" 

 :UPDATE: I took a look at what I added this morning and agree that it took the paragraph ""over the top"". While the ""trace contaminants"" issue is extremely important with chlorocarbons, citing the specific example of dioxin in 2,4,5-T (the ""Agent Orange"" debacle) was excesively inflamatory. The chemist will review the article as now revised.  ('''' "