SSI Enriched Air Nitrox Exam 2024/2025
When oxygen becomes toxic to body tissues, it most noticeably and immediately affects the:
Bones and blood
Lungs and central nervous system
Central nervous system and feet
Lungs and circulation system correct answersLungs and central nervous system
How is the ppO2 of a breathing gas calculated?
Multiply cylinder pressure by the fraction of nitrogen (FN2) in the cylinder
Multiplying ambient pressure by the fraction of oxygen (FO2) in the breathing gas
Dividing ambient pressure by the fraction of oxygen (FO2) in the breathing gas
Multiplying air pressure by the fraction of oxygen (FO2) in the breathing gas correct answersMultiplying
ambient pressure by the fraction of oxygen (FO2) in the breathing gas
What does ppO2 mean?
Nitrox
Air
Partial pressure of oxygen
Partial pressure of nitrogen correct answersPartial pressure of oxygen
The threshold for CNS oxygen toxicity appears to be at a ppO2 of:
1.4 ata
1.6 ata
, 1.1 ata
32% correct answers1.1 ata
The risk of CNS Oxygen Toxicity becomes more substantial above:
A ppO2 of 1.6 ata
A dive time of 30 minutes with air at 66 feet
A ppO2 of 1.4 ata
1000 feet of altitude correct answersA ppO2 of 1.6 ata
Pulmonary Oxygen Toxicity (the Lorrain Smith Effect) poses no real risk to recreational divers because:
Pulmonary Oxygen Toxicity does not lead to problems.
The required exposure time before symptoms arise is well below the duration of most sport dives
The risk of Pulmonary Oxygen Toxicity becomes more substantial on a single short dive above a ppO2 of
1.6 ata
The required exposure time before symptoms arise is well beyond the duration of most sport dives
correct answersThe required exposure time before symptoms arise is well beyond the duration of most
sport dives
Since CNS Oxygen Toxicity is among the greatest of risks in nitrox diving, you must be able to recognize:
Its positive aspects in deep diving
Its warning signs and symptoms, both in yourself and others
Its warning signs and symptoms, only in yourself
Its treatment correct answersIts warning signs and symptoms, both in yourself and others
What is the best way to compare the levels of oxygen found in various types of breathing gas?
Amount of breathing gas in the cylinder
When oxygen becomes toxic to body tissues, it most noticeably and immediately affects the:
Bones and blood
Lungs and central nervous system
Central nervous system and feet
Lungs and circulation system correct answersLungs and central nervous system
How is the ppO2 of a breathing gas calculated?
Multiply cylinder pressure by the fraction of nitrogen (FN2) in the cylinder
Multiplying ambient pressure by the fraction of oxygen (FO2) in the breathing gas
Dividing ambient pressure by the fraction of oxygen (FO2) in the breathing gas
Multiplying air pressure by the fraction of oxygen (FO2) in the breathing gas correct answersMultiplying
ambient pressure by the fraction of oxygen (FO2) in the breathing gas
What does ppO2 mean?
Nitrox
Air
Partial pressure of oxygen
Partial pressure of nitrogen correct answersPartial pressure of oxygen
The threshold for CNS oxygen toxicity appears to be at a ppO2 of:
1.4 ata
1.6 ata
, 1.1 ata
32% correct answers1.1 ata
The risk of CNS Oxygen Toxicity becomes more substantial above:
A ppO2 of 1.6 ata
A dive time of 30 minutes with air at 66 feet
A ppO2 of 1.4 ata
1000 feet of altitude correct answersA ppO2 of 1.6 ata
Pulmonary Oxygen Toxicity (the Lorrain Smith Effect) poses no real risk to recreational divers because:
Pulmonary Oxygen Toxicity does not lead to problems.
The required exposure time before symptoms arise is well below the duration of most sport dives
The risk of Pulmonary Oxygen Toxicity becomes more substantial on a single short dive above a ppO2 of
1.6 ata
The required exposure time before symptoms arise is well beyond the duration of most sport dives
correct answersThe required exposure time before symptoms arise is well beyond the duration of most
sport dives
Since CNS Oxygen Toxicity is among the greatest of risks in nitrox diving, you must be able to recognize:
Its positive aspects in deep diving
Its warning signs and symptoms, both in yourself and others
Its warning signs and symptoms, only in yourself
Its treatment correct answersIts warning signs and symptoms, both in yourself and others
What is the best way to compare the levels of oxygen found in various types of breathing gas?
Amount of breathing gas in the cylinder
