Fault with Erica's Hazmat/Biological suit!
Theres a fault with the suits that they are all wearing, that is that they needed to have an air supply of some sort. The air supply could be an external one ,connected by an air hose or they needed full faced respirators with an air tank on their backs if they were to wear those big bulky blue suits. Without either option they all would have suffocated in their protective suits after not too long.
Something like what Mira Sorvino was wearing at the start Mimic would have been more realistic to see. :)
Mistakes like this really spoil a movie for me. :(