What should a supervisor verify about the air used for breathing?

• A. It meets required purity standards
• B. It is produced by the divers' portable compressor
• C. It has high humidity
• D. It has minimal oxygen content

Answer: (A)

Breathing air must be safe because any contaminant or incorrect oxygen level can endanger divers quickly. The main idea is that the air supplied for breathing should meet established purity standards, meaning it has been tested and certified to contain no harmful levels of contaminants such as hydrocarbons, carbon monoxide, sulfur compounds, moisture, or particulates. This protects divers from poisoning, narcosis, and oxygen-related hazards, and it also helps ensure the regulators and equipment function reliably.

In practice, a supervisor checks the source of the air, the certification or certificate of analysis, and that the supply system is routinely tested and maintained. The oxygen content should be appropriate (not dangerously low or high) and within the expected range for breathing air, while moisture and oil should be kept to levels that won’t cause freezing, corrosion, or microbial growth in the system.

Producing air with a portable compressor or having high humidity aren’t acceptable assurances by themselves, and minimal oxygen content would be unsafe. The safest and most reliable criterion is that the air meets required purity standards.