What characteristics define a pre-existing lab type I?

The characteristics of a pre-existing lab type I are best defined by having a 2-hour fire rating and installed sprinklers. This combination plays a crucial role in ensuring safety and compliance with fire codes for laboratories, especially those that may involve flammable gases or materials. The 2-hour fire rating indicates that the structural integrity of the building can withstand fire for a significant period, allowing for safe evacuation and minimizing the risk of fire spreading.

Additionally, the presence of sprinklers enhances this fire protection system by actively working to suppress or extinguish any fire that may occur, further safeguarding the lab environment and the materials within it. The integration of both a solid fire rating and an effective sprinkler system meets essential safety standards that are critical for laboratories dealing with potentially hazardous substances.