HYDROFLUORIC ACID
STANDARD OPERATING PROCEDURE TEMPLATE
Type of SOP: Process Hazardous Chemical Hazard Class
To customize this SOP, add lab-specific information to the sections below marked in RED, as applicable. Completion of the last section (“Lab-Specific Information”) is required. Also, any of the content below may be amended with lab-specific information to enhance worker safety as desired.
HAZARD OVERVIEW
Hydrofluoric acid (HF) is a highly corrosive liquid and is a contact poison. It should be handled with extreme care (i.e., beyond what is generally required to handle other mineral acids). Owing to its low dissociation constant, HF as a neutral lipid-soluble molecule penetrates tissue more rapidly than typical mineral acids. Because of the ability of hydrofluoric acid to penetrate tissue, poisoning can occur readily through exposure of skin or eyes, or when inhaled or swallowed. Symptoms of exposure to hydrofluoric acid may not be immediately evident. HF interferes with nerve function, meaning that burns may not initially be painful. Accidental exposures can go unnoticed, delaying treatment and increasing the extent and seriousness of the injury.
HF is a calcium seeker. A person can’t sense when it comes in contact with the skin. But, it dissolves the calcium in the bone. HF burns are not evident until a day later. If not stored, handled and disposed of properly, HF can pose a serious threat to the health and safety of laboratory personnel, emergency responders and waste handlers. Hence, it is important to thoroughly understand the properties of HF and follow all safety protocols to properly store and handle HF.
EXPOSURE LIMITS
Cal-OSHA has established maximum inhalation exposure limits for workers in occupational settings for over 500 chemicals. These are known as Permissible Exposure Limits and can not legally be exceeded. For hydrofluoric acid the PEL is quite low:
0.4 ppm - 8 hour time-weighted average exposure
1 ppm - 15 min. time-weighted average exposure (short term exposure limit)
Therefore, work with hydrofluoric acid should always be done in a fume hood, glove box, or in totally-sealed containers to keep inhalation exposures as low as possible. Contact EH&S if you believe you are being exposed. In some instances EH&S can do quantitative exposure monitoring. Because HF is also a serious skin contact hazard, skin exposure should also be absolutely minimized.
PERSONAL PROTECTIVE EQUIPMENT (PPE)
See the PPE information under Sec. II of the UCSB Chemical Hygiene Plan regarding:
· the UC PPE Policy and policy summary (what PPE is needed and when/where to use)
· obtaining your PPE via use of the Laboratory Hazard Assessment Tool
· glove selection criteria
· respirator use, etc.
At minimum, complete protection of the eyes and skin is essential. Neoprene gloves are recommended.
ENGINEERING/VENTILATION CONTROLS
For further information see the following pages in Sec. II of the UCSB Chemical Hygiene Plan:
· Fume Hood Usage Guide
· Criteria for Implementing Engineering Controls
SPECIAL HANDLING PROCEDURES AND STORAGE REQUIREMENTS
· Ensure that you have all the PPE required for handling HF.
· HF must always be stored in plastic (Nalgene / polypropylene) containers. DO NOT store HF in glass bottles/containers.
· Store in corrosive/acid storage cabinet within a secondary containment (Nalgene/ polypropylene tray or tub).
· Do not store in the top most shelf of the storage cabinet. Note: In general, do not store chemicals at or above eye level.
· Ensure the container is tightly closed at all times.
· Do not store with oxides, organic chemicals, bases or metals.
· Carefully carry the stock bottle in a rubber maid bottle carrier/Nalgene secondary container to the wet bench/chemical fume hood and pour out desired amount into a smaller container.
· Place stock bottle back in corrosive chemical storage cabinet with cap tightly closed.
· Lab buddy system is highly recommended when handlingHF. Lab emergency contact information must be readily available. The lab personnel musthave easy access to a telephone (landline or cell phone).
SPILL AND INCIDENT PROCEDURES
See directions under the “Chemical Incident” tab of the UCSB Emergency Information Flipchart – should already be posted in all labs.
In case of skin contact
Immediately (within seconds) flush affected area for at least 15 minutes. Remove all contaminated clothing. Call 911 from a campus phone to get immediate emergency medical attention. Wearing compatible gloves, massage calcium gluconate gel into the affected area. Re-apply every 15 minutes until medical help arrives. Note: Hydrofluoric acid exposure is often treated with calcium gluconate, a source of Ca2+ that sequesters the fluoride ions. HF chemical burns can be treated with a water wash and 2.5% calcium gluconate gel, or special rinsing solutions. However, because it is absorbed, medical treatment is necessary; rinsing off is not enough. Intra-arterial infusions of calcium chloride have also shown great effectiveness in treating burns. In some cases, amputation may be required.
In case of eye contact
Use Emergency Eyewash immediately. Call 911 from a campus phone to get immediate emergency medical attention. Continue flushing eyes until emergency responders arrive.
DECONTAMINATION
Using proper personal protective equipment as outlined above, decontaminate equipment and bench tops using soap and water and properly dispose of all chemical and contaminated disposables as hazardous waste following the guidelines below.
WASTE DISPOSAL
See “Chemical Waste Disposal” in Sec. II of the UCSB Chemical Hygiene Plan.
PRIOR APPROVAL/REVIEW REQUIRED
As they deem necessary, the PI/supervisor should insert here any prior approval or review needed before an individual can do the operation.
DESIGNATED AREA
As they deem necessary, the PI/supervisor should insert here any information about whether a special use-area is designated for this material/process.
SAFETY DATA SHEETS
Found online at: http://ehs.ucsb.edu/labsafety/msds
LAB-SPECIFIC INFORMATION (required) (Examples of appropriate content)
Add appropriate lab-specific information here describing how this material(s) is generally used. E.g., name of protocol, typical frequency done, quantities used, temperature and any additional safety measures, etc.
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