What is the maximum concentration of propylene glycol allowed in antifreeze solutions?

The maximum concentration of propylene glycol allowed in antifreeze solutions is 40%. This concentration is important because while propylene glycol is less toxic compared to ethylene glycol, its concentration must still be limited to ensure effective performance and safety in various applications, especially within water-based fire protection systems.

Antifreeze solutions that exceed this concentration may not provide optimal freeze protection, which can adversely affect the system's operation during cold weather conditions. It's also crucial to adhere to specific guidelines and codes that outline the appropriate use of antifreeze in these systems, ensuring reliability and compliance with safety standards.

Understanding the recommended concentration is essential for professionals in the field, as using solutions that are too concentrated can lead to issues such as increased viscosity and decreased flow in the system, potentially compromising its functionality.