Toxic fluorinated compounds as by-products of certain BF3-catalysed industrial processes

WE have embarked on a programme of toxicity tests on a range of industrial chemicals that are manufactured using boron trifluoride (BF 3 ) as a catalyst. Although this study is still in its early stages, we feel it opportune to draw attention to the fact that in some of the samples we have detected low concentrations of fluorinated compounds, some of which merit serious toxicological concern. The most notable example we have uncovered concerns some industrial chemicals that are manufactured from ethylene oxide using BF 3 as catalyst. On the basis of the results of toxicological studies of these products, we suspected fluoroacetate precursors as contaminants, and subsequent chemical analysis has confirmed the presence of low concentrations of 2-fluoroethanol and/or 2–(2–fluoroethoxy) ethanol. These two compounds are known to be very toxic to mice (LD 50 10 and 15 mg kg −1 respectively) and are regarded as fluoroacetate precursors 1,2 . The latter is the addition product of 2-fluoroethanol and ethylene oxide (equation 1), and 2-fluoroethanol is the formal addition product of fluoride ion to ethylene oxide (equation 2).