Toxicology and Biohazards Flashcards
7 cards from real COHN practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Toxicology and Biohazards flashcards as text
Which route of exposure is the MOST common pathway for occupational chemical poisoning?
Answer: Inhalation
Inhalation is the most common occupational exposure route because workers breathe contaminated air continuously, providing direct access to the large surface area of the lungs.
A healthcare worker receives a needlestick injury from a patient with unknown HIV status. According to CDC guidelines, post-exposure prophylaxis (PEP) should be initiated within:
Answer: 72 hours
CDC guidelines recommend initiating HIV PEP as soon as possible, ideally within hours of exposure, but no later than 72 hours for maximum effectiveness.
Hydrogen sulfide (H₂S) is particularly dangerous because at high concentrations it:
Answer: Paralyzes the olfactory nerve, eliminating the warning odor
At high concentrations, H₂S rapidly paralyzes the olfactory nerve so workers lose the rotten-egg warning odor and can be overcome without realizing the danger.
The concept of 'skin notation' (Sk) on a chemical's TLV indicates that:
Answer: Significant absorption through intact skin can contribute to total body burden
Skin notation alerts occupational health professionals that dermal absorption of the chemical can be significant enough to add to systemic toxicity, even when air levels are controlled.
A construction worker is found unconscious in a confined space where fuel combustion equipment was used. The FIRST priority action is:
Answer: Put on supplied-air SCBA before entering to rescue
Confined space rescuers must use supplied-air SCBA because entering without respiratory protection leads to multiple fatalities — the majority of confined space deaths are untrained would-be rescuers.
Which biological monitoring specimen is BEST for assessing recent (within 24-48 hours) organic solvent exposure?
Answer: End-exhaled breath or urine sample
End-exhaled breath captures volatile organic solvents directly, and urine collected at end of shift detects rapidly-cleared metabolites that reflect recent exposure.
Under SARA Title III, what is the primary purpose of Tier II chemical inventory reporting?
Answer: To inform local emergency planners and fire departments about hazardous chemical storage
SARA Title III Tier II reports notify local emergency planning committees (LEPCs) and fire departments about hazardous chemicals stored on-site to facilitate emergency response planning.