United States
Environmental Protection
Agency
Office of Pesticides
and Toxic Substances
«EPA Title III Section 313
Release Reporting
Guidance
EPA 560/4-88-004J
February 1988
Estimating Chemical Releases From
Roller, Knife, and Gravure Coating
Operations
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Estimating Chemical Releases From
Roller, Knife, and Gravure Coating Operations
Facilities performing coating operations
may be required to report annually any
releases to the environment of certain
chemicals regulated under Section 313, Title
III, of the Superfund Amendments and
Reauthorization Act (SARA) of 1986. If your
facility is classified under SIC codes 20
through 39 and has 10 or more full-time
employees, for calendar year 1987 you must
report all environmental releases of any
Section 313-listed chemical or chemical
category manufactured or processed by your
facility in an amount exceeding 75,000
pounds per year or otherwise used in an
amount exceeding 10,000 pounds per year.
For calendar years 1988 and 1989 (and
beyond), the threshold reporting quantity for
manufactured or processed chemicals drops
to 50,000 and 25,000 pounds per year,
respectively.
This document has been developed to
assist those using roller, knife, and gravure
coating equipment in the completion of Part
III (Chemical Specific Information) of the
Toxic Chemical Release Inventory Reporting
Form. Included herein is general information
on toxic chemicals used and process wastes
generated, along with several examples to
demonstrate the types of data needed and
various methodologies available for esti-
mating releases. If your facility performs
other operations in addition to coating, you
must also include any releases of toxic
chemicals from these operations.
Step One
Determine if your facility processes or
uses any of the chemicals subject to
reporting under Section 313.
A suggested approach for determination
of the chemicals your facility uses that could
be subject to reporting requirements is to
make a detailed, review of the chemicals and
materials you have purchased. If you do not
know the specific ingredients of a chemical
formulation, consult your suppliers for this
information. If they will not provide this
information, you must follow the steps
outlined to handle this eventuality in the
instructions provided with the Toxic Chemi-
cal Release Inventory Reporting Form.
The list presented here includes chemi-
cals typically used in coating operations that
are subject to reporting under Section 313.
This list does not necessarily include all of
the chemicals your facility uses that are
subject to reporting, and it may include many
chemicals that you do not use. You should
also determine whether any of the listed
chemicals are created during processing at
your facility.
Solvents: Approximately 50 solvents are
on the Section 313 list; these include
1,1,2-trichloroethane, n-butyl alcohol,
ethylene glycol, methyl ethyl ketone,
2-ethoxyethanol, xylene, and toluene
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Pigments: Primarily metal-containing
compounds such as titanium dioxide,
zinc oxide, white lead, barium sulfate,
chromium oxide, nickel titanate, and
cobalt chromite
Additives: Curing agents, surfactants,
defoamers, thickeners, film control
agents, and plasticizers such as dibutyl
phthalate, dimethyl phthalate, dioctyl
phthalate, ammonia, and diethanolamine
Polymer and resin precursors
(residues/impurities): Ethyl acrylate,
formaldehyde, vinyl chloride, vinyl
acetate, methyl acrylate, acrylic acid,
acrylonitrile, ethylene glycol, melamine,
vinylidene chloride, styrene,
1,3-butadiene, and phenol
Step Two
Determine if your facility surpassed the
threshold quantities established for
reporting of listed chemicals last year.
You must submit a separate Toxic Chemi-
cal Release Inventory Reporting Form for
each listed chemical that is "manufactured,"
"processed," or "otherwise used" at your
facility in excess of the threshold quantities
presented earlier. Manufacture includes
materials produced as byproducts or impu-
rities. Toxic compounds that are incorpo-
rated into your products (for example,
pigments, polymer and resin precursors)
would be considered "processed" because
they become part of the marketed finished
product. Carrier solvents, degreasing sol-
vents, cleaning agents, and other chemicals
that do not become part of the finished
product would be considered "otherwise
used."
The amount of a chemical processed or
otherwise used at your facility represents the
amount purchased during the year, adjusted
for beginning and ending inventories. To
ascertain the amount of chemical in a mixed
formulation, multiply the amount of the
mixture (in pounds) by the concentration of
the chemical (weight percent) to obtain the
amount of chemical processed.
Example: Determining whether tolu-
ene was used in sufficient quantity
last year to require reporting under
Section 313.
During 1987, a coil coating facility
used two different coating formulas, one
containing 38 percent toluene (by weight),
and the other, 25 percent toluene (by
weight). "Pure" (98 percent) toluene was
also purchased for use as a coating
thinner. Purchasing and inventory records
indicate the following:
• 100,000 pounds of the 38 percent
toluene coating was purchased in
1987; 2,000 pounds was in storage at
the beginning of the year, and 7,000
pounds was in storage at the end of
the year.
• 50,000 pounds of the 25 percent
toluene was purchased in 1987; 5,000
pounds was in storage at the begin-
ning of the year, and none was in
storage at the end of the year.
• 25,000 pounds of the 98 percent
toluene was purchased in 1987; none
was in storage at either the beginning
or the end of the year.
The quantity of toluene used can be
calculated as follows:
[(2,000 Ib x 0.38) + (5,000 Ib x 0.25)]
(beginning inventory) +
[(100,000 Ib x 0.38) + (50,000 Ib x
0.25) + (25,000 Ib x 0.98)]
(purchased) -
(7,000 Ib x 0.38) (ending inventory)
= 74,350 Ib
Because this is in excess of the 10,000-
pound reporting threshold for "otherwise
used" chemicals, a Toxic Release Inventory
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Reporting Form must be completed for
toluene.
A listed chemical may be a component of
several formulations you purchase, so you
may need to ask your supplier for informa-
tion on the concentration (percentage) of the
chemical in each. For chemical categories,
your reporting obligations are determined by
the total amounts of all chemicals in the
category. For example, if zinc oxide and zinc
sulfate are used as pigments, the quantity of
zinc compounds processed is the sum of the
amounts of ZnO and ZnSO4 present. For a
substance such as cobalt chromite (CoCr2O4),
the amount used must be considered in
determining whether the threshold is met for
both cobalt-containing and chromium-
containing compounds.
You must complete a report for each
chemical for which a threshold is exceeded.
The thresholds apply separately; therefore, if
you both process and use a chemical and
either threshold is exceeded, you must report
for both activities. If neither threshold is
exceeded, no report is needed.
Step Three
Identify points of release for the
chemical(s) subject to reporting.
An effective means of evaluating points of
release for listed toxic chemicals is to draw a
process flow diagram identifying the opera-
tions performed at your facility. The figure
below is an example flow diagram for coating
operations. Because each facility is unique,
you are strongly urged to develop a flow
diagram for your particular operations that
details the input of materials and chemicals
and the waste sources resulting from the
operation of each unit.
The principal potential sources of chemi-
cal release in typical coating operations are:
• Releases of volatile organic com-
pounds from the coating application
and dryer areas
SOLID WASTE,
NONAQUEOUS LIQUID WASTE,
1 ' AND/OR WASTEWATER
Example Flow Diagram of Roll Coating
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• Excess coating mix and solvent from
the cleanup of the coating applicator,
coating lines, and empty coating
drums
• Transfer from rail cars or tank trucks
to storage tanks and subsequent
transfer to processing tanks
• Breathing losses from vents on
storage tanks
• Agitation of mixing tanks that are
vented to the atmosphere
• Evaporation of solvent from the coated
substrate after it leaves the coating
lines
• Wastes from control equipment used
to reduce air emissions from the
coating applicator and dryer
Step Four
Estimate releases of toxic chemicals.
After all of the toxic chemicals and waste
sources have been identified, you can esti-
mate the releases of the individual chemicals.
Section 313 requires that releases to air,
water, and land and transfers to offsite
facilities be reported for each toxic chemical
meeting the threshold reporting values. The
usual approach entails first estimating re-
leases from waste sources at your facility
(that is, wastewater, air release points, and
solid waste) and then, based on the disposal
method used, determining whether releases
from a particular waste source are to air,
water, land, or an offsite disposal facility.
In general, there are four types of release
estimation techniques:
• Direct measurement
• Mass balance
• Engineering calculations
• Emission factors
Descriptions of these techniques are provided
in the EPA general Section 313 guidance
document, Estimating Releases and Waste-
Treatment Efficiencies for the Toxic Chemical
Release Inventory Form.
Provisions of the Clean Air Act, Clean
Water Act, Resource Conservation and Re-
covery Act, and other regulations require
monitoring of certain waste streams. If
available, data gathered for these purposes
can be used to estimate releases. When only
a small amount of direct measurement data
is available, you must decide if another
estimation technique would give a more
accurate estimate. Mass balance techniques
and engineering assumptions and calcula-
tions can be used in a variety of situations to
estimate toxic releases. These methods of
estimation rely heavily on process operating
parameters; thus, the techniques developed
are very site-specific. Emission factors are
available for some industries in publications
referenced in the general Section 313 guid-
ance document. Also, emission factors for
your particular facility can be developed in-
house by performing detailed measurements
of wastes at different production levels.
The mass balance technique for esti-
mating emissions is well suited for coating
operations because of the numerous environ-
mental release points involved and the ease
with which the ultimate fate of waste'chemi-
cals can be determined (that is, process
solvents and volatile components of the coat-
ings are released to air, whereas nonvolatile
components of the coating that do not
become part of the product are released as
solid waste or wastewater from clean opera-
tions). Direct measurement of waste sources
is applicable in any situation; however, such
measurements are not routinely performed
for many of the coating chemicals subject.to
reporting.
To estimate toxic chemical releases by
mass balance, one must know the quantity of
chemical purchased (adjusted for changes in
inventory) and the quantity retained in the
coated product. The difference in these two
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quantities yields the amount of chemical
released as waste. An engineering assump-
tion is then used to determine the method of
release (air emission, wastewater, solid
waste). For coating operations, the following
assumptions can be used:
• All volatile organic compounds
present in the applied coating formu-
lation, such as solvent coating
carriers and unpolymerized resin
precursors, can be assumed to be
released as air emissions.
• The portion of nonvolatile compounds
in the coating formulation that is not
retained on the coated substrate can
be assumed to be released during
cleaning as solid waste (including
nonaqueous liquid waste) or waste-
water, depending on the cleanup
method.
• All solvents used during cleanup of
coating equipment can be assumed to
end up as solid waste (nonaqueous
liquid waste) and/or air emissions,
depending on the cleanup method.
Toxic Releases to Air
The mass balance approach is easily
applied to solvent carriers of coating solids
because they are purposely volatilized during
coating and drying. Therefore, the quantity
purchased (adjusted for inventory changes) is
the quantity released to air. If a control
device is used, the quantity of the solvent
released should be adjusted for removal
efficiency. If solvent is recovered from the
control device and reused (as a carrier) in the
process, the total quantity of solvent released
to the air will still be equal to the quantity of
solvent purchased, adjusted for inventory
change (because the solvent recovery is an
internal reuse, and the benefit of the control
device manifests itself in a reduction in the
quantity of solvent purchased). If the re-
covered solvent is shipped offsite instead of
being reused, the quantity of solvent released
to air would equal the difference between the
quantity used (quantity purchased adjusted
for inventory change) and the quantity re-
covered. In this case, the quantity recovered
would be reported as "transferred to offsite
locations."
In some coating processes, a small
amount of solvent may be retained in the
product. Although this is usually a negligible
amount, if a rough value of the quantity
retained is known, it can be subtracted from
the quantity released to air.
Unpolymerized resin precursors are
usually present in small quantities in organic
coating formulations. Typically, these com-
pounds are highly volatile and will be re-
leased to air during drying. The entire
quantity present in the purchased coating
(adjusted for inventory changes) can be
assumed to be emitted to air. Amounts of
chemicals in purchased formulations in
concentrations below the 1% de minimis level
(0.1% for carcinogens), however, do not have
to be considered in threshold calculations.
Again, if a control device is used for the dryer
and coating area exhaust, its efficiency
should be factored into the estimated releases
of these compounds.
Example: Estimating releases of
volatile toxic compounds from a
coating formulation.
A direct roll coater is used to apply an
alkyd-urea-formaldehyde resin top coat on
plywood paneling. Urea-formaldehyde
resin makes up 45 percent of the coating
solids, and according to the manufacturer,
this urea-formaldehyde resin contains
1.5 percent free formaldehyde. The
density of the coating solids is 10 pounds
per gatton of solids. As purchased, the
coating containing xylene has 8 pounds of
solids per gallon of coating. Before it is
applied, the coating is thinned with xylene
at the coating facility to yield 4 pounds of
soUds per gallon of coating.
According to purchasing and inventory
records, 10,000 gallons of the purchased
coating formulation was processed during
1987. Assuming complete volatilization of
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QSP » QSR+QSW
QSP = (dxCTxCA) + QSW
where QSP = total quantity of nonvolatile
solids in coating processed
QSR = total quantity of nonvolatile
solids retained in substrate
QSW = total quantity of nonvolatile
solids wastes
d = density of solids
CT = coating thickness
CA = coated area
A relationship can be used to determine
an overall coating transfer efficiency for an
application/coating combination.
(QSR+QSP)=te
QSP x te = QSR
QSPx(l-te) = QSW
where te = overall transfer efficiency
For an individual toxic compound present
as a nonvolatile solid, the overall transfer
efficiency can be used to make a direct
estimate of releases from the quantity of the
chemical in the purchased coating (adjusted
for inventory changes).
QCP x (1 - te) = QCW
where QCP = quantity of nonvolatile solid
chemical processed
QCW = quantity of nonvolatile solid
chemical wasted
Example: Using a mass balance to
estimate releases of nonvolatile toxic
compounds from coating formulations.
A roll coater applies a water-based
polyester resin paint to metal coil The
formulation contains titanium dioxide
CTiOJ and white lead (PbCOJfor coloring.
According to Information provided by the
manufacturer, the paint contains 14.5
pounds of nonvolatile solids per gallon of
coating, and the density of the solids is
15.3 pounds per gallon. Also, the titanium
dioxide and white lead represent 32 and
19 percent by weight of the nonvolatile
solids. EPA has proposed to remove TiO2
from the Section 313 list; however, this
example is also representative of the use of
a mass balance to estimate releases of
other similar compounds.
Purchasing and inventory records
indicate that 39,000 gallons of this
formulation was processed during 1987.
Production records indicate that
13,200,000 square feet of coil received a
3-mil coat of this formulation. The roll
coater is cleaned with a water wash, and
the resultant wastewater is discharged to
the local sewers. The quantity ofTiO2 and
Pb released via wastewater can be
estimated by the following calculations:
Amount of nonvolatile solids processed =
39,000 gal coating x
10.5 Ib solids/I gal coating
= 409,500 Ib
Volume of solids applied to coil =
13,200,000 ft2 coil x
0.003 in. thickness +
12 in./1 ft x
7.48 gal/IJt?
= 24,684 gal
Amount of solids applied to coil =
24,684 gal solids x
15.3 Ib solids /I gal solids
= 377,665 Ib
Coating solids transfer efficiency =
377,665 Ib (appUed) •*•
409,500 Ib (processed)
= 0.933
Amount ofTiO2 processed =
409,500. Ib (solids processed) x 0.32
(TiO2 wt. percent)
= 131,040 Ib
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Amount ofTiO2 released =
131,040 Ib processed x(l- 0.933)
= 8,780 Ib
Amount o/PbCO3 processed =
409,500 Ib (solids processed) xO.19
(Pb wt. percent)
= 77,805 Ib
Amount ofPb released =
77,805 Ib PbCO3 processed x
(1 - 0.933) x
1 mole PbCO3/267 Ib PbCO3 x
207 Ib Pb/1 mole PbCO3
= 4,041 Ib
Because the wash water leaves the facility
through local sewers, 8,800 pounds ofTiO2
and 4,000 pounds ofPb would be reported
as "discharged to POTW."- If the roll coater
was cleaned by a "dry" method and the
cleanup wastes were drummedfor
shipment to a waste recovery or disposal
facility, the same calculations would apply
and the amounts would be reported as
"transferred to an off site location."
Toxic Releases Via Solid Waste
As mentioned in the preceding sections,
solid and nonaqueous liquid wastes are
generated in "dry" coating cleanup opera-
tions. These wastes contain cleanup solvents
and nonvolatile coating solids that were not
transferred to the substrate. The mass
balance techniques demonstrated in the
example concerning cleanup operations are
also applicable to releases via solid and
nonaqueous liquid wastes.
Toxic chemical releases via solid and
nonaqueous liquid wastes may be measured
directly by using data gathered for com-
pliance with RCRA regulations. Many spent
solvents are listed as hazardous waste under
RCRA Waste Codes F002 through F005.
These codes may apply to spent solvents used
to clean up the coating applicator and
surrounding area. Many spent cleanup
solvents may also be considered hazardous
under RCRA because of EP toxicity or ignition
characteristics.
The RCRA manifesting procedure for
hazardous waste shipped offsite requires
documentation of quantities shipped. Treat-
ment, storage, and disposal facilities must
perform detailed chemical and physical
analyses on the wastes. The waste also may
be analyzed at your facility. Therefore,
estimates of releases for several compounds
can be made by direct measurement.
Other Toxic Releases
Coating operations produce other wastes
from which toxic chemicals may be released.
These include:
• Residues from pollution control
devices
• Product rejects
• Used equipment
• Empty chemical containers
Releases from these sources may already
have been accounted for, depending on the
release estimation methods used. These
items (and any other of a similar nature)
should be included in your development of a
process flow diagram.
The contribution of sources of wastes
such as cleaning out vessels or discarding
containers should be small compared with
process losses. If you do not have data on
such sources (or any monitoring data on
overall water releases), assume up to 1 per-
cent of vessel content may be lost during
each cleaning occurrence. For example, if
you discard (to landfill) "empty" drums that
have not been cleaned, calculate the release
as 1 percent of normal drum content. If the
drums are washed before disposal, this may
contribute 1 percent of the content to your
wastewater loading.
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vvEPA
United States
Environmental Protection
Agency
Office of Pesticides and
Toxic Substances, WH-562A
Washington, D.C. 20460
Official Business
Penalty for Private Use
$300
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