Hazardous Waste Minimization Guide

Waste minimization is any action that reduces the amount and/or toxicity of chemical wastes that must be shipped off-site for disposal as hazardous waste. It is incumbent upon every member of the University community to be aware of the environmental and financial impacts of hazardous chemical waste and to actively seek to minimize the volume of hazardous waste that is generated. The management of this waste should be an integral part of the laboratory setup and operating procedures and laboratory managers should conduct an annual review of their waste management procedures. The success of the University of Florida’s Waste Minimization Program is dependent on the conscientious participation of every individual at the University.


Waste Minimization

This guide has been designed to give some general examples of waste minimization activities and to be a resource for laboratory managers as they design and manage their laboratory procedures. Using this guide, laboratory managers can adopt specific procedures for their particular laboratory setup.

Presently, there are three general methods for waste minimization:

  • Source Reduction
  • Recycling
  • Treatment

Source Reduction

The most desirable method of waste minimization is source reduction. This is defined as, any activity that reduces or eliminates the generation of chemical hazardous waste at the source. This can be accomplished by good materials management, substitution of less hazardous materials, and good laboratory procedures.

Examples: Reduction of Chemical Waste Generation at the Source

Implement a departmental/laboratory waste minimization policy and train all employees and students.

Do not mix hazardous and non-hazardous wastes.

Evaluate procedures to see if a less hazardous or a non-hazardous reagent can be substituted.

Centralize purchasing of chemicals within the department or laboratory.

Date all chemical containers when received so that the older chemicals will be used first.

Keep on file, updated MSDS’s for all chemicals in laboratory inventory.

Inventory chemicals and identify their location at least once a year.

Update inventory as chemicals are purchased or used up.

Purchase chemicals in the smallest quantities needed. Do not over purchase chemicals (see section l).

Label all chemical containers to prevent the generation of unknowns.

When considering a new procedure, initially obtain the chemicals needed from another lab or purchase small quantities.

Consider the use of microscale experiments.

Consider the use of demonstrations or video presentations as a substitute for some student experiments.

Consider using pre-weighed or pre-measured reagent packets where waste generation is high.

Avoid the use of reagents containing arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver.

Eliminate the use of chromic acid cleaning solutions altogether. Use non-hazardous solutions such as Alconox and Pierce RBS35.

Substitute red liquid (spirit-filled), digital, or thermocouple thermometers for mercury thermometers.

Consider using detergent and hot water for cleaning parts instead of solvents.

Use latex-based paints which are typically non-hazardous. Recycle excess or waste latex paints.

Dispose of excess, non-latex paints as a hazardous waste.

Utilize vendors that will recycle used antifreeze.

Keep laboratory clean and orderly. 

Recycling

The second option for waste minimization is recycling. When a waste material is used for another purpose, treated and reused in the same process, or reclaimed for another process, this is called recycling.

Examples

Re-distill used-solvents.

When solvents are used for cleaning purposes, use contaminated solvents for the initial cleaning and use new solvents for the final rinse.

Purchase compressed gas cylinders (including lecture bottles) from manufacturers who will accept the return of the empty or partially used cylinders.

Return excess pesticides to the distributor.

Treat photographic waste with a silver recovery unit (call EH&S).

Do not contaminate used oil with solvents or heavy metals.

Re-circulate unused, excess chemicals within your department.

Reclaim metallic mercury.

Use non-hazardous solvents or cleaning solutions in industrial parts washers. 

Treatment

The least preferable technique for waste minimization is treatment. The most common treatment is elementary neutralization.

Examples

Consider the possibility of including detoxification and/or neutralization steps in your laboratory procedures.

Destain ethidium bromide gels in order that they can be disposed of in the trash.


Cost Control Methods

An equally important aspect of an effective waste minimization program is the reduction of disposal costs through the proper segregation of various waste streams once they have been generated. The mixing of waste streams can significantly increase disposal costs and complicate disposal methods.

The importance of proper separation of chemical wastes into their various groupings can not be over emphasized. The University of Florida disposes of the following waste streams in large quantities. Except in special circumstances, the volume of waste and not necessarily the concentration is the critical factor in determining costs of disposal. As a result, EH&S requests that laboratories and shops make an effort not to dilute their wastes anymore than is necessary.

Liquid Waste Streams Generated at the University of Florida

Flammable Liquids

Flammable Acidic & Alkaline Mixtures

Halogenated Solvents

Chromerge & Chromium-bearing Wastes

Formalin & Formaldehyde Solutions

Liquids with Heavy Metals

Photographic Wastes

Non-Latex Paints & Solvents

Latex Paints

Used Oil

Miscellaneous Waste Streams

Unknowns Chemicals

Unused or Excess Chemicals

Mercury & Mercury Compounds

Compressed Gas Cylinders

** The following sections on specific liquid wastes are meant to give laboratories/shops some information on how to minimize the cost of disposal of these waste streams by proper segregation of the wastes and volume reduction. In some situations, these suggestions will be difficult or impractical to implement, in which case, consult with EH&S (392-8400) to determine the best method for collection and disposal. 

Flammable Liquids

Examples: acetone, methanol, ethanol, toluene, xylene, and acetonitrile

Flammable liquid wastes are typically burned as fuel in waste disposal incinerators and as a result, disposal is relatively easy and inexpensive. For this reason, the lower the water content in the waste – the less expensive the costs of disposal. Solvents contaminated with materials not permitted for incineration will require alternative, costly treatment methods.

Disposal Costs Reduction Suggestions 

Minimize water content of waste by minimizing any unnecessary dilution.

Keep separate, if possible, from wastes that contain heavy metals, pesticides, cyanide, acute hazardous wastes (P-listed, see the Hazardous Waste Management Guide), etc. These wastes tend to drive up the costs of disposal, because of the need for more complex waste treatment.

Recycle or redistill solvents.

Investigate the use of nonflammable, biodegradable alternative solvents.

Replace solvent-based inks in printing operation with soy-based inks.

Make multiple uses of cleaning solutions before disposing to them. 

Flammable Acidic & Alkaline Mixtures

Examples: phenol & chloroform, acetic acid & methanol, potassium hydroxide & methanol

Flammable acidic and alkaline mixtures are difficult to dispose of due to their corrosive nature. These wastes can cost at least four times (4X) more to dispose of than other flammable liquids.

Disposal Costs Reduction Suggestions

Minimize unnecessary dilution of wastes.

Do not mix unnecessarily with other solvents.

Keep acidic and alkaline wastes separate to minimize the risk of reactions.

Minimize the volume of these wastes by keeping separate from other waste streams.

Keep separate, if possible, from wastes that contain heavy metals, pesticides, cyanide, acute hazardous wastes (P-listed, see the Hazardous Waste Management Guide), etc. These wastes tend to drive up the costs of disposal, because of the need for more complex waste treatment. 

Halogenated Solvents

Examples: methylene chloride, chloroform, carbon tetrachloride, trichloroethane, trichloroethylene

Not only are many halogenated solvents (solvents containing Cl –, F –, and Br –) carcinogenic, but they are difficult to dispose of and can cost three times (3X) more to dispose of as compared to non-halogenated solvents. An effort to keep halogenated and non-halogenated wastes in separate containers would significantly reduce disposal costs.

Disposal Costs Reduction Suggestions

Minimize unnecessary dilution of wastes.

Keep separate from acidic or alkaline waste streams.

Keep halogenated wastes separate from non-halogenated wastes.

Substitute non-halogenated solvents in place of halogenated solvents in parts washers or other solvent processes.

Keep separate, if possible, from other waste streams that contain heavy metals, pesticides, cyanide, acute hazardous wastes (P-listed, see the Hazardous Waste Management Guide), etc. These wastes tend to drive up the costs of disposal, because of the need for more complex waste treatment.

Recycle or redistill solvents.

Investigate the use of alternative non-halogenated solvents. 

Chromerge & Chromium-bearing Wastes

The University of Florida discourages the use of chromerge for the cleaning of laboratory glassware. There are alternative glassware cleaning solutions available in most chemical supplier catalogs (example: Alconox, Pierce RBS-35, NoChromix, etc.). Chromium is of concern due to its toxic characteristics. Researchers who use chromium as a part of a procedure in their laboratory, should investigate the viability of alternative procedures or chemicals.

Disposal Costs Reduction Suggestions (If it is necessary to use chromium or chromerge in your laboratory procedures)

Minimize the volume of waste generated by eliminating any unnecessary dilution.

Keep separate, if possible, from other waste streams that contain other heavy metals, pesticides, cyanide, acute hazardous wastes (P-listed, see the Hazardous Waste Management Guide), etc. These wastes tend to drive up the costs of disposal, because of the need for more complex treatment of these wastes. 

Formalin & Formaldehyde Solutions

Disposal Costs Reduction Suggestions

Minimize the volume of waste generated by eliminating any unnecessary dilution.

Do not mix with any other waste streams.

Use “Formalternate” (Flinn Scientific) or ethanol as an alternative to formaldehyde for the storage of biological specimens. 

Liquids with Heavy Metals

Treatment and disposal of metal solutions (aqueous solutions containing arsenic, barium, cadmium, chromium, copper, lead, mercury, osmium, selenium, silver, etc.) varies depending on the type and concentration of the metal present in the waste. EH&S recommends the substitution of less hazardous metals for those procedures that involve heavy metals.

Disposal Costs Reduction Suggestions

Keep heavy metal solutions separate from other wastes.

Minimize the volume of waste generated by eliminating any unnecessary dilution.

Call EH&S (392-8400) if you have any questions about appropriate disposal or segregation methods.

Consider options for reducing the amount of metals used in laboratory experiments (example: microscale experiments).

Substitute less hazardous metals.

Eliminate metal catalysts in chemical procedures and allow more time for completion of reactions.

Use silver recover units in dark rooms for fixer waste (see the Photographic Materials Guide).

Precipitate out precious and semiprecious metals. 

Photographic Wastes

EH&S has developed a detailed guide on safety issues and the proper disposal of photographic materials. To receive a copy call 392-8400 or access the in EH&S Website 

Non-Latex Paints & Solvents

Non-latex paints and solvents are hazardous waste due to their flammable nature and/or toxic components. Please submit a Chemical Waste Pickup Request Form for any excess, un-used paints and solvent or paint-related waste streams (paint rags & brushes) to EH&S for disposal.

Disposal Costs Reduction Suggestions

Minimize the volume of waste generated by reducing any unnecessary dilution.

Use latex paints whenever possible.

Call EH&S (392-8400) if you have any questions about appropriate disposal or segregation methods.

Clean out stockpiles of old paints and send them to EH&S for disposal or contact other departments that may be able to make use of them.

Minimize your inventory of paints and solvents. Only order enough to satisfy immediate needs.

Call EH&S (392-8400) for the guide – Handling Procedures for Oil and Other Maintenance-Related Waste or access the Maintenance related Waste Guide

Latex Paints

Latex Paints are not considered hazardous. EH&S has a recycling program for excess latex paints and as a result, disposal is relatively easy and inexpensive. Submit a Chemical Waste Pickup Request Form for any excess latex paints to EH&S for disposal.

Disposal Costs Reduction Suggestions

Minimize the volume of waste generated by reducing any unnecessary dilution.

Do not mix with non-latex paints or any hazardous materials.

Clean out stockpiles of old paints and send them to EH&S for disposal or contact other departments that may be able to make use of them.

Call EH&S (392-8400) if you have any questions about appropriate disposal or segregation methods.

Call EH&S (392-8400) for the guide – Handling Procedures for Oil and Other Maintenance Related Waste or access the Maintenance related Waste Guide

Used Oil

Used oil is not considered a hazardous waste. EH&S has a recycling program for used oil and disposal is simple, as long as water contamination is minimal and there has been no contamination with any hazardous substances.

Disposal Costs Reduction Suggestions

Minimize the volume of waste generated by reducing any unnecessary dilution or addition of water.

Avoid contamination with hazardous materials. If the oil has been contaminated or exposed to heavy metals, solvents and/or chemicals, it is potentially hazardous. Identify contamination source on the label so that EH&S can dispose of the oil properly.

Call EH&S (392-8400) if you have any questions about appropriate disposal or segregation methods.

Call EH&S (392-8400) for the guide – Handling Procedures for Oil and Other Maintenance Related Waste or access the Maintenance related Waste Guide

Unknown Chemicals

The generation of unlabeled and unidentified chemicals can become an expensive waste disposal challenge. The number of unknown chemicals can be significantly reduced simply by making a concerted effort to label all containers in the laboratory. Unknown chemicals cost up to ten times (10X) more to dispose of than properly labeled and identified chemicals. Containers should be labeled with the chemical constituents, the name of the person(s) responsible for the chemicals and the date that the chemicals were placed in the container. The processing and handling of unknowns is a complicated and labor intensive process due to the chemical analysis that must be conducted on each container prior to shipping and disposal.

The University encourages laboratories to clean out any stockpiles of unknown chemicals that have accumulated in the laboratory over the years. In addition, lab managers should emphasize the importance of labeling and make it a fundamental part of the laboratory policy. If a researcher/graduate student is leaving the University of Florida, all samples and chemical formulations generated by that person, must be clearly labeled for content and disposed of prior to their departure. If samples are being saved for future analysis, they must be properly identified and there must be a clear time-line for disposal of these samples. EH&S’ Department of Laboratory Safety has a guideline on Laboratory Closeout Policy

Unused or Excess Chemicals

The American Chemical Society estimates that 40% of the chemical waste generated by labs consists of unused chemicals. As a result, EH&S encourages departments/laboratories to purchase chemicals only in amounts that will be used within the next six to nine months. Bulk purchases may be cheaper (price per unit) for laboratories, however if these chemicals are unused, disposal costs will far outweigh any savings. The American Chemical Society (ACS) has an excellent publication for your use – Less is Better: Laboratory Chemical Management Waste Reduction.

If your laboratory has excess or unused chemicals and does not have any use for these chemicals, EH&S recommends that you contact members within your department to see if another laboratory can use them. If you are unable to share these chemicals within your department, contact EH&S and we will attempt to find a home for them. EH&S will soon have a chemical recycling page on the EH&S webpage for laboratories to post excess, unused chemicals. There will also be a periodic list of available chemicals emailed to departments or laboratories that request it. Check EH&S webpage for information on the Excess Chemical Recycling Program. Large chemical stockpiles pose an unnecessary threat to the university community. These chemicals should be periodically cleaned out, saving only those that are needed, and future purchases should be made on an “as needed basis” only.  

Mercury & Mercury Compounds

Mercury-bearing wastes requires special treatment, as a result, they are expensive for the University to dispose of.

EH&S Recommendations 

All mercury and mercury-bearing wastes are kept separate from all other wastes.

Mercury thermometers and manometers be replaced with non-mercury containing instruments.

If you must use a mercury thermometer, purchase those with a teflon coating.

Separate out metallic mercury so that it can be recycled.

Print out and read EH&S’s information on mercury spills.

Use alternative procedures that do not make use of mercury compounds.

Use mercury-free catalysts or simply let the reactions run longer.

Evaluate laboratory procedures to eliminate or minimize the use of mercury and mercury compounds. 

Compressed Gas Cylinders

Compressed gas cylinders pose two issues of concern: safety and disposal costs.

Safety Concerns

Physical hazards associated with pressurized and aging cylinders.

Inhalation (corrosive/toxic gases) and asphyxiation hazards associated with the gases in the cylinder.

Disposal Concerns

Most of the large standardized gas cylinders are recycled by the distributors and disposal is easy and relatively inexpensive. However, the specialized gas cylinders (lecture bottles, bubbler, etc) are typically not accepted back by the distributor. Due to the nature of the cylinder and its contents, disposal of these cylinders becomes quite expensive.

Before Purchasing Cylinders

Check within the department for existing cylinders that are available for use.

Attempt to establish accounts with suppliers who will allow for the return of unused product and/or empty cylinders.

Call EH&S (392-8400) if you have any questions about cylinder handling and disposal. 


Conclusion

Each laboratory manager and Principal Investigator should make waste minimization an active and ongoing component of their overall laboratory management strategy. The University of Florida’s Waste Minimization Program is dependent on the willing and active participation of the whole University community.

The University of Florida has a Waste Minimization Committee which is actively seeking ways to reduce the amount of waste generated at the University of Florida. The Committee is continually seeking feedback from the university community on how the Waste Minimization Program can be improved.

Feedback and suggestions are welcomed at EH&S (352) 392-8400 or P.O. Box 112725.