion to help responders and planners estimate hazard zones.
Question 4: In the context of chemical risk assessment, 'dose-response assessment' establishes what relationship?
- The route of exposure versus the chemical's persistence in soil
- The relationship between the amount of chemical exposure and the likelihood or severity of health effects (Correct answer)
- The distance a chemical travels from its release point
- The cost of medical treatment versus the severity of injury
Correct answer: The relationship between the amount of chemical exposure and the likelihood or severity of health effects
Dose-response assessment defines how increasing doses of a chemical lead to increasing probability or severity of adverse health effects in exposed populations.
Question 5: A 'bowtie' risk analysis diagram combines which two analytical methods?
- HAZOP and FMEA
- Fault Tree Analysis (left side) and Event Tree Analysis (right side) (Correct answer)
- What-If analysis and checklist review
- PHA and consequence modeling
Correct answer: Fault Tree Analysis (left side) and Event Tree Analysis (right side)
The bowtie model places the hazardous event at its center, with FTA mapping causes on the left and ETA mapping consequences/barriers on the right.
Question 6: Which EPA guidance document provides the standard framework for conducting baseline risk assessments at contaminated Superfund sites?
- EPA Risk Assessment Guidance for Superfund (RAGS) (Correct answer)
- EPA RCRA Corrective Action Plan
- EPA TSCA Chemical Risk Evaluation
- EPA Integrated Risk Information System (IRIS) manual
Correct answer: EPA Risk Assessment Guidance for Superfund (RAGS)
EPA's Risk Assessment Guidance for Superfund (RAGS) provides the methodological framework for conducting human health risk assessments at CERCLA sites.
CHMM CHMM Risk Assessment and Hazard Analysis 2
In Fault Tree Analysis (FTA), what does a 'top event' represent?