How to Use a Centrifuge Safely

UC San Diego researchers working with a centrifuge must complete a “Centrifuge” hazard control plan (HCP).

This HCP must be preapproved by the principal investigator prior to beginning any work with this equipment.

Follow manufacturer instructions meticulously to avoid metal fatigue, distortion, and corrosion.

Serious damage from a mechanical failure (e.g., rotor failure, tube, or bucket failure) can include damaged equipment, laboratory space, and worker injury.

• Review the operating manual before using a centrifuge. Get a copy from the manufacturer if it's not available in the lab.
• Maintain and operate the centrifuge according to manufacturer instructions.
• Examine the centrifuge often for damage or poor maintenance.
• Properly train users. Post operating instructions that include safety precautions on the unit.
• Know how to contact your vendor in case of problems.

Control rotor hazards!

High-speed rotor heads are prone to metal fatigue. Failure to discard rotors after a predetermined amount of use can result in dangerous and expensive rotor disintegration.

Avoiding rotor failure is critically important.

Follow these guidelines to reduce the risk of rotor failure:

• Use the correct rotor with the correct centrifuge (i.e., Beckman rotors in Beckman centrifuges).
• Use sealed rotors, sealed buckets, or a guard bowl with a gasket and cover, as well as safety centrifuge tubes (tube or bottle carrier with sealable cap or "O" gasketed cap).
• Record the purchase date of each rotor, along with manufacturing date and serial number.
• Read the operating manual for your machine before using the equipment and follow manufacturer specifications for the rotors and tubes. Keep the manuals near the unit for easy reference.
• Follow the manufacturer's operating instructions. Maximum speed and sample density ratings designated by the manufacturer for each rotor are intended to prevent stress failures.
• Before running an ultracentrifuge, confirm the classification decal on the ultracentrifuge matches the classification decal on the rotor.

Ultracentrifuge rotor use and service tracking:

• Keep a log book for each rotor, recording the length of time and speed for each use.
• Use the log book to track and discard rotors according to the manufacturer's recommended schedule.
• Ultracentrifuge machines must have the rotor log accessible.  
• If the ultracentrifuge log cannot be found, the rotors must be changed and a new log started.

Aerosols are a cloud of very small liquid droplets produced whenever energy is applied to a liquid, and such liquid is allowed to escape into the environment.

Aerosols may be created when filling centrifuge tubes, removing plugs or caps from tubes after centrifugation, removing supernatant, resuspending sedimented pellets, and by the very process of centrifugation.

The greatest aerosol hazard is created if a tube breaks during centrifugation.

Minimize aerosols when centrifuging biohazardous material:

• Fill and open centrifuge tubes, rotors, and accessories in a biological safety cabinet (BSC).
• Use sealed tubes and safety buckets that seal with O-rings. Before each use inspect tubes, O-rings, and buckets for cracks, chips, erosions, bits of broken glass, etc.
• Do not use aluminum foil to cap centrifuge tubes—it may detach or rupture during centrifugation.
• Avoid the use of celluloid (cellulose nitrate) tubes with biohazardous materials. Celluloid centrifuge tubes are highly flammable and prone to shrinkage with age. They distort on boiling and can be highly explosive in an autoclave. If celluloid tubes must be used, an appropriate chemical disinfectant must be used to decontaminate them.
• Avoid overfilling centrifuge tubes to prevent closures from becoming wet. After tubes are filled and sealed, wipe them down with disinfectant.
• Add disinfectant to the space between the tube and the bucket to disinfect material in the event of breakage during centrifugation.
• Always balance buckets, tubes, and rotors properly before centrifugation.
• Open centrifuge tubes that contain biohazardous specimens inside a BSC with the tube pointed away from you.
• Do not decant or pour off supernatant. Use a vacuum system with appropriate in-line reservoirs and filters. For more information, contact EH&S Biosafety, (858) 534-5366.
• Work in a BSC when resuspending sedimented material. Use a swirling rotary motion rather than shaking. If shaking is necessary, wait a few minutes to permit the aerosol to settle before opening the tube.
• Small low-speed centrifuges may be placed in a BSC during use to reduce aerosol escape.
• High-speed centrifuges pose additional hazards. Precautions should be taken to filter the exhaust air from vacuum lines.

Questions about biohazardous materials?

Contact EH&S Biosafety, (858) 534-5366.

Before running the centrifuge:

• Operate centrifuges only in designated research space to ensure adequate ventilation.
• Use metal or plastic tubes (other than nitrocellulose) whenever possible.
• Check tubes for cracks before each use. Inspect the inside of the cups for rough walls caused by erosion. Remove any adhered matter.
• Do not use aluminum foil to cap centrifuge tubes—it may detach or rupture during centrifugation.
• Do not scratch or otherwise damage the aluminum oxide layer that protects the machine's underlying metal.
• Make sure the rotor, tubes, and spindle are dry and clean and that the rotor is properly seated and secured to the drive hub. Tubes must be properly balanced in the rotor (½ gram at 1 G is roughly equivalent to 250 kilograms @ 500,000 G's).
• Reduce speed as specified in the manual for running high-density solutions, plastic adapters, or stainless steel tubes.
• Set and confirm the proper run speed each time to prevent over-speeding.

If a tube breaks during the run:

• Turn off the centrifuge and allow the contents to stand undisturbed for 15 minutes before opening.
• Contact an Environment, Health & Safety specialist in biosafety, radiation safety, or chemical safety if you are unsure how to handle the spill: (858) 534-3660.
• Clean and disinfect the rotor in a chemical fume hood if possible.
• If infectious or radioactive material was placed in the centrifuge, plan proper decontamination and cleanup.
• See the "Be prepared for accidental spills" section below for more information.

When the run is complete:

• Make sure the rotor has STOPPED before opening the centrifuge lid when the run is complete.
• Clean and disinfect tubes, rotors, and centrifuge interiors after use. Never leave a centrifuge in a contaminated state.
• Follow the manufacturer's cleaning and disinfection recommendations to avoid rotor fatigue, distortion, and corrosion. Maintenance of tubes, rotors, and other components requires considerable care. No single method is suitable for all items.
• Wash only the buckets of a swinging bucket rotor. Never immerse the body of the rotor — the hanger mechanisms are hard to dry and can rust.

Infectious materials:

High-speed centrifuge chambers are connected to a vacuum pump. If there's a breakage or accidental dispersion of infected particles, the pump and pump oil will become contaminated. Take these precautions:

• Place a HEPA filter between the centrifuge inner chamber and the vacuum pump when containment is needed.
• Work within a biosafety cabinet when filling centrifuge tubes or bottles, and when loading or removing them from the rotor (to provide containment in case a tube or bottle leaks or breaks).
• See the "Aerosols" section above for more information.

The principal investigator (PI) or a knowledgeable designee must provide and document appropriate safety training.

• Inform employees about the safe use of centrifuges, their specific hazards, and possible health effects.
• Explain possible routes of exposure of material used in centrifuges, as appropriate:
  • Skin contact
  • Eye exposure
  • Inhalation
• Provide personal protective equipment (PPE) and engineering controls, and train employees in their proper use.
• Keep training records on file, including:
  • Information covered
  • Date
  • Names
  • Employee signatures

Related links:

• Safety Training for Lab and Research Employees

• Wear this personal protective equipment:
  • Lab coat with sleeves fully extended to the wrists
  • Safety glasses or splash goggles and face shield
  • Gloves, compatible with the hazardous material being processed
  • Full-length pants
  • Closed-toe shoes

Related links:

• Personal Protective Equipment
• PPE Support for Researchers

Contact an Environment, Health & Safety specialist in biosafety, radiation safety, or chemical safety if you need assistance:

• Call (858) 534-3660 during business hours.
• After hours, call Campus Police at (858) 534-4357 (534-HELP).

General spill preparedness:

• Keep a chemical spill kit easily accessible.
• Read How to Handle Chemical Spills in Laboratories.
• Print and keep the Safety Data Sheet for any hazardous materials routinely used in the centrifuge with your emergency supplies.
• Know the location of safety equipment, including:
  • Eye wash and emergency shower
  • First aid kit
  • UC San Diego Emergency Guide
• Clean up small-scale spills only if you have been properly trained.
  • Restrict access to the spill.
  • Wearing proper PPE, clean and disinfect the centrifuge interior and head (or cups) according to manufacturer instructions.
  • Dispose of all spill containment material as hazardous waste. Consult Hazardous Waste for chemical, biological, and radioactive waste disposal procedures.

Biohazardous spill inside a centrifuge

• If infectious material was placed in the centrifuge, clear area of all personnel.
• Wait 30 minutes for aerosol to settle before attempting to clean up spill.
• Wear a lab coat, safety glasses and gloves during cleanup.
• Remove rotors and buckets to the nearest biological safety cabinet for cleanup.
• Thoroughly disinfect inside of centrifuge.
• Discard contaminated disposable materials using appropriate biohazardous waste disposal procedures (check with your lab manager).

Radioactive material

Minor spills (microcurie amounts in a single room) can result in contamination of the floor, lab surfaces, equipment, and personnel.

• Read How to Clean Up Minor Radioactive Contamination before processing radioactive material in the centrifuge.

Maintenance

• Follow manufacturer instructions for maintenance.
• Read the "Mechancial failure" section above for critical maintenace details.

Cleaning

Moisture, chemicals, strong cleaning agents, and other substances can corrode centrifuge parts. 

• Follow manufacturer instructions for cleaning.
• Keep the centrifuge clean and dry.
• Use distilled water and mild detergent for cleaning, then dry the surface thoroughly.
• Do not use strong alkaline or acid cleaners that could damage the finish and corrode the metal shell.

Storage

• Store and use centrifuges only in well-ventilated locations.
• Never locate centrifuges in corridors or administrative spaces.
• Store all fixed-angle vertical tube and near-vertical tube rotors upside down, with the lids or plugs removed.
• Store swinging bucket rotors with the bucket caps removed.
• Store all rotors in a dry environment—not in the centrifuge.
• Do not use a rotor after the expiration date permanently marked (on some models) on the rotor or rotor accessories.
• Take expired components out of service.

Give first aid treatment, then seek medical attention immediately for any and all hazardous material exposures.

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

• 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. Affected individuals may need help holding their eyes open under water.
• Ingestion: Seek medical attention immediately.
• For all exposures:
  • 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 the California Poison Control System, (800) 222-1222, if additional information is needed.

• Working With Laboratory Equipment, 6.C.6.2 Centrifuges, "Prudent Practices in the Laboratory: Handling and Disposal of Chemicals" (1995), The National Academies Press.