ehs logo

Health & Safety Manual - Biological Safety

2.6 Laboratory Equipment

2.6.1 Water Baths
2.6.2 Cryostats
2.6.3 Mixers, Sonicators, and Blenders
2.6.4 Needles and Syringes
2.6.5 Lyophilizers

In additional to electrical and mechanical considerations, laboratory equipment poses hazards related to the materials used in them.  Some equipment may be one-of-a-kind with each requiring its own learning curve before it can be safely used.  Some equipment becomes obsolete relatively quickly and with each new piece, comes the need to relearn some operational aspect.

Be sure that ‘owners’ manuals’ are readily accessible and when in doubt, contact a customer service representative.  Do-it-yourself fixes are not only dangerous but may invalidate warranties.  Senior lab personnel should be responsible for ensuring that new staff are familiar with the safe operation of equipment.

There also may be specific requirements for moving sophisticating machinery in which case a customer service official should be contacted or the users’ manual carefully reviewed.

2.6.1 Water Baths
Water baths may become contaminated by organisms incubated in them or through amplification of water or airborne organisms.  Iodine-based or phenolic disinfectants are recommended for intermediate temperature baths.  A 1/1,000 dilution of household bleach is also effective but may corrode water bath components.  It has been reported that placing a few pennies (copper) in the bath will inhibit microbial growth.  Never use sodium azide; it is fairly toxic and drain disposal is illegal and may result in the formation of explosive metal azides. Consult the manufacturer to determine the recommended disinfectant.  Do not leave water baths on overnight or when they will be unattended for an extended period of time.

Go to Top

2.6.2 Cryostats

Cryostats should be regularly decontaminated with a tuberculocidal hospital disinfectant (see Decontamination, section 2.7).  Trimmings and tissue sections should be treated as potentially infectious.  Never attempt to clear debris from a blade with your finger; always use a brush or other mechanical device to prevent contact with the blade.  When changing blades use protective gloves and handle the blades with forceps or tongs.  Pre-soaking blades in a disinfectant solution prior to cleaning (removal of debris) will reduce the number of viable microorganisms. 

2.6.3 Mixers, Sonicators, and Blenders
Mixers, sonicators, and blenders produce large quantities of aerosols.  Models designed to contain aerosols are available.  These devices should be operated within a BSC with a disinfectant-moistened towel placed over the top.  Open only after allowing time for aerosols to settle.  If possible, avoid using glass bowls.  Sonication may be safely performed by placing a tightly capped specimen tube in a beaker of water and putting the probe in the water, not in the tube.

2.6.4 Needles and Syringes
Sharps should only be used when no other alternative is available.

  • Use blunt needles, pipettes, or canulas to aspirate fluids instead of hypodermic needles; substitute plastic for glass when possible.
  • Use only needle-locking units or units in which the needle is an integral part of the syringe.
  • Dispose all needles properly in a "sharps" container immediately after use.
  • Dispose of unused needles in sharps containers.
  • Never recap, shear, break, or bend needles under any circumstances.  Expel air and bubbles into a disinfectant-moistened pad. 
  • Refer to section 2.3.3.2 for more information on safe needle devices.

2.6.5 Lyophilizers
Lyophilizers produce a dry solid that is very easily dispersed.  They should be fitted with a HEPA filter or vented to a BSC when used for drying suspensions of infectious material.  Ampoules of lyophilized solids should be opened only in a BSC; place a disinfectant-moistened pad over the scored line when opening the ampoule.  Disinfect chamber surfaces and any material collected in the vapor trap. 

Go to Top