HAZWOPER 40 Final Exam (2026/2027 Update)
Hazardous Waste Operations & Emergency Response |
OSHA-Compliant Certification Exam
Q1: A Site Supervisor arrives at a former industrial property to begin preliminary site
assessment. The area contains abandoned drums with deteriorated labels, visible soil
staining, and a strong solvent odor. According to 29 CFR 1910.120, what is the first
required action before any personnel enter the site?
A. Collect soil samples for laboratory analysis to identify contaminants
B. Conduct a preliminary site evaluation and implement appropriate site control
measures [CORRECT]
C. Don Level A PPE and begin drum characterization immediately
D. Contact the EPA Regional Office for emergency response authorization
Correct Answer: B
Rationale: B is correct. [CORRECT] 29 CFR 1910.120(c)(1) requires that site
characterization and analysis be performed before site entry to identify specific hazards
and determine appropriate safety and health control measures. The preliminary
evaluation must assess potential conditions that may pose inhalation or skin absorption
hazards, and establish site control measures including the site map, work zones, and
communication protocols. Why A is wrong: Sampling cannot occur safely without first
establishing site control and hazard recognition procedures. Why C is wrong: Level A
PPE selection requires knowledge of specific hazards; premature entry without site
evaluation violates the hierarchy of controls and may expose workers to unknown risks.
Why D is wrong: EPA notification is required for reportable quantity releases, but the
immediate priority is worker safety through proper site evaluation and control.
,Q2: During air monitoring at a hazardous waste site, a four-gas meter displays the
following readings: Oxygen 19.5%, LEL 15%, H₂S 8 ppm, CO 25 ppm. The site Safety and
Health Plan specifies work can proceed only when O₂ is 19.5-23.5%, LEL <10%, and no
toxic exposures exceed PELs (H₂S PEL 10 ppm, CO PEL 50 ppm). What is the
appropriate immediate action?
A. Continue work with increased ventilation and continuous monitoring
B. Evacuate personnel immediately and re-evaluate the work plan [CORRECT]
C. Switch to supplied-air respirators and continue operations
D. Document the readings and continue with 15-minute monitoring intervals
Correct Answer: B
Rationale: B is correct. [CORRECT] 29 CFR 1910.120(h)(1)(i) requires that atmospheric
monitoring be performed to identify and quantify airborne levels of hazardous
substances. The LEL reading of 15% exceeds the established 10% action level in the
SSHP, indicating a potentially explosive atmosphere. 1910.120(h)(2) mandates that
work be restricted when flammable atmospheres exceed 10% LEL. Immediate
evacuation is required because: (1) explosion risk is imminent, (2) the SSHP action level
has been triggered, and (3) the permit-required confined space or hazardous
atmosphere protocols must be activated. Why A is wrong: Ventilation in a 15% LEL
environment may increase explosion risk through static electricity or equipment
sparking. Why C is wrong: Respiratory protection does not address the explosive hazard;
PPE is never a substitute for engineering controls in flammable atmospheres. Why D is
wrong: Documentation does not mitigate immediate life-threatening hazards.
Q3: A Hazardous Materials Technician is selecting PPE for a task involving direct
contact with liquid benzene (known human carcinogen, skin permeant) with potential
,for splash and vapor exposure. Benzene vapor concentration is estimated at 50 ppm
(PEL 1 ppm, IDLH 500 ppm). Which PPE level is minimum required?
A. Level D with chemical-resistant apron and organic vapor cartridge respirator
B. Level C with full-facepiece air-purifying respirator and chemical-resistant clothing
C. Level B with positive-pressure SCBA and fully encapsulating chemical-resistant suit
[CORRECT]
D. Level A with positive-pressure SCBA and totally encapsulating chemical-protective
suit
Correct Answer: C
Rationale: C is correct. [CORRECT] 29 CFR 1910.120(g)(3) and Appendix B establish
PPE selection criteria. Level B is required when: (1) highest level of respiratory
protection (SCBA) is needed due to unknown or IDLH potential, AND (2) lesser level of
skin protection is acceptable because the primary hazard is respiratory with potential
liquid splash (not gas-tight environment). Benzene is a skin permeant carcinogen
requiring chemical-resistant clothing, but the vapor concentration (50 ppm, below IDLH)
and splash potential indicate Level B is sufficient. Level A is reserved for unknown
concentrations or gases/vapors that are harmful to skin. Why A is wrong: Level D
provides no respiratory protection; benzene requires respiratory protection at 50 ppm.
Why B is wrong: Level C APRs are prohibited when skin absorption potential exists for
carcinogens, and concentration approaches or exceeds 10×PEL. Why D is wrong: Level
A is excessive when vapor concentration is known and below IDLH, and splash (not
immersion) is the contact hazard.
Q4: (Site Diagram Interpretation) A Site Safety Plan includes the following zone
configuration for a drum removal operation: Exclusion Zone (Hot Zone) is the immediate
drum storage area; Contamination Reduction Zone (CRZ) is a 15-foot wide corridor with
decon stations; Support Zone (Cold Zone) is the clean equipment and command post
, area. The prevailing wind is from the northwest at 5 mph. Where should the
Decontamination Line be established?
A. On the southeast boundary of the Exclusion Zone, perpendicular to wind flow
B. On the upwind (northwest) boundary of the Exclusion Zone, with CRZ between
Exclusion and Support Zones [CORRECT]
C. On the downwind (southeast) side of the Support Zone for convenience
D. Inside the Exclusion Zone adjacent to the drums to minimize worker travel
Correct Answer: B
Rationale: B is correct. [CORRECT] 29 CFR 1910.120(d)(2) requires that work zones be
established to prevent exposure migration and ensure effective decontamination. The
Decontamination Line must be positioned: (1) upwind of contamination sources to
prevent vapor intrusion into the decon process, (2) at the boundary between Exclusion
Zone and CRZ to ensure personnel are decontaminated before entering cleaner areas,
and (3) with the CRZ acting as a buffer between contaminated and clean zones. This
configuration prevents recontamination of clean personnel/equipment and follows the
clean-to-dirty progression principle. Why A is wrong: Perpendicular placement doesn't
optimize wind protection; southeast is downwind, allowing vapors to flow through
decon. Why C is wrong: Placing decon on the downwind side of the Support Zone
contaminates the clean area and violates zone integrity. Why D is wrong: Decon inside
the Exclusion Zone exposes decon personnel to continuous contamination and prevents
clean area establishment.
Q5: A worker reports symptoms of dizziness, headache, and nausea after 3 hours of
work inside Level B PPE. The ambient temperature is 85°F with 80% humidity. Vital
signs: HR 110, BP 140/90, T 101.2°F oral. What is the most likely diagnosis and
immediate action?
Hazardous Waste Operations & Emergency Response |
OSHA-Compliant Certification Exam
Q1: A Site Supervisor arrives at a former industrial property to begin preliminary site
assessment. The area contains abandoned drums with deteriorated labels, visible soil
staining, and a strong solvent odor. According to 29 CFR 1910.120, what is the first
required action before any personnel enter the site?
A. Collect soil samples for laboratory analysis to identify contaminants
B. Conduct a preliminary site evaluation and implement appropriate site control
measures [CORRECT]
C. Don Level A PPE and begin drum characterization immediately
D. Contact the EPA Regional Office for emergency response authorization
Correct Answer: B
Rationale: B is correct. [CORRECT] 29 CFR 1910.120(c)(1) requires that site
characterization and analysis be performed before site entry to identify specific hazards
and determine appropriate safety and health control measures. The preliminary
evaluation must assess potential conditions that may pose inhalation or skin absorption
hazards, and establish site control measures including the site map, work zones, and
communication protocols. Why A is wrong: Sampling cannot occur safely without first
establishing site control and hazard recognition procedures. Why C is wrong: Level A
PPE selection requires knowledge of specific hazards; premature entry without site
evaluation violates the hierarchy of controls and may expose workers to unknown risks.
Why D is wrong: EPA notification is required for reportable quantity releases, but the
immediate priority is worker safety through proper site evaluation and control.
,Q2: During air monitoring at a hazardous waste site, a four-gas meter displays the
following readings: Oxygen 19.5%, LEL 15%, H₂S 8 ppm, CO 25 ppm. The site Safety and
Health Plan specifies work can proceed only when O₂ is 19.5-23.5%, LEL <10%, and no
toxic exposures exceed PELs (H₂S PEL 10 ppm, CO PEL 50 ppm). What is the
appropriate immediate action?
A. Continue work with increased ventilation and continuous monitoring
B. Evacuate personnel immediately and re-evaluate the work plan [CORRECT]
C. Switch to supplied-air respirators and continue operations
D. Document the readings and continue with 15-minute monitoring intervals
Correct Answer: B
Rationale: B is correct. [CORRECT] 29 CFR 1910.120(h)(1)(i) requires that atmospheric
monitoring be performed to identify and quantify airborne levels of hazardous
substances. The LEL reading of 15% exceeds the established 10% action level in the
SSHP, indicating a potentially explosive atmosphere. 1910.120(h)(2) mandates that
work be restricted when flammable atmospheres exceed 10% LEL. Immediate
evacuation is required because: (1) explosion risk is imminent, (2) the SSHP action level
has been triggered, and (3) the permit-required confined space or hazardous
atmosphere protocols must be activated. Why A is wrong: Ventilation in a 15% LEL
environment may increase explosion risk through static electricity or equipment
sparking. Why C is wrong: Respiratory protection does not address the explosive hazard;
PPE is never a substitute for engineering controls in flammable atmospheres. Why D is
wrong: Documentation does not mitigate immediate life-threatening hazards.
Q3: A Hazardous Materials Technician is selecting PPE for a task involving direct
contact with liquid benzene (known human carcinogen, skin permeant) with potential
,for splash and vapor exposure. Benzene vapor concentration is estimated at 50 ppm
(PEL 1 ppm, IDLH 500 ppm). Which PPE level is minimum required?
A. Level D with chemical-resistant apron and organic vapor cartridge respirator
B. Level C with full-facepiece air-purifying respirator and chemical-resistant clothing
C. Level B with positive-pressure SCBA and fully encapsulating chemical-resistant suit
[CORRECT]
D. Level A with positive-pressure SCBA and totally encapsulating chemical-protective
suit
Correct Answer: C
Rationale: C is correct. [CORRECT] 29 CFR 1910.120(g)(3) and Appendix B establish
PPE selection criteria. Level B is required when: (1) highest level of respiratory
protection (SCBA) is needed due to unknown or IDLH potential, AND (2) lesser level of
skin protection is acceptable because the primary hazard is respiratory with potential
liquid splash (not gas-tight environment). Benzene is a skin permeant carcinogen
requiring chemical-resistant clothing, but the vapor concentration (50 ppm, below IDLH)
and splash potential indicate Level B is sufficient. Level A is reserved for unknown
concentrations or gases/vapors that are harmful to skin. Why A is wrong: Level D
provides no respiratory protection; benzene requires respiratory protection at 50 ppm.
Why B is wrong: Level C APRs are prohibited when skin absorption potential exists for
carcinogens, and concentration approaches or exceeds 10×PEL. Why D is wrong: Level
A is excessive when vapor concentration is known and below IDLH, and splash (not
immersion) is the contact hazard.
Q4: (Site Diagram Interpretation) A Site Safety Plan includes the following zone
configuration for a drum removal operation: Exclusion Zone (Hot Zone) is the immediate
drum storage area; Contamination Reduction Zone (CRZ) is a 15-foot wide corridor with
decon stations; Support Zone (Cold Zone) is the clean equipment and command post
, area. The prevailing wind is from the northwest at 5 mph. Where should the
Decontamination Line be established?
A. On the southeast boundary of the Exclusion Zone, perpendicular to wind flow
B. On the upwind (northwest) boundary of the Exclusion Zone, with CRZ between
Exclusion and Support Zones [CORRECT]
C. On the downwind (southeast) side of the Support Zone for convenience
D. Inside the Exclusion Zone adjacent to the drums to minimize worker travel
Correct Answer: B
Rationale: B is correct. [CORRECT] 29 CFR 1910.120(d)(2) requires that work zones be
established to prevent exposure migration and ensure effective decontamination. The
Decontamination Line must be positioned: (1) upwind of contamination sources to
prevent vapor intrusion into the decon process, (2) at the boundary between Exclusion
Zone and CRZ to ensure personnel are decontaminated before entering cleaner areas,
and (3) with the CRZ acting as a buffer between contaminated and clean zones. This
configuration prevents recontamination of clean personnel/equipment and follows the
clean-to-dirty progression principle. Why A is wrong: Perpendicular placement doesn't
optimize wind protection; southeast is downwind, allowing vapors to flow through
decon. Why C is wrong: Placing decon on the downwind side of the Support Zone
contaminates the clean area and violates zone integrity. Why D is wrong: Decon inside
the Exclusion Zone exposes decon personnel to continuous contamination and prevents
clean area establishment.
Q5: A worker reports symptoms of dizziness, headache, and nausea after 3 hours of
work inside Level B PPE. The ambient temperature is 85°F with 80% humidity. Vital
signs: HR 110, BP 140/90, T 101.2°F oral. What is the most likely diagnosis and
immediate action?
