One thing I try to do is build "sheltering in place intelligence" into my SARA fixed facilities, Offsite Response Plans. Included in these preplans are a list of buildings that have a higher than normal evacuation time. I try to include information on the sites capability to evacuate or their ability to shelter in place and also, an estimate on how long a person could remain safe by staying in place. One needs to be sure of the level of, disaster planning, exercising and training that has been put into place. After all you "play as you practice".

Surveying the adjacent areas near a chemical facility in advance plus, developing and continually maintaining preplans that include the possibility of sheltering in place (which includes making sure a building that might be subjected to this procedure trains and exercises it), will help to alleviate the confusion and anxiety should a chemical emergency occur in a fixed facility. Chemical emergencies that occur during transportation however are outside the parameters of this level of planning. Coming up with an estimate of time/dosage is key to making it work in either scenario.