What should be tested first in a confined space?

The correct focus in a confined space is to test for oxygen levels first. This is crucial because the atmosphere within a confined space can become rapidly unsafe if oxygen levels drop below safe thresholds, typically below 19.5%. Since oxygen is vital for human survival, ensuring that there is enough oxygen available is the first step before assessing other hazards.

Once oxygen levels are confirmed to be adequate, other atmospheric conditions can be evaluated, such as potential toxic gas levels and combustibility risks. Testing for toxicity or combustibility without first confirming safe oxygen levels could expose workers to immediate life-threatening dangers, especially in environments prone to hazardous atmospheres. Therefore, prioritizing oxygen testing not only aligns with safety protocols established by OSHA but is also a fundamental safety practice in confined space operations.