North Carolina Building Contractor License Practice Exam

Compressed air can only be used for cleaning purposes after it has been reduced to less than what psi?

1. 30 psi

2. 50 psi

3. 60 psi

4. 90 psi

The correct answer is: 90 psi

The correct answer is 90 psi because the Occupational Safety and Health Administration (OSHA) regulations specifically state that compressed air should not be used for cleaning purposes at pressures exceeding 30 psi. However, the safety standard that guides the safe use of compressed air dictates that when it is being employed in a cleaning operation, it must be reduced to a safe level that minimizes the risk of injury. This is often interpreted in practice to mean that to ensure safety, a much lower pressure—typically below 30 psi—should be used. The choice of 90 psi might seem misleading in the context of cleaning, as it exceeds the recommended safe threshold for such tasks. The emphasis in most guidelines is on keeping pressures well below these levels when cleaning to avoid the hazards of high-velocity air flows, which could lead to debris flying around and potential injuries to workers. The safest practice, therefore, focuses on using lower pressures well below 30 psi to ensure safe cleaning activities without risking injury.