In this study, we analysed Acetaldehyde fumes leakage in a closed room. To analyse the leakages of different types of gases inside the room or laboratories with the help of Fire Dynamics Simulator. Today, it is a well-founded Computational program for thermal dynamics developed by a renowned institution. In this experiment, we simulated for acetaldehyde fumes leakage in an enclosed space for certain volume. We compared with FDS simulation results of acetaldehyde and bromine fumes data has been collected and presented in the form of graphical representation. In that graph shows the time taken by a chemical fume to spread in a closed room.