College of Life and Environmental Sciences College Hydrofluoric Acid (HF) usage Policy Overview. Hydrogen Fluoride is used within certain colleges at The University of Exeter for a variety of research led processes. This policy includes our requirements for training, safe handling; correct disposal and spillages as well as first aid responses that all users need to be aware of. This information within this policy, in conjunction with the material safety data sheet (MSDS) and the Control of Substances Hazardous to Health (CoSHH) risk assessment is required to be read as part of the training requirements of the College. A risk assessment will be required as part of every procedure that involves HF. This should be a checklist of how the protocol has been made as safe as possible and protocol‐specific instructions on what to do if something goes wrong. (For example, the procedure should only be conducted in a ducted (vented) hood that is scrubbed; a spotter is present familiar with the emergency procedure etc). Introduction. Hydrofluoric acid (Hydrogen Fluoride, HF) is probably one of the most toxic and corrosive acid used within the University (ranked 1 of the most hazardous compounds to human health in five out of 6 of the accepted rankings). Solutions of HF are clear, colourless liquids, anhydrous HF is a gas at room temperature. Regardless of its physical state and concentration HF has an irritating pungent odour. HF differs from other acids due to the fluoride ions ability to penetrate the skin, causing destruction to deep tissue layers. A 2% concentration of HF to the body can be result in fatality. In the body HF reacts with ubiquitous calcium and magnesium ions and can therefore disable many tissues and organs whose functions depend on these ions. The exposure to HF may not be initially painful and symptoms may not occur immediately, sometimes taking several hours, but when the acids begins to react it attacks the calcium in the bones. Under most circumstances without treatment HF exposure results in severe or even lethal damage to the heart, liver, kidneys and nervous system. In all cases HF exposure requires immediate professional medical attention. Physical Properties of HF. Compound: Synonyms: CAS No: Molecular Formula: Molecular Weight: Boiling Point: Specific Gravity: Vapour Pressure: Vapour Density: Hydrofluoric Acid Hydrogen Fluoride, Fluoric Acid, Hydrofluoride, Fluorine Monohydride, HF 7664‐39‐3 HF 20.01 20oC at 760mm Hg 0.99 at ‐7oC 400mm Hg 0oC 0.7 (air=1) 1 College of Life and Environmental Sciences pKa: Description: Solubility: Flammability: 3.15 Colourless gas or fuming liquid, disagreeable, pungent odour < 1ppm Miscible with water with release of heat Non‐flammable Chemical Properties. HF etches glass due to the strong bonds formed between fluoride ions and the silicon molecules in glass. It will also react with glazes, enamels, pottery, concrete, rubber, most metals (especially cast iron) as well as many organic compounds. Upon reaction with metals hydrogen gas can be generated that has the potential to cause an explosive atmosphere. HF should never be stored directly in a steel cylinder due the potential release of hydrogen as detailed above. (Details of appropriate storage vessels can be found in appendix A). Health Effects. WARNING!!! In case of skin contact. Hydrofluoric (HF) acid burns require immediate and specialized first aid and medical treatment. Symptoms may be delayed up to 24 hours depending on the concentration of HF. After decontamination with water, further damage can occur due to penetration/absorption of the fluoride ions. Treatment should be directed toward binding the fluoride ion as well as the effects of exposure. Skin exposures can be treated with a 2.5% calcium gluconate gel repeated administered until burning ceases. More serious skin exposures may require subcutaneous calcium gluconate that can only be administered by experienced medical personnel, due to the potential for tissue injury. Absorption can readily occur through the subungual areas and should be considered when undergoing decontamination If inhaled. Inhalation of high concentrations of HF can result in burns to the mucous membranes and cause obstruction to the airway and acute pulmonary oedema. Symptoms may include coughing, choking, chest tightness, chills, fever and a bluing of the skin. In case of eye contact. HF can cause severe eye burns including the destruction or opacification of the cornea. In severe cases blindness can occur. If swallowed. Ingestion of HF may cause severe burns to the mouth, oesophagus and stomach with severe systematic effects such as hypocalcaemia occurring. 2 College of Life and Environmental Sciences Training. All individuals must report to their laboratory manager before commencement of any work involving HF. They must attend a formal presentation that will be delivered by a designated trainer. All users must also read the HF safety standard at http://lifesciences.exeter.ac.uk/healthsafety/policies/HF/ this document, relevant protocols, MSDS and CoSHH forms. Once this has been completed the user must complete and date the relevant part of the college compliance form http://lifesciences.exeter.ac.uk/healthsafety/hsform/ Only once all of the above has been completed, to the satisfaction of the laboratory manager, can the user commence their work. Their standard of compliance will be monitored by the laboratory manager to ensure all good practices are being maintained. If the laboratory manager is not satisfied at any time that the user is adhering to safe practices they have the right to remove that user from the laboratory until such time that they are satisfied. The HSE produce a document that can be used as a quick guide to hydrofluoric acid poisoning that will be distributed to all users, a copy of this leaflet can be found at http://www.hse.gov.uk/pubns/indg307.pdf Safety Precautions. Preparation and Handling. 1. All users who are proposing to use HF must attend the College HF safety course (Please contact your local laboratory manager to arrange); this training includes information on the hazards, safe use of, spillage and handling of HF. 2. Before any work can be carried out all users must read and understand the MSDS and CoSHH form associated with the protocol to be followed. If this process has not been assessed previously a full risk CoSHH risk assessment must be completed and agreed with the College Safety Office. 3. Before work commences inform other lab users that HF is to be used and if space is limited. Always put up appropriate warning notices. 4. Lone working out of hours with HF is strictly forbidden. 5. A Buddy system should be used for this work where reasonably practicable. 6. Where practical the HF container should be fitted with a HF rated dispenser to minimize the possibility of spillage. These should be pump only and have pressure release valves. 7. Use Teflon/plastic beakers/apparatus NOT GLASS (Details of appropriate vessels can be found in appendix A) 8. Safety Equipment/Personal protection equipment (PPE) will be provided by the laboratory manager including visors/ goggles, gloves (guidance of glove types can be found at http://www.hse.gov.uk/pubns/indg330.pdf but please refer to glove manufacturers information to determine the correct type) , aprons and lab coats. Always check the availability and condition of safety equipment; check gloves for pinholes and the date on them prior to any work being carried out. Use heavy duty acid protection gloves (red) or double glove with the thinner nitrile gloves, always consider which is more appropriate. 3 College of Life and Environmental Sciences 9.
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Wear face visor or goggles, in addition a Perspex screen may be required /used. A lab coat with a heavy duty plastic apron over must be worn. Wear shoes that protect the feet (NO FLIPFLOPS OR OPEN TOED SHOES). All skin surfaces are to be covered. Where practical a Fume hood certified for HF work must be used with the scrubber unit switched on. Make sure fume hood/ working area are free of clutter, appropriately labelled and have been serviced. [this should be tailored to the risk assessment ‐eg. in some circumstances a visor reduces visibility increasing risk] Calcium Glutonate gel (HF antidote gel) will be available in the orange HF first aid kit close to where you are carrying out your work. Familiarise yourself with the procedure for using the antidote gel prior to starting any work. A qualified first aiders should be aware when you are starting work and be easily contacted, the names of these individuals will be on a list, with contact details, within the laboratory. Eye wash bottles will be available within the laboratory, please ensure these are close to hand. Always work standing up, the use of lab stools is strictly forbidden. Consider the quantity of HF needed, try to use minimum amounts required. this should be explained/justified on the risk assessments Storage. 1. HF must be stored in a cool, dry place away from incompatible materials. HF reacts with many materials including concrete, glass, oxidisers, alkalis, other acids water, combustibles and many organic compounds. HF, where possible, should be stored within a plastic lined acid cabinet when not in use. If this is not possible the HF should be stored in a suitable secondary container and stored within a metal cabinet. HF should be stored in containers made from polyethylene or fluorocarbon BUT should never be stored in glass vessels (Details of appropriate vessels can be found in appendix A). 2. All HF containers should be labelled clearly explaining the risks associated with it, name of user, date and concentrations of HF should also be indicated on all containers. 3. The storage area should be clearly identified and clear of any obstructions and be only accessible to authorised individuals. 4. If HF is to be transported a secondary container must be used. These secondary containers must fully enclose the primary one and made from the materials previously noted. Spills. 1. Laboratories that use HF should have their own dedicated spill kit. These kits are available from the College Safety Office. 2. In the case of a small spill and you feel happy to clear it up, please follow the below instructions: I.
Evacuate the area. II.
Put on appropriate personal protective equipment. III.
Use the HF spill kit to clean up the spill as directed by the kits enclosed instructions. 4 College of Life and Environmental Sciences 3. In case of a large spill: I.
Evacuate the area. II.
If a fire, explosion or toxicity hazard exists set off the fire alarm and evacuate the building as normal. A person should be available to let the fire service know of the risks associated. III.
Call Estate Patrol (3999) and inform them of the spill and you have called the fire service. They will take action to call all other parties as they see fit. IV.
Do not enter the area until instructed to do so by the fire brigade and/or Estate Patrol. Disposal. 1. All used HF must be disposed of by the University nominated specialist disposal contractor, details of which can be obtained from the College Safety Office: cles‐[email protected] 2. All HF waste must be placed in an appropriate container, labelled with the building location, lab number, type of waste (including concentrations) and date. These details must be passed on to the lab manager so they can arrange appropriate disposal. 3. HF waste should never be mixed with any other waste; this will eliminate issues of non compatibility. 4. Any empty HF containers must be treated as containing hazardous residues therefore treat as HF waste and disposed of in the same manner. First Aid Treatment Skin Contact 1. Immediately (within seconds) proceed to a safety shower and flood the affected body area thoroughly with large amounts of water. 2. Remove all contaminated clothing, footwear and jewellery while rinsing (remove goggles last; double bag contaminated clothes). 3. If a 2.5% calcium gluconate gel is available, rinsing maybe limited to 5 minutes. If it is not available, continue to flush until medical help is available. 4. Apply calcium gluconate gel to affected area by massaging into skin while flushing with water. [First aider must always wear appropriate gloves!] 5. PVC, nitrile or neoprene gloves must be worn while touching the victim. 6. While the victim is being rinsed with water, call Estate Patrol on ext. 3999. Indicate that a person has been exposed to hydrofluoric acid and an ambulance maybe required. 7. With gloves on: apply calcium gluconate gel every 15 minutes and massage continuously. If pain does not subside within 20 to 30 minutes, injections of a 5% calcium gluconate by a professional medical practitioner may be required. 8. Continue applying calcium gluconate gel while transporting the victim to the emergency room at Royal Devon and Exeter Hospital (RD&E). Either the first aider or a co‐worker should go with the victim to ensure that the ambulance goes to RD&E. 9. Inform responders and all others that the exposure involved hydrofluoric acid (HF). Provide the medical personnel with all relevant information relating to the HF. (A pack will be made available within the spill kit and first aid kit to take to the hospital). 5 College of Life and Environmental Sciences Eye Contact 1. Immediately proceed to an eye wash station and flush eyes with water for at least 15 minutes. Hold the eyelids open and away from the eye during irrigation. If the person is wearing contact lenses, the lenses should be removed, if possible. 2. While the eye is being rinsed with water, call Estate Patrol on ext. 3999. Indicate that a person has been exposed to hydrofluoric acid. 3. If available, flush eyes with a sterile 1‐% calcium gluconate solution. Do not apply calcium gluconate gel to eyes. It is critical to irrigate beneath the eyelids. 4. Urgently, take the victim to the RD&E accident and emergency department. Either the first aider or a co‐worker should go with the victim to ensure that the ambulance goes to RD&E. (A pack will be made available within the spill kit and first aid kit to take to the hospital). 5. Ice water compresses may be applied to the eyes while transporting the victim to the accident and emergency department at the RD&E. 6. Inform the medical personnel that the exposure involved hydrofluoric acid. Provide the doctor with all relevant information relating to the HF. Inhalation 1. Remove victim from the exposure and get them to fresh air. 2. If the victim is not breathing, begin artificial respiration immediately. Avoid mouth to mouth contact by using mouth guards or shields. 3. Call Estate Patrol on ext. 3999. Indicate that a person has been exposed to hydrofluoric acid. 4. Oxygen should be administered as soon as possible by a trained individual. 5. Arrange transportation of the victim to RD&E either the first aider or a co‐worker should go with the victim to ensure that the ambulance goes to RD&E and to relay any relevant information to the medical staff. (A pack will be made available within the spill kit and first aid kit to take to the hospital). 6. Inform the medical personnel that the exposure involved hydrofluoric acid. Provide the doctor with all relevant information relating to the HF. Trained personal may elect to provide calcium gluconate (2.5%) by nebulizer. Ingestion 1. Call Estate Patrol on ext.3999. Indicate that a person has been exposed to hydrofluoric acid. 2. Have the victim drink large amounts of water as quickly as possible to dilute the acid. Do not induce vomiting or administer activated charcoal. 3. Arrange transportation of the victim to RD&E. 4. Inform the medical personnel that the exposure involved hydrofluoric acid. Provide the doctor with all relevant information relating to the HF. (A pack will be made available within the spill kit and first aid kit to take to the hospital). 6 College of Life and Environmental Sciences Designated Hospital: Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, Devon, EX2 5DW 01392 411611 ‐ this is the switchboard number for the whole of the RD&E Appendix A Compatible materials for use with HF ( http://www.coleparmer.com/Chemical‐Resistance) Material Compatibility Material Compatibility ABS plastic D‐Severe Effect Epoxy N/A Acetal (Delrin®) D‐Severe Effect Fluorocarbon (FKM) B‐Good Aluminum D‐Severe Effect Hastelloy‐C® B‐Good Brass N/A Hypalon® B‐Good Bronze B1‐Good Hytrel® D‐Severe Effect Buna N (Nitrile) D‐Severe Effect Kalrez A‐Excellent Carbon graphite N/A Kel‐F® A‐Excellent Carbon Steel D‐Severe Effect LDPE N/A Carpenter 20 D‐Severe Effect Natural rubber D‐Severe Effect Cast iron D‐Severe Effect Neoprene D‐Severe Effect Ceramic Al203 N/A NORYL® D‐Severe Effect Ceramic magnet B‐Good Nylon D‐Severe Effect ChemRaz (FFKM) A‐Excellent Polycarbonate D‐Severe Effect Copper B‐Good Polyetherether Ketone (PEEK) D‐Severe Effect CPVC C1‐Fair Polypropylene C1‐Fair EPDM D‐Severe Effect Polyurethane D‐Severe Effect 7 College of Life and Environmental Sciences PPS (Ryton®) D‐Severe Effect stainless steel ‐ 304 B1‐Good PTFE A‐Excellent stainless steel ‐ 316 B1‐Good PVC C‐Fair Titanium D‐Severe Effect PVDF (Kynar®) A‐Excellent Tygon® D‐Severe Effect Silicone D‐Severe Effect Viton® B‐Good Explanation of Footnotes. 1. Satisfactory to 22°C 2. Satisfactory to 48°C Ratings ‐‐ Chemical Effect 
A = Excellent. 
B = Good ‐‐ Minor Effect, slight corrosion or discoloration. 
C = Fair ‐‐ Moderate Effect, not recommended for continuous use. Softening, loss of strength, swelling may occur. 
D = Severe Effect‐‐ not recommended for ANY use. 
N/A = Information not available. 8