Please settle a debate for me about cockroach bombs.

My ex thinks it’s okay to set off a cockroach bomb in the roof while we are in the house with all the windows shut. He believes leaving the fan on in the bathroom will create a negative air flow? He says that’s the only way the bomb could get in the house …

I said no we should listen to the instructions that say you need to leave immediately for 2 hours. He argued that he could control where the bomb dispersed and that it is safe. I said would you really do that with a baby in the house or me?

I think it’s common sense to not be around a cockroach bomb while it’s going off but he still disagreed with me. The roof can’t be sealed and I don’t believe you can control where the cockroach bomb goes. Am I wrong?