United States
Environmental Protection
Agency
Office of Pesticides
and Toxic Substances
EPA 560/4-88-0046
January 1988
&EPA Title 111 Section 313
Release Reporting
Guidance
Estimating Chemical Releases From
Semiconductor Manufacturing
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Estimating Chemical Releases From
Semiconductor Manufacturing
Manufacturers of semiconductors may be
required to report annually any releases to
the environment of certain chemicals reg-
ulated 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
(semiconductor manufacturers generally fall
under SIC code 3674) 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 semiconductor manufacturers 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 estimating releases. If your
facility performs other operations in addition
to semiconductor manufacturing, 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 Chem-
ical Release Inventory Reporting Form.
The list presented here includes chem-
icals typically used in the manufacture of
semiconductors that are subject to reporting
under Section 313. This list does not nec-
essarily 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: Acetone, aniline, chlorinated
fluorocarbons, chlorobenzene, chloroform,
chloromethane, methanol, methyl ethyl
ketone, methyl isobutyl ketone, tetra-
chloroethylene, 1,2,4-trichlorobenzene,
1,1,1-trichloroethane .
Dopants: Antimony, arsenic, cadmium,
phosphorus, selenium, zinc
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Electroless solutions: Formaldehyde
Etch components: Chlorine, hydro-
chloric acid, hydrogen fluoride, nitric
acid, phosphoric acid, sodium hydroxide,
sulfuric acid
Carrier gas: Ammonia
Solder components: Lead, silver
Metallization components: Beryllium,
chromium, copper, nickel, vanadium
Photoresist chemicals: Ethylene glycol,
toluene, xylene
Step Two
Determine if your facility surpassed the
threshold quantities established for
reporting of listed chemicals last year.,
^ ^
You must submit a separate Toxic Chem-
ical 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, a
dopant applied to a metal) would be con-
sidered "processed" because they become
part of the marketed finished product.
Degreasing solvents, 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: Calculating annual use of
acetone through purchases! and
inventory changes.
Opening stock
5,000lb
Plus purchases during year 12,000 Ib
Less closing stock
Total use
17,000 Ib
6,000 Ib
11,000 Ib
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.
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.
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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
on the right is an example flow diagram for
semiconductor manufacturing. 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.
Wastewater and "solid" wastes are likely
to be the primary releases to consider. If
water is treated on site, you may also have a
sludge or other waste containing the chemi-
cal. Other releases may come from discarded
containers or samples, vessel washings, or
(for some substances) volatilization to the air.
All releases must be accounted for when
reporting.
SILICON
WAFER
SILICON COMPOUND
DEPOSITION
±
ACID
DEIONIZED
WATER
APPLICATION OF
PHOTORESIST
UV LIGHT
EXPOSURE
DEVELOPING
ETCH
DEIONIZED
WATER RINSE
DOPING
SPENT ACID
WASTEWATER
EXHAUST
ACID OR
SOLVENT
ACID OR
SOLVENT RINSE
SPENT ACID
OR SOLVENT
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
METAL
DEPOSITION
PASSIVATION
DICING INTO
CHIPS
ASSEMBLY
Example Flow Diagram of
Semiconductor Manufacturing
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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 esti-
mation technique would give a more accurate
estimate. Mass balance techniques and
engineering assumptions and calculations
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.
Toxic Releases Via Wastewater
Because of the need to comply with EPA
regulations for metals and Total Toxic Organ-
Ics from semiconductor processing, you may
have monitoring data specific to some of the
chemicals you use. You can calculate annual
releases using this information in the
following manner:
Amount of chemical released in
wastewater =
concentration in wastewater x
daily volume of wastewater x
days/year for which data apply
Review all monitoring data to determine aver-
age representative concentrations to use in
this calculation. In the case of chromium,
copper, cobalt, or any other metal-containing
substances, releases should be reported only
for the metal content.
The total releases of a chemical should
equal the amount used during the year
minus the amount incorporated into products
minus the amount destroyed in onsite treat-
ment. For the metals you use, it will be
particularly helpful to estimate the amount
incorporated into products before proceeding
to individual release estimates, as this will
provide a reference point.
If no monitoring data are available for
wastewater, you can estimate the release in
one of the following ways:
1) Use of mass balance
If no wastewater monitoring data exist,
calculate releases to process water based on
a mass balance of the process:
Amount of chemical released in
wastewater =
amount used -
amount incorporated in product -
amount accounted for in other wastes
If your facility uses a listed mineral acid
or base, but this acid or base is effectively
neutralized in use or during wastewater
treatment (to pH 6 to 9, as required by most
effluent standards), no release quantities
should be reported. If the acid or base is
transformed into a reportable substance,
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however, you must estimate the quantity of
this substance manufactured to determine if
the "manufactured" threshold value has been
reached. For example, sulfuric acid neutral-
ized by sodium hydroxide yields sodium
sulfate, which is a listed chemical.
2) Use of published data on the
semiconductor industry
The table on the right gives minimum and
maximum concentrations of approximately
50 of the listed chemicals in the untreated
wastewater from semiconductor facilities. If
you use one of these chemicals and do not
have data on your waste stream, you can
multiply maximum concentrations times your
daily wastewater discharge flow to obtain
daily and annual release estimates.
Example: Using published wastewater
discharge concentrations to calculate
annual use of 1,2-diphenylhydrazine.
During 1987 a plant used 1,2-di-
phenylhydrazine throughout the year. In
the absence of monitoring data at the site,
Amount in untreated wastewater =
maximum concentration x
daily volume of wastewater x
days/year for which data apply
Using the maximum concentration reported
for 1,2-diphenylhydrazine:
Amount of 1,2-diphenylhydrazine =
0.022 mg /liter x
40,000,000 liters/day x
1 lb/454,000 mg x
260 days/year
= 504 Ib
Using this approach, the plant in this
example could report releases to
wastewater of 500 pounds of 1,2-
diphenylhydrazine.
Measured Concentrations of Selected
Section 313 Chemicals in Untreated
Wastewater from Semiconductor
Manufacturing Facilities8
Parameter
Benzene
Benzidine
Chlorobenzene
1 ,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1 , 1 -Dichloroethane
Chloroform
1 ,2-Dichlorobenzene
1 ,3-Dichlorobenzene
1 ,4-Dichlprobenzene
1, 1-Dichloroetriylene
1 ,2-Dichlorophenol
1 ,2-Diphenylhydrazlne
Ethylbenzene
Fluoranthene
Methylene chloride
Chlorodibromomethane
Naphthalene
2-Nitrophenol
4-Nitrophenol
Phenol
Bis(2-ethylhexyl)phthalate
Burylbenzylphthalate
n-Dibutyl phthalate
n-Diociyl phthalate
Diethyl phthalate
Dimethyl phthalate
Tetrachloroethylene
Toluene
2,4-Dichlorophenol
Trichloroethylene
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Copper
Cyanide
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Min. cone.,
mg/liter
<0.01
<0.01
<0.01
0.0029
0.0002
<0.01
0.004
0.001
0.0027
0.0011
<0.01
<0.01
<0.01
0.0002
<0.01
0.005
0.005
<0.01
0.002
<:0.01
0.0004
0.002
<0.01
0.0009
<0.01
<0.01
<0.01
0.0002
0.002
<0.01
0.0049
<0.0005
<0.003
<0.001
<0.001
<0.001
<0.001
<0.005
<0.005
<0.04
<0.001
<0.001
0.005
<0.002
<0.001
<0.001
<0.001
0.001
Max. cone.,
mg/liter
0.190
27.1
7.7
0.01
2.6
186.0
14.8
14.8
0.071
0.022
0.107
2.4
1.504
0.70
3.10
5.7
0.750
0.013
0.280
0.01
0.80
0.14
0.071
3.5
0.187
0.067
<0.015
0.008
1.150
0.48
2.588
0.01
1.459
0.209
0.051
4.964
0.045
0.013
0.012
0.214
0.289
Data obtained from Development Document for
Effluent Limitations Guidelines and Standards for
Electrical and Electronic Components.
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If wastewater is treated before release,
you must adjust releases for the effectiveness
of the treatment. If available, data on the
operation of your treatment facility should be
used. If not, consult the EPA publication,
Development Document for Effluent Limita-
tions Guidelines and Standards for Electrical
and Electronic Components, for information
on removal achieved by recommended
treatment systems where available.
Toxic Releases Via Solid Waste
Wastewater treatment may transfer the
chemical to sludge. You may have data on
the concentration of metals in your sludge
and can calculate release as pounds of sludge
times concentrations of the chemical. Alter-
natively, the loss in the sludge can be
estimated by:
Amount of metal in sludge =
amount lost from process -
amount released in discharged water
or
Amount of metal in sludge =
amount of metal in influent to
treatment x
wastewater treatment efficiency
The latter approach would be appropriate if
monitoring data for untreated wastewater
and measured removal efficiencies were
available (for example, in published sources).
For organic chemicals in general, some
degradation in treatment may occur so all of
the chemical is not transferred to the sludge.
You can estimate the amount of organic
compounds in the sludge by using measured
data or by subtracting the amount biode-
graded from the total amount removed in
treatment. The amount of removal can be
determined from operating data, and the
extent of biodegradation might be obtained
from published studies. If the biodegrad-
ability of the chemical cannot be measured or
is not known, you should assume that all
removal is due to absorption to sludge.
Toxic Releases to Air
Your facility will release to air some vola-
tile compounds, particularly solvents. The
following is the simplest way to estimate this
loss:
Amount of solvent released to air =
solvent use -
solvent in wastewater -
solvent in "solid" wastes -
solvent destroyed by treatment -
solvent incorporated in products
This approach should provide a reasonably
accurate estimate in most cases, especially if
other releases are small compared with the
air releases.
Individual contributions to air releases
from storage tanks, valves, etc., can be
calculated by using the approaches docu-
mented in Estimating Releases and Waste-
Treatment Efficiency for the Toxic Chemical
Release Inventory Form.
Other Toxic Releases
Semiconductor manufacturing produces
other wastes from which toxic chemicals may
be released. These include:
• Residues from pollution control
devices
• Wash water from equipment
cleaning
• Product rejects
• Used equipment
• Empty chemical containers
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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.
Step Five
Complete the Toxic Chemical Release
Inventory Reporting Form.
After estimating the quantity of each
chemical released via wastewater, solid
waste, and air emissions, you must deter-
mine the amount of each chemical released to
water, land, or air or transferred to an offsite
disposal facility. This determination will be
based on the disposal method you use for
each of your waste streams. Enter the re-
lease estimates for each chemical or chemical
category in Part III of the Toxic Chemical
Release Inventory Reporting Form. Also enter
the code for each treatment method used, the
weight percent by which the treatment
reduces the chemical in the treated waste
stream, and the concentration of the chem-
ical in the influent to treatment (see instruc-
tions). Report treatment methods that do not
affect the chemical by entering "0" for
removal efficiency.
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For More Information
Emergency Planning
and Community
Right-to-Know
Hotline
Small Business
Ombudsman
Hotline
(800) 535-0202
or
(202) 479-2449
(in Washington, D.C.
and Alaska)
(800) 368-5888
or
(703) 557-1938
(in Washington, D.C.
and Virginia)
The EPA brochure, Title III Section 313
Release Reporting Requirements (EPA 560/4-
87-001) presents an overview of the new law.
It identifies the types of facilities that come
under the provisions of Section 313, the
threshold chemical volumes that trigger re-
porting requirements, and what must be
reported. It also contains a complete listing
of the chemicals and chemical categories
subject to Section 313 reporting. The EPA
publication, Estimating Releases and Waste-
Treatment Efficiencies for the Toxic Chemical
Release Inventory Form (EPA 560/4-88-002),
presents more detailed information on gen-
eral release estimation techniques than is
included in this document.
8
*U.S. Government Printing Office : 1988 - 516-002/80169
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