NFPA-99 Practice Exam

What materials should not be contained in the interconnecting hose for systems handling oxygen at pressures greater than 350 psi?

1. Brass.

2. Copper.

3. Polymeric.

4. Stainless steel.

The correct answer is: Polymeric.

For systems handling oxygen at pressures greater than 350 psi, it is crucial to avoid using polymeric materials in the interconnecting hoses. This is primarily due to the fact that polymeric materials can become unstable in the presence of high-pressure oxygen environments. Oxygen can react with these materials, potentially leading to degradation, combustion, or even explosive reactions. In contrast, metals such as brass, copper, and stainless steel are generally considered more suitable for use in high-pressure oxygen systems. These materials are stable and resistant to the negative effects that oxygen can impart under pressure. Therefore, the selection of materials for hoses in high-pressure oxygen systems is critical to ensure safety and prevent any risk of ignition or failure that could result from using inappropriate materials.