Seal off the area. There's a possible chemical explosion in five minutes.

7 seconds sound clip from the Last Action Hero movie soundboard.

You can hear this line at 01:11:45 in the Blu-ray version of the movie.

Quote context

[...]

- All right. Let's go.

- It's behind the eight ball, you moron.

- Somebody once told me I talk too much. No more words.

- Whiskers! Where the hell have you been?

- Sorry, Jack. Fur ball problem.

- Seal off the area. There's a possible chemical explosion in five minutes.

- Thanks, Whiskers. I owe you one.

- Forget it. You saved my fur plenty of times.

- You see the hook of that crane? I want it on top of the roof in two minutes. Go.

- Wait. How do I get them to do that?

[...]