Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm.

How long does it take to die from phosphine gas?

TIME COURSE: Adverse health effects generally occur within the first few hours following inhalation of phosphine. Cardiovascular complications may cause death within 12 to 24 hours following exposure.

How much phosphine can kill you?

As has been stated above, phosphine is a very toxic gas, not only for insects but for human beings as well. A concentration of 2.8 mg per liter of air is deadly for a human.