the quantities of deca-BDE found were in the ~TRILLIONTHS of a gram [~100 picograms/cm2].
to make mice have neurological symptoms, they had to dose them with .8 MILLIGRAMS/kilo of bodyweight, a quantity billions of times higher...
see:
http://www.computertakeback.com/docUploads/bfr_r ep ort.pdf?CFID=4748427&CFTOKEN=85189172