Decontamination: Emergency, Gross, Technical, and Mass Decon Practice Questions

25 multiple-choice questions on Decontamination: emergency, gross, technical, and mass decon for paramedic and EMT students, from Chapter 50 (Hazardous Materials). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. Under OSHA's HAZWOPER terminology, decontamination is defined as:

   1. A. Neutralizing chemicals on the skin with an opposing agent
   2. B. Removing hazardous substances to prevent foreseeable health effects
   3. C. Proving with a meter that no trace of the agent is left on a person
   4. D. Bagging contaminated clothing so it can be sent for laboratory tests
   Show answer

   Answer: B. Removing hazardous substances to prevent foreseeable health effects

   OSHA defines decon as removing hazardous substances from people and equipment to the extent needed to prevent foreseeable health effects. Neutralizing agents can cause heat injury, and a meter cannot confirm that every trace is gone.

2. Removing a contaminated patient's clothing is a key first step in decon because it:

   1. A. Removes most of the contamination, up to about 90%
   2. B. Removes a small share; washing does the real work
   3. C. Lets the agent evaporate from the skin more slowly
   4. D. Lets the hospital identify the chemical by its odor
   Show answer

   Answer: A. Removes most of the contamination, up to about 90%

   Clothing traps liquids, vapors, and particles, and disrobing removes the large majority of contamination, often cited as up to 80% to 90%. Washing then removes what remains on the skin.

3. Before the decon corridor is ready, a worker soaked with a corrosive liquid walks toward you screaming in pain. The best action is to:

   1. A. Have him wait until the decon corridor is ready
   2. B. Place him in your ambulance and irrigate en route
   3. C. Wipe the liquid off with dry towels and transport
   4. D. Perform emergency decon with the water at hand
   Show answer

   Answer: D. Perform emergency decon with the water at hand

   Emergency decon is used for life- or skin-threatening contamination when there is no time to wait: strip clothing and flush with any water available, such as a hose line. Moving him into the ambulance contaminates the crew and vehicle.

4. Gross decon is best described as the:

   1. A. Final phase, done at the receiving hospital
   2. B. Thorough multistep wash of the entry team
   3. C. First phase, removing most contamination
   4. D. Decon reserved for radioactive dust
   Show answer

   Answer: C. First phase, removing most contamination

   Gross decon is an initial, rapid step, such as disrobing and a rinse, that removes the bulk of the contaminant. Thorough multistep cleaning of entry personnel and equipment is technical decon.

5. Technical decon at a hazmat incident is mainly used for:

   1. A. Entry team members and their equipment
   2. B. Large crowds of walking contaminated people
   3. C. Patients who were exposed to a vapor
   4. D. Patients who arrive at the ED on their own
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   Answer: A. Entry team members and their equipment

   Technical decon is a planned, multistep process, chosen for the specific agent, to clean entry personnel and their PPE and tools before they leave the warm zone. Large crowds are handled by mass decon.

6. A chemical release at a stadium has contaminated hundreds of people. Fire crews set up a ladder pipe system between two engines. This is an example of:

   1. A. Technical decon for the stadium's own entry teams
   2. B. Dry decon using absorbent materials
   3. C. Definitive decon as done in the emergency room
   4. D. Mass decon with high volume, low pressure water
   Show answer

   Answer: D. Mass decon with high volume, low pressure water

   Mass decon uses fire apparatus, such as ladder pipes or fog nozzles on two engines, to create a high-volume, low-pressure shower that many people can walk through quickly. Technical decon is a slow, multistep process for entry teams and their equipment, far too slow for hundreds of people. Dry decon uses absorbent material without water, which a ladder pipe shower is not. Definitive decon is done at the hospital, not with fire engines at the scene.

7. During decon, water should be delivered at low pressure mainly because high pressure can:

   1. A. Wash it off too fast
   2. B. Drive the agent into the skin
   3. C. Dilute the soap past usefulness
   4. D. Cool the runoff below freezing
   Show answer

   Answer: B. Drive the agent into the skin

   High-pressure streams can abrade the skin and force contaminants deeper, increasing absorption, and can injure the patient. A high volume of water at low pressure rinses effectively and safely.

8. The ideal water temperature for patient decon is:

   1. A. As hot as tolerated
   2. B. Tepid or lukewarm
   3. C. Ice cold
   4. D. Room temperature or colder
   Show answer

   Answer: B. Tepid or lukewarm

   Tepid water is comfortable enough that people stay in the shower and does not cause hypothermia. Hot water dilates skin vessels and can increase absorption, while cold water risks hypothermia and poor compliance.

9. At a mass decon site, walking patients differ from nonambulatory patients in that walking patients:

   1. A. Need more staff per patient than others
   2. B. Must wait until last
   3. C. Can skip decon if they have no symptoms
   4. D. Can decon themselves with direction
   Show answer

   Answer: D. Can decon themselves with direction

   Ambulatory patients can disrobe and wash themselves while staff give instructions, so they move through decon quickly. Nonambulatory patients need hands-on help and more time and staff per patient.

10. When many contaminated people arrive at a mass decon line at once, the highest priority for decon generally goes to those who:

    1. A. Are the least injured and can move the fastest
    2. B. Were far from the release point
    3. C. Have symptoms or liquid on them
    4. D. Had vapor exposure but feel well now
    Show answer

    Answer: C. Have symptoms or liquid on them

    Mass decon triage puts first those with signs of exposure, visible liquid contamination, or exposure closest to the release, so people who were far from the release go later. People exposed only to vapor with no symptoms can wait, after removing their outer clothing. Sending the least injured first speeds the line but delays those most at risk.

11. Several office workers were exposed only to a vapor that drifted into their building. They have mild eye irritation and no liquid on their skin. Their decon needs are most likely:

    1. A. Removing outer clothing, little more
    2. B. A full head-to-toe technical decon each
    3. C. A soap scrub followed by a bleach rinse
    4. D. Eye irrigation for at least 60 minutes
    Show answer

    Answer: A. Removing outer clothing, little more

    Vapors leave little residue on the skin, so people exposed only to a gas or vapor usually need only outer clothing removed and fresh air; clothing can still off-gas. Liquids and solids are the main reason for wet decon.

12. Dry decon, which consists of disrobing and blotting the skin with absorbent material, is most appropriate when:

    1. A. The skin is covered with a strong acid or alkali
    2. B. The agent is a noncaustic liquid on the skin
    3. C. The agent is a liquid that burns on contact
    4. D. The patient's eyes are exposed to the chemical
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    Answer: B. The agent is a noncaustic liquid on the skin

    PRISM guidance treats dry decon (disrobing, then blotting and rubbing exposed skin with absorbent material) as the default for most liquid chemical exposures, because it removes most of the contaminant quickly and avoids the cold, delay, and runoff of wet decon, even when water is available. Caustic agents are the main exception: strong acids and alkalis keep burning and need prompt wet decon with large volumes of water. A liquid that burns on contact is caustic by definition. Eye exposures need water irrigation, which dry decon cannot provide. Protocols vary, and wet decon is added when symptoms persist after dry decon.

13. Decon runoff is flowing toward a storm drain while patients are being washed. The correct approach is to:

    1. A. Stop decon until the runoff can be contained
    2. B. Move the patients to wash in the storm drain
    3. C. Keep decon going; try to contain runoff
    4. D. Wash patients with less water to cut runoff
    Show answer

    Answer: C. Keep decon going; try to contain runoff

    Life safety comes before environmental protection: decon should not be delayed to contain water, though crews should try to dam or divert it when possible. Using less water makes decon less effective.

14. A contaminated patient has had only a quick rinse, and the hospital is 5 minutes away. The crew wants to leave now. Decon should be completed before transport because:

    1. A. The hospital will refuse patients who are still wet
    2. B. The rinse was of no real value
    3. C. Antidotes cannot be given until decon is done
    4. D. The patient can contaminate the crew, rig, and ED
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    Answer: D. The patient can contaminate the crew, rig, and ED

    Incomplete decon lets the agent off-gas or transfer to the crew, the ambulance, and emergency department staff, creating secondary casualties and closing the hospital. A short transport time does not remove that risk. Antidotes such as atropine can be given before decon is finished when the patient needs them. Hospitals prepare to decon arriving patients rather than refuse them, and a quick rinse does remove some of the agent, just not enough.

15. During decon, a patient's contaminated clothing and valuables should be:

    1. A. Double-bagged, sealed, and labeled
    2. B. Rinsed and returned to the patient after decon
    3. C. Placed in one large bag shared by the group
    4. D. Left in the warm zone unbagged
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    Answer: A. Double-bagged, sealed, and labeled

    Clothing and belongings are sealed in labeled bags, often double-bagged, so they do not off-gas, can be returned or examined as evidence, and are not mixed up. One shared bag mixes up belongings and loses evidence, and unbagged clothing left in the warm zone keeps off-gassing. Rinsing does not clean clothing well enough to return it safely.

16. A contaminated worker has an open laceration on his forearm. During decon, you should:

    1. A. Cover the wound tightly and wash around it later
    2. B. Flush the wound and eyes, then wash head to toe
    3. C. Wash head to toe first and leave the wound for last
    4. D. Scrub the wound with a stiff brush and some soap
    Show answer

    Answer: B. Flush the wound and eyes, then wash head to toe

    Open wounds and mucous membranes absorb chemicals quickly, so they are flushed first, then the rest of the body is washed from the head down. Covering the wound before flushing traps the agent in it.

17. During mass decon in cold weather, a family with a 4-year-old arrives at the decon line. You should:

    1. A. Separate the child so staff can decon him faster
    2. B. Skip decon for the child, who is lower risk
    3. C. Keep the child with a parent and warm him after
    4. D. Use cooler water, since children overheat
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    Answer: C. Keep the child with a parent and warm him after

    Children should stay with a caregiver during decon to reduce fear and keep the family together, and they lose heat quickly, so warm water, drying, and blankets are needed. Separating a young child from the parent causes panic and poor cooperation and risks losing track of the child. Children are at higher, not lower, risk from many agents because of their size, faster breathing, and thinner skin. Cool water speeds hypothermia, the main thermal risk for children in decon; overheating is not the concern.

18. After mass decon on a cold day, the most important step for patients leaving the decon line is to:

    1. A. Send them home to change clothing
    2. B. Triage them first, then give blankets
    3. C. Move them indoors and let them air-dry
    4. D. Dry them and give gowns or blankets
    Show answer

    Answer: D. Dry them and give gowns or blankets

    Wet, undressed patients become hypothermic quickly, so they are dried and given gowns, blankets, or a warm area before triage and treatment, not after. Air-drying, even indoors, leaves them wet and losing heat by evaporation. Sending them home lets possibly exposed people leave without evaluation.

19. Compliance with mass decon improves most when responders:

    1. A. Provide privacy and clear instructions
    2. B. Use a fast single line for everyone
    3. C. Let each person decide on clothing
    4. D. Separate families so the lines move faster
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    Answer: A. Provide privacy and clear instructions

    People are more likely to disrobe and wash when there is privacy, such as separate lines or screens, and when they understand why and how to do it. A single shared line removes privacy, and separating families makes parents and children resist. Leaving clothing to personal choice means many keep contaminated clothes on. Confusion and fear lead people to leave and go to a hospital still contaminated.

20. A nonambulatory, contaminated patient is on a backboard in the decon corridor. To decon his back, the team should:

    1. A. Log-roll him, wash his back, use a clean board
    2. B. Leave the back for the hospital to wash at a later time
    3. C. Sit him upright on the board to reach his back at once
    4. D. Pour water under the board and let it run beneath him
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    Answer: A. Log-roll him, wash his back, use a clean board

    Nonambulatory patients are washed front and back, which requires log-rolling with spinal motion precautions as needed and moving to a clean device so the old one does not recontaminate them. Water poured under the board will not clean the back.

21. After decon, a patient exposed to a volatile solvent smells of the chemical on his breath in the ambulance. This means:

    1. A. The decon failed and must be repeated at once
    2. B. He may still off-gas; ventilate the unit
    3. C. The solvent was not volatile, so there is no risk
    4. D. His skin is still covered and he needs dry decon
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    Answer: B. He may still off-gas; ventilate the unit

    Patients who inhaled or absorbed a volatile agent can exhale it after skin decon, so crews should open vents or windows and use the exhaust fan. This is not a decon failure; it is a reason to keep ventilating.

22. A contaminated patient's sweatshirt is soaked with a liquid pesticide. The best way to remove it is to:

    1. A. Pull it off over the head quickly to save time
    2. B. Leave it on and rinse it with water first
    3. C. Rinse the face first, then pull it off overhead
    4. D. Cut it off rather than pull it over the head
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    Answer: D. Cut it off rather than pull it over the head

    Disrobing removes most of the contamination, and it should come before any washing. A garment that would have to be pulled over the head is cut off instead, so the soaked fabric is not dragged across the face, eyes, nose, and mouth, where the agent is absorbed or inhaled most easily. Pulling it over the head, even quickly, wipes the agent across those membranes. Rinsing the clothed patient first spreads the agent onto more skin and delays the step that removes most of it. Rinsing the face and then pulling the shirt over it simply recontaminates the face.

23. In a technical decon line, the entry team member's PPE is removed:

    1. A. Before entering the corridor, so the suit stays clean
    2. B. In the cold zone, once the rehab area is reached
    3. C. After the suit is washed and rinsed in the corridor
    4. D. In the hot zone, right after the work is complete
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    Answer: C. After the suit is washed and rinsed in the corridor

    The outside of the suit is washed and rinsed first, then the suit and SCBA are removed by the decon team, often with a final personal shower, so contamination does not reach the wearer or cold zone. Removing the suit in the hot zone would expose the wearer.

24. During decon of a patient who is not breathing adequately, the decon team in the warm zone can:

    1. A. Start an IV and give fluid boluses during decon
    2. B. Open the airway and control severe bleeding
    3. C. Intubate the patient before beginning the wash
    4. D. Hold care until decon is completed
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    Answer: B. Open the airway and control severe bleeding

    Simple life-saving steps, such as opening the airway, controlling major bleeding, and giving antidote auto-injectors, may be done in the warm zone by trained personnel in PPE. Advanced procedures such as IVs and intubation are hard to do in PPE and usually wait for the cold zone.

25. At the entry to a technical decon corridor, an entry team member should first:

    1. A. Remove the face piece
    2. B. Take off the outer gloves by hand
    3. C. Leave tools at the tool drop
    4. D. Step into the final personal shower
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    Answer: C. Leave tools at the tool drop

    The tool drop lets entrants leave contaminated tools at the start of the corridor so their hands are free for the decon steps and tools can be reused in the hot zone. Removing the SCBA face piece at the start risks inhaling the agent.