THINK DETAILS FOR TREE 4

.        Consider (partial) evacuation  or shelter-in-place? 

If no time is available for response, evacuation or shelter-in-place would have to be considered as likely options.  There is no widely accepted method for the selection of an appropriate exposure limit for general populations subjected to toxic vapours or gases and the principles outlined in (2) above could serve as a rough guideline that may assist in establishing a “safe” distance.  For guidance on evacuation and shelter-in-place see First Response actions in Chemical accidents, found in INFORMATION COMPONENT