United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-96/150 January 1997
*& EPA Project Summary
Environmental Assessment of
Shop Towel Usage in the
Automotive and Printing
Industries
W. Pullman, M. Wolf, R. Thomas, P. Fitzpatrick, and P. Craig
To further its research in Life Cycle
Assessment (LCA) while assisting the
EPA Office of Water evaluate the envi-
ronmental impacts associated with wo-
ven shop towels, the National Risk Man-
agement Research Laboratory collected
shop towel usage and emissions infor-
mation using a streamlined life cycle
approach. The assessment identified
the environmental impacts and usage
trends of shop towels in the printing
and automotive repair industries. Four
types of shop towels were evaluated:
woven, nonwoven, paper, and rags. The
resource requirements and emissions
during the manufacture, usage and dis-
posal of each shop towel were com-
pared, with primary focus on the usage
and disposal of shop towels. (The full
report was submitted in fulfillment of
Contract No. 68-C4-0020 by Lockheed
Martin Environmental Systems and
Technologies under the sponsorship of
the United States Environmental Pro-
tection Agency. This report covers a
period from June 1994 to May 1996
and the work was completed as of No-
vember 1996.)
This Project Summary was developed
by EPA's National Risk Management
Research Laboratory, Cincinnati, OH,
to announce key findings of the re-
search project that is fully documented
in a separate report of the same title
(see Project Report ordering informa-
tion at back),
Introduction
An environmental assessment using
streamlined life cycle principles was con-
ducted to identify the environmental im-
pacts'and usage trends of shop towels in
the printing and automotive repair indus-
tries. The shop towels are used to clean
equipment and to wipe up contaminants
for a variety of operations. The four types
of shop towels evaluated were woven,
nonwoven, paper, and rags. Woven tow-
els that become contaminated from usage
are cleaned at industrial laundries and are
a significant contributor to the contami-
nant loading of liquid discharges from the
laundries. The cost of cleaning woven tow-
els at industrial laundries is increasing as
local regulations restrict the allowable con-
taminants in the liquid discharge. The print-
ing industry continues to use woven tow-
els rather than nonwoven and paper tow-
els and may use alternative towel clean-
ing methods in the future. The automotive
repair industry continues to use woven
towels, but is slowly converting to non-
woven and paper towels due to their ad-
equate capability and low cost.
Streamlining Process
The environmental assessment de-
scribed here utilized the methodology for
life cycle assessment (LCA) as described
by the EPA (EPA, 1993), but a full LCA
was not conducted. The limits of the as-
sessment as conducted "are given below:
• The assessment provided a brief
analysis of the raw materials acquisi-
tion and manufacturing subsystems
with a detailed analysis of the indus-
trial usage and postusage sub-
systems.
• The assessment analyzed the energy
and water inputs for all subsystems,
but an analysis of emissions was con-
ducted only for the industrial usage
subsystem.
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• The starting point of the raw material
subsystem for this assessment was
the materials used to produce the fi-
bers for the shop towels.
• The assessment focused on the dif-
ferences among the shop towels,
therefore areas of similar'energy and
water usage among all shop towels
were not examined in detail. For ex-
ample, the energy for transportation
of shop towels from the manufacture
point to the user was considered simi-
lar for all shop towels and therefore
was not quantified.
• The impact assessment was based
on quantified pollutant emissions in
the industrial usage subsystem, and
estimated pollutant emissions in the
raw materials, manufacturing, and the
postusage subsystems. The shop tow-
els analyzed were limited to the most
common types currently used in the
automotive and printing industries.
Inventory Assessment
The following shop towel categories
were evaluated:
• Woven towels (cotton/polyester blend)
• Nonwoven towels (wood pulp/polyes-
ter blend and 100% polypropylene)
• Paper towels (wood pulp with bind-
ers)
• Rags (cotton/polyester blend, equiva-
lent to woven- towels)
Impact Assessment
The impact assessment was based on
air emissions, liquid discharges, and solid
wastes identified in the inventory assess-
ment of the four types of shop towels.
Potential environmental impacts for each
subsystem were identified, but quantifica-
tion of the impacts associated with these
subsystems was not conducted. Potential
environmental impacts and, to a limited
extent, human health impacts were ad-
dressed in relation to general impact sub-
categories.
Results
Water Usage
Woven towels and paper towels re-
quire similar life cycle quantities of water
(18,000 and 16,000 Ib per 1,000 towels,
respectively). Nonwoven towels require
less than 3,500 Ib of water per 1,000
towels. The raw material acquisition sub-
system accounts for the majority of water
usage for both woven towels and paper
towels. Water usage for woven towels is
dominated by the production of cotton.
Water usage for paper towels is domi-
nated by the manufacture of butadiene
and styrene binders.
Energy Usage
The life cycle energy requirements are
highest for paper towels (950,000 British
thermal units [Btu] per 1,000 towels), fol-
lowed by nonwoven towels (520,000 to
860,000 Btu per 1,000 towels; dependent
on composition). Woven towels required
the least amount of energy (72,000 Btu
per 1,000 towels). Primary energy usage
for all shop towels occurs in the raw ma-
terial acquisition subsystem. Energy re-
quirements for the nonwoven and paper
towels are dominated by the processing
of petroleum-based fabrics and binders.
Although the energy required for a single
woven towel usage cycle is roughly simi-
lar to the energy required for a single
nonwoven and paper usage cycle, the net
energy usage for woven towels is low due
to their reuse.
Emissions
In the raw materials acquisition sub-
system, the production of wood pulp is
the primary source of environmental emis-
sions for all shop towel categories ana-
lyzed, followed by petroleum product
manufacturing and cotton production. How-
ever, emissions related to shop towels
account for a very small percentage of
total emissions from these industries. The
wood pulp manufacturing process for the
nonwoven and paper towel generates
wastewater with biochemical oxygen de-
mand (BOD) and total suspended solids
(TSS) loading. Air emissions may include
reduced sulfur compounds and volatile or-
ganics such as chloroform and methanol,
depending on the process used to manu-
facture wood pulp. The manufacture of
petroleum products that are used in wo-
ven, nonwoven, and paper towels pro-
duces airborne and waterborne organic
emissions. Cotton production may result
in fertilizers, herbicides, and pesticides in
field runoff (liquid effluent).
The primary activities of fiber produc-
tion, weaving, matting, and packaging re-
sult in relatively minor emissions from the
shop towel manufacturing subsystem. The
wet laid process to convert wood pulp to a
fiber for nonwoven and paper.towels gen-
erates wastewater with BOD and TSS
loading.
The washwater effluent from woven
towel laundering is the only significant liq-
uid discharge in the industrial usage sub-
system. Woven towels account for a small
fraction of the articles cleaned in a typical
industrial laundry, but are responsible for
the majority of the contaminant loading
(organics, inorganics, and metals) in the
wastewater effluent. Treatment of the ef-
fluent to remove contaminants may occur
at the industrial laundry or at a publicly-
owned treatment works (POTW). The ca-
pability for contaminant removal at the
industrial laundry or the POTW is depen-
dent on local regulations, and is highly
variable throughout the United States.
Air emissions in the industrial usage
subsystem are primarily from evaporation
of volatile contaminants collected on the
shop towel. Volatile organic compound'
(VOC) emissions can occur during han-
dling and storage of all types of contami-
nated shop towels and during the wash-
ing of woven towels. Solvent washing of
woven towels results in a minor increase
in VOC emissions compared to water
washing. (Herod, 1995)
Disposal of shop towels and sludge oc-
curs in the postusage subsystem. The
weight of sludge from washing woven tow-
els (88 Ib per 1,000 towels) is similar to
the weight of contaminated single-use tow-
els (68-74 Ib per 1,000 towels) entering
the landfill. The sludge from woven towel
washing contains an average of 22% wa-
ter. Single-use towels (nonwoven, paper,
and rags) do not contain the water associ-
ated with woven towel sludge, but the
shop towel enters the landfill along with
the contaminants. Rags have the greatest
disposal weight (110 Ib per 1,000 towels)
due to single-use and higher towel den-
sity compared to nonwoven and paper
towels.
Sludge generated from the water wash-
ing of woven towels is commonly sent to
municipal landfills, while the sludge gen-
erated from solvent washing of woven tow-
els is incinerated. Single-use shop towels,
along with the contaminants, are sent di-
rectly from the automotive or printing shops
to landfills. Incineration of single-use shop
towels is uncommon due to higher costs
as compared to landfills, and is conducted
only when the shop towels cannot be land
filled because of regulatory restrictions.
Impacts
Air quality impacts were relatively minor
for all shop towels. VOC emissions could
result in minor smog generation impacts.
A small amount of acid rain precursor
emissions are generated during the pro-
duction of wood pulp.
Adverse water quality impacts occur in
the production of wood pulp, production of
petroleum-based intermediate materials,
and woven towel laundering. Common im-
pact areas for all shop towels include
aquatic life, oxygen depletion, and chemi-
cal/biological content. Aquifer contamina-
tion could occur from field runoff during
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cotton production. Alterations of water pH
in localized areas may occur due to wood
pulp production and cotton cloth produc-
tion.
Adverse human health impacts occur
primarily through inhalation or ingestion of
contaminants. Irritant/sensitizer effects and
respiratory effects resulting from airborne
pollutants are the most common impact
areas. Dermal contact of pesticides and
herbicides during cotton production has
the potential for gastrointestinal and re-
productive effects. The variety of organic
compounds (cleaners, lubricants, etc.) as-
sociated with all shop towel usage may
result in exposure to potential carcino-
gens that will affect the liver, kidneys, and
central nervous system.
Conclusions
The following conclusions have been
reached through the evaluation of the shop
towel life cycle and offer a "snapshot" of
current shop towel usage.
Inputs
The total water requirements were simi-
lar for woven and paper towels, and were
about ten times greater than for nonwoven
towels. Laundering woven towels is usu-
ally regarded as a large water consump-
tion process, but the wet laid process for
manufacturing paper towels consumes
more water than the laundering process
for woven towels. Woven towels have the
lowest relative energy requirement due to
their capacity for reuse.
Outputs
Woven, nonwoven, and paper towel
wastes generated from the industrial us-
age and postusage subsystems were simi-
lar in total weight. However, the volume
occupied in the landfill is variable because
woven towel waste is primarily in the form
of sludge, while nonwoven and paper towel
waste consists of the towel and contami-
nants.
Liquid discharges to the environment
are generated during woven towel wash-
ing because the effluent treatment pro-
cess at the laundry or the POTW is not
100% efficient in removing contaminants.
Impacts
Environmental impacts from woven
towel usage are greatest in the industrial
usage subsystem, which is consistent for
reusable materials. Water quality impacts
occur because processes for treating laun-
dry effluent do not remove all contami-
nants from the water prior to discharge.
Environmental impacts from nonwoven
towel usage occur primarily in the raw
material acquisition and manufacturing
subsystems, which is consistent for single
usage materials. Impacts associated with
nonwoven towels are dependent on the
materials used to manufacture the towel.
The manufacturing process for nonwoven
towels that contain petroleum-based ma-
terials generates air emissions composed
of organic compounds. The manufacture
of nonwoven towels that contain wood-
based materials generates air and water
emissions that could contain sulfur and
chlorine compounds.
The environmental impacts from paper
towel usage occur primarily in the raw
material acquisition and manufacturing
subsystems, again consistent for single
usage materials. The conversion of wood
to cellulose acetate is responsible for the
majority of air and water quality impacts
associated with paper towel usage.
Environmental impacts attributable to the
postusage subsystem are similar for all
shop towels. The contaminants generated
from the woven towel usage are divided
between sludge that enters the landfill
(>90%) and liquid discharge that enters
the environment (<10%). All contaminants
on the single-use towels will usually enter
the landfill with the towel. The primary
difference between disposal of sludge that
is generated from woven towel laundering'
and disposal of single-use towels with their
associated contaminants is the volume
occupied in the landfill. The, single-use
towel/contaminant combination has a lower
density than the woven towel sludge and
will occupy a larger volume in the landfill.
The use of solvent washing for woven
towels has the potential to significantly
reduce the amount of sludge sent to the
landfill since the sludge from solvent wash-
ing is usually incinerated. However, the
incineration of solvent washing sludge will
result in a small increase in air emissions.
There were no distinct human health
impact differences noted among the shop
towels. The by-products of shop towel pro-
duction and use have towel-dependent
impacts, but it is not feasible in this as-
sessment to determine a clear distinction
of the impact differences for the shop tow-
els.
The fuill report was submitted in fulfill-
ment of Contract No. 68-C4-0020 by
Lockheed Martin Environmental Systems
and Technologies under the sponsorship
of the U.S. Environmental Protection
Agency.
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W Pullman, M. Wolf, R. Thomas, P. Fitzpatrick, and P. Craig are with Lockheed
Martin Environmental Systems and Technologies, Las Vegas NV89119
Jim Bridges is the EPA Project Officer (see below).
The complete report, entitled "Environmental Assessment of Shop Towel Usage in
the Automotive and Printing Industries," (Order No. PB97-133698; Cosf $25 00
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
. Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
National Risk Management Research 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
EPA/600/SR-96/150
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
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