Firegeezer notes: Last Thursday a seemingly-minor chemical leak at an oil refinery in Joliet, Illinois, brought assisting responses from four fire departments and several ambulances for standby. The leak happened at an alkylation unit which makes high octane blending ingredients for gasoline and the leak was a discharge of propane that contained hydrofluoric acid mixed in it.
So how does that earn such a heavy response? We asked Senior Fire Instructor John Sachen, who concentrates on hazardous chemicals, to explain to us the dangers of HF which is liable to be found in at least one home in any neighborhood. He reports:
While most states have no refineries using HF, it is present in many research and teaching laboratories and production facilities. It is also sought after for its glass etching property — often without any knowledge of its hazards by both the seller and the user and is therefore is transported through all states at least in lab quantities. To see the extent of home glass etching just Google: HF glass etching.
From Wikipedia (Edited for Critical Emergency Response Information): Hydrogen fluoride is a chemical compound with the formula HF. It is the principal industrial source of fluorine (F), often in the aqueous form as hydrofluoric acid, and thus is the precursor to many important compounds including pharmaceuticals and polymers (e.g., Teflon). HF is widely used in the petrochemical industry as a catalyst and as a component of many superacids.
HF boils just below room temperature (68F) and is a gas, whereas compounds that boil above 70F are classified as liquids. As a gas, HF is lighter than air and forms white fuming clouds when released. Its odor is very penetrating. HF’s toxicity is from its ionization in water which results in the fluoride ion (-F) being available to immediately and permanently replace the calcium in bones and tissue.
Aqueous solutions of HF, called hydrofluoric acid, are strongly corrosive and fume in air. Upon contact with moisture, including tissue, hydrogen fluoride gas immediately converts to hydrofluoric acid, which is very corrosive and toxic, and requires immediate medical attention. Even with prompt medical care, serious HF exposure can be fatal. Strong HF solutions may exhibit acid burn symptoms but weak solutions will not — but still must be treated as a serious exposure. One important aspect is that if even moderate HF burns are not treated appropriately the action on tissue causes liquefaction necrosis (tissue death similar to attack by strong bases — see photo below), and potentially lethal hypocalcemia.
Immediate flushing with volumes of water for fifteen minutes, including eye irrigation, can reduce the risk of serious injury but all exposures must be considered serious and medical treatment is require. Responders must exercise extreme care that they are isolated from splashing and misting resulting from flushing during decontamination — remove all victims clothing and consider it contaminated (HF is hygroscopic).
The risk of down wind contact with fume releases can be reduced with water sprays but the runoff will be contaminated and is a serious hazard that must be contained or otherwise mitigated.
Never apply burn salves, ointments or other treatments in the field unless ordered by a physician or poison control center knowledgeable in HF treatment or as part of the treatment protocol of an emergency HF response program.
Home glass polisher accident
Response teams should study MSDS information such as: http://www.praxair.com/praxair.nsf/0/F5322947A3AB1C8285256E5B0068EF96/$file/HydrogenFluoride-Canada-2007.pdf for HF as a gas and: http://www.jtbaker.com/msds/englishhtml/H3994.htm as the 70% acid. Whenever possible, teams should train on HF response protocols from local facilities that use HF. The training should include eye irrigation and application of calcium gluconate and similar emergency treatments.
Caution – There are a several online videos that show a person demonstrating HF in front of a window without a fume hood or appropriate PPE including respiratory protection, and using procedures that have high risk of fume and liquid contact. One small splatter of 70% HF on open skin or inhalation of HF fumes would constitute a very serious exposure. That video is inappropriate and should not be used for training.
Photos of HF burns on this web site:
http://emedicine.medscape.com/article/773304-media
Overview of HF injuries on emdicine.medscape.com:
http://emedicine.medscape.com/article/773304-overview
Chemtrec Information:
http://www.chemtrec.com/NR/rdonlyres/C15D0DC3-4C99-4144-9441-11E55C410858/0/CHEMTRECGuideforEmergencyResponders.pdf
John Sachen, Senior Fire Instructor
University of Missouri – Fire and Rescue Training Institute
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