United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-94/007 September 1994
ENVIRONMENTAL
RESEARCH BRIEF
Waste Minimization Assessment for a Manufacturer
of Paints and Lacquers
Richard J. Jendrucko*, Rebecca A. Bachschmidt*,
and Gwen P. Looby**
Abstract
The U.S. Environmental Protection Agency (EPA) has funded
a pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the expertise to do so. In an effort to assist these manufactur-
ers Waste Minimization Assessment Centers (WMACs) were
established at selected universities, and procedures were
adapted from the EPA Waste Minimization Opportunity As-
sessment Manual (EPA/625/7-88/003, July 1988). That docu-
ment has been superseded by the Facility Pollution Prevention
Guide (EPA/600/R-92/088, May 1992). The WMAC at the Uni-
versity of Tennessee performed an assessment for a plant that
manufactures lacquers and paints. Raw materials, including
additives and solvent or water, are blended at mixing stations.
The resulting mixture may be ground in a sand-mill or a
pebble-mill. Next, the mixture is pumped to the let-down tanks
where additives, tints, resins, and solvent or water are added.
After testing and any required adjustments, the product is
packaged. The team's report, detailing findings and recom-
mendations, indicated that waste solvent is the waste stream
generated in the greatest quantity and that significant cost
savings could be achieved by implementing a computer-based
system for batch scheduling, inventory, and waste documenta-
tion.
This Research Brief was developed by the principal investiga-
tors and EPA's Risk Reduction Engineering Laboratory, Cincin-
nati, OH, to announce key findings of an ongoing research
project that is fully documented in a separate report of the
same title available from University City Science Center.
University of Tennessee, Department of Engineering Science and Mechanics.
University City Science Center, Philadelphia, PA.
Introduction
The amount of waste generated by industrial plants has be-
come an increasingly costly problem for manufacturers and an
additional stress on the environment. One solution to the
problem of waste generation is to reduce or eliminate the
waste at its source.
University City Science Center (Philadelphia, PA) has begun a
pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the in-house expertise to do so. Under agreement with EPA's
Risk Reduction Engineering Laboratory, the Science Center
has established three WMACs. This assessment was done by
engineering faculty and students at the University of
Tennessee's (Knoxville) WMAC. The assessment teams have
considerable direct experience with process operations in manu-
facturing plants and also have the knowledge and skills needed
to minimize waste generation.
The waste minimization assessments are done for small and
medium-size manufacturers at no out-of-pocket cost to the
client. To qualify for the assessment, each client must fall
within Standard Industrial Classification Code 20-39, have gross
annual sales not exceeding $75 million, employ no more than
500 persons, and lack in-house expertise in waste minimiza-
tion.
The potential benefits of the pilot project include minimization
of the amount of waste generated by manufacturers and re-
duced waste treatment and disposal costs for participating
plants. In addition, the project provides valuable experience for
graduate and undergraduate students who participate in the
program and a cleaner environment without more regulations
and higher costs for manufacturers.
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Methodology of Assessments
The waste minimization assessments require several site visits
to each client served. In general, the WMACs follow the proce-
dures outlined in the EPA Waste Minimization Opportunity
Assessment Manual (EPA/625/7-88/003, July 1988). The WMAC
staff locate the sources of waste in the plant and identify the
current disposal or treatment methods and their associated
costs. They then identify and analyze a variety of ways to
reduce or eliminate the waste. Specific measures to achieve
that goal are recommended and the essential supporting tech-
nological and economic information is developed. Finally, a
confidential report that details the WMAC's findings and recom-
mendations (including cost savings, implementation costs, and
payback times) is prepared for each client.
Plant Background
This plant manufactures lacquers and consumer and industrial
water-based and solvent-based paints. It operates 4,000 hr/yr
to produce approximately 1.5 million gal of paint and lacquer
annually.
Manufacturing Process
The raw materials used by this plant include pigments, resins,
fillers, plasticizers, dryers, preservatives (for water-based paints),
solvents, and water. Water-based paints represent about one-
third of the total production; the remainder is solvent-based.
The production processes for water-based and solvent-based
products are very similar; the major distinction between the
processes is the use of water or solvent.
Specified amounts of raw materials are prepared for batches of
product in the pre-batch area. Those ingredients, other addi-
tives, and solvent or water are blended at one of several
mixing stations. Pigment dispersion is checked and if it is
unacceptable the mixture is ground in a sand-mill or a pebble-
mill. If lacquer is being manufactured, the liquid from the mills
is sent to a separate building where additives are incorporated
and the resulting mixture is pumped into drums.
For products other than lacquers, the mixture is pumped from
the mixing station or from the mills to one of several letdown
tanks where additives, tint, resins, and solvent (or water) are
added. The viscosity, dry gloss, translucency, color, and other
physical properties of the product are tested in the laboratory
and adjustments are made as needed. The product is pumped
from the letdown tanks through filters to an automated filling
unit or gravity-fed to drums and tankers.
An abbreviated process flow diagram is shown in Figure 1.
Existing Waste Management Practices
This plant already has implemented the following techniques to
manage and minimize its wastes:
• When possible, cleaning solvents are reused in paint formu-
lation.
• Plastic liners are used in steel pails to reduce cleaning
wastes.
• Obsolete products and products returned by customers are
blended into new products when feasible.
Solvents
Nitrocellulose
Ethylcellulose
Product to
shipping
Product to
shipping
Product to
shipping
Figure 1. Abbreviated process flow diagram.
- Plant personnel are evaluating the possible purchase of a
distillation unit for the recovery of spent solvents that are
currently shipped off-site.
Waste Minimization Opportunities
The type of waste, the source of the waste, the waste manage-
ment method, the quantity of the waste, and the annual waste
management cost for each waste stream identified are given in
Table 1.
Table 2 shows the opportunities for waste minimization that the
WMAC team recommended for the plant. The minimization
opportunity, the type of waste, the possible waste reduction
and associated savings, and the implementation cost along
with the simple payback time are given in the table. The
quantities of waste currently generated by the plant and pos-
sible waste reduction depend on the production level of the
plant. All values should be considered in that context.
It should be noted that the financial savings of the minimization
opportunities result from the need for less raw material and
from reduced present and future costs associated with waste
management. Other savings not quantifiable by this study in-
clude a wide variety of possible future costs related to chang-
ing emissions standards, liability, and employee health. It also
should be noted that the savings given for each opportunity
reflect the savings achievable when implementing each waste
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minimization opportunity independently and do not reflect du-
plication of savings that would result when the opportunities
are implemented in a package.
This research brief summarizes a part of the work done under
Cooperative Agreement No. CR-814903 by the University City
Science Center under the sponsorship of the U.S. Environmen-
tal Protection Agency. The EPA Project Officer was Emma
Lou George.
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/S-94/007
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