I thought the whole point of organic is that there are no pesticides being used in the first place.
AFAIK they could spray the crops with arsenic and it could still be "organic".
Organic: vinegar (http://www.sciencelab.com/msds.php?msdsId=9922769) (LD50): 3310 mg/kg [Rat]
Of course there are hundreds of different chemicals to look at, and LD50 is not the only measure. It is enough to back up my claim though.