LESS IS BETTER

Introduction

Chemicals that have no further use are waste chemicals and must
be disposed of properly. In a laboratory, these wastes can
include reaction products as well as unwanted chemicals.

An objective of the American Chemical Society (ACS) is to promote
alternatives to landfilling for the disposal of laboratory
chemical wastes. One method is to reduce the amount of chemicals
that may become wastes. This approach differs from other
practices in that it is rooted in the philosophy that "less is
better."

The "less is better" concept depends on the establishment of a
comprehensive chemical management system. Through such an
approach, all the sources of potential waste generation are
identified and are managed to reduce the amount of hazardous
chemical wastes produced in laboratory operations. Other
advantages of this system include conserving resources and
minimizing the potential harm to personnel in the event of an
accident.

Some waste chemicals are legally declared and classified as
hazardous under government regulations. Many additional
chemicals, if improperly handled, may be hazardous because of
their potential for harm. Generators of any quantity of hazardous
chemical wastes have a legal as well as an ethical obligation to
dispose of these wastes in such a manner so as no risk is posed
to the public or the environment. Thus, federally-designated
hazardous wastes must be carefully collected, separated,
packaged, labeled, recorded, and disposed of in strict accordance
with prescribed regulations.

Not all chemicals, however have a potential for harm - they are
classed as non- hazardous. Some non-hazardous materials may be
safely and legally disposed of through the sewer system or as
vapors in a hood and ventilating system. Other non- hazardous
substances may be removed by the sanitary trash collector. Some
wastes are incinerated while others like solvents may be purified
and reused. Because of the diversity of the wastes generated in
laboratories, prudent disposal of these chemicals demands
considerable expertise and attention.

This bulletin discusses the various techniques that can be
employed to develop a "less is better" philosophy of hazardous
waste management, as well as the practical benefits that can be
gained from implementing such a program. It is intended for those
persons responsible for managing laboratory hazardous waste
chemicals in industry, academe, and elsewhere: chemists at the
bench, professors and science teachers, research directors and
laboratory managers, stockroom managers, business managers,
purchasing agents, and safety personnel. The bulletin is composed
of five sections that address waste reduction through management
techniques such as purchasing control, inventory control, surplus
chemical exchange, reclamation, and recycling. The fifth section
presents practical examples of minimizing waste through careful
and comprehensive planning in teaching and research laboratories.

The Impact of Purchasing Strategy

The chemicals used in laboratories are usually less costly than
the associated labor and equipment required to manage them. As a
matter of convenience, chemicals are frequently purchased in only
one package size, often in large quantities. The user selects the
size and often will opt for the maximum reasonable quantity with
the lowest unit purchase price.

Subsequent storage of chemicals in excess of short term need may
seem to have a monetary advantage. However rising storeroom
expenses and associated disposal costs are changing that
assumption. Liabilities associated with the risks to safety and
health from unplanned chemical exposure to stored chemicals also
contribute to the escalation of laboratory operating costs.

When a quantity of a chemical is used from a small or large
container the unused remainder of the substance (that is, the
excess chemical) is retained. Many experimenters prefer to begin
a new procedure or each new phase of an experiment with fresh
material dispensed from unopened, original containers.
Partially-filled containers thus accumulate in the laboratories
and storerooms. These excess chemicals are often disposed of at
the conclusion of a project, when another scientist takes over
the laboratory or when the laboratory is refurbished for a new
use.

Unused chemicals can constitute as much as 40% of the hazardous
waste generated from laboratories. This waste consists of
chemicals still in their original containers which have outlived
or appear to have outlived their usefulness due to partial
degradation over time or from a judgment being made that the
chemical will not be used in the future. Excess quantities of
such chemicals are found in the storerooms, on laboratory
shelves, under benches, in hoods, and in various other places.

The surplus from large containers places increased demands, in
terms of expense, time, and workforce, on the waste removal
function. By contrast, when chemicals are drawn from the
storeroom in small packages, less material circulates throughout
the organization and smaller amounts ultimately require disposal.
The inventoried package size is, therefore, critical for
minimizing waste.

If for example, 300 ml of material is dispensed from a 500 ml
container, frequently the balance of 200 ml is disposed of. When
300 ml is taken from a 1000 ml or larger container the 700 ml
balance may remain stored on the laboratory shelf for many years.
Most of the remaining chemical is never used in another
laboratory procedure. This translates into higher costs for the
materials actually used and into additional costs for disposal of
the unused portions.

Extended storage of unused chemicals increases the risk of
accidents. Smaller quantity purchases result in less unused
chemicals being stored and reduce the potential for chemical
exposure to personnel. Smaller bottles tend to break less often
than larger ones. If they do break, spillage is less and cleanup
is easier and safer. Personnel safety reasons alone justify
limited inventories of smaller packages.

Purchasing-Disposal Economics

The real cost of a chemical includes its initial purchase price
plus the ultimate disposal costs. From the viewpoint of
purchasing, the quantity actually used relative to the quantity
purchased governs the unit purchasing cost. The perceived economy
of purchasing chemicals in large quantity containers may be
deceptive.

Consider phenol in an example of purchasing a large "economical
size" package rather than in a smaller size container or
containers more consistent with the immediate need. We will
assume that the same quantity of phenol will be used in either
case and that any remaining chemical will be disposed of.

Phenol is available in 500 ml bottles at a cost (in 1984 dollars)
of $15.50 per bottle or in 2500 ml bottles at a cost of $52.00.
If 1000 ml are used in either of the purchasing examples, the
cost of phenol used is 3.1 cents/ml and 5.2 cents/ml,
respectively. Large container purchases are only economical if a
significant portion of the chemical is actually used. In this
example, 1677 ml from the larger bottle must be used before the
cost per ml comes down to the 3.1 cents cost per ml of purchase
in the smaller bottles.

Now consider the disposal costs for the excess unused material
from either of the containers. From the viewpoint of disposal
economics, our example, reagent phenol, is classified by EPA as a
toxic organic. Phenol is corrosive and flammable. If ingested, it
is a severe health hazard; on skin contact it is toxic by
absorption. If it gets into a drinking water source, chlorination
in a water-treatment plant will convert it to bad tasting
chlorophenols. Because of these characteristics, liquid phenol
requires costly preparation by waste disposal experts before it
can be discarded.

Hazardous wastes, such as phenol, are accumulated, stored,
packaged, labeled, and disposed of in accordance with specific
federal and state regulations. A "lab pack" is the usual package
of choice for laboratory waste disposal. A lab pack is a DOT
specified 17H metal drum of 55 gallon capacity that is filled
with waste materials in their purchased or stored packages.

Regulations require that inert packing material be used to
surround  each inside package in order to separate and maintain
the integrity of the small bottles and cans containing the
wastes. Packing material must be sufficient to absorb any liquid
released from broken or leaking internal packages. The maximum
liquid volume of waste contained in the lab pack will be about 15
gallons.

The cost (in 1984 dollars) of a filled lab pack, including its
preparation, packaging, labeling, transport, and disposal in a
secure landfill averages $340 ($23 per gallon of contained waste
based on the 15-gallon maximum capacity). Some waste haulers will
decline to pick up a single lab pack and some have a minimum
charge that is equivalent to a two- or four-drum price.

Partially filled containers occupy as much space in the lab pack
as do full containers of the same maximum volume. Therefore, the
most cost-effective lab pack is that which contains the largest
number of filled containers. However because of safety
precautions, disposal services that prepare lab packs will not
normally dispense or pour waste from one package into another to
fill up a container.

A lab pack, properly prepared, will accommodate about 52 500-ml
bottles. At a cost of $340 for the lab pack, 500 ml bottles cost
$6.54 each, no matter how much waste they contain. A 2500 ml
bottle is worth $22.57 in lab pack space.

Assume that we have used 1000 ml of phenol for our experiment.
Two 500 ml bottles will be empty and, if properly rinsed into the
reaction vessel, will be clean, and not require disposal. The
unit total cost of phenol used from these bottles will only be
the purchase price of 3.1 cents/ml.

The 1000 ml of phenol used from the 2500 ml  bottle cost $52.00
and if it is disposed of with (or without) the remaining liquid,
will cost another $22.67 for disposal. The total
purchase-disposal cost for the 1000 ml of phenol from the 2500 ml
bottle is $74.67, making the unit total cost 7.5 cents/ml used.

Even if the breakeven purchase volume of 1677 ml is taken into
account, the larger cost for disposal of the 2500 ml bottle with
some remaining phenol makes the total cost greater than using
1677 ml from four 500 ml bottles. When using the smaller size
containers, three empty bottles will be cleaned and only the one,
still partially-filled 500 ml bottle will be disposed of. In this
last comparison the unit total costs per ml used is 4.1 cents and
4.5 cents respectively

This illustration demonstrates that the favorable purchase price
of the larger package can quickly be offset by the disposal costs
for that package and its residues. The phenol example also shows
the significant and sometimes unrecognized costs associated with
the disposal aspect of hazardous chemical usage. The purchase of
many small containers rather than one large container may be the
most cost-effective and safest way to acquire laboratory
chemicals.

Phenol represents one laboratory chemical that currently can be
disposed of in a landfill using a lab pack. However certain kinds
of chemical wastes such as peroxides, reactive metals, and
explosives cannot be disposed of in lab packs. Disposal costs for
these wastes are usually considerably higher than those for lab
packs. For example, at one institution, 20 one-pound bottles of
picric acid were disposed of by detonation by a commercial waste
disposal firm. The cost (1982) was $160 per bottle; a total of
$3200. The price of picric acid at that time was $16 per one
pound bottle.

Using these economic illustrations, an examination of the
purchase, storage, use, and disposal cycle reveals that
standardization of the smaller package size of chemicals for
laboratory use makes good management sense.


Inventory Control

A comprehensive chemical management system makes efficient use of
purchasing strategy with minimal interference to teaching and
research functions. It requires information about the kinds,
quantities, location, and status of all the chemicals within a
particular laboratory or facility. Tracking a chemical from
purchase and receipt to disposal, in effect, may benefit the
institution by reducing the possibility of duplicate purchases.
Careful inventory control also minimizes the waste generated from
old, partially-used containers of chemicals that age on
laboratory shelves, and reduces the chance for accidents.

A comprehensive approach to chemical management requires
substantial information and a modern file or data system. Some
laboratories have instituted data networks and others are
establishing such operations, each appropriate for and tailored
to the needs and resources of the respective laboratory. For
example, a data system linked to bar code labeling has proven to
be successful at some facilities. Each chemical container has a
bar code identification number plus a unique number to identify a
particular container. The chemical is followed through the system
using bar code readers within the facility. This allows simple
tracking of each particular material. The inventory is readily
accessed by laboratory workers who use the chemical formula,
chemical name, or trade name, and check the inventory by location
or "owner" name.

The choice of a coding sequence is an important consideration in
this particular type of inventory system. Bar code "system 39" is
advocated by the U.S. Government's Department of Defense, end
might be a logical "universal" code for laboratory chemicals (and
apparatus). Chemical Abstracts registry numbers are universally
accepted for identifying specific chemicals. Additional coding
might be desirable for manufacturer identification, dating, and
reference to chemical safety data. The Scientific Apparatus
Makers Association, in conjunction with chemical manufacturers
and hospital suppliers, developed a common basis for coding which
was made available to the scientific community through the Health
Industry Bar Code Council early in 1984.

A computer-based inventory system is another example of a
comprehensive data network for chemical management. One
industrial company uses such a system to operate a central
storeroom from which chemicals are taken as needed and any excess
is returned for use by others. A significant savings again is
realized by reducing inventory and storage and by minimizing
surplus chemicals that become waste. The success of this system
depends on quality control and rapid supply of the required
materials by the central storeroom to the laboratory worker as
well as the full cooperation of all laboratory personnel.

Inventory systems offer the possibility of linking the search for
a chemical with electronic ordering when the desired material is
not found on site. Most major chemical suppliers provide
electronic access to their catalogs. Ready access to safety
information might also be introduced into the system for helping
in an emergency or aiding in compliance with OSHA "Hazard
Communication" standards or state "Right- To-Know" laws.

A readily available inventory listing is a requirement for the
sharing of surplus chemicals (see next section). Most
laboratories store unwanted chemicals in some facility separate
from the main, new chemicals store. room. These
materials-including non-commercial research and development
products-can become a disposer's nightmare as they age.
Frequently they have less than adequate labeling, yet they are
often just what the research chemist needs for a special project.
An inventory control would allow ready access to these materials
and, thus, avoid unnecessary purchasing.

A record of materials that must be disposed of as wastes can be
enlightening. For example, an indication that the management
strategy is worthy of reevaluation is a record showing that
significant quantities of a particular chemical are being
regularly discarded by a project. The record also might show that
various quantities of a single chemical are being discarded among
many different projects. Combined purchases and inhouse
distribution could provide considerable cost savings on such a
chemical. Many laboratory workers may be surprised to learn how
their materials fit into the total chemical management scheme of
their organization and, thus, they can become more conscientious
of purchasing efficiency and minimizing waste generation.

The systems described may be beyond the current resources of many
academic and small industrial laboratories. The systems do
provide working models, however that can be adapted to the
resources available for each facility In some cases an elaborate
inventory can be accommodated by access to a central main frame
computer. A smaller data system accessed by a microcomputer or
even a card file system may be appropriate, sufficient, and
economically feasible for the chemical inventories of smaller
laboratories. The effectiveness of any inventory system, whether
it involves a sophisticated computer data base or simple
handwritten cards, depends on the cooperation of those using it.
No one system is best. Each organization must decide what works
best for it and how to gain effective support of the laboratory
personnel using the system.

Surplus Chemical Exchange; Recycling

Many of the materials now treated as waste are actually surplus
quantities of perfectly good chemicals. Both opened and unopened
containers of these chemicals can accumulate in laboratories.
With containers that have been previously opened, some
uncertainty may exist regarding the chemicals' purity. However
often a high degree of purity is not required for certain
reactions and uses, and many potential users would be quite
willing to accept opened containers of appropriate chemicals.
These chemicals should be exchanged rather than left as a waste.
Through a surplus chemical exchange, these materials become part
of the inventory of the entire chemical management system.

Both active and passive chemical exchanges currently exist. In a
passive surplus exchange, brochures listing available chemicals
are made available to potential users. Interested parties then
direct inquiries to the central exchange which relays this
information to the person in possession of the substance. Any
subsequent negotiations are left to the two parties involved. To
date, most passive chemical exchanges have concentrated on the
exchange of relatively large quantities of surplus industrial
chemicals. In a number of cases, however laboratory chemicals
hove effectively been exchanged within a facility

An active exchange, on the other hand, involves an intermediary
who brings together the originator and the potential user. This
is usually done for a fee and the intermediary may actually take
possession of the materials. Such an exchange requires time and
effort and can prove to be very effective because of the greater
variety and quantity of chemicals made available to potential
users.

The most effective surplus chemical exchange programs have proven
to be in house operations. Since the history of a particular
chemical is usually easy to obtain from colleagues, the passive
exchange operation is the most common. Such exchanges have been
developed in a number of relatively large industrial and
university laboratories. The computerized programs that were
described in the previous section contribute greatly to exchange
programs by providing centralized information on the quantity and
types of chemicals available in the laboratories.

Some manufacturers or suppliers will accept unopened containers
of surplus chemicals within limited periods of time after the
date of purchase. This practice, however, does not necessarily
solve the overall problem of waste disposal or contribute to
waste reduction. The manufacturer also may hove to dispose of the
materials if the costs of handling and purifying the materials
exceed the value of the chemical in question.

Laboratory chemicals that have been used in experiments cannot be
considered surplus chemicals. Often they must be purified for
further use. Legal liability and the need for quality control
require that the use of recycled chemicals normally be restricted
to in- house use. When recycling is appropriate, it should be
encouraged within the chemical management system. For example,
noble metals such as mercury and silver are commonly reclaimed
because of their value. Laboratory redistillation of solvents is
a practice increasingly used by cost-conscious laboratories.

Under certain conditions, the recycling or reclamation of
laboratory solvents can be a worthwhile waste reduction method.
It must be recognized that most laboratories do not generate
enough solvents to warrant the on-site transportation and
reprocessing costs associated with commercial solvent recyclers.
The economics of these factors demand large quantities to justify
on-site handling. The only viable recycling of solvents from
laboratories involves redistillation in-house. Small stills are
readily available for this reprocessing; the problems that must
be addressed are those of labor costs and collection procedures.
Because of the low labor costs available from students, recycling
is perhaps most practical in an academic laboratory In any
laboratory, a commitment must be made to establish and enforce
collection procedures.

While such reclamation is effective within a laboratory for reuse
of its own reagents other uses also are possible. A teaching
laboratory for example, may be able to redistill and use toluene
that is collected from a number of research laboratories. Other
reclaimed materials such as spent acids and solvents may be used
in routine maintenance of buildings.


Waste Reduction In the Laboratory

The safe handling and use of chemicals and their potential
environmental impact upon disposal must be a major consideration
for all laboratories-industrial as well as academic. One common
sense approach to reducing the risks posed by exposure to the
hazards of the laboratory wastes that are inevitably produced is
to minimize the use of hazardous materials.

For example some spent glassware cleaning solutions are hazardous
waste after use. Chromic acid solution is corrosive (sulfuric
acid) as well as toxic (hexavalent chromium) and requires special
care in disposal. Also, alcoholic potassium hydroxide solution is
flammable and corrosive. These properties make caution necessary
when packaging for disposal and when selecting a disposal option.
Though such materials are effective for their intended purpose,
they present hazard problems from the standpoint of both safety
and disposal. These types of cleaning baths add to a laboratory's
hazardous waste stream and should be replaced by one of several
proprietary laboratory detergents which usually are highly
effective when used properly.

Some academic laboratory procedures still specify benzene or
carbon tetrachloride as reagents or solvents. These compounds
often can be replaced by less hazardous materials. This results
not only in safer procedures, but also in wastes that may be be
hazardous in some respects. The same is true of other
commonly-used hazardous materials. For example, in the standard
qualitative test for halide ions, cyclohexane and carbon
tetrachloride are equally effective for extracting the halogen.
If cyclohexane is used instead of the traditional carbon
tetrachloride, the organic layer of the extract is less hazardous
and is more readily disposed. Qualitative analysis schemes for
heavy metals have been developed that replace sulfide ion by
hydroxide ion as a central reagent. Both the reagent and the
precipitated (waste) product are significantly less hazardous. In
some organic syntheses, hypochlorite ion can replace chromate ion
or other oxidizers, thereby avoiding the problems of disposing of
the hazardous waste that contains chromium (VI) and other
hazardous materials.

In a physical chemistry laboratory, less hazardous materials can
be used for experiments. For example, in the measurement of vapor
pressure-temperature relationships by isotensiscope, isopropyl
alcohol is as suitable as carbon tetrachloride. Determination of
molecular weight by freezing point lowering methods have often
used benzene, a classified carcinogen, as the solvent. In such
measurements, cyclohexane works about as well as benzene and the
cooling curves seem no more difficult to interpret than those
using benzene.

In the analytical laboratory numerous options are available to
chemists who wish to reduce the quantities of hazardous wastes
generated. Extraction solvents can be selected so as to minimize
hazards and increase recoverability. Sample sizes can be reduced,
thus reducing the quantities of extraction solvents and/or
derivatization reagents. In a recent case, a laboratory was
extracting a 500 cc of highly contaminated sludge with 500 cc of
solvents. The laboratory was able to reduce the sample and
extraction solvent volumes to 100 cc each while maintaining the
desired detection limits. This reduction affected two waste
streams in the laboratory - waste hazardous sample material and
waste solvent.

When the use of hazardous materials cannot be avoided, many
experiments still can be carried out on a very small scale,
thereby limiting the quantity of hazardous waste produced. Such
minor microscale experiments developed for safety purposes have
the added advantage of teaching good laboratory techniques.
Small-scale syntheses and analyses not only involve the use of
smaller quantities of reagents but they also result in smaller
quantities of waste-filter cakes, filter papers, filtrate from
washings, and distillation residues. Sometimes it is possible
simply to evaporate filtrates, washings. or other liquid residues
from small.scale reactions to further reduce the amount of
potentially hazardous waste. Another advantage of small-scale
reactions is the fact that the glassware used is not as easily
broken as is larger scale glassware. Broken glassware that are
contaminated with hazardous materials are themselves hazardous
wastes.

Many analytical procedures involve hazardous reagents and
products that result in hazardous waste. HPLC, for example, can
result in significant quantities or waste solvents. To minimize
the hazardous waste problem in such operations, the specific
solvent to be used and the utility of recycling it must be
carefully considered. Even when syntheses must be done on a
moderately large scale, the identity and purity of the products
formed can be verified on a semimicro  or microanalytic scale
using GLC, HPLC, GC/MS, NMR, spot plates, and chemical
microscopy.

Many organic and inorganic synthesis procedures have been
successfully designed so that the product of one synthesis is the
starting material for the next. Chains of from two to five or six
steps have thus been designed with a good variety of syntheses.
When each step is complete, characterizing measurements are made
on a few milligrams of material. The rest goes back into the
process so that no product from the earlier steps is left to be
disposed of or to be stored. Even in such sequences, however
there may be filtrates, filter cakes, still bottoms, and the like
to be disposed of. With judicious planning, the volume of such
hazardous materials can be reduced to a minimum.

Hazardous waste can often be eliminated or minimized by simple
in-house reagents or use of smaller-scale procedures. Such
treatments should be incorporated and described within normal
laboratory procedures, either in laboratory manuals or in the
experimental sections of procedures published in the research
literature.

Waste prevention and minimization are as consequential to
economics as they are to environmental protection and human
health and safety. They also are particularly important aspects
of education. Emphasizing safety considerations to students is a
clear responsibility of instructors at all levels of education.

Each chemical management scheme-both industrial and academic- is
only as good as the conscientious people using it. The successful
systems that have waste prevention and reduction as goals often
are those that are supported at the highest management levels. To
achieve these goals, reduction, elimination, and treatment of
hazardous waste have become an essential part of laboratory work.
In these situations, "less is better" is not simply a concept to
be understood or an afterthought applied to planning. Rather
"less is better" is the norm, and cost savings, as well as
protection of human health and the environment are the benefits.