EPA LEAD INSPECTOR PRACTICE TEST
2026 CORE QUESTIONS AND ACCURATE
ANSWERS REVIEW PACK
◉ How often should you perform a leak test for XRF analyzers?
Answer: Every 6 months
◉ How much energy is required for cobalt-57 to excite an electron?
Answer: 128 keV
◉ What are the units of measurement for radiation exposure?
Answer: rad = energy per unit of mass of material rem = rad * QF
(quality factor) ... corrects for variables like the type of tissue
◉ Regulatory dose limits for radiation
Answer: - Whole body: 5 rem/year - Skin/extremities: 50 rem/year -
Declared pregnant worker: 0.5 rem/gestation period
◉ What practice is in place with respect to maintaining levels of
radiation exposure?
Answer: ALARA (As Low As Reasonably Achievable) - Minimize time
- Maximize distance - Maximize shielding
, ◉ True/False: An XRF analyzer can take accurate readings from any
surfaces
Answer: False; readings must be from flat surfaces
◉ PCS
Answer: Performance Characteristics Sheet = provides information
on how to use an XRF analyzer
◉ Who calibrates an XRF analyzer?
Answer: - The manufacturer calibrates the machine - The inspector
checks the calibration ... this is done the the start of a job, every 4
hours during the job, and at the end of a job. Involves THREE checks
... values must be filled out on a form. Positives must be between 0.8
and 1.2 mg/cm2
◉ SRM
Answer: - Standard Reference Material = mylar (homogenous) lead
coating of 1.02 mg/cm2 - Established by NIST (National Institute for
Standards and Technology)
◉ What are the possible XRF readings?
Answer: - Positive: at or greater than 1.0 mg/cm2 - Negative: less
than 1.0 mg/cm2 - Inconclusive: must take a paint chip sample or
2026 CORE QUESTIONS AND ACCURATE
ANSWERS REVIEW PACK
◉ How often should you perform a leak test for XRF analyzers?
Answer: Every 6 months
◉ How much energy is required for cobalt-57 to excite an electron?
Answer: 128 keV
◉ What are the units of measurement for radiation exposure?
Answer: rad = energy per unit of mass of material rem = rad * QF
(quality factor) ... corrects for variables like the type of tissue
◉ Regulatory dose limits for radiation
Answer: - Whole body: 5 rem/year - Skin/extremities: 50 rem/year -
Declared pregnant worker: 0.5 rem/gestation period
◉ What practice is in place with respect to maintaining levels of
radiation exposure?
Answer: ALARA (As Low As Reasonably Achievable) - Minimize time
- Maximize distance - Maximize shielding
, ◉ True/False: An XRF analyzer can take accurate readings from any
surfaces
Answer: False; readings must be from flat surfaces
◉ PCS
Answer: Performance Characteristics Sheet = provides information
on how to use an XRF analyzer
◉ Who calibrates an XRF analyzer?
Answer: - The manufacturer calibrates the machine - The inspector
checks the calibration ... this is done the the start of a job, every 4
hours during the job, and at the end of a job. Involves THREE checks
... values must be filled out on a form. Positives must be between 0.8
and 1.2 mg/cm2
◉ SRM
Answer: - Standard Reference Material = mylar (homogenous) lead
coating of 1.02 mg/cm2 - Established by NIST (National Institute for
Standards and Technology)
◉ What are the possible XRF readings?
Answer: - Positive: at or greater than 1.0 mg/cm2 - Negative: less
than 1.0 mg/cm2 - Inconclusive: must take a paint chip sample or
