Lessons Learned—Fluoride Exposure

Abstract

Laboratory workers are potentially exposed to a wide range of chemical hazards while performing experimental research. Moreover, unique combinations of chemicals can generate hazards that the individual chemical compounds would not produce. Thus, researchers may lack proper personal protective equipment to adequately protect themselves. A recent incident is examined in which a researcher suffered a painful hydrofluoric acid (HF) burn when working with a solution of lithium hexafluorophosphate (LiPF6) dissolved in a mixture of dimethyl carbonate and ethylene carbonate. Under ambient conditions, LiPF6 can produce HF, which by itself does not easily permeate nitrile gloves. However, the carbonate mixture rapidly permeates nitrile gloves. The mixture carried HF through the nitrile gloves allowing for rapid permeation. The compounding hazards led to nitrile gloves being inadequate protection for such an experiment. This Letter describes this incident and discusses how a proper risk assessment could prevent similar incidents from occurring.

Large-Scale Practical Synthesis of Boc-Protected 4-Fluoro-l-Proline

“…Etching on the glass assembly was observed during the lab reaction; it is highly recommended to wear appropriate personal protective equipment (PPE) and adhere to the standard operating procedure (SOP) while performing the reaction. 31 Ultimately, for the pilot-plant campaign, we chose to implement an inherently safer process in which a toluene layer with 13 was obtained from inexpensive commercially available nosyl chloride (12) by treatment with potassium fluoride (KF) in biphasic media such as toluene and water using 18-crown-6 as the phase transfer catalyst at 50−55 °C. The use of a single solvent was a major advantage of the developed process in the case of recovery and reuse of solvents.…”

“…In view of safety during the pilot batch, a solution of 13 in the toluene layer was directly used for the next reaction instead of solid isolation. Etching on the glass assembly was observed during the lab reaction; it is highly recommended to wear appropriate personal protective equipment (PPE) and adhere to the standard operating procedure (SOP) while performing the reaction …”

Lessons Learned—Fluoride Exposure and Response

“…Most hydrofluoric acid is consumed in the manufacture of fluorine-containing chemicals, metal pickling, and petroleum alkylation. However, HF is used in a multitude of applications requiring manual manipulation of the acid and can also be produced during various chemical reactions, for example, alkyl carbonate solutions of lithium hexafluorophosphate …”

“…However, HF is used in a multitude of applications requiring manual manipulation of the acid and can also be produced during various chemical reactions, for example, alkyl carbonate solutions of lithium hexafluorophosphate. 1 HF exists as a gas or as an aqueous liquid with concentrations ranging from parts per million levels to nearly 100% anhydrous acid. While HF is very corrosive to human tissue, it is also a powerful systemic toxin, directly destroying skin, eye, bone, and tendon tissue.…”

Welcome to ACS Chemical Health & Safety

“…In preparation of this first issue of ACS Chemical Health & Safety , as Editor-in-Chief, I found myself again contemplating MSDSs, now referred to as Safety Data Sheets (SDSs), because of two near miss incident descriptions authors had submitted. The near misses addressed two hazards I was not familiar with, the exothermic reactivity of lithium metal in nitrogen and a solvent-induced chemical decomposition pathway combined with nitrile glove permeability that resulted in a researcher’s exposure to hydrofluoric acid . It is easy to say that a better risk assessment could have prevented the incidents, but I found myself wondering what risk decisions I would have made without the benefit of hindsight.…”