Let's introduce the dangers of science - mad science.
How often do you think, explosives have been invented? Quite a few times until the inventor survived the blast. There are explosives in existance we have no knowledge of because they are so dangerous that no inventor has survived to tell the story. The second name of "rocket engine testing engineers" is "Himmelfahrtskommando". Luckily biotechnology hasn't advanced that far, yet, because we would know.
Translated to the game: some science labs are prone to explode when researching dangerous stuff like explosives or rockets. In the case of alien technology related research, there is a risk of an alien escaping the labs and running havoc - you better get your turrets ready.
What did you think when you started feeding alien eggs to your science labs; an omelette?
EDIT:
FIRE, I FORGOT THAT SCIENCE LABS CATCH FIRE BY SCHEDULE ALMOST, THERE WILL BE FIRE! 
