United States
           Environmental Protection
           Agency
Office of Pesticides
and Toxic Substances
EPA 560/4-88-004q
March 1988
v°/EPA     Title 111 Section 313
           Release Reporting
           Guidance
           Estimating Chemical Releases From
           Rubber Production and Compounding
           Emergency Planning and
           Community Right-to-Know Act of 1986

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            Estimating Chemical Releases From
           Rubber Production and Compounding
   Facilities engaged in rubber production
and compounding 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 (rubber production and com-
pounding facilities generally fall under SIC
codes 2822 and 2830) 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 who produce rubber 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 rubber production, 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 sun/ect 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 in-
formation, you must follow the steps outlined
to handle this eventuality in the instructions
provided with the Toxic Chemical Release
Inventory Reporting Form.
   The list presented here includes chemi-
cals typically used in rubber production 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.
Synthetic rubber manufacturing
   Monomers: 1,3-butadiene, styrene,
   acrylonitrile, ethylene, ethylene glycol,
   propylene glycol, propylene, 1,3-toluene
   diisocyanate, ethylene dichloride,
   epichlorohydrin, acrylic acid,  ethyl
   acrylate; butyl acrylate, chloroprene,
   ethylene oxide
   Retarders:  Phthalic anhydride,
   n-nitrosodiphenylamine

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   Catalysts: Cobalt compounds, nickel
   compounds, titanium tetrachloride
   Antioxidants: Phenylene diamine
   Short stops: Hydroquinone
   Solvents: Toluene, methyl chloride
   (chloromethane) ,1,1,2-trichloroethane
   Cooling tower corrosion inhibitors:
   Chromium compounds, zinc compounds
   Miscellaneous chemicals:  Sodium
   hydroxide, sulfuric acid, various additives
Rubber compounding
   Processing aids:  Zinc compounds
   Accelerators: Zinc compounds, ethylene
   thiourea, diethanolamine
   Age restorers: Nickel compounds,
   hydroquinone, phenol, alpha-
   naphthylamine, p-phenylenediamine
   Vulcanizing agents: Selenium
   compounds, zinc compounds, lead
   compounds
   Initiator: Benzoyl peroxide
   Accelerator activators: Zinc com-
   pounds, lead compounds, ammonia
   Plasticizers: Dibutyl phthalate,
   dioctylphthalate, bis (2-ethylhexyl
   adipate)
   Miscellaneous ingredients: Titanium
   dioxide, cadmium compounds, organic
   dyes, antimony compounds
            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,
monomers, plasticizers, and vulcanizing
agents) would be considered "processed"
because they become part of the marketed
finished product. Acids, caustics, solvent
carriers, 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
   sodium hydroxide at a synthetic
   rubber manufacturing facility.
      In 1987, a synthetic rubber plant
   purchased 70,000 gallons of a 50 percent
   sodium hydroxide solution for use in its
   caustic washing process. At the beginning
   of the year, 10,000 gallons of this solution
   was in storage, and 5,000 gallons re-
   mained in storage at the end of the year.
   According to Section 313 definitions,
   sodium hydroxide is considered "otherwise
   used" in this process. The quantity of
   sodium hydroxide otherwise used during
   the year can be estimated by the following
   calculation:
   Annual usage of solution =
       10,000 gallons (beginning inventory) +
       70,000 gallons (purchased) -
      5,000 gallons (ending inventory)
      = 75,000 gallons

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    Amount qfNaOH used =
       75,000 gallons ofNaOH solution x
       1.5253 (specific gravity of
       50%NaOH) +
       8.33 Vb/gal (density of water) x
       0.5 Ib NaOH/1 Ib solution
       = 476,866 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.
           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 figures
presented in this pamphlet are example flow
diagrams for synthetic rubber production by
the emulsion production process. 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 re-
sulting from the operation of each unit.
    Releases from synthetic rubber produc-
 tion are primarily in the form of wastewater.
 Wastewater from these facilities comes from
 one of three sources:  1) utility wastewater,
 such as cooling tower blowdown; 2) process
 wastewater, such as the decant water from
 solvent separators; and 3) wastewater from
 equipment and area washdowns. Process
 wastewater and equipment cleanup waste-
 water are usually combined in a single plant
 effluent stream.
    Solid wastes  in this production process
 are present primarily as suspended solids in
 plant wastewater. The rubber solids that
 collect on much of the process equipment are
 either removed by hand or washed off with
 water and discarded in the general plant
 wastewater. These solids are subsequently
 removed from the wastewater treatment plant
 as sludge.
    Atmospheric  releases (primarily mono-
 mers) generally emanate from the monomer
 recovery process, absorber vents, and drying
 operations.  Fugitive emissions of gaseous
 organic compounds are possible from vir-
 tually all of the processes associated with
 synthetic rubber manufacturing.  These
 fugitive emissions include minor leaks to the
 atmosphere from pumps, relief valves and
 fittings, and from loading, unloading, and
 storage operations.
    Releases from rubber compounding
 facilities are primarily in the form of fugitive
 air emissions and solid wastes. Fugitive air
 emissions occur primarily from mixing opera-
 tions. Solid wastes generally occur in the
 form of scrap and scorched rubber; dusts and
 powders from fabric filters in the mixing and
 compounding areas and from unloading,
 storage, and equipment cleanup operations;
and contaminated lubricating oil "oozings"
from process mixers.
   Your reporting must account for all
releases.

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             AIR RELEASE
                  CAUSTIC


   UNINHIBITED MONOMER
                                                                   PRODUCT
                                                                   SHIPMENTS
                        WASTEWATER
Example Flow Diagram for Crumb Rubber Production by Emulsion Polymerization
     (adapted from Source Assessment:  Rubber Processing State-of-the-Art)

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                 CARBON BLACK
                            OIL
             RUBBER, POLYMERS
                MISC. CHEMICALS
BANBURY
 RUBBER
 MIXING
                                        I
                                                       AIRBORNE PARTICULATE
                                                          TO FABRIC FILTER
          T
FINISHED
PRODUCT
                                  SPILLS, LEAKS,
                                 FUGITIVE LOSSES
                                 OF DRY CHEMICALS
         SCRAP
        RUBBER
                  Example Plow Diagram of Rubber Compounding Process
            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
   Recovery 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.
       The complexity of the rubber manufac-
   turing and compounding processes, the many
   separate steps involved, and the irregular
   batch-type operation make release estimation
   a difficult task.  When direct measurement
   data are not available, emission factors and

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mass balances, supplemented by engineering
assumptions, must be used.  Mass balance
estimates are most effective for chemicals
that are "otherwise used," such as catalysts,
solvents, acids, and bases. Because these
chemicals do not become part of the product,
the quantity used is equal to the quantify
released as waste before treatment.  Engi-
neering assumptions can then be used to
determine into which media the chemical is
released (air, wastewater, or solid waste).
Caution should be exercised when using the
mass balance technique to estimate chemical
releases when the raw material input and
product output streams are large, as small
errors in purchasing and production data can
lead to large errors in release estimates.
    The mass balance estimation technique is
quite applicable to rubber compounding
operations because of the precision required
when weighing out additives for the rubber
recipe. Given detailed information on chemi-
cal Inputs and knowledge of the quantity of
chemical retained in the product and chemi-
cally transformed during processing, one can
calculate chemical releases by determining
the difference.

Toxic Releases Via Wastewater
    Ideally,  the wastewater streams will be
combined into a single effluent stream for
which measurements of flow and concen-
trations are available. Some monitoring
information may be available from waste-
water discharge permits and in-house
sampling studies. Wastewater flows and
release parameters such as biochemical
oxygen demand, chemical oxygen demand,
suspended  solids, etc., will be summarized on
your discharge permit;  however, concen-
trations for specific listed compounds may
not be available.
    When direct measurement information is
unavailable, an alternative estimation tech-
nique must be used.  For "otherwise used"
compounds with extremely low vapor pres-
sures (for example, metal catalysts), you may
assume that all of the chemical used is
released in wastewater. If wastewater treat-
ment is used, a portion of these compounds
will be transferred to the wastewater sludge
or biodegraded, whereas the remainder will
be discharged with the wastewater.
   Example: Using a mass balance to
   estimate releases of cobalt compounds
   from a cobalt-based catalyst.
       In 1987, a synthetic rubber production
   facility produced 80,000 pounds of
   polybutadiene. A homogeneous cobalt-
   based catalyst was used in the reaction
   process.  Samples of the rubber product
   contained 170 ppm of cobalt. Purchasing
   and inventory records indicate that 64,000
   pounds ofCoCl2 catalyst was processed.
       Assuming that the catalyst is the only
   source of cobalt in the process and that all
   equipment-cleaning wastes are washed
   into the facility's sewers, the quantity of
   cobalt released can be estimated by mass
   balance.  The quantity of cobalt lost as
   waste is  calculated as follows:
   Amount of cobalt entering process =
       64,000 lbCoCl2x
       59 Ib Co/130 Ib CoCl2
       = 29,046  Ib

   Amount of cobalt in product =
       80,000 tons polybutadiene x
       2,000 Ib/ton x
       170 Ib cobalt/1,000,000 Ib
       polybutadiene
       = 27,200  Ib

   Amount of cobalt lost as waste =
       29,046 Ib (entering process) -
       27,200 Ib (in product)
       = l,846lb

       It can be assumed that the 1,846
   pounds of cobalt was lost through
   equipment washdowns. If untreated
    wastewater from the facility was
   discharged to a publicly owned treatment

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    works (POTW), the facility could report that
    1,900 pounds of cobalt was "transferred to
    POTW." If pretreatment was provided on
    site and a wastewater sludge was
    generated, estimates of the quantity of
    cobalt released as solid waste would also
    have to be considered.
       The problems  inherent with the use of
    mass balances for large processes are
    evident if you assume that the quantity of
    cobalt found in the poly butadiene product
    was 200 ppm rather than 170 ppm. At
    200 ppm, the quantity of cobalt leaving as
    product would be  32,000 pounds, which
    exceeds the quantity of cobalt entering the
    process. Thus, a small analytical error in
    the product stream could cause a large
    error in the release estimation.

Toxic Releases to Air
    Atmospheric emissions data may be
available from process monitoring informa-
tion (vent flows and concentrations), air
operating permits, or the technical literature.
Most of the information available on air emis-
sions will be in the form of total VOC and
particulate emissions. Engineering calcu-
lations and assumptions can often be used to
convert this type of information into releases
of specific toxic compounds.  If mass balance
calculations are used, you can assume that
any releases of extremely volatile compounds
(such as  butadiene) will be to the
atmosphere.
    'Example:  Using an emission factor to
    estimate atmospheric releases from a
    monomer recovery process.
       A monomer plant produces 40,000 tons
    of crumb emulsion latex per year. Emis-
    sion measurement data are not available,
    and an accurate mass balance calculation
    is difficult to perform because  of the large
    input and output streams.  According to
    ERA'S Compilation of Air Pollutant Emis-
    sion Factors, total volatile organic
    emissions are approximately 5.2 pounds
    per ton of latex produced. An  occupational
    monitoring program at this plant indicated
    that butadiene concentrations in the
    ambient air were typically 9 times greater
    than styrene concentrations. Because
    butadiene and styrene will make up the
    vast majority of the VOC emissions, it can
    be assumed that total butadiene and
    styrene air releases are 5.2 pounds per ton
    of latex.  Based on the 9-to-l ratio of
    butadiene to styrene, process releases can
    be calculated as follows:
    Amount of 1,3-butadiene released =
       40,000 tons latex x
       5.2 Ib volatiles/1 ton latex x 90%
       = 187,200 Ib
    Amount of styrene released =
       40,000 tons latex x
       (5.2 Ib volatiles/1 ton latex) x 10%
       = 20,800 Ib
       These releases are sent to ajlare
    before being discharged to the atmosphere.
    Based on the manufacturer's experience
    and test data, the flare destruction
    efficiency is assumed to be 90 percent.
    Thus, the plant in this example could
    report annual releases of 19,000 pounds
    of 1,3-butadiene and 2,100 pounds of
    styrene.
    Air releases from rubber compounding
operations, which are typically  in the form of
particulates, are often controlled by fabric
filters. If the fabric filter efficiency and quan-
tity of particulate captured are  known or can
be estimated, air releases can be calculated.
The specific chemical composition of the
fabric filter dusts can then be used to esti-
mate air releases of toxic chemicals.

Toxic Releases Via Solid Waste
    In general, only direct measurement and
mass balance techniques are useful for esti-
mating toxic chemical releases  in wastewater
treatment sludge. Direct measurement data
for wastewater sludge are 6ften required
before disposal will be approved.  If direct
measurement data are used to  estimate

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wastewater releases, you may find a mass
balance estimation technique useful for
estimating releases via wastewater sludge.
   Estimating solid wastes generated from
rubber compounding operations usually
requires mass balances and/or engineering
calculations.  For example, If the quantity of
scrap rubber discarded and the concentration
of a toxic constituent in the rubber product
are known, multiplying these values will yield
an estimate of the release of the constituent
in the scrap (solid waste). The key to this
approach is knowing the concentrations of
toxic chemicals In the rubber product.
   Example:  Estimating zinc releases in
   solid wastes from a rubber
   compounding operation.
       Based on the recipes used, a rubber
   compounder knows the concentration of
   zinc oxide in a particular rubber mixture is
   2.5 percent by weight. Production records
   indicate that 2,000 tons of this rubber
   mixture was manufactured in 1987.
   Purchasing and inventory records indicate
   that 105,000 pounds of zinc oxide was
   processed during the year. The quantity of
   zinc oxide (and thus zinc) lost as solid
   waste can be calculated by mass balance
   asfottows:
   Amount ofZnO in product =
       2,000 tons rubber product x
       2,000 Ib/tonx
       0.025 Ib ZnO/1 tb product
       -100,000 Ib
   Amount of ZnO in solid waste =
       105,000 Ib ZnO (processed) -
       100,000 Ib ZnO (in product)
       - 5,000 Ib
   Amount of zinc in waste =
       5,000 Ib ZnO x
       O.SlbZn/l'lbZnO
       = 4,000 Ib
   It may be assumed that all of the zinc lost
   through cleanups, scrap rubber, and fabric
   filter participate (assuming the fabric filter
   capture efficiency is high) is released as
   solid waste.

Other Toxic Releases
   Other wastes in the rubber production
and compounding industry from which toxic
chemicals may be released include:
   •   Residues from pollution control
       devices
   •   Wash water from equipment
       cleaning
   •   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 duririg
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.
                                            8

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            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 chemi-
cal 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.
Additional Sources of Information
on Releases From Rubber
Production and Compounding
U.S. Environmental Protection Agency.
Source Assessment: Rubber Processing
State-of-the-Art. EPA-600/2-78-004. PB
281423/4. Cincinnati, Ohio. March 1978.
U.S. Environmental Protection Agency. The
Rubber Processing Chemicals Data Base.
EPA-600/2-84-030. January 1984.
U.S. Environmental Protection Agency.
Compilation of Air Pollutant Emission Fac-
tors, Fourth Edition. AP-42. Research
Triangle Park, North Carolina.  September
1985.
U.S. Environmental Protection Agency.
Industrial Process Profile for Environmental
Use. Chapter 9: The Synthetic Rubber
Industry. EPA-600/2-77-023.  Cincinnati,
Ohio.  February 1977.
                                          10
                          *U.S. Government Printing Office : 1988 - 516-002/80179'

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