What is the first step in atmospheric testing for confined spaces?

The first step in atmospheric testing for confined spaces is to check oxygen levels. This is crucial because oxygen is essential for human survival, and improper levels can lead to asphyxiation or other health risks. In confined spaces, the natural circulation of air may be restricted, leading to a potential buildup of gases that can displace oxygen or reduce its concentration to dangerous levels.

Establishing a safe oxygen level ensures that workers entering the space can breathe properly. If the oxygen concentration is below the acceptable range (typically between 19.5% to 23.5% for breathable air), it indicates an immediate risk. Addressing oxygen levels first helps in creating a safer working environment before assessing for other hazards, such as toxic gases or combustible vapors. After confirming adequate oxygen levels, testing can proceed to assess other atmospheric conditions.