308A Safety Regulations and Trade Practices 2 — Questions and Answers
Question 1: What ventilation method is most effective when soldering or brazing in an enclosed or partially enclosed space?
- Opening windows for natural cross-ventilation
- Local exhaust ventilation (LEV) positioned directly at the source (Correct answer)
- General dilution ventilation using ceiling-mounted fans
- No special ventilation is needed for low-temperature soldering
Correct answer: Local exhaust ventilation (LEV) positioned directly at the source
Local exhaust ventilation captures fumes at the point of generation before they can disperse into the worker's breathing zone, making it far more effective than dilution ventilation.
Question 2: What is the safest way to manually carry a large sheet of metal from a storage area to a workstation?
- Hold the sheet flat overhead to clear other workers
- Carry it vertically using cut-resistant gloves, folded edges facing away, tip pointing downward (Correct answer)
- Drag the sheet along the floor to minimize lifting strain
- Stack multiple sheets together to reduce the number of trips
Correct answer: Carry it vertically using cut-resistant gloves, folded edges facing away, tip pointing downward
Carrying sheet metal vertically in gloves with protected edges and the leading corner pointing down minimizes the risk of cuts and loss of control.
Question 3: According to Canadian occupational health standards, what is the permissible 8-hour noise exposure limit that triggers mandatory hearing protection?
- 75 dB(A)
- 85 dB(A) (Correct answer)
- 90 dB(A)
- 100 dB(A)
Correct answer: 85 dB(A)
Canada's federal and most provincial OHS regulations set 85 dB(A) as the 8-hour time-weighted average threshold above which hearing protection is mandatory.
Question 4: Before entering a confined space such as a large duct plenum to perform sheet metal work, what must happen?
- A supervisor must verbally approve entry
- Atmospheric testing must be completed and a confined space entry permit obtained (Correct answer)
- Simply inform a nearby coworker of your location
- Turn off all electrical equipment inside the space
Correct answer: Atmospheric testing must be completed and a confined space entry permit obtained
Canadian OHS regulations require atmospheric testing for oxygen levels, flammable gases, and toxic substances, plus a signed entry permit, before any confined space entry.
Question 5: What does the acronym SDS stand for, as introduced under the updated WHMIS 2015 standard?
- Safety Data System
- Standard Data Sheet
- Safety Data Sheet (Correct answer)
- Substance Detection Summary
Correct answer: Safety Data Sheet
SDS (Safety Data Sheet) replaced the older MSDS (Material Safety Data Sheet) under WHMIS 2015, which aligned Canada's system with the Globally Harmonized System (GHS).
Question 6: When using an angle grinder to cut sheet metal, what is the most important safety precaution for the surrounding work area?
- Wet down the area with water to control sparks
- Clear combustibles and erect fire-resistant barriers around the work area (Correct answer)
- Ensure combustible materials are nearby for quick access after cutting
- Work in a sealed, unventilated room to contain sparks
Correct answer: Clear combustibles and erect fire-resistant barriers around the work area
Grinder sparks can travel several metres and ignite combustible materials; removing combustibles and using spark barriers is essential fire prevention.
Question 7: Which type of respiratory protection is recommended when power-grinding stainless steel in a shop environment?
- No protection is needed as stainless steel fumes are inert
- A disposable N95 dust mask is fully adequate
- A half-face respirator fitted with P100 particulate filters (Correct answer)
- A supplied-air breathing apparatus is always required
Correct answer: A half-face respirator fitted with P100 particulate filters
Grinding stainless steel produces fine hexavalent chromium particles, a known carcinogen; a half-face respirator with P100 filters provides adequate protection for shop environments.
308A Safety Regulations and Trade Practices 2
What ventilation method is most effective when soldering or brazing in an enclosed or partially enclosed space?