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Laboratory Chemical Disposal
The Basics of Laboratory Chemical Disposal
Before You Undertake Any Disposal Procedure—
Please Read this Narrative!
Chemical disposal is a routine part of laboratory science programs. Most lab
activities will generate some leftover chemicals, solutions and chemical byproducts
that will require proper disposal. Advance planning and preparation will help you
minimize the amount of hazardous waste generated and reduce the time and
resources needed to dispose of excess nonhazardous chemicals or chemical
byproducts.
Every school should have a Chemical Hygiene Plan that outlines appropriate
policies and procedures for disposing of laboratory chemical byproducts and
correctly identifying hazardous waste requiring licensed disposal. The first step in
any laboratory waste policy should attack the problem at its source—where and
when waste is generated. Careful planning, tailoring lab activities to clear curriculum
objectives, adopting microscale lab techniques and substituting safer chemicals
will help you reduce the amount of waste generated. (See the article “16 Steps to
Minimize Chemical Disposal” on page 733.)
Laboratory chemical disposal requires specific knowledge and procedures.
Knowing the type of sewer system your school has and understanding all federal
state, and local regulations that may apply are important steps in laboratory
chemical disposal. Before you choose a disposal method, it is absolutely essential
that you review your plans with regulatory officials. Do not assume that because we
publish a set of disposal methods that these methods are “approved” or have the
“blessing” of regulatory officials—NOT SO! In publishing laboratory waste disposal
methods, we assume that:
You will consult with local regulatory officials before proceeding.
You will act responsibly with respect to all regulations.
The quantity of material involved is very small (i.e., laboratory quantities).
Only trained personnel will attempt the methods.
DO NOT USE THESE METHODS if they do not meet local regulations, if the quantity of
material is not small or if you are not comfortable with a disposal procedure.
Advance knowledge, preparation and planning also will allow you to dispose of
laboratory waste safely and effectively. There are three main categories of laboratory
waste generated:
Biological or biomedical waste (preserved materials, “live” material remains,
culture products)
Chemical waste (unused testing solutions, reaction products, stains and
indicators)
Hazardous waste requiring licensed disposal
Biological Waste
Biological science experiments may produce hazardous waste. Special attention
should be paid to all microbiological culture products since they may contain
harmful organisms. Preserved materials, deceased living materials and all “sharps”
also deserve special attention prior to disposal. To assist with handling biological
wastes, Flinn Scientific has developed a biological waste disposal procedure. Please
review pages 754–755 for a thorough discussion and detailed procedures for the
safe disposal of of biological waste materials.
Chemical Waste From Laboratory Experiments
Before performing any laboratory activity, review the properties of the chemicals
required and any products that may be generated. If the reactants or products
present unique hazards or will require specialized disposal (e.g., flammable
organic solvents), consider modifying the experiment or finding a different
experiment that will teach the same concept. Flinn Scientific maintains an
extensive library of tested laboratory activities. Please call (1-800-452-1261) or
email us (flinn@flinnsci.com) for suggestions of safe laboratory activities.
The catalog entry for every chemical listed in the Chemicals section of this Flinn
Scientific Catalog/Reference Manual includes a Flinn Suggested Disposal Method
number in the product description. Simply look up the product in the alphabetical
section of the chemical listings and determine the disposal number. Then refer to
this Suggested Disposal Methods on pages 736–753.
For best results, incorporate treatment of leftover chemicals and reaction
byproducts into any laboratory activity involving chemicals. Collect all solutions
or similar products in a centrally located container. For example, if students are
working with acidic solutions with a pH <2, have them pour their products into one
beaker placed in the hood or other central location. The acid solution may then be
neutralized with base according to Flinn Suggested Disposal Method #24b at the
end of the lab period. Making disposal a routine part of every lab activity teaches
students that concern for the environment is everyone’s responsibility and that
scientists working in the lab also take this responsibility seriously.
Inventory Management and Laboratory Chemical Disposal
Chemicals, supplies and equipment tend to accumulate in the science department
over time and can lead to hazardous situations. Effectively managing the chemical
inventory in the school will help you reduce the amount of chemical waste and
the potential impact of waste disposal on your school’s budget and resources. The
chemical storeroom should be cleaned out on a regular basis. Before you undertake
chemical cleanout and disposal, enlist the active consent and participation of
school or district administrators and facilities or risk managers to provide adequate
resources. Hasty responses to chemical disposal are often expensive, unsafe or
harmful to the environment.
Inspecting and Preparing the Inventory
Carry out a preliminary inspection to determine if cleanout and disposal are
warranted. Look for the following:
• Bottles and containers that are broken, corroded or have crystals growing around
the caps or liquid seeping out of closures.
• Inappropriate storage containers, such as beakers, flasks, buckets, plastic soda
bottles or food jars.
• Poorly labeled containers used for storing solutions or transferring chemicals.
Labels must have the chemical name, concentration, date and appropriate hazard
information and warnings.
Prepare or update the annual chemical inventory and identify chemicals you
want to keep. Laboratory chemicals and preserved materials that are no longer
part of the curriculum should be removed as should chemicals that are dangerously
toxic, potentially explosive, contaminated or decomposed, mislabeled, out-of-date
or present in surplus amounts. Assemble a list of chemicals requiring disposal.
Include the full name of the chemical, the quantity printed on the bottle’s label and
the number of bottles of each size. The size of the bottle is often more important
than the quantity of material if the whole bottle must be removed and shipped to a
disposal facility. The cost may be equal whether there are 1 or 100 bottles in a drum.
Chemical Disposal
Research the properties of unneeded chemicals to determine any that may be
neutralized, reduced, precipitated and/or disposed of in the trash or down the drain.
The description for each chemical in your current Flinn Scientific Catalog/Reference
Manual includes a disposal number. This number refers to one of the generally
allowed, suggested disposal methods listed in the reference section of the catalog.
Please verify state and local regulations that may apply as some methods may not
be permitted in particular areas. Disposal options also may be limited by the type
of septic system the school has.
LABORATORY CHEMICAL DISPOSAL continued on next page.