40 Questions
What is the primary purpose of using Air Conditioners in ventilation?
To establish a positive means of ventilating confined spaces
What must be prepared and approved prior to confined space entry?
Ventilation plan
Why is it essential to have Air Movers ready for use?
In case of Air Conditioners shutdown or emergency
What is a critical consideration when preparing a rescue plan?
All of the above
When is a rescue plan mandatory?
For all confined space entry types
What is a key factor in determining the ventilation requirements?
The type of material being ventilated
What is the primary purpose of a ventilation plan?
To determine the ventilation rate required
Why is it essential to have a positive means of ventilating confined spaces?
To establish a safe working environment
What is the maximum allowable concentration of CO and NH3 in terms of PPM?
25
What is the maximum wet bulb globe temperature or ambient temperature allowed for confined space entry?
35°C or 46°C
What type of ventilation system is not allowed to ventilate confined spaces?
Nitrogen
What is the minimum classification for a confined space until it is tested and verified?
A category
What is the requirement for fans and air movers used in ventilation of confined spaces?
They must be electrically bonded and grounded
What type of blower is allowed to ventilate confined spaces?
Pneumatic driven blower
What is the minimum requirement for gas testing in confined spaces?
Flammable gases and vapors (LEL) below 5%
What is an alternative to ventilation in confined spaces?
Air conditioners
What is the primary purpose of venting during depressurization or purging?
To release gases or vapors to the atmosphere
What is the purpose of a lifeline or retrieval line in a confined space?
To maintain contact with a person in a dangerous situation
What is the primary hazard associated with explosive substances?
Sudden release of pressure and heat
What is the primary purpose of ventilation in a confined space?
To remove hazardous gases and vapors
What is the purpose of a breathing apparatus in a confined space?
To provide a stable air supply
What is the primary purpose of gas testing in a confined space?
To identify the presence of hazardous gases
What is the primary hazard associated with extreme temperatures?
Risk of heat stroke
What is the primary purpose of a rescue plan in a confined space?
To rescue persons in a confined space
What is the minimum oxygen content required in a confined space?
19.5%
Which of the following is a requirement for energy isolation in a confined space?
Positive Isolation by installing rated blind / disconnecting line
What is the purpose of gas testing in a confined space?
To detect oxygen content
What should be covered in the immediate area during confined space entry?
Sewer openings
What is the maximum oxygen content allowed in a confined space?
22.0%
Which of the following is a requirement for ventilation in a confined space?
Providing air ventilation
What is the purpose of posting sign boards in a confined space?
To indicate the presence of oxygen deficient atmosphere
What should be removed / isolated in a confined space?
Radiation sources
What is the minimum concentration of vapor in air below which propagation of flame will not occur in the presence of an ignition source?
Lower Explosion Limit (LEL)
What is the role of a Gas Tester?
A person who has undergone training on the use of gas detecting equipment and is authorized to conduct gas test
What is the maximum concentration of a flammable/combustible gas, vapor, mist, or dust in air that will support combustion when an ignition source is present?
Upper Explosive Limit (UEL)
What is the oxygen level in an Oxygen Enriched Atmosphere?
More than 22.5% by volume
Who is responsible for countersigning permits with regards to hot taps and work on flare headers?
General Manager
What is the threshold for an Oxygen Deficient Atmosphere?
Less than 19.5% by volume
What is the purpose of a gas test?
To determine the LEL and UEL of a gas
What is the effect of an Oxygen Enriched Atmosphere on combustible materials?
It causes combustible materials to burn violently when ignited
Study Notes
Confined Space Requirements
- Flammable gases and vapors (LEL) below 5%
- Potential toxic air contaminants: CO and NH3 maximum allowable concentration is 25 PPM
- Wet bulb globe temperature ≤ 35°C or Ambient Temp ≤ 46 °C as maximum
Ventilation Requirements for Confined Space
- Ventilation plan shall be prepared and approved as per IMRS 13-02-01-23
- Positioning of mechanical aspirators, drawing of fresh air, routing of exhaust air
- Air conditioners can be installed as an alternate of ventilation wherever it is convenient
- A positive means of ventilating confined space shall be established and kept operated the entire time while work is in progress
Rescue Plan Preparation and Requirements for Confined Space Entry
- Rescue plan is mandatory for all Confined Space entry types
- Rescue Plan shall consider the hazards outcome of the JSA, location of the work, number of workers, duration and period of work, and resources needed for the rescue
Definitions
- Wet-bulb globe temperature (WBGT): estimates the effect of temperature, humidity, wind speed, and radiation on humans
- Explosive substance: a chemical substance that causes a sudden release of pressure, gas, and heat when subjected to shock, pressure, high temperature, or chemical reaction
- Rescue plan: a plan used to rescue persons from the Confined Space regardless of confined Space category
- Lifeline/Retrieval line: a line used for preserving or saving life in a dangerous or potentially dangerous situation
- Venting: allowing gases or vapors to be released to the atmosphere or flare or a recovery system during depressurization or purging
- Ventilation: ventilating a vessel or area by using an air-moving device to draw fresh air through the vessel or area
- Breathing Apparatus: line-air supplied via manually operated pump or cylinders of compressed air, self-contained apparatus carried by the wearer or a recycled air system
Confined Space Hazard Identification and Preparation
- Confined space hazard identification shall be recognized by posting sign boards stating the confined space condition
- Preparation includes:
- Free of dangerous chemical substances/liquid as far as practically possible for “A” category and mandatory for “B” category
- Energy isolation in terms of electrical isolation, positive isolation, and radiation source removal
- No process material remains
- Sewer openings in immediate area shall be covered
- Air shall be tested, and ventilation shall be provided
- Communication systems shall be available
Ventilation Requirements and Gas Testing for Confined Space
- Oxygen content between 19.5% to 22.0%
- Canisters, cartridge, and other forms of filter mask do not constitute Breathing apparatus
Definitions
- Lower Explosion Limit (LEL): the minimum concentration of vapor in air below which propagation of flame will not occur in the presence of an ignition source
- Threshold Limit Value (TLV): toxic gas concentration above which it is not safe to work extended periods
- Upper Explosive Limit (UEL): the maximum concentration of a flammable/combustible gas, vapor, mist, or dust in air that will support combustion when an ignition source is present
- Gas Tester: a person who has undergone training on the use of gas detecting equipment and is authorized to conduct gas tests
- Oxygen Deficient Atmosphere: an atmosphere containing less than 19.5% by volume oxygen at sea level
- Oxygen Enriched Atmosphere: an atmosphere containing more than 22.5% oxygen by volume
This quiz covers safety guidelines for industrial workplaces, including flammable gases, toxic air contaminants, and temperature regulations.
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