How to Handle Perchloric Acid

Required: Before beginning a new project, get approval from your principal investigator (PI) to work with perchloric acid.

• If concentrations greater than 85% will be used, special precautions are required. Contact the chemical safety officer, (858) 822-1579, before beginning work.

Required: A PI or a knowledgeable designee must provide appropriate safety training.

• Instruct employees about the hazards and risks of handling perchloric acid and how to protect themselves. Ensure that:
  • A safety protocol is written into the research procedure.
  • Material Safety Data Sheets (MSDS), the manufacturer's handling instructions, and UCSD standard operating procedures are carefully read.
• Inform employees about possible health effects and routes of exposure (e.g., ingestion, inhalation, and skin contact).
  • See: Exposure response
• Provide and train employees in the correct use of:
  • Personal protective equipment
  • Engineering controls
• Make sure everyone understands what to do in case of emergency by posting emergency procedures in the lab:
  • Emergency Guide
  • Spill preparedness
• Consult the chemical safety officer, (858) 822-1579, on training procedures for any new or revised projects that will:
  • Use large quantities of perchloric acid
  • Heat perchloric acid
• Keep training records that include:
  • Information covered
  • Date
  • Names
  • Employee signatures

Evaluate the hazards before beginning work:

• Consult safety resources:
  • MSDSs
  • Chemical Safety Summary: Perchloric Acid (and Inorganic Perchlorates), Prudent Practices in the Laboratory: Handling and Disposal of Chemicals (1995), The National Academies Press
• Consider these hazards specific to perchloric acid:
  • Health hazards:
    • Irritatation of the skin, eyes, and respiratory tract
    • Painful burns and even death when exposed body parts come in contact with perchloric acid
  • Explosion hazards:
    • Anhydrous (dehydrated) perchloric acid: Perchloric acid is noncombustible. However, anhydrous perchloric acid and certain perchlorate salts of organic, organometallic, and inorganic cations present a serious explosion hazard due to their unstable nature and ability to react violently with many organic materials (e.g., wood, paper, cotton, etc.).
    • Aqueous perchloric acid can cause violent explosions if operations cause concentration or evaporation, or if it's in concentrations greater than normal commercial grade strength (72%). At concentrations less than 72%, aqueous perchloric acid will not decompose spontaneously.
  • Hot, concentrated solutions are extremely dangerous.
    • When used cold, 70% perchloric acid acts as a strong acid and is not considered to be a strong oxidizing agent.
    • When heated, perchloric acid acts as a strong oxidizing agent.
      • Important: NEVER heat perchloric acid in a regular fume hood. Use a wash-down type fume hood. Contact the chemical safety officer, (858) 822-1579, for more information.
    • More concentrated solutions are strong oxidizers, and increases in temperature increase the oxidizing power of perchloric acid.
  • Do not use perchlorates as drying agents if there is any possibility of contact with organic compounds or of proximity to a dehydrating acid strong enough to concentrate the perchloric acid (e.g., a drying train that has a bubble counter containing sulfuric acid). Use a safer drying agent.

• Wear this personal protective equipment (PPE):
  • Lab coat with sleeves fully extended to the wrists
  • Safety glasses or splash goggles and face shield
  • Rubber gloves
  • Full-length pants
  • Rubber apron
  • Closed-toe shoes
• Follow these PPE guidelines:
  • Always double-check your PPE before each use of perchloric acid.
  • Leave all personal protective equipment in the lab when your work is complete.

Perchloric acid is one of the strongest and most corrosive acids. Use and store it with extreme care.

See Chemical Storage and Inventory Guidelines and follow these specifics:

• Label all containers with this information:
  • Name of the material
  • Concentration
  • Warnings
  • Date, when appropriate
  • Preparer's initials, when appropriate
• Label the work area with a sign saying "Perchloric Acid Use Area."
• Isolate perchloric acid from organic materials.
  • Do not store in wooden cabinets or on paper-lined shelves.
• Contact an EH&S Research Assistance Program specialist if you have questions about chemical and container compatibility.

Perform a dry run of your process to work out any potential pitfalls.

• Use less dangerous, more stable products when you can.
• Restrict access to the work area.
• Keep container sizes and quantities in the work area as small as possible.
• Line work surfaces with removable plastic-backed absorbant paper.
• Required for evaporations:
  • Contact the chemical safety officer, (858) 822-1579, before attempting to perform any perchloric acid evaporations.
  • Conduct evaporations of perchloric acid only in a wash down hood.
    • Specifically designed for perchloric acid use, these special fume hoods allow systematic washdowns with water after evaporations, putting the perchlorates back into solution and avoiding inadvertent explosions due to shock or heat.

  Important: If perchloric acid is inappropriately heated in a standard fume hood, accumulation of perchlorates in the fume hood or the associated duct work can make servicing the hood dangerous.

  If you suspect equipment has been contaminated with perchloric acid, contact an EH&S Research Assistance Program specialist. The following actions are required before the fume hood can be serviced or placed in operation:

  • Have the hood tested for perchlorates by a qualified outside vendor.
  • If test results are positive for perchlorate contamination, remediation of the fume hood and associated duct work must be performed by a qualified vendor before the room and fume hood can be cleared.
    • Contact the chemical safety officer, (858) 822-1579, for qualified vendors.
    • The PI or the department responsible for the equipment is responsible for testing and remediation.

Perchloric acid spills are very serious and require immediate cleanup.

• Read How to Handle Chemical Spills in Laboratories.
• Keep a chemical spill kit easily accessible.
• Know the locations and how to use the nearest:
  • Eyewash and emergency shower
  • First aid kit
  • Emergency Guide
  • MSDS: Print and keep a copy with your emergency supplies
• Clean up only very small quantities of dilute perchloric acid, and only if you have been properly trained. If you decide to clean up a spill yourself:
  • Use only materials appropriate for perchloric acid (e.g., chemical absorbent pads).
  • Never use organic materials such as paper towels or cloth rags.
• Dispose of all spill containment material as hazardous chemical waste.

Treat any exposure seriously, no matter how slight it may seem at the moment.

• All exposures:
  • Give first-aid treatment, and then seek medical attention immediately at an emergency room.
  • Call Campus Police at (858) 534-4357 (534-HELP) and request an ambulance, if transportation is necessary.
  • Call Poison Control, (800) 222-1222, if additional information is needed.
• Ingestion:
  • Seek medical attention immediately.
• Skin exposure:
  • Flush exposed skin with water for at least 15 minutes while removing any contaminated clothing.
• Eye exposure:
  • Flush eyes with water for at least 15 minutes. The affected person may need help holding their eyes open under water.

Read these articles to help you identify and dispose of hazardous waste:

• Identify hazardous chemical waste
• Store and dispose of hazardous chemical waste
• Store and dispose of extremely hazardous chemical waste
• Request a hazardous waste collection