Final answer:
The minimum fire rating for all interior walls separating the laboratory from other portions of the building is typically one hour.
Step-by-step explanation:
The minimum fire rating for all interior walls separating the laboratory from other portions of the building can vary depending on local building codes and regulations. However, a common requirement is to have a fire rating of at least one hour.
The fire rating of a wall refers to the amount of time it can resist the spread of fire and provide protection. It is determined by the construction and materials used in the wall. Walls with a one-hour fire rating are typically constructed using fire-resistant materials such as concrete, gypsum board, or steel.
These walls are designed to withstand fire for at least one hour, allowing people inside the laboratory to evacuate safely and giving firefighters enough time to control the fire.