Ontario Operator-in-Training (OIT) Practice Exam

An operator smells hydrogen sulphide at the entrance of a deep confined space. What actions should the operator take?

1. Enter the space immediately to assess the situation

2. Wait outside while calling for help

3. Do not enter until there is no hydrogen sulphide detected and safety equipment is in place

4. Use a fan to ventilate the area

The correct answer is: Do not enter until there is no hydrogen sulphide detected and safety equipment is in place

When an operator detects the smell of hydrogen sulphide at the entrance of a deep confined space, the immediate priority is to ensure safety. Hydrogen sulphide is a toxic gas that can be very dangerous, even in low concentrations, as it can lead to serious health risks or even fatalities upon exposure. Selecting the choice to refrain from entering until there is no detectable hydrogen sulphide present and proper safety equipment is operational prioritizes the health and safety of the operator. This means waiting for proper ventilation and monitoring equipment to assess the levels of the gas, ensuring a safe environment before any entry is considered. This approach is critical because hydrogen sulphide can cause rapid incapacitation and can often be undetectable in high concentrations, with a characteristic odor that may become intolerable or unidentifiable in extreme cases. Safety equipment, such as personal protective gear and gas detection tools, are essential to mitigate any potential hazards related to exposure. Determining the air quality and ensuring that all safety protocols are followed helps prevent accidents and injuries, exemplifying a responsible and precautionary approach to hazardous work environments.