Hydrofluoric Acid and HF Management

In recent times, there is much chemical misbehaviour observed. Be it out of no knowledge or negligence. Let us understand about Hydrofluoric Acid and HF Management in this article.

 Why do accidents happen in handling? :

 It is common for Operators/Technicians to display complacency after an extended period of time without refresher training or reminders of why it is vital to respect the material/substance or process in use at any time in any given organisation.

 

To this end:

  • Identify and report all Sites/Laboratories storing, handling and using Hydrofluoric Acid, must confirm there is a site-specific Management Plan for storing, handling and using Hydrofluoric Acid. Refer to Appendix for an example. If a Management Plan is available confirm it has been reviewed and is current.
  • Review and update Risk Assessment/JSEA with workers and specialists.
  • All workers, involved in storing, handling and using Hydrofluoric Acid, must receive initial and refresher (at least 2-yearly) training in the safe storage, handling and use of Hydrofluoric Acid.
  • Sites storing, handling and using Hydrofluoric Acid, must ensure the relevant areas of laboratories are clearly identified and segregated. Hydrofluoric Acid must be secured when not in use, by the relevant laboratory team leader.
  • First aid options need to include “Hexifluorine” as the initial treatment for contact with Hydrofluoric Acid, followed by the application of Calcium Gluconate. Before transfer to the appropriate Hospital Emergency Department with the most up to date version of the Hydrofluoric Acid Safety Data Sheet.
  • All HF Technicians and 1st Aiders must be trained in the application of “Hexifluorine” and Calcium Gluconate, including preparation to transfer the injured worker to the hospital.

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ACTIONS TO FOLLOW
  • Always post any Safety violation Notice to site notice boards, educating will lessen the chances of reoccurrence.
  • Identify Sites/Laboratory storing, handling and using Hydrofluoric Acid.
  • Confirm a HF Management Plan is available and up to date and facilities are compliant to requirements.
  • Review and update site Risk Assessment, JSEA, etc.
  • Ensure initial and refresher training is up to date.
  • Ensure appropriate first aid supplies (“Hexifluorine” and Calcium Gluconate) are available and 1st Aiders are trained in its use.
  • Distribute to Relevant Business Managers and QHSE Network members.

APPENDIX

Example Hydrofluoric Acid Management Plan

  1. PURPOSE

Hydrofluoric Acid is an extremely hazardous chemical with serious risk of poisoning by inhalation, swallowing or skin contact. This management plan identifies the hazards associated with Hydrofluoric Acid and describes the precautions to be followed to manage the potential risk for exposure to Hydrofluoric Acid.

  1. SCOPE OF APPLICATION

This management plan may apply to all laboratories and laboratory staff where Hydrofluoric Acid is stored and used.

  1. SAFETY

  • ONLY personnel trained in handling HF can use this substance – NO EXCEPTIONS.
  • ALL designated PPE is to be worn at all times when handling HF.
  • The work area must be designated and segregated from other areas of the laboratory.
  • DO NOT use glass with Hydrofluoric Acid.
  • All First Aid supplies and equipment must be checked before handling HF.
  • All designated First Aiders must be advised when people are handling HF.
  • The local medical facility must be advise HF is used on-site and an MSDS provided.
  • ALWAYS consider replacing HF with a less hazardous substance. 
  1. PROCEDURE

DANGER:

EVERY CONTACT WITH HYDROFLUORIC ACID MUST BE TREATED IMMEDIATELY AND CORRECTLY, AS CONTACT MAY BE FATAL.

Contact with concentrated strong hydrofluoric acid (40% or more) is usually immediately apparent. Hydrofluoric Acid penetrates rapidly and deeply below fat layers binding and depleting tissue calcium. Immediate excruciating pain is felt. Unchecked, destruction of tissue continues for days or even weeks. Penetration becomes deeper, resulting in extensive tissue necrosis involving tendons and bone. These burns initially have a bleached, then grey-purple leathery appearance, later becoming black. Swelling and blistering may occur before extensive, slow healing ulcers form. Some possible symptoms may include: pain, nausea and vomiting or bloody vomiting, spasms and collapse and /or coma. There may also be heart, nerve and intestinal problems.

There is a major risk of systemic toxicity following inhalation, ingestion or skin burns. Inhalation may lead to chemical pneumonitis, haemorrhagic pulmonary oedema or laryngeal oedema. Skin burns may become gangrenous and spread. Severe corneal damage may occur with eye contact.

Lesser concentrations may not be immediately painful and with concentrations of less than 20%, many hours may elapse before pain occurs. This is due to the slowness of in penetrating the layers of skin. Although this delay occurs, destruction of subcutaneous tissue inevitably ensues, following the pattern described above.

There is no exception to this, whether it be the slightest contact with 100% hydrofluoric acid or 1% hydrofluoric acid vapour.

Kloss and Bruce. Toxicology in a Box. McGraw-Hill Education 2014.
Source: Kloss and Bruce. Toxicology in a Box. McGraw-Hill Education 2014.

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5.1       RESPONSIBILITY

Laboratory managers are responsible to ensure relevant personnel are trained to use Hydrofluoric Acid and use the substance correctly.

Supervisors are responsible for ensuring that all safety precautions are followed when Hydrofluoric Acid is in use.

 5.2       General Instructions for Use

  1. Supervisor and First Aid Officer should be contacted before starting work with hydrofluoric acid. An announcement should be made to the immediate area of the laboratory that use of Hydrofluoric Acid is to commence.
  2. Work in a designated area clearly delineated with floor markings and signage to restrict access to the work area.
  3. Hydrofluoric Acid must be stored in a separate lockable container in a fume hood. A clear, visible sign should be placed on the outside of the container. Hydofluoric acid must never be stored with other chemicals in an easily accessible location.
  4. MSDS must be enlarged and present in a visible location on inside and outside of the fume hood. Training on MSDS interpretation must be conducted.
  5. Carry out all work in a well-ventilated fume hood with the sash down as far as practical, wearing designated PPE including elbow length neoprene or nitrile rubber gloves; rubber apron and full-face mask as a minimum personal protective clothing requirement.

DANGER:

DO NOT use glass with Hydrofluoric Acid as this will destroy the glass and contaminate the sample with salts leached from the glass. Platinum, plastic or Teflon apparatus must be used at all times.   After a sample has been neutralized with boric acid solution, then a glass apparatus may be used.

  1. All apparatus used must be rinsed with 10% boric acid and water before leaving the fume hood.
  2. Carefully evaporate sample on low heat to avoid splatter. High heat should never be used when using Hydrofluoric Acid.
  3. Never dispense more than 10 mL of hydrofluoric acid at any time. Supervisor/ qualified chemist must be present during all dispensing of Hydrofluoric Acid.
  4. No more than 80 mL of Hydrofluoric Acid may be in use at any one time. ( ie. 4 crucibles each with 10 mL).
  5. Evacuate the Laboratory in cases where a Fume Hood handling Hydrofluoric Acid fails or when a spill of Hydrofluoric Acid occurs.

5.3       Instructions for First Aid Administration

There are 2 first aid treatments available for contact with Hydrofluric Acid:

  • Calcium Gluconate, and
  • Hexafluorine solution (IF AVAILABLE).

IMPORTANT:

Laboratory Managers must inform all personnel working with Hydrofluoric Acid of the specific first aid treatment available at that laboratory and ensure they are trained in its use and how to report every occurrence involving Hydrofluoric Acid.

IMPORTANT:

In all cases of contact with Hydrofluoric Acid, ALWAYS seek secondary Medical attention due to the severity of Hydrofluoric Acid.

  1. Activate the emergency alarm button if available on site. Inform a first aid officer and call an ambulance immediately if any skin contact occurs.  It is likely that a burning sensation will not occur immediately upon contact due to the concentration of acid used in this laboratory.
  2. Any person who is to treat the burn must be wearing rubber gloves BEFORE touching any part of the skin or clothing of the person affected, this to stop further spreading of the acid.

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Calcium Gluconate

3a.         Wash all skin contacts with copious amounts of water in the safety shower for at least one minute, removing all affected clothing . 2% calcium gluconate gel should be applied liberally to the affected area and continuously massaged into the skin for at least 15 minutes or until medical aid becomes available.  Continue washing burn with copious amounts of water until ambulance arrives ( only if calcium gluconate gel is not applied), supply the paramedics with a copy of the MSDS. Efferverscent Calcium Glutonate solution may also be consumed as per product instructions.

Hexafluorine

3b.       Remove all affected clothing. Hexafluorine solution is applied liberally until full contents of container is used and then seek secondary medical attention due to the severity of Hydrofluoric Acid.

  1. All injured workers must be escorted at all times when being transported to a medical facility.

IMPORTANT:

Only use Hexafluorine (full contents) and then seek secondary Medical attention due to the severity of Hydrofluoric Acid.

5.4       Clean-up of Hydrofluoric Acid

  1. Use appropriate gloves.
  2. In event of a spill, dose spill with boric acid powder (or lime in sodium carbonate solution) and rinse with water.
  3. Wipe up with paper towel and place in a plastic bucket to soak in boric acid solution to ensure neutralization for at least 30 minutes. Paper towels may then be disposed off in a hazardous waste bin.
  4. All spills must be reported to the respective personnel.
  5. For routine clean up, all plasticware must be rinsed with 10% boric acid then liberally with water when testing is complete. Surfaces must be rinsed with 10% boric acid then wiped down with water.

 5.5       Disposal of Hydrofluoric Acid

  1. An acid disposal waste unit must be present in a fume hood.
  2. Neutralize with 10% boric acid then add water.
  3. Soak all waste paper in 10% boric acid for at least 30 minutes.
  4. All waste paper should be disposed of in hazardous waste bin after decontamination.
  5. Liquid waste may be disposed of as acid waste.

5.6       Unsuitable Working Materials

  1. Glass, Quarzes/silicate ceramics. Will corrode most metals to some degree.
  2. Silicon compounds, fluorine, strong bases, potassium permanganate and bismuth acid.

5.7       Training Requirements

  1. All personnel handling and using Hydrofluoric Acid must complete the internal training module titled “Safe Handling of Hydrofluoric Acid in Laboratories”.
  2. All other site personnel are to complete the internal training module titled “Hydrofluoric Acid Awareness Training”.
  3. Retraining is carried out every 2-years to refresh the importance of and the correct methods to use with Hydrofluoric Acid.

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