x-xEPA
United States
Environmental Protection
Agency
Research and Development
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
EPA/600/S-92/044 Oct. 1992
ENVIRONMENTAL
RESEARCH BRIEF
Waste Reduction Activities and Options for a
Fabricator and Finisher of Steel Computer Cabinets
Kevin Gashlin and Daniel J. Watts*
Abstract
The U.S. Environmental Protection Agency (EPA) funded a
project with the New Jersey Department of Environmental
Protection and Energy (NJDEPE) to assist in conducting waste
minimization assessments at 30 small- to medium-sized busi-
nesses in the state of New Jersey. One of the sites selected
was a fabricator and finisher of steel computer cabinets A site
visit was made in 1990 during which several opportunities for
waste minimization were identified. These opportunities include
improved painting technology, rationalization of metal-working
oils and coolants, and changes in degreasing solvent manage-
ment. Implementation of the identified waste minimization op-
portunities was not part of the program. Percent waste reduction,
net annual savings, implementation costs and payback periods
were estimated.
This Research Brief was developed by the Principal Investiga-
tors and EPA's Risk Reduction Engineering Laboratory in Cin-
cinnati, OH, to announce key findings of this completed as-
sessment.
Introduction
The environmental issues facing industry today have expanded
considerably beyond traditional concerns. Wastewater, air
emissions, potential soil and groundwater contamination, solid
waste disposal, and employee health and safety have become
increasingly important concerns. The management and dis-
posal of hazardous substances, including both process-related
wastes and residues from waste treatment, receive significant
attention because of regulation and economics.
* New Jersey Institute of Technology, Newark, NJ 07102
As environmental issues have become more complex, the
strategies for waste management and control have become
more systematic and integrated. The positive role of waste
minimization and pollution prevention within industrial operations
at each stage of product life is recognized throughout the
world. An ideal goal is to manufacture products while generat-
ing the least amount of waste possible.
The Hazardous Waste Advisement Program (HWAP) of the
Division of Hazardous Waste Management, NJDEPE, is pursu-
ing the goals of waste minimization awareness and program
implementation in the state. HWAP, with the help of an EPA
grant from the Risk Reduction Engineering Laboratory, con-
ducted an Assessment of Reduction and Recycling Opportuni-
ties for Hazardous Waste (ARROW) project. ARROW was
designed to assess waste minimization potential across a
broad range of New Jersey industries.
The project targeted 30 sites to perform waste minimization
assessments following the approach outlined in EPA's Waste
Minimization Opportunity Assessment Manual (EPA/625/7-88/
003). Under contract to NJDEPE, the Hazardous Substance
Management Research Center at NJIT assisted in conducting
the assessments. This research brief presents an assessment
of a fabricator and finisher of steel computer cabinets (1 of the
30 assessments performed) and provides recommendations
for waste minimization options resulting from the assessment.
Methodology of Assessments
The assessment process was coordinated by a team of techni-
cal staff from NJIT with experience in process operations,
basic chemistry, and environmental concerns and needs. Be-
cause the EPA waste minimization manual is designed to be
primarily applied by the inhouse staff of the facility, the degree
IAA) Printed on Recycled Paper
-------
of involvement of the NJIT team varied according to the ease
with which the facility staff could apply the manual. In some
cases, NJIT's role was to provide advice. In others, NJIT
conducted essentially the entire evaluation.
The goal of the project was to encourage participation in the
assessment process by management and staff at the facility.
To do this, the participants were encouraged to proceed through
the organizational steps outlined in the manual. These steps
can be summarized as follows:
• Obtaining corporate commitment to a waste minimization
initiative
• Organizing a task force or similar group to carry out the
assessment
• Developing a policy statement regarding waste minimiza-
tion for issuance by corporate management
• Establishing tentative waste reduction goals to be achieved
by the program
• Identifying waste-generating sites and processes
• Conducting a detailed site inspection
• Developing a list of options which may lead to the waste
reduction goal
• Formally analyzing the feasibility of the various options
• Measuring the effectiveness of the options and continuing
the assessment.
Not every facility was able to follow these steps as presented.
In each case, however, the identification of waste-generating
sites and processes, detailed site inspections, and development
of options was carried out. Frequently, it was necessary for a
high degree of involvement by NJIT to accomplish these steps.
Two common reasons for needing outside participation were a
shortage of technical staff within the company and a need to
develop an agenda for technical action before corporate com-
mitment and policy statements could be obtained.
It was not a goal of the ARROW project to participate in the
feasibility analysis or implementation steps. However, NJIT
offered to provide advice for feasibility analysis if requested.
In each case, the NJIT team made several site visits to the
facility. Initially, visits were made to explain the EPA manual
and to encourage the facility through the organizational stages.
If delays and complications developed, the team offered assis-
tance in the technical review, inspections, and option develop-
ment.
The Steel Computer Cabinet Fabricator
The production of the steel cabinets is fundamentally a three
step operation: cutting and shaping the sheet metal; applying
the finish; and assembling the cabinet. The facility operates as
a job shop, depending on orders from computer equipment
manufacturers. The computer manufacturer sets the specifica-
tions for the cabinets and the facility is responsible for produc-
ing items which meet the specifications. The facility uses com-
plex technology, such as computer-aided design and manufac-
turing techniques in the metal cutting and shaping applications.
The cutting and shaping is highly automated involving com-
puter-aided design and computer-aided manufacturing equip-
ment and processes. This technology is useful in minimizing
waste of materials because care and effort is put into optimum
parts layout and reduction of redundancy. However, the metal-
working activity requires a wide variety of metal-working fluids
and oils. It is not clear why so many different types of these
liquids are used; presumably it is based on recommendations
of the manufacturers of each of the machines.
After the metal-working stage, the metal parts are vapor de-
greased using 1,1,1-trichloroethane as solvent. Following the
degreasing, the metal surface is etched using nitric acid and
then sodium hydroxide. The etching process is useful in pro-
moting adherence of the paint to the metal surface. The cleaned
and etched surface is primed and then painted.
The facility has three painting systems: a conventional air-
assisted spray, an electrostatic disc spray, and a powder coat-
ing system. The paint system used depends upon the type of
coating desired and the physical properties of the coating
system which must be used. The type of coating and other
finish conditions are usually specified by the computer company
which is the customer of this facility. The specifications re-
quired by the customers limit the ability of the facility to optimize
a pollution prevention initiative.
After being painted the metal parts are assembled, inspected,
and shipped to the customer.
The company has already committed itself to technological
excellence and has made substantial investments to optimize
its manufacturing capability. This philosophy has now been
extended to efforts in pollution prevention. An example of this
is the acquisition of the equipment for powder coating.
Waste Streams and Existing Waste
Management
The metal-working fluids are reused until the properties of the
fluid are no longer sufficient for the cooling/lubricating function
needed. At that time they are drummed and sent for disposal
offsite. About 7100 gal of this material is disposed of annually.
The vapor degreaser is used until the grease and oil content
reduces the effectiveness of the chlorinated solvent. At that
time the degreaser is emptied and the contaminated solvent is
sent offsite for disposal. It is estimated that about 7000 Ib of
this waste stream is generated annually.
The etching process (typically used for aluminum parts) gener-
ates 110 gal of nitric acid waste and 440 gal of caustic waste
annually. These waste streams are also sent offsite for disposal.
The painting process generates VOC emissions which were
not quantified as well as sludges, thinners, and clean up
wastes. The total quantity of wastes from sludges, thinners,
and cleanups is about 3300 gal each year. This material is also
sent offsite for disposal. In addition, about 2360 gal of spent
filters from the spray booths are sent offsite for disposal each
year.
Waste Minimization Opportunities
The type of waste currently generated by the facility, the
source of the waste, the quantity of the waste and the annual
treatment and disposal costs are given in Table 1.
Table 2 shows the opportunities for waste minimization recom-
mended for the facility. The type of waste, the minimization
opportunity, the possible waste reduction and associated sav-
ings, and the implementation cost along with the payback
times are given in the table. The quantities of waste currently
generated at the facility and possible waste reduction depend
-------
Table 1. Summary of Current Waste Generation
Waste Generated
Source of Waste
Metal Working Fluids
Chlorinated Solvent
Nitric Acid
Caustic Solution
Paint and Thinner
Contaminated Filters
Lubricants and coolants from
metal cutting and forming
Vapor degreasing operation
Surface etching process
Surface etching process
from
W
ition
om painting
spray booth
Annual Quantity
Generated
7, 100 gal
7,000 Ib
1 10 gal
440 gal
3,300 gal
2,360 gal
Annual
Costs
$48,200
$3,200
$160
$1,320
$15,380
$13,860
Table 2. Summary of Waste Minimization Opportunities
Waste Stream Minimization Opportunity
Reduced
Annual Waste Reduction Net Implementation Payback
Quantity Percent Annual Savings Cost Years*
Metal Working Fluids
Chlorinated Solvent
Nitric Acid and
Caustic Etching
Wastes
Thinners, Paints,
and Clean up
Solvents
Contaminated Filters
Select the smallest number
possible of fluid types.
Larger volumes of the same
fluid should make recycling possible.
A mobile recycling service may
be possible.
If chlorinated solvent is
required, consider an onsite
distillation capability
Another alternative would be to
investigate water based degreasing
systems. Such a system would eliminate
vapor emissions and would present less
risk than the current system. It is not
known, however, if currently available
alternatives would meet performance
characteristics for this system.
It may be permissible to combine these
two streams at the site resulting in at
least a portion, depending upon the initial
pH which can be discharged to the POTW.
Segregate by solvent type and paint
clean up type. Use contaminated solvent
as first pass through in clean up of spray
equipment. Use mildly contaminated solvent
as thinner for next batch of paint.
Any metal particles should produce
a liquid which is not hazardous.
This should be confirmed by appropriate
testing. Disposal as non-hazardous
water solution would significantly
lower disposal costs.
Improve capture efficiency of spraying
by selection of most effective spray
system and appropriate adjustment of
the system.
5600 Ib
660 gal
787 gal
1778 gal 25%
$12,000
80%
$4240
$5,000
220 gal 50%
20%
$740
$3700
$2,000
33% $6620 $20,000
(When the value of the paint saved
is also considered the savings becomes
much greater. Paint at $100 per gal
yields an additional annual savings of
$49,000, shortening the payback period
to less than one year.)
immed.
1.2
immed.
0.5
3.0
' Savings result from reduced raw materials and treatment and disposal costs when implementing each minimization opportunity independently.
•ffV.S. GOVERNMENT PRINTING OFFICE: 1994 - 550-067/80159
-------
on the level of activity of the facility. All values should be
considered in that context.
It should be noted that the economic savings of the minimiza-
tion opportunity in most cases results from the need for less
raw material and from reduced present and future costs asso-
ciated with waste treatment and disposal. It should also be
noted that the savings given for each opportunity reflect the
savings achievable when implementing each waste minimization
opportunity independently, and do not reflect duplication of
savings that would result when the opportunities are imple-
mented in a package. Savings not quantifiable by this study
include a wide variety of possible future costs related to changing
emission standards, liability, and employee health. Also, the
equipment depreciation is not factored into the calculations.
There is substantial opportunity for pollution prevention at this
facility in the area of coating application technology. A signifi-
cant portion of the total waste stream from this facility is related
to paint application. Therefore efforts to make more efficient
use of the coating and to reduce the need for cleaning and
capture of paint which is not employed in coating the product
will be a positive contributor to pollution prevention.
At the time of the assessment there was a particular problem
with a specialty paint which was being used in large volumes
with poor covering efficiencies. The viscosity of the paint and
curing catalyst system was very high, even after thinning by
the prescribed procedure. As a result, only about 40% of the
paint was actually getting on the computer cabinets because of
overspray caused by the inability to effectively control the
spraying equipment. Because the paint/catalyst combination
cost about $100/gal this was an economic problem, and because
the overspray was captured on filters in the spray booth and
sent offsite for disposal as hazardous waste, it was also a
pollution problem.
An option suggested as a result of the assessment was to
investigate the use of a high volume low pressure (HVLP)
spraying system. Use of such a system has improved the
covering efficiency to 60% resulting in cost savings both in
material purchasing and in waste treatment costs.
This Research Brief summarizes a part of the work done under
cooperative Agreement No. CR-815165 by the New Jersey
Institute of Technology under the sponsorship of the New
Jersey Department of Environmental Protection and Energy
and the U.S. Environmental Protection Agency. The EPA Project
Officer was Mary Ann Curran. She can be reached at:
Pollution Prevention Research Branch
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
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-92/044
------- |