Which of the following is NOT one of the four most common types of respirators?

The correct answer is the Industrial Gas Mask (IGM) because it is not widely recognized as one of the four most common types of respirators. The primary types of respirators include the Self-Contained Breathing Apparatus (SCBA), Supplied-Air Respirator (SAR), and Air Purifying Respirator (APR), each serving specific purposes in protecting users from different types of airborne contaminants.

Self-Contained Breathing Apparatus (SCBA) is designed for use in oxygen-deficient environments or when hazardous gases are present. It provides the user with a personal air supply, making it essential for firefighters and rescuers in emergencies.

Supplied-Air Respirator (SAR) connects to a central air source, allowing for continuous fresh air supply. This type is suitable for operations in environments with high levels of contaminants where air quality cannot be ensured.

Air Purifying Respirators (APR) work by filtering out specific contaminants from the air, suitable in situations where the air is not immediately dangerous to life or health, but where particulates, gases, or vapors may pose a risk.

The Industrial Gas Mask, while used in various applications, does not fit into the primary categories recognized in occupational safety guidelines as commonly as the others. Its function might