Confined Space Awareness Course 2026

1. 第1题，共25题

   Which of these is part of the general definition of a confined space?

   • AIt is not built for people to stay in
   • BIt is always smaller than a car
   • CIt has no openings of any kind
   • DIt is always found below ground level
   显示答案

   答案: A. It is not built for people to stay in

   A confined space is not designed for continuous human occupancy, has limited entry or exit, and can be hazardous.

2. 第2题，共25题

   Is a confined space always small?

   • ANo, but it is always underground
   • BYes, it is smaller than a closet
   • CYes, it fits only one person
   • DNo, it can be large, like a silo
   显示答案

   答案: D. No, it can be large, like a silo

   CCOHS notes that a confined space, despite its name, is not necessarily small. Silos and tanks can be very large.

3. 第3题，共25题

   Which of these is most likely to be a confined space?

   • AA machine shop
   • BA storage tank
   • CAn office
   • DA walk-in freezer
   显示答案

   答案: B. A storage tank

   Storage tanks are confined spaces. Ontario's guideline says offices, shops and walk-in freezers are designed for occupancy.

4. 第4题，共25题

   Normal air contains about how much oxygen?

   • A30%
   • B21%
   • C15%
   • D50%
   显示答案

   答案: B. 21%

   Normal air is about 21% oxygen. Lower levels can cause collapse and death.

5. 第5题，共25题

   Under Ontario's confined spaces rules, oxygen outside which range is an atmospheric hazard?

   • A15% to 19.5%
   • B19.5% to 23%
   • C25% to 30%
   • D10% to 15%
   显示答案

   答案: B. 19.5% to 23%

   Ontario treats oxygen below 19.5% or above 23% by volume as an atmospheric hazard.

6. 第6题，共25题

   Why should you never use pure oxygen to freshen the air in a confined space?

   • AOxygen is far too costly to use this way
   • BOxygen makes the space far too cold
   • COxygen makes gas detectors stop working
   • DExtra oxygen makes fires far more likely
   显示答案

   答案: D. Extra oxygen makes fires far more likely

   Too much oxygen greatly increases the risk of fire and explosion. CCOHS says never substitute oxygen for fresh air.

7. 第7题，共25题

   Nitrogen, argon and carbon dioxide can be deadly in a confined space. Why?

   • AThey push out oxygen
   • BThey are extremely loud
   • CThey are always burning
   • DThey make floors slippery
   显示答案

   答案: A. They push out oxygen

   These simple asphyxiants displace oxygen. Unconsciousness or death can follow within minutes.

8. 第8题，共25题

   Which toxic gas does CCOHS name as a confined space hazard?

   • AHydrogen sulphide
   • BClean, fresh air
   • CPlain water vapour
   • DHelium gas
   显示答案

   答案: A. Hydrogen sulphide

   CCOHS gives hydrogen sulphide and carbon monoxide as examples of toxic gases in confined spaces.

9. 第9题，共25题

   What is engulfment?

   • ASlipping on a wet ladder rung
   • BGetting lost inside a long dark tunnel
   • CBeing cut by moving machine parts
   • DBeing buried by grain, sand or liquid
   显示答案

   答案: D. Being buried by grain, sand or liquid

   Engulfment means being trapped or buried by shifting or collapsing bulk material, or by flooding liquid.

10. 第10题，共25题

    Why is a problem inside a confined space more dangerous than the same problem in an open room?

    • APhones and radios never work inside
    • BThe floor is always wet and slippery
    • CEscape and rescue are much harder
    • DThe lighting is always switched off
    显示答案

    答案: C. Escape and rescue are much harder

    There is less margin for error, rescue and self-rescue are harder, ventilation is poor and conditions can change quickly.

11. 第11题，共25题

    Where should the air in a confined space first be tested?

    • AFrom outside, before anyone enters
    • BAt the entrance after work starts
    • CFrom the nearest office window
    • DFrom inside, after the first worker enters
    显示答案

    答案: A. From outside, before anyone enters

    Air should be tested from outside the space before anyone enters.

12. 第12题，共25题

    In BC, pre-entry air testing must be done no more than how long before a worker enters?

    • A24 full hours
    • B8 hours
    • C20 minutes
    • D2 hours
    显示答案

    答案: C. 20 minutes

    BC's OHS Regulation s. 9.25 requires testing to be completed not more than 20 minutes before entry.

13. 第13题，共25题

    Under Ontario's guideline, cold work (no sparks or flames) may be done only if flammable gas is below what level?

    • A75% of the LEL
    • B100% of the LEL
    • C10% of the LEL
    • D50% of the LEL
    显示答案

    答案: C. 10% of the LEL

    Ontario's decision chart allows cold work below 10% of the lower explosive limit; hot work needs less than 5%.

14. 第14题，共25题

    In Ontario, at what flammable gas level is entry into a confined space not allowed at all?

    • A5% of the LEL or more
    • B25% of the LEL or more
    • CEntry is always allowed
    • D1% of the LEL or more
    显示答案

    答案: B. 25% of the LEL or more

    Ontario's guideline allows inspection only below 25% of the LEL. At 25% or more, entry is not permitted.

15. 第15题，共25题

    What does LEL stand for in air testing?

    • ALow-energy lockout level
    • BLowest entry level
    • CLegal exposure limit
    • DLower explosive limit
    显示答案

    答案: D. Lower explosive limit

    Flammable gas readings are given as a percentage of the lower explosive limit (LEL).

16. 第16题，共25题

    In Ontario, how often must a new entry permit be issued?

    • AOnce each year for every space
    • BOnce for the whole life of the building
    • CEach time work is done in the space
    • DOnly when a new worker is hired
    显示答案

    答案: C. Each time work is done in the space

    Ontario's regulation (s. 10) requires a separate entry permit each time work is to be performed in a confined space.

17. 第17题，共25题

    Which item must an Ontario entry permit include?

    • AThe results of the air tests
    • BThe cost of the rescue equipment
    • CThe workers' home phone numbers
    • DThe forecast for the next week
    显示答案

    答案: A. The results of the air tests

    The permit lists the location, work, hazards and controls, time period, attendant, entries and exits, equipment and atmospheric test results.

18. 第18题，共25题

    Where must the attendant be during a confined space entry in Ontario?

    • AOutside and near the entrance
    • BAt the front gate
    • CInside the space with the workers
    • DIn the site office
    显示答案

    答案: A. Outside and near the entrance

    Ontario's guideline says the attendant stays outside and near the entrance and does not enter.

19. 第19题，共25题

    A worker inside collapses. The attendant is alone at the entrance. What should the attendant do?

    • AClose the cover to trap the gas inside
    • BGo in at once to pull them out
    • CStay outside and call for rescue
    • DWait to see if they wake up
    显示答案

    答案: C. Stay outside and call for rescue

    The attendant must not enter. They call for emergency rescue right away, keep communication and support the rescue.

20. 第20题，共25题

    According to CCOHS, about what share of confined space deaths are would-be rescuers?

    • AAbout 25%
    • BWell under 1% of them
    • CAbout 5% at most
    • DAbout 60% or more
    显示答案

    答案: D. About 60% or more

    CCOHS reports that more than 60% of confined space deaths are would-be rescuers.

21. 第21题，共25题

    In Ontario, what must be in place before anyone enters a confined space?

    • AOnly a phone for calling 911
    • BA visitor sign-in sheet at the gate
    • CA ready on-site rescue plan
    • DA first aid poster on the wall
    显示答案

    答案: C. A ready on-site rescue plan

    Ontario (s. 11) requires written on-site rescue procedures ready for immediate use and enough trained rescuers before entry. Calling 911 alone does not count.

22. 第22题，共25题

    In BC, in a low or moderate hazard confined space, a standby person must check on the workers inside at least how often?

    • AOnly at the very end
    • BEvery 20 minutes
    • CEvery 2 hours
    • DOnce per shift
    显示答案

    答案: B. Every 20 minutes

    BC's OHS Regulation (ss. 9.34 and 9.35) requires checks at least every 20 minutes in low and moderate hazard spaces. In high hazard spaces the standby person must monitor the workers continuously.

23. 第23题，共25题

    Under Ontario's rules, how must entrances be handled if unauthorized entry is possible?

    • APainted a bright colour only
    • BSecured, or barricaded and signed
    • CLeft open to let in fresh air
    • DWatched by a camera, nothing more
    显示答案

    答案: B. Secured, or barricaded and signed

    Ontario (s. 17) requires each entrance to be secured, or to have adequate barricades, warning signs or both.

24. 第24题，共25题

    Before a confined space is closed up after work, what must be checked?

    • AThat the permit is thrown away
    • BThat the lights are turned off
    • CThat the gas detector is charging
    • DThat no one is still inside
    显示答案

    答案: D. That no one is still inside

    CCOHS says no confined space should be closed off until it has been verified that no person is inside.

25. 第25题，共25题

    Under Ontario's regulation, who must receive adequate training?

    • AEntrants, attendants and rescuers
    • BOnly the local fire department
    • COnly the supervisor who signs off
    • DOnly the workers who go inside
    显示答案

    答案: A. Entrants, attendants and rescuers

    Ontario (s. 8) requires adequate training for every worker who enters a confined space or does related work, such as attendants and rescuers.

键盘：按1–4作答，按 Enter 进入下一题。