Safer Products for Use in the Lab

• Ethidium Bromide Substitutes
• • SYBR Safe™ DNA gel stain (Invitrogen)- less mutagenic than ethidium bromide, though acute toxicity may be higher; does not require UV light for visualization
  • GelRed and GelGreen- less mutagenic than ethidium bromide; is visualized with UV light
  • GelStar
  • EZ-Vision
  • SafeGLO
• Sodium Azide – Preservative Substitute:
  • Purchase a dilute solution of sodium azide. Avoiding the powder reduces the risk of exposure. Note that even if a dilute solution is purchased it will still be considered P-list waste if sodium azide is the only active ingredient.
  • Consider using 1-2% 2-chloroacetamide as a preservative. Care still must be taken with 2-chloroacetamide as it is a GHS skin sensitizer category 1 and reproductive hazard category 2. It is has a low vapor pressure (0.05 mm Hg at 68F) so should be weighed only in a chemical fume hood or exhausted biosafety cabinet. Note that most BSCs on campus are NOT exhausted. Follow the Toxic Powder Guidelines.
• PMSF/DFP Substitute: Pefabloc SC Protease Inhibitor
  • PMSF (phenylmethylsulfonyl fluoride) and DFP (diisopropyl phosphorofluoridate) are widely used for protease inhibition during protein isolation. PMSF is a high risk chemical due to reactivity with water and acids. DFP is particularly hazardous due to its acute toxicity. Consider using Pefabloc® SC as an alternative. In addition to being safer to handle, it is readily soluble in water and therefore more stable in aqueous buffers, providing more reliable protection for your protein.
• Eliminate Isopropyl Alcohol in Controlled Rate Cell Freezing
  • Use CoolCell or other alcohol-free container designed for the purpose. (Isopropyl alcohol is flammable, a peroxide former, and could cause frostbite if spilled at -80°C.)
• Xylene Substitute:
  • Use ParaClear, a Naphtha-petroleum derivative, for clearing, deparaffinization and staining
• Toluene for Benzene
• Paraformaldehyde Flakes and Granules in Lieu of Powder
• Formaldehyde/Formalin Substitutes

Purchase prefilled specimen containers or consider these alternatives:

• Histo-Fix
• Mirsky’s Fixitive
• Prefer
• Shandon Glyo-Fixx ™

• Pre-cast Gels in Lieu of Handling SDS and Acrylamide Powders:
  • Invitrogen precast gels
  • Precast Polyacrylamide Gels
• 2,2’-thiodiethanol (aka thiodiglycol) - Substitutes for Tissue Clarification:
  • Use 50% w/w glycerol (in water)
• Cyanogen Bromide - Substitute for cleaving proteins:
  • Consider Endoproteinase Glu-C instead. (Note: This is a skin & respiratory sensitizer. Handle as described here.)
• Copper-ammonia Complex-Substitute for Beer’s Law studies
  • In Beer’s Law studies, use iron-salicylic complex instead of copper-ammonia complex.
• Chromium (IV) oxidants-oxalyl chloride/dimethyl sulfoxide- Substitute
  • In Swern oxidation of alcohols, use organic oxidants instead
• Fluoride and fluorinating reagents Substitute
  • Use perchloryl fluoride – F-TEDA-B54 (1-chloromethyl-4-fluoro- 1,4 diazonia [2,2,2] bicyclotane) instead
• Mercury sulfate or selenium metal catalysts Substitute
  • In Kjeldahl analyses, use copper sulfate catalysts instead.
• Organic solvent Substitutes for liquid-liquid extraction or chromatography:
  • Supercritical carbon dioxide for organic solvents in high-performance chromatography
  • Toluene for benzene (less toxic)
  • Methyl tert-butyl ether for diethyl ether (does not form explosive peroxides)

For academic substitutions, use nonhazardous chemicals in chemistry teaching laboratories. For example:

• Potassium sodium tartarate in density studies
• Calcium chloride, magnesium sulfate, sodium carbonate, potassium chloride, potassium iodate, and sodium oxalate in “unknown” studies, calorimetric studies, molal volume studies, synthesis studies, or kinetic measurement studies

• Use a less pathogenic surrogate organism: Using less pathogenic species or strains of organisms may lower the biosafety level and health risk if exposed. For example, use a bacteriophage as a surrogate for a virus or an avirulent or attenuated strains for certain bacteria (e.g., using Mycobacterium tuberculosis strain H37Ra instead of H37Rv).
• Use a less hazardous gene delivery method: If using first or second generation lentiviral vectors for gene delivery, consider using a third generation lentiviral vector instead. Older generations of lentiviral vectors may generate replicating and pathogenic virus. Third generation lentiviral vectors employ a split gene packaging strategy requiring multiple recombination events that essentially render it incapable of generating replication competent virus.

• Replace lab glass with plastic: using plastic instead of glass can greatly reduce potential injuries and exposures from broken glass.
• Cell Culture Media Aspiration
  • Polystyrene aspirating pipets should be used in lieu of glass Pasteur pipets. These sterile, non-plugged, non-graduated pipets can be used for all vacuum-aspirating procedures. Individually wrapped pipets feature thermoformed paper/plastic wrap to prevent contamination. Non-pyrogenic.
• Cell Spreader Alternatives
  • Glass cell spreaders, especially spreaders homemade from Pasteur pipets, present several potential hazards. Thin glass can easily break and present potential puncture, cut, and/or biological exposure hazards. It is also very difficult to tell if glass is hot or cold, so it could cause burns or a fire. Several alternatives are listed below:
    • Metal or disposable plastic spreaders are less likely to break or cause potential punctures or cuts.
    • Glass plating beads are another way to spread cells and can also allow for batch spreading of plates.
    • Paperclip spreaders - straighten a large-size paperclip to make an "L" shape. Wrap in foil and sterilize in an autoclave or an oven, dip into a container of alcohol, or heat in a flame before use.
    • Toothpicks, coffee stirrers, and wooden craft sticks - these don't work quite as well as other spreader tools because their rough edges tend to scratch agar plates, but they are fairly effective for spreading larger volumes of liquid. Place in envelopes, foil, or glass test tubes and sterilize in an autoclave or an oven before use.
• Cutting Agarose Gel
  • Plastic coverslips may be used as a substitute for unprotected razor blades or glass coverslips.
  • Gel excision pipette tips can be used to safely remove narrow bands from agarose gels using a pipette.
  • Disposable plastic gel razors can also be used to safely cut gels instead of metal razor blades or glass coverslips.
• Retractable Safety Scalpels
  • Safety scalpels retraction feature hides the blade in the safety position, thereby reducing accidental cuts.
• Opening Boxes and Packages
  • Box cutters should be used instead of unprotected razor blades. There are many options available from Amazon, Grainger, etc. Some have ceramic blades that will not cut skin, some have retractable blades, and others protect the user by placing the blade where it can cut a sheet of cardboard but not your fingers.
• Disposable Hemocytometers
  • C-Chip Disposable Hemocytometers as a substitute for glass hemocytometers.

• Disposable Loops and Needles
• Disposable Cell Spreaders
• Bacti-Cinerator Electric Loop/Needle Sterilizer

Consider the following substitutions for cleaning, sterilizing, and rinsing agents:

• For cleaning lab glass, use “No-Chromix,” enzymatic cleaners, detergents, and similar items instead of chromerge (sulfuric acid-sodium dichromate).
• For histology labs, use alcohol fixative, which is less toxic, instead of formaldehyde or citric acid-based preparatory chemicals.
• For sterilizing equipment, use quaternary amine detergents instead of isopropyl alcohol, particularly in medical studies.
• For dehydrating and rinsing processes, use ethanol instead of methanol.

• For thermometer substitution, use alcohol/glycol instead of mercury.

The products recommended below are suggestions but do not constitute an exhaustive list. 

• Benchtop Glass Disposal Boxes
• Floor Glass Disposal Boxes
• Peroxide Testing Strips
• Small Biohazardous Sharps Container
• Spill Kit - Universal Cleanup

For assistance in selecting lab safety products, contact EH&S at ehs@twu.edu or 940-898-4001, option 3.