Guidelines

Working Safely with Hydrofluoric Acid - Guidelines

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1. Purpose and Objectives

The purpose of this guideline is to provide information on hydrogen fluoride and hydrofluoric acid to minimise the likelihood of injuries and illnesses occurring from its use and storage.

2. Definitions, Terms, Acronyms

HF - Hydrofluoric acid or hydrogen fluoride gas.

SDS - Safety Data Sheet.

PPE - Personal Protective Equipment.

3. Guidelines Scope/Coverage

This guideline applies to all University workers and students who use, store, handle, transport and/or dispose of hydrogen fluoride and hydrofluoric acid.  

4. Guidelines Statement

All workers and students at The University of Queensland have a duty under the Work Health and Safety Act 2011, to ensure that the risk of exposure to hydrofluoric acid and hydrogen fluoride is eliminated or minimised as far as possible. 

5. Risk Management

5.1 Risk Assessment

Hydrofluoric acid is used in a wide range of laboratories because of its ability to dissolve silicon and silica containing materials. It is also used to selectively etch and brighten metals. Because of these unique properties it cannot be readily substitued by other less hazardous acids.

Hydrofluoric acid (HF) readily penetrates the skin and deeper tissues, binding to calcium and causing tissue damage including decalcification of bone. Hydrogen fluoride may cause severe, painful burns to the skin, eyes, mucous membranes and severe respiratory irritation. Large burns, or exposure to very concentrated solutions may result in gastro intestinal problems, cardiac arrhythmias and death.

Guidelines on which HF burns have a high probability of systemic producing toxicity are:

  1. Exposure of 1% of body surface area to 50% or greater HF solution.

  2. Exposure of 5% of body surface area to any HF solution (Kirkpatrick JJR et al. 1995).

The palm of the casualty’s hand represents approximately 1% of the body’s surface area.

Persons working with dilute HF solutions should be aware that delayed pain can occur after skin exposure, and where any direct contact occurs, in addition to immediate first aid (see section 5.3.1), post exposure advice and examination should be sought from a medical doctor.

All workplaces and research laboratories throughout the University of Queensland should ensure the following:

Prior to working with hydrofluoric acid a risk assessment must be documented with reference to the safety data sheet (SDS) for the concentration of HF being used. In some cases PPE above the normal disposable nitrile gloves, safety glasses, lab coat and closed in footware will be required. Careful consideration of storage and spills procedures must be given and suitable controls must be in place and included in the risk assessment. 

5.2 Training and competency

All personnel working at the University are required to complete mandatory online General Workplace and Annual Fire Safety training.  Personnel working in laboratories and with chemicals are required to complete additional online training modules for Laboratory and Chemical Safety. Specific training in regards to the chemical properties of HF and the first aid treatment required for exposed workers must also be provided.

5.3 Emergency procedures

5.3.1 Spills

The spills category must be assessed during the risk assessment process and prior to handling this substance. The category of spill is determined based on concentration of the chemical, quantity and where the spill occurs. Worker PPE must be in place and extra attire must be on hand before cleaning up minor spills and must be appropriate to the clean up task.

Major Spill

  • In the event of an unexpected spill of HF, leave the area and ensure others leave too, then contact UQ Security on x53333 (or emergency number as stated on your UQ Emergency Procedures Card)and your local Work Health and Safety Coordinator or Safety Manager for advice. 

  • Prevent others entering the area. Do not attempt to clean up any major spills.

  • If the worker has been contaminated, the contaminant must be removed immediately - don PPE including gloves and remove any contaminated clothing from the person, then move them to a safety shower/eyewash and wash off the contaminants thoroughly (at least 20 minutes under shower or eyewash as appropriate). Contact your local First Aid Officer and UQ Healthcare for advice. See Section 5.3.2 First Aid below.

  • Do NOT use water to clean up.

  • Do NOT touch the spilled material.

  • Use emergency PPE: PVC overalls, PVC boots, half face respirator with Type B* gas filter, (self-contained breathing apparatus for major spills) if removing a casualty from the affected work area.

* Type B gas filter is for use against specified inorganic gases and acid gases

Minor spills

Minor spills should be cleaned up immediately. A suitable spill kit should be on hand where this chemical is being used and stored that contains absorbents e.g. magnesium sulphate pad, suitable for HF (no silicates - toxic silicon tetrachloride gas reaction product with HF). HF is highly corrosive to metals and ceramics and should not be washed into drains unless very dilute. Prevent HF from entering the drains by use of spill kit absorbent pads. All waste should be collected into plastic Chemwaste containers and returned to the UQ Science Store for disposal.

5.3.2 First aid

The severity of HF burns is largely dependent on the surface area contaminated with the substance and the concentration of the acid. For more information on chemical burn first aid please refer to PPL 2.60.22 First Aid for Burns including Chemical Burns.  Obtain urgent medical advice or transport the patient to hospital by ambulance, explaining to emergency staff and the casualty the importance of early treatment and the risk of a delayed reaction. Keep the patient quiet, warm and comfortable. Do not permit the patient to return to work or to go home without medical examination because of the possibility of delayed symptoms.

 Skin contact:

  • Immediately flush body and clothes with large amounts of water, using a safety shower if available.

  • Remove contaminated clothing wearing PVC gloves and drench the area with water for a sufficient period of time, usually one to two minutes, to remove all hydrofluoric acid.

  • Apply calcium gluconate gel (2.5%- available in 25gm tubes), to and around the contaminated area and massage in with gloved fingers. White specks appearing around the contaminated area indicate that the desired reaction has taken place.

  • Continue to massage affected skin with repeated application of gel for at least 30 minutes or until medical treatment becomes available.

  • For burns to hand, place gel in a latex/nitrile glove and put this on the hand or cover with a gel soaked dressing and lightly bandage.

  • Seek medical assistance and send calcium gluconate gel with patient. Repeat application during transit to hospital.

  • If no gel is available, continue flushing until medical assistance arrives.

Eyes

  • Irrigate the eyes immediately and copiously with water or isotonic saline (normal saline, 0.9% sodium chloride in sterile water) until advised to stop by a medical practitioner or Poisons Information Centre (tel:13 11 26) or for at least 30 minutes.

  • Remove contact lenses if necessary and continue flushing.

  • ALWAYS obtain specialist medical attention continue flushing during transport to hospital if possible.

  • Do not apply calcium gluconate gel to eyes.

Inhalation

  • Rescuers must wear respiratory protection (self contained breathing apparatus in the case of a MAJOR leak or spill).

  • Transfer the casualty to an uncontaminated area.

  • If breathing stops, clear airway and give expired air or cardiopulmonary resuscitation as needed. Oxygen should be given by Security, an advanced First Aid Officer, doctor or ambulance officer.

6. Obligations

6.1 Supervisors

  • Make safety data sheets (SDS) available to all staff to provide information on chemical use.

  • Ensure that risks are eliminated or minimized as far as reasonably practicable.

  • Provide supervision and training in the safe use of these materials.

  • Provide assistance with the risk assessment process and to ensure the assessment is comprehensive and accurate.

  • Review and approve the risk assessment, and to ensure all controls outlined in the assessment are followed by workers at all times.

  • Ensure that all appropriate safety systems and equipment are in place, fully operational and used correctly.

  • Ensure that all incidents involving these materials are investigated as soon as possible and that corrective actions (including review and modification of risk assessment and SOPs) are implemented to prevent recurrences.

6.2 Workers and students

  • Ensure that risks are eliminated or minimised as far as reasonably practicable.

  • Provide assistance with the risk assessment process, help ensure the assessment is comprehensive and accurate.

  • Follow safe operating procedures and to use the controls outlined in the risk assessment.

  • Wear all PPE required and ensure it is maintained in good condition.

  • Report any changes to procedures to the supervisor that may change the risk assessment in place.

Reference:

Kirkpatrick JJR, Enion D.S, Burd D.A.R. Hydrofluoric acid burns; a review, Burns, Vol 21, pp 483-493 1995

7. Contacts for Further Information

Occupational Health and Safety Division

hsw@uq.edu.au

Custodians
Director, Occupational Health and Safety Mr Jim Carmichael
Custodians
Director, Occupational Health and Safety Mr Jim Carmichael