following section. The Agency request comments on alternative
spectroscopy techniques such as absorption measurements that may be
used to rapidly estimate oil concentrations in the water during a
discharge event.
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    \19\ Henry, C.B., Roberts, P.O., Overton, E.B., A Primer on In
Situ Fluorometry to Monitor Dispersed Oil, IOSC 1999;246.
    \20\ Coble, P.G., (2007) Marine Optical Biogeochemistry: The
Chemistry of Ocean Color, Chem. Rev., Vol. 107, pp. 402-418.
    \21\ Bugden, J.B.C., Yeung, C.W., Kepkay, P.E., Lee, K. (2008)
Application of Ultraviolet Fluorometry and Excitation-Emission
Matrix Spectroscopy (EEMS) to Fingerprint Oil and Chemically
Dispersed Oil in Seawater, Mar Pollut Bull, Vol. 56, pp. 677-685.
    \22\ Conmy, R.N., Coble, P.G., Farr, J., Wood, A.M., Lee, K.,
Pegau, W.S, Walsh, I.D., Koch, C.R., Abercrombie, M.I., Miles, M.S,
Lewis, M.R., Ryan, S.A., Robinson, B.J., King, T.L., Kelble, C.R.,
and Lacoste, J. (2014) Submersible Optical Sensors Exposed to
Chemically Dispersed Crude Oil: Wave Tank Simulations for Improved
Oil Spill Monitoring, Environ Sci Technol, Vol. 48, pp. 1803-1810.
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     Fluorescence signatures. In addition to in-situ
fluorometry, the proposal requires the responsible party to conduct a
fluorescence intensity analyses on water samples collected to determine
fluorescence signatures of the dispersed oil. EPA proposes to use
fluorescence signatures as a relatively simple and rapid means to
assess dispersion effectiveness. This includes but is not limited to,
identifying the peak wavelength position, magnitude and ratios of
fluorescence intensity of the dispersed oil. For example, measuring the
reduction in an intensity ratio after applying dispersant to the oil in
seawater may provide an estimate of the effect of chemical
dispersion.23 24 Ratios of fluorescence intensity are
derived from the three dimensional excitation/emission matrix spectra
(EEMS) acquired by combining multiple emission spectra obtained from
oil exposed to individual excitation wavelengths typically using a
scanning spectrofluorometer. If the optimal excitation and emission
bands are known, then these ratios may be derived from measuring the
fluorescence intensity at two different fixed emission wavelengths at a
single fixed excitation wavelength. The ratios are calculated by
dividing the fluorescence intensity of the shorter emission band by the
fluorescence intensity of the longer band. Studies have shown that
adding dispersants to crude petroleum oil increases the fluorescence
intensity of the longer emission band, driving down the value of the
ratio. Although individual petroleum oils may have common spectral
characteristics, the ideal three-dimensional EEMS for the discharged
oil should be obtained from scanning the source oil. Therefore, the
monitoring should include procedures to obtain the EEMS using the
source oil to determine the optimal excitation-emission wavelengths.
The Agency

request comments on alternative techniques or measurements that may be
used to rapidly assess dispersion effectiveness during a discharge
event.
---------------------------------------------------------------------------

    \23\ Bugden, J.B.C., Yeung, C.W., Kepkay, P.E., Lee, K. (2008)
Application of Ultraviolet Fluorometry and Excitation-Emission
Matrix Spectroscopy (EEMS) to Fingerprint Oil and Chemically
Dispersed Oil in Seawater, Mar Pollut Bull, Vol. 56, pp. 677-685.
    \24\ Kepkay, P.E., Yeung, C.W., Bugden, J.C.B., Li, Z., and Lee,
K. (2008) Ultraviolet Fluorescence Spectroscopy (UVFS): A New Means
of Determining the Effect of Chemical Dispersants on Oil Spills,
IOSC, pp. 639-644. http://ioscproceedings.org/doi/abs/10.7901/2169-3358-2008-1-639.
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     Dissolved oxygen (DO). Dissolved oxygen is an important
variable to monitor in the application of dispersants, particularity in
subsurface waters that may inform operational decisions. For surface
dispersant application, dissolved oxygen is expected to be higher in
the mixed layer in the surface water. Dissolved and/or dispersed oil
represents a readily available carbon source for microbial oxidation,
and this metabolic activity can lead to a decrease in the DO content in
the water column. The oil degrading community in the water is an
important DO sink for the mass transfer of hydrocarbons in the
subsurface, and advantage can be taken of this fact during a response.
The decline in DO due to hydrocarbon biodegradation could approach or
exceed levels of concern (i.e., hypoxia) and thus be detrimental to
surrounding organisms (e.g., invertebrates and vertebrates). Dissolved
oxygen, which relies on the diffusion of molecular oxygen through a
membrane in the sensor, is commonly measured during oceanographic
survey cruises using an in-situ DO instrument that provides real-time
results. However, a DO sensor instrument that passes through a
dissolved and/or dispersed oil layer is subject to contamination by the
oil and could lead to questionable measurements if such fouling of the
electrodes occurs, particularly at depths where the dissolved and/or
dispersed plume depth are expected to coincide with depressions in
dissolved oxygen. Therefore, the Agency is concerned that relying
solely on measurements from in-situ oxygen instruments may lead to an
erroneous interpretation of oxygen data. Thus, the Agency believes that
ex-situ confirmatory DO measurements should also be conducted using
Winkler titrations to confirm in-situ dissolved oxygen measurements.
     Total petroleum hydrocarbons, individual resolvable
constituents, including volatile organic compounds, aliphatic
hydrocarbons, monocyclic, polycyclic, and other aromatic hydrocarbons,
including alkylated homologs, and hopane and sterane biomarker
compounds. The Agency is proposing that the responsible party analyze
each water sample collected for total petroleum hydrocarbons (TPHs),
individual resolvable constituents, including volatile petroleum
hydrocarbons, and branched and normal aliphatic hydrocarbons. The
analysis would also include monocyclic, polycyclic and other aromatic
hydrocarbons (e.g., heterocyclic aromatic hydrocarbons), including
their alkylated homologs, and hopanes and steranes biomarker compounds.
TPHs are best measured using gas chromatograph (GC) equipped with a
flame ionization detector (FID). TPH analysis measures total alkanes
and aromatics, can be obtained relatively quickly, and provides a good
measurement for initial screening. Given that PAHs and biomarkers are
typically measured using GC/MS, the proposal includes GC/MS analysis to
provide the alkanes, PAHs, and biomarker (e.g., hopane) specificity
important in identifying certain oil constituents that may be present
in the oil discharge. Identifying the concentrations of PAHs and
biomarkers assists responders in making informed operational decisions
regarding the dispersant application because these compounds can be
compared against the composition of the source oil, which serves as a
reference to determine the degree of weathering for oil.
     Carbon Dioxide (subsurface only). The aerobic
biodegradation of oil constituents not only consumes dissolved oxygen,
but would also produce carbon dioxide. Increases in the concentration
of carbon dioxide that coincide with decreases in the concentration of
dissolved oxygen would provide credible evidence that biodegradation of
oil is occurring. Thus, the Agency believes that measuring the in-situ
carbon dioxide for subsurface dispersant applications would be a good
indicator of microbial oxidation and inform the OSC on the potential
fate.
     Methane if present (subsurface only). The microbial
degradation of methane may contribute to a reduction in dissolved
oxygen. Thus, the Agency believes that, when present, subsurface in-
situ methane measurements are an important factor to consider in
evaluating dissolved oxygen levels.
     Heavy metals analysis, including nickel and vanadium.
Crude petroleum oil may contain certain heavy metals, including nickel
and vanadium.25 26 27 Dispersing oil may increase the
bioavailability of certain associated heavy metals to marine organisms.
Therefore, the Agency is proposing to include heavy metal analysis as
part of the sampling analyses to be conducted.
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    \25\ Barwise, A. J. G. and Whitehead, E. V. (1980). Separation
and Structure of Petroporphyrins. In: Advances in Organic
Geochemistry 1979. (A. G. Douglas and J. R. Maxwell, eds.),
Pergamon, New York, pp. 181-92.
    \26\ Barwise, A. J. G. (1990). Role of Nickel and Vanadium in
Petroleum Classification. Energy & Fuels, 4, 647-52.
    \27\ All, M.F., Bukharl, A., and Saleem, M., (1983) Trace Metals
in Crude Oils from Saudi Arabia, Ind. Eng. Chem. Prod. Res. Dev.
1983, Vol 22, pp. 691-694.
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     Turbidity. Turbidity is a general measure of water
clarity. Turbidity is determined by measuring how much material
suspended in water decreases the passage of light through the
water.\28\ Suspended materials may include soil particles (clay, silt,
and sand), algae, plankton, microbes, and other substances. This
measure provides a quick assessment of suspended materials in receiving
waters from other water bodies and is useful in determining the
presence of materials that could interfere with oil particle size
determinations. Alternatively, the Agency is requesting comments on
whether there are other physical measurements in the water that would
provide similar timely information, or that can serve as validation for
turbidity values collected in situ.
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    \28\ http://water.epa.gov/type/rsl/monitoring/vms55.cfm.
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     Water temperature. Water temperature typically is measured
using an electronic thermometer on the conductivity-temperature-depth
(CTD) instrument. When combined with salinity and pressure, temperature
measurements are used to calculate water density, which may change
along the vertical profile. Along with the horizontal subsurface
currents and the rise velocity of the dispersed oil, the ambient
density gradient is an important factor in determining the behavior of
dispersed oil in the water column. Water temperature is also an
important variable that may influence the effectiveness of dispersant
applications. For example, cold temperatures may, among other
environmental factors, impact the effectiveness of dispersants as it
affects certain oil properties (e.g., viscosity). Colder temperatures
also may affect the degree of oil weathering (e.g., evaporation), and
the amount of dispersant/oil mixing energy (wave action) needed to
effectively disperse oil relative to warmer temperatures.
     pH. The pH is a simple standard measurement used to
analyze water quality that can affect chemical or biological processes
in water. pH also determines the solubility and biological availability
of chemical constituents such as heavy metals.
     Conductivity. Conductivity is measured by passing a
current through the water in a CTD instrument, which is then compared
against known salinities to obtain the water salinity. When combined
with temperature, and pressure, salinity measurements are

used to calculate water density, which may change significantly along
the vertical profile. Along with the horizontal subsurface currents and
the rise velocity of the dispersed oil, the ambient density gradient is
an important factor in determining the behavior of dispersed oil in the
water column.

The Agency requests comment on the proposed approach to water column
sampling. Alternatives must include a rationale in order for the Agency
to consider them for final action.
(c) Oil Distribution Analyses
    The proposal requires that the responsible party, in consultation
with the OSC and using best available technologies, characterize the
dispersant effectiveness and oil distribution, considering the
condition of the oil, dispersant, and dispersed oil components from the
discharge location. EPA believes this is necessary to inform sampling
locations by assessing the horizontal and vertical boundaries of the
dispersed oil plume and the direction of likely transport. The majority
of the sampling can then be focused on known or suspected locations and
depths of the dispersed oil. Based on the initial water sampling
results to characterize the boundaries of the dispersed oil, the
sampling design can be tailored to optimize sampling. The Agency
proposes that the responsible party characterize the dispersant
effectiveness to determine the changes in the condition of the oil due
to weathering, which can include changes in oil viscosity due to water
uptake (e.g., mousse). Weathered oil that mixes with water may result
in significant emulsification (e.g., water-in-oil emulsions), which in
turn may decrease the dispersant's chemical effectiveness and diminish
biodegradability. Therefore, the characterization of dispersant
effectiveness should provide a reasonable estimate to the extent (e.g.,
distance from the discharge source) in which the dispersant can be
applied to the oil and still be effective. The Agency believes this
will result in better dispersant applications and minimize excessive
dispersant use. The Agency requests comment on this approach.
Alternatives posed must include a rationale for the Agency to consider
them for final action.
(d) Ecological Characterization
    The Agency proposes that the responsible party characterize the
ecological receptors (e.g. aquatic species, wildlife, and/or other
biological resources), their habitats, and exposure pathways that may
be present in the discharge area, in consultation with the OSC.
Exposure pathways, such as ingestion, refer to the way in which
ecological receptors may come into contact with discharged oil and
result in exposure that would be detrimental to ecological receptors.
The Agency believes that the ecological characterization should include
those species that may be in sensitive life stages, transient or
migratory species, breeding or breeding-related activities (e.g.,
embryo and larvae development), and threatened and/or endangered
species that may be exposed to oil, dispersed oil, and dispersant,
which in turn will assist the OSC in managing response actions,
including those actions that were determined not to be needed. In
developing the characterization of ecological receptors, the
responsible party may refer to relevant sources of information such as
applicable expedited decision-making plans, environmental assessments
or statements, Federal and state environmental databases (e.g., ACP--
Fish and Wildlife and Sensitive Environments Annex; NOAA--Environmental
Sensitivity Indices; NOAA--NMFS Southeast Area Monitoring and
Assessment Program; EPA--National Coastal Assessment \29\) or through
studies conducted by universities or other research-oriented
institutions.
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    \29\ http://www.epa.gov/emap/nca/.
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    The proposal requires the responsible party to consult with the OSC
to determine an acute toxicity level of concern for the dispersed oil
using available dose/response information relevant to potentially
exposed species. The envisioned approach would be to monitor acute
toxicity in the water column concurrently with dispersed oil sampling
for fluorometry, particle size, and water quality (e.g., dissolved
oxygen). The TPH concentrations in water samples taken throughout the
water column could then be compared to TPH-based ecotoxicity benchmarks
(EBs). Water samples collected for comparison of aqueous TPH
concentrations to EBs would be analyzed and reported within the
timeframe necessary to make operational decisions (e.g., within 24
hours of collection). Sampling could also be performed in areas without
dispersant application to distinguish toxicity associated with
physically dispersed oil from that of chemically dispersed oil.
    While EBs may have already been established during the development
of contingency plans, they can also be derived at the time of an
incident. One approach is to use a species sensitivity distribution
(SSD),\30\ which allows for species relevant to the location of the
discharge to be considered. An SSD is a probability distribution of the
sensitivity of a group of species to a toxicant.\31\ SSDs could be
developed for representative oils (e.g., crude oils) using existing
acute toxicity values for mortality or immobility (e.g., 48 and 96 hr
LC50) where sufficient species diversity are available
(e.g., toxicity data for 10 or more species). For example, the EBs
could be computed from the fifth percentile of the SSD as the hazard
concentration 5 percent (HC5), as they are considered protective of 95%
of species, have been used by EPA for developing ambient water quality
criteria, and are generally accepted by the international
community.\32\ Chronic toxicity benchmarks may be derived applying
safety factors to the acute toxicity EBs. The Agency requests comments
on the proposed approach to ecotoxicity assessment, and whether it
should consider making SSDs a requirement for deriving EBs. If
alternative approaches are suggested, the commenter must include an
appropriate rationale in order for the Agency to consider them for
final action.
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    \30\ Barron, M.G., Hemmer, M.J., and Jackson, C.R., (2013)
Development of Aquatic Toxicity Benchmarks for Oil Products Using
Species Sensitivity Distributions, Integr Environ Assess Manag, Vol.
9, pp. 610-615.
    \31\ Aldenberg, T. and Jaworska, J.S., (2002) Uncertainty of the
Hazardous Concentration and Fraction Affected for Normal Species
Sensitivity Distributions, Ecotox and Environ Safety, Vol. 46, pp.
1-18.
    \32\ Barron, M.G., and Wharton, S., (2005) Survey of
Methodologies for Developing Media Screening Values for Ecological
Risk Assessment, Integrated Environmental Assessment and Management,
Vol. 1, pp. 320-332.
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(e) Immediate Reporting
    The proposal requires the responsible party to immediately report
to the OSC any deviation of more than 10 percent of the mean hourly
subsurface dispersant use rate for the total dispersant volume
authorized for that 24 hour use, and the reason for the deviation
(e.g., equipment malfunction). The Agency believes that inconsistent
dispersant application rates confound data sampling interpretation due
to variations in the DOR. The proposal, however, provides a margin for
variation within 10 percent of the mean hourly subsurface dispersant
application rate to account for equipment performance. The Agency
believes this margin to adequately account for variations in dispersant

injection equipment without being overly restrictive. EPA requests
comments on whether it should consider a similar requirement for
dispersant surface application.
    The Agency also is proposing to require the immediate reporting of
ecological receptors, including any threatened or endangered species
that may be exposed to dispersed oil based on trajectory modeling and
the estimated acute toxicity level of concern. Results from daily
sampling (e.g., droplet size distribution, TPH) would provide input
data to refine predictions of the likely dispersed oil direction using
trajectory modeling. Further, results may also inform decisions to
alter dispersant application in order to minimize effects on biological
resources.
(f) Daily Reporting
    The proposal requires daily reporting of sampling and data analyses
collected within the timeframe necessary to make operational decisions
(e.g., within 24 hours of collection), including documented
observations, photographs, video, and any other information related to
dispersant use, unless an alternate timeframe is authorized by the OSC.
Daily reporting would also include the total amount of dispersant used
for the previous reporting period. Additionally, the proposal would
require a schedule for any data analyses that require time beyond 24
hours due to analytical methods; this schedule is not to exceed 120
hours (i.e., 5 days) unless authorized by the OSC. Timely sample
analyses afford the OSC and other responders with multiple relevant
data that can be analyzed together to inform situational awareness of
dispersant operations and adjust dispersant application if necessary.
The Agency believes that a 120-hour window for analyses requiring
additional time provides an adequate opportunity to conduct all
requested analyses in a timely manner without being overly restrictive.
Finally, the proposal requires the responsible party to report the
estimated daily transport of dispersed and non-dispersed oil, and
associated volatile petroleum hydrocarbons if applicable, and
dispersants, using the best available trajectory modeling. This
information is intended to assist response planners to coordinate
response activities and to schedule monitoring activities based on the
expected transport of oil and dispersed oil.
4. Data and Information Requirements for Product Schedule Listing
    The Agency is proposing to revise the data and information
requirements for listing products on the Schedule in Sec.  300.915 of
Subpart J. The proposed amendments revise the efficacy and toxicity
testing protocols and listing criteria for all chemical and biological
agents on the Schedule. Additionally, the Agency proposes revisions to
the requirements for general product information, Confidential Business
Information (CBI) claims, submission package contents, EPA review and
listing procedures, requests for decision review, changes to products,
transitioning products from the current Schedule to the new Schedule,
mandatory product disclaimer, and removal of products from the
Schedule.
(a) General Product Information
    The Agency is proposing to consolidate the general submission
requirements applicable to all types of agents that may be listed on
the Schedule in paragraph (a) of Sec.  300.915. Subsequent regulatory
paragraphs in this section are proposed to include requirements
specific to each product category. Additionally, the Agency is
proposing to require some additional information, as applicable,
regarding products that are submitted for Schedule listing
consideration. The proposed general information requirements for all
products are proposed to be revised as follow:
     Submitter: Name, physical address, email, telephone
number, identity of submitter (i.e., manufacturer, vendor, importer,
distributor, designated agent for the manufacturer), and documentation
of such identity.
     General Product: All name(s), brand(s), and/or
trademark(s) under which the product is to be sold; Safety Data Sheet
(SDS); sample product labels for all name(s), brand(s), and/or
trademark(s); chemical or biological agent categories under which the
product is submitted for listing, including information on the specific
process(es) through which the product affects the oil, and the specific
environment (waters and/or adjoining shorelines) on which it is
intended to be used.
     Supplier: Names, physical addresses, emails and telephone
numbers of the primary distributors, vendors, importers, and/or
designated agent acting on behalf of the manufacturer.
     Product Storage: Maximum, minimum and optimum temperature,
humidity and other relevant conditions for product storage; impact on
product performance if the product is not stored within recommended
limits; and anticipated shelf life at the recommended storage
conditions.
     Product Use: Recommended procedures, including product
concentrations, application ratios, types of application equipment,
conditions for use, and any application restrictions. The procedures
must address variables such as weather, water salinity, water
temperature, types and weathering states of oils or other pollutants,
and product and oil containment, collection, recovery and disposal, and
include supporting documentation and standard methods used to determine
them.
     Environmental Fate: Known measured data and supporting
documentation on the persistence, bioconcentration factor,
bioaccumulation factor, and biodegradability of the product and all of
its components.
     Physical/Chemical Properties and Formulation: Physical
state and appearance; vapor pressure; flash point; pour point;
viscosity; specific gravity; particle size for solid components; pH;
citation of standard methods used to determine the physical/chemical
properties; identity of all components in the product, including each
specific component name; corresponding Chemical Abstract Service (CAS)
Registry Number; the maximum, minimum, and average weight percent of
each product component; and the intended function of each component
(e.g., solvent, surfactant).
     For products that contain microorganisms, enzymes and/or
nutrients: All microorganisms and weight percent by current genus and
species, including any reclassifications; all enzymes and their
International Union of Biochemistry (I.U.B.) number(s); Enzyme
Classification (EC) code numbers; the source of each enzyme, units, and
specific oil-degrading activity; name(s) and maximum, minimum, and
average weight percent of the nutrients contained in the product;
citation or description of the methodology used to determine product
components; certification, including data, methodology, and supporting
documentation, indicating that the product does not contain levels that
exceed the National Ambient Water Quality Criteria lowest density value
for the following: Bacterial, fungal, or viral pathogens or
opportunistic pathogens, including, but not limited to, enteric
bacteria such as Salmonella, fecal coliforms, Shigella, Coagulase
positive

Staphylococci, and Beta Hemolytic Streptococci or enterococci.
     National Water Quality Standard Contaminants:
Certification, including data, methodology, and supporting
documentation, indicating that the product does not contain levels that
exceed the National Water Quality Standards lowest aquatic life acute
value for the following contaminants: Metals reasonably expected to be
in the product including arsenic, cadmium, chromium, copper, lead,
mercury, nickel, vanadium, zinc; cyanide; chlorinated hydrocarbons;
pesticides; polychlorinated biphenyls (PCBs); and polynuclear aromatic
hydrocarbons (PAHs).
     Certification, including data, methodology, and supporting
documentation, indicating that the product does not contain prohibited
agents (sinking agents, nonylphenol, or nonylphenol ethoxylates).
     Testing Laboratory Information: Name, address, contact
name, email, phone number; national or international accreditations.
     Laboratory Testing Data and Reports: All applicable
information, data and analysis specified in the testing protocols,
including raw test data and replicates, notes and observations,
calculated mean values and standard deviations, summary of stock
solution preparation, source and preparation of test organisms, test
conditions, and chain of custody forms.
     Production capacity: Estimated annual production volume;
average and maximum volume per day; time needed to reach that maximum
production rate (days).
     Performance Capabilities/Benefits: Recognition received
from, if applicable; national and/or international product testing or
use data, recognitions (e.g., EPA's Design for the Environment), and/or
certifications, informing the performance capabilities or environmental
benefits of the product.
    The proposed revisions group together and simplify the general
submission requirements applicable to all product types. EPA believes
reorganizing the general requirements in a central location will
clarify which requirements are applicable to all submissions, and which
are specific to each product type by including them in separate
sections. While most of the information listed above is currently
required to be submitted under Subpart J, the Agency is proposing
revisions to several of the existing general requirements and several
new data and information requirements. The Agency believes the proposed
revisions and added new requirements will better characterize the
nature of the product and will assist EPA in product listing decisions.
The information will also assist the RRTs in their area planning
activities, and the OSCs in authorizing the appropriate use of chemical
and biological agents. Details on the proposed additions and revisions
are as follow:
    (1) Identification and documentation by the submitter of its status
in relationship to the product as the manufacturer, vendor, importer,
distributor, or other designated agent of the manufacturer. This
proposed requirement is intended to clearly establish the point of
contact responsible for the submission, and to avoid any conflicts or
claims from unauthorized entities on products listed or submitted for
consideration.
    (2) Chemical or biological agent categories under which the product
is submitted for listing, including information on the specific
process(es) through which the product affects the oil, and the specific
environment(s) (water and/or adjoining shorelines) on which it is
intended to be used. Currently, when a product meets the definitions of
two or more product categories, a submitter must provide technical
product data for each of those product categories. After review of the
submitted technical product data, EPA makes a determination on whether
and under which category the ``mixed product'' should be listed on the
Schedule. It has been Agency policy to list products only under one
category to avoid confusion in the field during a response, and because
the process(es) through which the products affect the oil for different
product categories do not generally overlap or allow for multiple uses
of one product. However, EPA has received comments from responders,
vendors, and manufacturers who believe that it is appropriate for
certain products to be listed under more than one category. The Agency
is proposing to revise the current limitations for mixed products. The
proposal allows for products to be considered under multiple categories
provided they meet all of the listing requirements for each. To this
end, the Agency is also requiring that information be provided
identifying which environments the product is intended to be used for,
in the water and/or on the shoreline. EPA is soliciting comments on the
issue of multiple category product listing.
    (3) Copy of the Safety Data Sheet (SDS) required by the
Occupational Safety and Health Administration (OSHA) under their Hazard
Communication Standard (HAZCOM) for the product. EPA recognizes that
chemical and biological agents may contain substances that could cause
harm to oil spill responders who, if unaware of the product's formula,
may not wear the proper personal protective equipment. SDSs describe
the hazards that may be involved with the product and recommend safety
measures that would minimize or avoid adverse consequences that may
result from exposures. The Agency believes SDS information will be
useful to both OSCs and responders when authorizing and using the
product respectively, and that adding this new requirement for a
product SDS is appropriate. While the Agency believes that the relevant
SDS information should be that of the product, we request comment on
the value for responders of requiring an SDS for each individual
component. The Agency requests comments on this new requirement, as
well as whether the submitter should provide any additional information
on potential adverse human health effects based on the product's
formula and application methods not captured in the SDS, and how to
best communicate this information to product end users.
    (4) Sample product label for all names, brands, or trademarked
versions of the product that include the manufacture and expiration
dates of the product, as well as the conditions for storage. The Agency
would be allowing flexibility in complying with this requirement by
specifying that the submitter does not need to affix new labels to
comply with this section if existing labels already convey the required
information. This proposed requirement is not intended in any way to
supersede any other federal labeling requirement in place (e.g., OSHA's
HAZCOM). The proposed requirement is intended to assist the OSC in
ensuring that the product used to respond to an incident is still
viable and effective, and the oil spill response organizations (OSROs)
or any other responder that is storing the product to ensure that their
stockpile is viable and available to be authorized for use.
    (5) Recommended product use procedures. The Agency is proposing to
revise the requirement for providing information on the recommended
application procedures. While the proposal is maintaining the specific
elements included in the current requirement, the supporting
documentation and information on the standard methods the product
manufacturer used to establish the procedures is requested. EPA
believes that providing detailed information on the recommended product
use

procedures is necessary to inform the OSC when authorizing these
products. This supporting documentation and specific information on the
methods and standards used to establish them will inform OSCs and other
response personnel in selecting products that can be effectively used
under the operating conditions encountered for any given incident. The
Agency requests comment on the revised data requirement, and whether
there are other elements that should also be included to ensure the
proper use and application of the products.
    (6) Environmental fate information. The Agency is proposing to
request any known and available measured data and supporting
documentation on the persistence, bioconcentration factor,
bioaccumulation factor, and biodegradability of the product and all of
its components. The Agency currently has no restriction on use of
persistent bio-accumulative products. The Agency considered
requirements using existing testing protocols and modeling approaches
to establish thresholds for listing based on bioconcentration factors
(BCF) or bioaccumulation factors (BAF). These factors offer ratios of
the concentration of a particular chemical in a biological tissue per
concentration of that chemical in water surrounding that tissue, or in
the environment respectively. The Agency considered a tiered testing
approach, where the submitter would provide known BCF/BAF information
for listing purposes, but would also be required to provide testing
based on application rates authorized for use. That is, the lower
application rates would only require existing information or the use of
existing EPA models, while higher rates would require additional
testing of fish, bivalves, and earthworms, as needed.
    Similarly, there are no restrictions on the use of environmentally
persistent products. The Agency considered requiring the submitter to
use estimation techniques/models, such as the EPA model EPI
SuiteTM, which estimates environmental fate properties
(breakdown in water or air, etc.) that can indicate where a chemical
will go in the environment and how long it will stay there. A tiered
testing approach for larger quantity/duration spills as discussed above
for bioconcentration and bioaccumulation was also considered.
    EPA believes environmental fate information is necessary to inform
the OSCs when authorizing these products for use, given the potential
for their extended use in significant quantities. However, given that
the Agency can estimate these factors, it is only proposing to require
that available information or data be submitted on the product rather
than specific product testing, as specific product testing for these
factors can add significantly to the testing cost for each product. The
Agency requests comment on whether testing for products'
bioconcentration, bioaccumulation and biodegradation should be required
for listing purposes. Additionally, the Agency requests comment on
whether thresholds for BCF and BAF should be established for listing a
product on the Schedule.
    (7) New physical/chemical properties and removal of the
incorporation by reference of the measurement standards. The Agency is
proposing to add three new elements to the physical/chemical property
requirements: Physical state and appearance; vapor pressure; and
particle size for solid components. The Agency believes these basic
data requirements will provide added context when evaluating the
products for listing determinations. These, in combination with the
other general product information requirements, will assist the Agency
in evaluating the expected product behavior, and the process through
which it would affect the oil when used in the intended water and/or
shoreline environment. Additionally, the Agency is proposing to remove
the current incorporation by reference of specific standards to
determine physical/chemical properties, and replacing this with a
requirement for a citation of the standard methodology used to
determine these values. EPA believes that citing the standard
methodology used to determine the required values is sufficient in lieu
of specifying commonly recognized standard methodologies. The Agency
believes it is appropriate to make this change given the new
requirements for accredited laboratories to conduct testing.
    (8) Chemical Abstract Service (CAS) Registry Numbers for each
component in a product. The CAS Registry is a collection of information
covering a wide variety of substances identified from the scientific
literature since 1957. CAS Numbers serve as an international resource
for substance identifiers and are used by scientists, industry, and
regulatory bodies because it can be validated quickly and reliably.
This will assist the Agency in better characterizing a product's
components and assessing its specific process for affecting the oil
prior to listing on the Schedule.
    (9) Certification that bioremediation agents do not contain, at
levels that exceed the National Ambient Water Quality Criteria lowest
density value, bacterial, fungal, viral or opportunistic pathogens.
While providing information on these product contaminants is currently
required for bioremediation agents, there are no threshold levels for
product listing; a positive result for any of the above pathogens may
raise concern, but would not prevent the product from being listed on
the Schedule. The proposed requirement that these contaminants not
exceed the National Ambient Water Quality Criteria lowest density value
is intended to provide information for listing decisions that ensure
the use of bioremediation agents that will not result in exceeding
established water safety levels. The Agency believes that this
information is necessary to determine if a product is suitable for
listing, particularly for bioremediation agents, which could
potentially be used at recreational beaches. The Agency requests
comments on whether it should establish listing thresholds for products
based on this criteria, and whether the levels selected for
certification are appropriate for this application.
    (10) Certification that the product does not contain levels that
exceed the National Water Quality Standards lowest acute value for
aquatic life of the following contaminants: Arsenic, cadmium, chromium,
copper, lead, mercury, nickel, zinc, or any other heavy metal
reasonably expected to be in the product; cyanide; chlorinated
hydrocarbons; pesticides; polychlorinated biphenyls (PCBs); and
polynuclear aromatic hydrocarbons (PAHs). Providing information (i.e.,
upper limit/concentration, detailed analytical methods, and sample
preparation) on most of these contaminants is currently required for
all products, with no established threshold levels for product listing.
The Agency will continue to require information on the methodology and
the data and supporting documentation used to determine the levels of
these contaminants in a product. The Agency, however, will not specify
what analytical testing method the submitter should use to make these
determinations, as it currently does for chlorinated hydrocarbons,
allowing the submitter flexibility in testing their product.
Additionally, the Agency is proposing to require data on several new
contaminants: Pesticides, PCBs, and PAHs. The Agency's concern with
pesticides as contaminants is mostly due to their potential use on
organic sorbents (e.g., peat moss, corn cobs, and cellulose fibers).
The concern for PCBs is for their toxicity and classification as

persistent organic pollutants, having toxic effects such as endocrine
disruption. PAHs are potent atmospheric pollutants, of concern because
some compounds have been identified as carcinogenic, mutagenic, and
teratogenic. The proposed threshold requirements for all of these
contaminants is intended to provide information for listing decisions
that ensure the use of any product will not result in exceeding
established water safety levels. The Agency requests comments on
whether it should establish a listing threshold for products based on
these criteria, and whether the levels selected for certification are
the appropriate levels for this application. The Agency also requests
comments on whether there are any other contaminants that should be
included for evaluation of a product prior to listing.
    (11) Removal of the requirement for laboratories performing the
efficacy and toxicity testing for products to have prior experience
specific to the required methodology in lieu of recognized national or
international accreditations. Currently, laboratories performing
testing for products to be submitted for listing consideration are
required to document previous experience with the specific testing
methodologies in Appendix C to part 300. The Agency believes it is more
appropriate to require that laboratories be nationally or
internationally accredited. Accredited laboratories are expected to be
capable of following a prescribed testing protocol and good general
practices, providing assurance that the test results will be reliable.
Therefore, the Agency is proposing to remove the requirement for
laboratories to have previous experience specific to the methodologies
in Appendix C, and instead require that the laboratories hold
accreditations from recognized national or international organizations.
National and international accreditation organizations include, for
example, the International Organization for Standardization (ISO), and
the Laboratory Accreditation Bureau (recognized in the US through the
National Cooperation for Laboratory Accreditation (NACLA) and the
International Laboratory Accreditation Cooperation (ILAC)). The ISO
17025, Laboratory Competence standard, identifies high technical
competence and management system requirements to guarantee laboratory
test results and calibrations are consistently accurate. NACLA is a
national voluntary organization of regulators, accreditation bodies and
laboratories cooperatively working towards standardization of
laboratory accreditations throughout the industry; ILAC is the
international counterpart collaboration of laboratory and inspection
accreditation bodies. Established to ensure that laboratories are
subject to oversight by an authoritative body, accreditation
organizations have been evaluated by peers as competent and have signed
arrangements to enhance the acceptance of products and services.
Because interested parties can have confidence in the test results and
certifications provided by accredited laboratories, the Agency is
proposing to amend the laboratory requirement and believes that having
no prior experience with a specific methodology should not disqualify a
laboratory that has been accredited by an appropriate authoritative
body. However, the Agency reserves the right to not accept particular
lab data should EPA find cause to doubt the quality and integrity of
the work. EPA also reserves the right to conduct its own testing of any
product.
    (12) Estimated annual product production volume, average and
maximum amounts that could be produced per day, and time frame needed
to reach maximum production rate (days). While there is currently no
requirement for production capability information, the Agency believes
it is important for the OSCs and responders to have this information.
The availability of a product may impact decisions of authorization of
use, depending on inventory or production capabilities. This would
prove to be of key importance, for example, in the event of a major
environmental disaster (e.g., a SONS event).
    (13) Recognition received from EPA's Design for the Environment
(DfE). EPA's Design for the Environment (DfE) \33\ works in partnership
with industry, environmental groups, and academia to reduce risk to
people and the environment by finding ways to prevent pollution. DfE
evaluates human health and environmental concerns associated with
traditional and alternative chemicals and processes in a range of
industries in order to select safer chemicals and technologies. DfE
focuses its review of formulation ingredients on key environmental and
human health characteristics of concern within functional classes. This
allows formulators to use those ingredients with the lowest hazard in
their functional class, while still formulating high-performing
products. The DfE label means that EPA scientists have evaluated every
ingredient in the product to ensure it meets DfE's stringent criteria.
Products that meet the DfE criteria are safer chemical choices. In an
effort to encourage the development and use of safer technologies, the
Agency is proposing a requirement for the submitter to identify
products that have met and can be labeled DfE certified as part of the
general information, and would include this information in the NCP
Product Schedule Technical Notebook.\34\ This Technical Notebook
presents manufacturer's summary information on the conditions under
which each product is recommended to be used, and is a source of
information for the OSC in the event of a response.
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    \33\ http://www.epa.gov/dfe/.
    \34\ http://www.epa.gov/oem/docs/oil/ncp/notebook.pdf.
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    (14) International product certifications, testing or use data
informing the performance capabilities or environmental benefits of the
product. The Agency believes that any additional data available from
other countries may help identify the benefits or concerns for the
listing and/or the authorization of use of a product. The Agency,
however, is not proposing any specific listing criterion or threshold
associated with this broad information request, as some products
(particularly new formulations) may not have any of this additional
data available.
(b) Dispersant Testing and Listing Requirements
    The Agency is proposing revisions to the efficacy and toxicity
testing protocols, as well as establishing new thresholds for listing
dispersants on the Schedule in Sec.  300.915(b). The Agency proposes to
define dispersants as typically mixtures of solvents, surfactants, and
additives that promote the formation of small droplets of oil in the
water column by reducing the oil-water interfacial tension. These
droplets are driven into the water column by wave action. Emergency
response personnel need to know whether a dispersant or any other type
of chemical or biological agent on the Schedule could have negative
environmental impacts relative to the oil before decisions are made
about its use in a particular oil discharge situation. Consequently, it
is essential to consider comparative information about the efficacy and
the toxicity of these products. The proposed revisions are in response
to concerns not only for an increase in the frequency of planning for
the use of these agents, but also for their potential use in large
quantities, such as when responding to oil discharges from

oil tanker accidents and offshore well blowouts, as evidenced during
the Deepwater Horizon incident in 2010.
(1) Dispersant Efficacy
    Current Requirements: The current NCP Subpart J requires
dispersants to be tested for saltwater efficacy in order to determine
listing eligibility on the Schedule. Dispersant efficacy is tested
following the Swirling Flask Test (SFT) listed in Appendix C to part
300 of the NCP. This protocol was developed by Environment Canada to
provide a relatively rapid and simple testing procedure for evaluating
dispersant efficacy (i.e., the percentage of oil that is dispersed).
The procedure places seawater, oil, and a dispersant into an Erlenmeyer
flask, which is then placed on a shaker table for a specified period of
time. The flask is modified by the addition of a side spout attached to
the bottom of the flask, which allows the analyst to pour off dispersed
oil from the bottom into a collection vessel for extraction and
measurement. After 20 minutes, a sample of water is poured off and
chemically analyzed for dispersed oil. For products to be listed, they
must attain an efficacy value of 45 percent or greater average
dispersion efficacy of two different crude oils (South Louisiana Crude
(SLC) and Prudhoe Bay Crude (PBC)) at room temperature (20-23 degrees
Celsius ([deg]C)).
    Proposed Revisions: The Agency proposes to change the testing
protocol for measuring efficacy and adopt the Baffled Flask Test (BFT)
as the testing protocol for dispersant efficacy. The new BFT procedure
incorporates a redesign of the testing flask by eliminating the side
arm, incorporating baffles in the wall of the flask, and adding a
stopcock at the bottom, which improves reproducibility in the hands of
different operators. This protocol has undergone extensive peer review
\35\ and has been tested in several laboratories, providing
reproducible and repeatable results. The Agency also proposes revisions
to the efficacy listing criteria for dispersants to be listed.
Specifically, the dispersant must demonstrate that the lower 95%
confidence level (LCL95) of six replicate flasks meets the
new proposed efficacy listing criteria at two test temperatures. New
test oils representing a wider range of characteristics are also
proposed for this protocol: Alaska North Slope (ANS) and Intermediate
Fuel Oil (IFO-120) were tested for this proposal. Both oils are to be
tested at two temperatures: 5 [deg]C and 25 [deg]C. Finally, based on
the ANS and IFO-120 testing, the Agency proposes that dispersants
considered for listing must demonstrate that they attain all of the
following dispersant effectiveness (DE) values:

    \35\ Venosa, Albert D., National Risk Management Research
Laboratory, US EPA; Sorial, George A., Department of Civil &
Environmental Engineering, University of Cincinnati; King, Dennis
W., Statking Consulting; Round-Robin Testing of a New EPA Dispersant
Effectiveness Protocol, International Oil Spill Conference, 2001.

 ANS at 5 [deg]C: DELCL95 >=70%.
 ANS at 25 [deg]C: DELCL95 >=75%.
 IFO-120 at 5 [deg]C: DELCL95 >=55%.
 IFO-120 at 25 [deg]C: DELCL95 >=65%.

    The Agency tested eight of the dispersants currently listed on the
Schedule. Three of the eight dispersants clearly differentiated
themselves from the other five dispersants for having the best
DELCL95 efficacy results; they would meet all the proposed
thresholds. For the next best dispersant tested, the results were
substantially lower than those in the top group and would not meet all
the thresholds proposed today. This natural break in the results
provided the Agency with the basis for the proposed threshold criteria.
The Agency is also proposing to replace the SLC and PBC test oils
currently used for efficacy testing with two other oils that represent
a wider range of characteristics. The proposal is based on the results
of tests using ANS and IFO-120 oils with the new protocol. In proposing
two new oils for efficacy testing, the Agency is seeking to ensure that
the efficacy testing uses oils that represent a wider range of oil
gravities throughout the different geographic locations in the country
where dispersants might be used. The oils selected should exhibit
sufficiently different characteristics to produce results that have
statistically significant variation between them. The proposal is to
replace the SLC and PBC oils, both of which were light oils, with a
range of light-to-medium, and heavier oils. The light-to-medium gravity
ANS pipeline blend and the heavier refined product, IFO-120 were
selected for testing the protocol in this proposal. The current
protocol, testing 4 replicates of both the SLC and the PBC oils and
combining their results, provided one threshold criterion after
determining that each of the oils produced statistically similar
results. In contrast, the efficacy test results between the ANS and the
IFO-120 showed statistically significant differences at each
temperature. The Agency believes the use of ANS and IFO-120, or similar
oils that represent a wider range of oil gravities, will provide better
information on the efficacy of the products when used on different
types of oils.
    Additionally, the Agency is proposing that efficacy testing be
conducted at two different temperatures, 5 [deg]C and 25 [deg]C, rather
than at an ambient temperature range of 20-23 [deg]C as currently
required. The Agency recognizes the current and future interest in
arctic and deepwater drilling, and the continued oil production in the
southern, more tropical areas of the country. Given the potential range
of locations where dispersants may be used, the Agency believes it is
appropriate to have products tested at temperatures that would reflect
that range. These temperatures are intended to capture dispersant use
scenarios in a wide range of geographic locations and under different
temperatures that may occur in the same geographical location (such as,
for example, the deep sea and surface water in the Gulf of Mexico,
where the temperatures are typically 5 and 25 [deg]C, respectively).
    The Agency is also proposing to replace the current SFT with the
BFT, which is designed to be more representative of moderately
turbulent sea conditions where dispersants are more likely to be
successful when used. The revised testing protocol improves test
repeatability and reproducibility within and between laboratories, as
well as greatly reduces both the inherent error of the method and the
human error associated with the current SFT, as discussed below. In
addition, reporting the test results in terms of the product's
LCL95 accounts for between- and within-laboratory error
variability and the inherent error of the method. Only one number is
reported compared to a mean and standard deviation, as the variation
has already been subtracted in the reported number. Specifically:
     The new baffled trypsinizing flask design, fitted with a
glass stopcock positioned at the bottom side, promotes less
manipulation that could result in erroneous re-suspension of non-
dispersed oil, as in the SFT. The re-suspension of oil when using the
SFT test protocol was a major source of error. In the SFT, the flask
has a side arm spout, requiring the analyst to pick up the flask and
pour the contents out manually. Through that action, re-suspension of
the dispersed oil can easily take place, leading to potentially
erroneous results. In contrast, in the BFT, the flask contains a
stopcock at the bottom, so the analyst need only open the stopcock to
drain the contents from the flask without the potential of remixing or
re-suspending the dispersed oil.
     The BFT provides more turbulent mixing and better enables
more reproducible and repeatable dispersant

action than the SFT. The mixing energy within the flask is higher and,
as a result of this increased mixing energy, better dispersion is
possible. Turbulence is needed for the proper mixing of dispersant and
oil and for producing the sheer forces needed to create the small
droplet sizes with high surface area-to-volume ratio that promote the
effective dispersion of the oil into the water column. The BFT provides
such mixing and better enables more repeatable and reproducible
dispersant effectiveness than the SFT. The BFT was tested extensively
in a nine-participant round-robin inter-laboratory calibration test on
six commercial dispersant products.\36\ In addition, based on the
mixing energy that can be achieved using the new baffled flask, the
Agency believes a higher efficacy threshold is warranted. As a result
of this increased mixing energy, better dispersion is realized under
conditions more realistic of wave action in the sea.
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    \36\ Venosa, A. D., D. W. King, and G. A. Sorial. 2002. The
Baffled Flask Test for Dispersant Effectiveness: A Round Robin
Evaluation of Reproducibility and Repeatability. Spill Sci. &
Technol. Bulletin 7(5-6):299-308.
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     The variability both between analysts and within analysts
is substantially lower for the BFT compared to the SFT, as measured by
the coefficient of variation (CV). The CV is defined as the standard
deviation divided by the mean and is expressed in terms of percent; the
higher the CV, the greater the variability.37 38
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    \37\ Sorial, G. A., A. D. Venosa, K. M. Miller, E. Holder, and
D. W. King. 2004a. Oil Spill Dispersant Effectiveness Protocol--Part
I Impact of Operational Variables. ASCE. J. Env. Eng. Div.,
130(10):1073-1084.
    \38\ Sorial, G. A., A. D. Venosa, K. M. Miller, E. Holder, and
D. W. King. 2004b. Oil Spill Dispersant Effectiveness Protocol--Part
II Performance of the Revised Protocol. ASCE ASCE. J. Env. Eng.
Div., 130(10):1085-1093.
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    The Agency considered establishing listing thresholds for efficacy
based on the types of oil. The Schedule could list sub-categories of
dispersants based on gravities of the oil (i.e., light-medium or
heavy), so that a dispersant would only be authorized for use on oils
that fall within the range for which it tested effective. Similarly,
the Schedule could list dispersants based on temperature, allowing a
dispersant to be authorized for use only at the temperature for which
it tested effective. However, determining ranges or definitions for
when oil changes from light to medium or heavy, is challenging because
they may be affected by a number of external factors, including
temperature. Likewise, listing dispersants based on temperature would
require an additional degree of complexity to the authorization for
use, as the temperatures may change drastically in some geographical
regions affected by the same oil discharge. Even within more stable
geographical regions, there may be variations at the time of an oil
discharge that could affect the decision to use a dispersant stockpiled
for a different temperature range. While these more specific listing
approaches would provide more information on effective product choices,
the Agency is concerned about how such specific listing approaches may
contribute to OSC confusion in an emergency, the cost of stockpiling
multiple types of dispersants, or the immediate availability of the
appropriate dispersant in an emergency. Furthermore, the Agency is
proposing revisions to Subpart J to authorize RRTs to request
supplementary testing and information to provide greater flexibility in
tailoring testing conditions to address area- and site-specific
concerns. Given these factors, the Agency believes that it is
appropriate that only those dispersants that achieve efficacy for both
types of oils and at both temperatures be listed. Listing only the
products that achieve efficacy for both types of oils at both
temperatures would demonstrate a wide range of efficacy for the
product, and a single listing would facilitate authorizing their use
during a response action. The Agency requests comments on this
approach.
(2) Dispersant Toxicity
    Current Requirements: The current NCP Subpart J requires
dispersants to be tested for toxicity to saltwater species. This
information is available to the OSC for their consideration in
authorizing dispersant use. Dispersant toxicity is tested following the
protocols in Appendix C to part 300 of the NCP. The standard toxicity
test for dispersants involves exposing two saltwater species, the
inland silverside fish (Menidia beryllina or M. beryllina) and the
mysid shrimp (Americamysis bahia or A. bahia), to five concentrations
of the test product and No. 2 fuel oil, alone and in a 1:10 mixture of
product to oil. Reference toxicity tests are conducted using dodecyl
sodium sulfate (DSS) as a reference toxicant. The test length is 96
hours for M. beryllina and 48 hours for A. bahia. The concentration of
test product causing 50% lethality to the test organisms
(LC50) is calculated at the end of the exposure period.
    Proposed Revisions: The Agency proposes to revise the toxicity
testing requirements for dispersants, including the testing protocol
and the use of the test results. The proposal would require acute
toxicity testing for the dispersant alone, and the dispersant mixed
with both oils used for efficacy testing; the proposal is based on the
ANS and IFO-120 oils. While the Agency currently provides the toxicity
testing results to the OSC to assist in authorization of use
determinations, it is proposing to use these testing results to
determine eligibility for listing on the Schedule.
    Specifically, the Agency is proposing to require evaluations of
dispersant toxicity using acute toxicity tests following existing USEPA
effluent testing guidelines,39 40 modified for use with
dispersant product or dispersant product/oil mixtures, as detailed in
Appendix C to part 300. Measured toxicity values for dispersant product
and dispersant product/oil mixtures are proposed to include static
acute toxicity tests using A. bahia and M. beryllina. Developmental
toxicity using a sea urchin assay, and sub-chronic effects using A.
bahia and M. beryllina are also proposed to be conducted, but with
dispersant product only. The Agency is proposing the following toxicity
thresholds for listing dispersants on the Schedule:
---------------------------------------------------------------------------

    \39\ USEPA 2002a Methods for Measuring the Acute Toxicity of
Effluents and Receiving Waters to Freshwater and Marine Organisms,
Fifth edition. (Acute Methods Manual), Office of Water, Cincinnati,
OH. EPA-821-R-02-012.
    \40\ USEPA 2002b. Short-term Methods for Estimating the Chronic
toxicity of Effluents and Receiving Waters to Marine and Estuarine
Organisms, Third Edition. (Saltwater Chronic Methods manual). Office
of Water, Cincinnati, OH. EPA-821-R-02-014.
---------------------------------------------------------------------------

     Lethal concentration for 50% of the test species
(LC50) at the lower 95% confidence interval for all acute
toxicity tests greater than 10 ppm;
     Inhibition concentration for 50% of the test species
(IC50) at the lower 95% confidence interval greater than 10
ppm;
     No Observed Effect Concentration (NOEC) equal to or
greater than 1 ppm for sub-chronic toxicity.
    Test Oils and Oil Acute Toxicity Values. The Agency proposes to
replace the No. 2 fuel oil currently used for toxicity testing with two
test oils that better represent a wider range of characteristics and
that may be encountered during an incident. The proposal is based on
ANS and IFO-120, as previously discussed. In addition to making the
test oils consistent with the dispersant efficacy tests, testing oils
of different gravities also provides a better estimation of dispersant/
oil toxicity associated with differing oil constituencies, and
ultimately a better representation of the potential overall toxicity of
a product.
    The Agency proposes to conduct the oil-only acute toxicity tests
for the two reference oils, with both A. bahia and

M. beryllina, and provide this data for comparisons to dispersant and
dispersant-oil mixture acute toxicity tests. EPA will make all of the
reference oil toxicity test results available to the public on its Web
site, including raw data and calculated median LC50 values.
By providing this information, the Agency is reducing the number of
required toxicity tests the submitter would need to conduct.
Alternatively, the Agency considered requiring submitters to conduct
the oil acute toxicity testing as it would provide an opportunity to
detect anomalies in the submitted data. The Agency is requesting
comments on whether the submitter should be required to conduct the
oil-only acute toxicity testing for the two test oils.
    Dispersant and Dispersant-Oil Acute Toxicity Threshold. Using the
EPA toxicity classification scheme,\41\ LC50 values ranging
from 10 ppm to 100 ppm are classified as slightly toxic and above 100
ppm substances are considered acutely nontoxic to aquatic organisms.
For both M. beryllina and A. bahia, the Agency is proposing as the
threshold value the lower bound of the LC50 95% confidence
interval (CI) greater than or equal to 10 ppm for all toxicity tests to
qualify a dispersant to be listed on the Schedule. The rationale for
using the lower bound of the CI is that the CI should not contain any
values less than or equal to 10 ppm since theoretically, the
LC50 can fall anywhere within the CI. By using the lower CI,
the Agency is providing a conservative decision criterion for acute
toxicity, and by proposing a greater than or equal to 10 ppm threshold
level, it is establishing an adequate safety margin without being
overly restrictive.
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    \41\ http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysis_eco.htm#Ecotox.
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    Dispersant-Oil Mixture Acute Toxicity Protocol. The Agency is
proposing to substitute the existing preparation procedure for the
dispersant-oil mixture (DOM) in Appendix C to Part 300, Section 3
method for the preparation procedure for dispersant-oil mixture using a
modified protocol \42\ first described by Baron and Ka'aihue \43\ and
fully described by Hemmer et al.\44\ These new modified procedures for
preparation of the chemically enhanced water accommodated fractions
(CEWAFs) of dispersant-oil mixtures are used to make exposure
solutions. Evaluations of the dispersant-oil mixture toxicity using
acute toxicity tests follow existing EPA effluent testing
guidelines,45 46 modified for use with these exposure
solutions and are detailed in Appendix C to part 300. EPA proposes to
modify the variable loading preparation procedure described in Chemical
Response to Oil Spills: Ecological Research Forum (CROSERF) \47\ to a
variable dilution procedure to standardize the oil-to-water ratio and
provide a consistent chemical concentration in a test series.
Additionally, the modified preparation procedure provides economies in
analytical costs by reducing the need to analyze the composition of
every tested concentration. Chemical analysis for the total petroleum
hydrocarbon (TPH) concentration of the CEWAF stock solution is
required.
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    \42\ The modified protocol is based on a variable dilution
modification of the Chemical Response to Oil Spills: Ecological
Research Forum (CROSERF) testing protocol; Aurand, D. and G. Coelho
(Editors). 2005. Cooperative Aquatic Toxicity Testing of Dispersed
Oil and the ``Chemical Response to Oil Spills: Ecological Effects
Research Forum (CROSERF).'' Ecosystem Management & Associates, Inc.
Lusby, MD. Technical Report 07-03.
    \43\ Barron, MG, Ka'aihue L. 2003. Critical evaluation of
CROSERF test methods for oil dispersant toxicity testing under
subarctic conditions. Mar Pollut Bull 46:1191-1199.
    \44\ Hemmer, MJ, Barron, MG, Greene, R. 2011. Comparative
toxicity of eight oil dispersants, Louisiana sweet crude oil (LSC)
and chemically dispersed LSC to two aquatic species. Environ Toxicol
Chem, 30: 2244-2252.
    \45\ USEPA 2002a Methods for Measuring the Acute Toxicity of
Effluents and Receiving Waters to Freshwater and Marine Organisms,
Fifth edition. (Acute Methods Manual), Office of Water, Cincinnati,
OH. EPA-821-R-02-012.
    \46\ USEPA 2002b. Short-term Methods for Estimating the Chronic
toxicity of Effluents and Receiving Waters to Marine and Estuarine
Organisms, Third Edition. (Saltwater Chronic Methods manual). Office
of Water, Cincinnati, OH. EPA-821-R-02-014.
    \47\ CROSERF was established as a working group of industry,
government, and university scientists to coordinate and disseminate
research on chemical oil spill dispersants. CROSERF participants
developed aquatic toxicity testing protocols during 1994 to 2000
with the foremost objective of standardizing test methods and
reducing inter-laboratory variability.
---------------------------------------------------------------------------

    Sea Urchin Developmental Assay. The Agency is proposing to require
a sea urchin developmental assay (also referred to as an embryogenesis
assay) to assess the potential for a dispersant product to cause
adverse effects on the developmental process. During the Deep Water
Horizon spill event, the possible adverse effects of oil dispersants on
the developmental processes of fish and invertebrate species were
identified as critical issues of concern. By incorporating the sea
urchin developmental assay, the Agency is using it as a sensitive
surrogate test for pelagic early life stages. This assay would employ
an existing EPA test protocol \48\ routinely used in effluent testing.
As suggested for the dispersant acute toxicity test criteria with A.
bahia and M. beryllina, the Agency is proposing as the threshold value
the lower bound of the developmental IC50 95% confidence
interval greater than or equal to 10 ppm. For this test, the
IC50 is defined as the concentration of dispersant that
inhibits the development of 50% of exposed embryos. As described above
for acute toxicity levels, the Agency is adopting a similar rationale
for IC such that IC50 values ranging from 10 ppm to 100 ppm
are considered to cause slight adverse effects on the developmental
process, and above 100 ppm substances are considered to cause no
adverse effects. By using the lower CI the Agency is providing a
conservative decision criterion for developmental toxicity, and by
proposing a greater than or equal to 10 ppm threshold level it is
establishing an adequate safety margin without being overly
restrictive.
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    \48\ USEPA 1996. Short-term Methods for Estimating the Chronic
Toxicity of Effluents and Receiving Waters to West Coast Marine and
Estuarine Organisms. EPA/600/R-95/136.
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    Sublethal/Subchronic Studies. The Agency has limited information
concerning the possible sublethal effects of dispersants currently
listed on the Product Schedule. The Agency is proposing requirements
for subchronic assays (duration approximately 7 days) to be performed
with A. bahia and M. beryllina following established EPA short-term
methods for estimating chronic toxicity of effluents.\49\ While the
Agency considered requiring longer-term tests, it believes the 7-day
subchronic tests are reasonable alternatives for estimating chronic
toxicity. This information would also be of value as guidance to
regional responders and OSC's on possible adverse effects on survival
and growth of larval fish and invertebrates caused by longer-term
exposure to dispersants. The Agency is proposing a NOEC equal to or
greater than 1 ppm listing threshold level for sub-chronic effects.
This threshold level provides a tenfold safety factor from the proposed
acute toxicity threshold values. The tenfold safety factor is a common
practice in ecological risk assessment and thus the Agency believes it
provides an adequate safety margin without being overly restrictive.
The Agency is requesting comment on whether it should consider longer-
term tests (e.g., early life stage tests), which may be more relevant
to sublethal effects caused by longer

duration exposure to low concentrations of a dispersant product.
---------------------------------------------------------------------------

    \49\ USEPA 2002b. Short-term Methods for Estimating the Chronic
Toxicity of Effluents and Receiving Waters to Marine and Estuarine
Organisms, Third Edition. (Saltwater Chronic Methods manual). Office
of Water, Cincinnati, OH. EPA-821-R-02-014.
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Alternative Options
    In addition to the criteria discussed above, the Agency considered
calculating a toxicity threshold based on the ratio of the
LC50 of oil-alone to the LC50 of the dispersant-
oil mixture for M. beryllina and A. bahia to assist in comparing the
relative toxicity of crude oil to chemically dispersed oil. A ratio of
less than or equal to 1 would indicate the toxicity of the dispersant-
oil mixture is less than or equal to the toxicity of the oil-alone. The
Agency considered whether this ratio should be used as a criterion for
inclusion of dispersants on the Schedule or as guidance to emergency
responders. Using a less than or equal to 1 ratio as a guideline would
afford an adequate safety margin without being overly restrictive.
While the ratio would provide a simple, interpretable, and easily
justifiable value for determining acceptable toxicity levels of
dispersant-oil mixtures, it would not be specific to oils in particular
discharge situations. The Agency is requesting comment as to whether
such a value should be calculated, and if so, whether it should be an
additional listing criterion, or provided as information for the
responders to consider in authorizing dispersant use.
    The Agency also considered including geographically or ecologically
representative species in the testing protocol. The Agency believes,
however, that this issue is addressed by the proposed revisions to the
supplemental testing and information requirements in section
300.910(g), with the decisions of testing geographically and
ecologically representative species left to the discretion of the RRTs.
While inclusion of species from different phyla and habitats would
provide useful and important information on possible adverse effects of
dispersant products and dispersed oil, the proposed testing protocols
would need to be modified and validated. Further, the Agency is
concerned about balancing the time and cost associated with the
development of these tests on the part of the submitter rather than on
the end users.
    The Schedule currently requires no specific toxicity or efficacy
tests for subsea dispersant listing or authorization of use. While the
differences in toxicity values and efficacy may be affected by
application in subsea environments, the Agency believes that the
proposed requirements establish an adequate baseline for listing
dispersants on the Schedule and for authorizing their use by responders
in case of an incident. The Agency is addressing these concerns by
proposing new provisions for dispersant monitoring for all subsea use,
and requests comments on alternative testing and listing approaches to
specifically address subsea concerns.
(3) Limitations of Use
    The Agency is proposing a conditional use listing for dispersants.
The proposal specifies that dispersants may only be used in saltwater
environments. Dispersants are typically designed and traditionally used
for responding to oil discharges in saltwater. In general, the
effectiveness of dispersants decreases as the salinity of the water
decreases, given the same hydrophilic-lipophilic balance, and the
effectiveness is minimal in freshwater environments. Surfactants, the
main active ingredient in dispersants, sustain oil droplets in water by
orienting the lipophilic side of its molecule in the oil and the
hydrophilic side in the water. The hydrophilic side of the surfactant
is generally more soluble in waters with higher salinity values,
causing the oil droplets to be more stable in saline water
environments. In waters with no salinity, many dispersants have shown a
very low effectiveness or are sometimes completely ineffective.\50\
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    \50\ Fingas, M., (Ed.), 2011, Oil Spill Science and Technology,
Gulf Professional Publishing, pp. 513-518.
---------------------------------------------------------------------------

    The Agency is also concerned with using dispersants in freshwater
environments because of the limited dilution typically available as
compared with the open sea and because of the existence of water
intakes in rivers, streams, and lakes for use in drinking water
supplies. Using dispersants in freshwater has the potential for
compounding the impacts caused by already discharged petroleum
products, particularly near potable and non-potable subsurface water
intakes. The Agency does recognize, however, that as a last resort,
dispersants may have some limited applicability in freshwater. The
provision for authorization of use under Sec.  300.910(d) would allow
for exceptions to the prohibition on the use of dispersants in
freshwater in cases where there is an immediate threat to human life.
The Agency is requesting comment on this proposed listing limitation.
(c) Surface Washing Agent Testing and Listing Requirements
    The Agency is proposing to define Surface washing agents (SWA) as
substances that separate oil from solid surfaces, such as beaches,
rocks, or concrete, through a detergency mechanism that lifts and
floats oil for collection and recovery from the environment with
minimal dissolution, dispersion, or transfer of oil into the water
column. For this agent category, the Agency is proposing to revise the
toxicity testing protocols, to establish efficacy testing protocols,
and to establish both toxicity and efficacy listing thresholds in Sec.
300.915(c). The proposed revisions respond to concerns regarding their
frequent use and the potential for residual impacts after their use.
(1) Surface Washing Agent Efficacy
    Current Requirements: There are currently no efficacy testing
requirements in the NCP Subpart J for surface washing agents to
determine listing eligibility on the Schedule.
    Proposed Revisions: The Agency is developing a laboratory testing
protocol to evaluate the efficacy of SWAs in removing crude oil from a
solid substrate.\51\ Currently available efficacy testing protocols for
these agents are concerned with assessing the detergency, or cleaning
power, of the agents by quantifying the physical removal of oil from
non-vegetative substrates as a result of their use. The protocols
typically involve the application of oil to a solid substrate (or the
use of pre-oiled substrate), weathering of the oil on the substrate,
application of the agent to the oiled substrate, a contact period for
SWA penetration, and washing of the substrate with water. The fractions
of oil removed in the wash water and/or remaining on the substrate are
quantified. Oil removal efficiencies for surface washing treatments are
typically compared to the washing efficiency of water without surface
washing agents (untreated controls). Disadvantages or potential sources
of error have been identified in the existing protocols that may not
reflect field performance. Of concern are, for example, the use of
substrates (e.g., stainless steel, porcelain) with different wetting
and adhesion properties than natural substrates such as sand or gravel;
short weathering times insufficient for oil attachment; and the absence
of mixing energy during the washing step, which may lead to incomplete
detachment of partially released oil.
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    \51\ Koran, K.M., Venosa, A.D., Luedeker, C.C., Dunnigan, K.,
Sorial, G.A., 2009. Development and Testing of a New Protocol for
Evaluating the Effectiveness of Oil Spill Surface Washing Agents.
Mar. Pollut. Bull., 58: 1903-1908.
---------------------------------------------------------------------------

    The Agency's goal is to develop and evaluate a new bench-scale
testing protocol that would provide a standard for EPA to use in SWA
product

evaluation prior to listing on the Schedule. Changes over established
protocols the Agency considered include: Using natural substrates to
reflect the most commonly impacted shoreline material; establishing
sufficient weathering time to permit strong attachment of the oil to
the substrate surface; fully quantifiable approaches with known volumes
and precise measurements to allow mass balance; and a standardized and
reproducible methodology to minimize operator error. PBC oil was used
as the representative standard reference oil in developing the protocol
since it had previously been selected as one of two standard oils for
the Agency's published protocols for dispersant and bioremediation
agent testing. However, the Agency is proposing revisions to the
dispersant and bioremediation testing protocols, including replacing
the PBC reference oil. The protocol being developed has not been
tested: With the IFO-120 or the ANS oils that are proposed to be used
in the revised dispersant efficacy testing protocol; at multiple
temperatures; or to include freshwater systems. The Agency expects to
develop final recommendations for the testing protocol following round
robin testing after adjusting for the new variables. The Agency would
propose this protocol in the Federal Register through notice and
comment before adopting it as part of Subpart J requirements.
    Consequently, because of the additional work needed to finalize its
protocol, the Agency is proposing to allow the use of standard
recognized efficacy testing methodologies for surface washing agents.
An example of such a standard recognized methodology is the American
Society for Testing and Materials (ASTM) Standard Test Method for
Evaluating the Effectiveness of Cleaning Agents.\52\ Another
methodology is Environment Canada's Test Method.\53\ The capability of
a particular surface washing agent depends upon the application
procedures and the characteristics of the surface being cleaned, such
as size, shape, and material. The ASTM test method in particular covers
a procedure for evaluating the capability of the agents, providing a
relatively rough surface to which the oil can adhere. The Environment
Canada method uses a stainless-steel `trough' which is placed at a
specified angle. The target oil is placed on an area on the trough. The
treating agent is then applied in droplets to the surface of the oil
and after 10 minutes at 5-minute intervals, rinses of water are applied
to the trough. After drying, the trough is weighed and the removal
calculated from the weight loss. Repeatability is within 5%. The Agency
is requesting comment on available methodologies and its published
protocol to incorporate as the testing protocol for these agents. The
Agency also requests comment on whether the rule should identify the
specific methodologies to be used until EPA develops and adopts a new
testing protocol for SWA efficacy testing.
---------------------------------------------------------------------------

    \52\ ASTM Standard Test Method for Evaluating the Effectiveness
of Cleaning Agents. Designation: G122--96 (Reapproved 2008). ASTM
International, 100 Barr Harbour Dr., P.O. Box C-700 West
Conshohocken, Pennsylvania 19428-2959, United States
    \53\ Fingas, Merv and Fieldhouse, Ben; ``Surface-washing Agents
or Beach Cleaners'' (2010). Chapter 21 Surface-Washing Agents or
Beach Cleaners. In Oil Spill Science and Technology (p716). London:
Gulf Professional Publishing.
---------------------------------------------------------------------------

    The Agency is also proposing an efficacy threshold of 30% in either
fresh or salt water or both depending on the intended product use. This
is based on the efficacy data published in ``Surface-washing Agents or
Beach Cleaners.'' \48\ Numerous surface washing agent products,
including several from the Schedule were tested using the Environment
Canada methodology. The average efficacy of the surface washing agents
tested is approximately 30%. The Agency requests comments on this
approach and other efficacy test data available.
(2) Surface Washing Agent Toxicity
    Current Requirements: The current NCP Subpart J requires surface
washing agents to be tested for saltwater species toxicity. Surface
washing agent toxicity is tested following the dispersant toxicity
testing protocols in Appendix C to part 300 of the NCP.
    Proposed Revisions: The Agency is proposing revisions to the
toxicity testing requirements for surface washing agents, including the
testing protocol. While the Agency currently provides the toxicity
testing results to the OSC to assist in authorization of use
determinations, it is proposing to use these toxicity testing results
to determine listing eligibility on the Schedule.
    The proposed revisions to the testing protocols for surface washing
agents are detailed in Appendix C to part 300. The proposed acute
toxicity test protocol for surface washing agents is based on EPA's
protocol, Methods for Measuring the Acute Toxicity of Effluents and
Receiving Waters for Freshwater and Marine Organisms.\54\ The Agency
proposes to require surface washing agents be tested for acute toxicity
using fresh water species Ceriodaphnia dubia and Pimephales promelas,
or saltwater species Americamysis bahia and Menidia beryllina, or both,
depending on the intended product use. The concentration of test
product causing 50% lethality to the test organisms (LC50)
and lower and upper 95% confidence intervals (LCI95 and
ULCI95) are calculated at the end of the exposure period. To
be listed on the Schedule, surface washing agents must demonstrate an
acute lethal concentration for 50% of the test species
(LC50) at the lower 95% confidence interval greater than 10
ppm in either fresh or salt water, consistent with the acute toxicity
thresholds proposed for dispersants. EPA's toxicity classification
scheme \55\ classifies LC50 values ranging from 10 ppm to
100 ppm as slightly toxic and values above 100 ppm substances are
considered practically nontoxic to aquatic organisms. By proposing this
threshold level, the Agency is establishing an adequate safety margin
without being overly restrictive. The Agency requests comments on the
proposed acute toxicity methods (or any others available) and
thresholds for surface washing agents.
---------------------------------------------------------------------------

    \54\ http://water.epa.gov/scitech/methods/cwa/wet/upload/2007_07_10_methods_wet_disk2_atx1-6.pdf.
    \55\ USEPA 2010. http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysiseco.htm#Ecotox.
---------------------------------------------------------------------------

    The Agency is proposing provisions for conducting acute toxicity
tests with dispersant-oil mixtures, but not for any other agent,
including SWAs. EPA believes that non-dispersant products are not
likely to be used in the same quantities or durations as dispersants
and some may be recovered making a requirement to conduct toxicity
tests of product/oil mixtures unnecessary. There may be concerns,
however, for increased product toxicity because of their interaction
with the oil. Thus, the Agency is requesting comment on the need for
acute toxicity tests conducted with surface washing agents-reference
oil mixtures. A protocol for preparation of product/oil mixtures for
toxicity testing is available for review in the docket.
(3) Limitations
    The Agency is proposing a conditional use listing for SWAs. The
proposal specifies that these products may only be used in those water
environments for which the product was tested and for which it met the
listing threshold criteria. The Agency recognizes that products may
yield effective results in certain environments and not in others.
Products that may be

effective in freshwater environments may not necessarily be so in
saltwater environments, and vice versa. The Agency is proposing this
limitation to allow product manufacturers the flexibility to select
which environment the product is to be tested and authorized for use,
either saltwater, fresh water, or both environments. Therefore, the
product would be listed and could only be authorized for use in those
water environments for which it was tested and for which it met both
the efficacy and toxicity listing criteria.
(d) Bioremediation Testing and Listing Requirements
    The Agency is proposing to define bioremediation agents as
biological agents and/or nutrient additives deliberately introduced
into a contaminated environment to increase the rate of biodegradation
and mitigate any deleterious effects caused by the contaminant
constituents. Bioremediation agents include microorganisms, enzymes,
and nutrient additives such as fertilizers containing bioavailable
forms of nitrogen, phosphorus and potassium. For this agent category,
the Agency is proposing to revise the efficacy testing protocols, to
establish toxicity testing protocols, and to establish both efficacy
and toxicity listing thresholds in Sec.  300.915(d).
(1) Bioremediation Agent Efficacy
    Current Requirements: Bioremediation agent efficacy is currently
tested following the protocols in Appendix C to part 300 of the NCP.
The current bioremediation agent efficacy testing protocol is designed
to determine a product's ability to biodegrade oil by quantifying
changes in the oil composition resulting from biodegradation using
natural seawater as the test water. The protocol tests the
bioremediation agent for microbial activity and quantifies the
disappearance of saturated hydrocarbons and PAHs in weathered oil; for
purposes of the proposal the Agency tested the protocol using ANS
521.\56\ The sample preparation procedure extracts the oil phase into
dichloromethane (DCM), with a subsequent solvent exchange into hexane.
The analytical technique uses a high-resolution gas chromatograph/mass
spectrometer (GC/MS); GC/MS provides for a high degree of chemical
separation and spectral resolution. Concurrently with the chemical
analysis, a microbiological analysis is also performed to determine and
monitor the viability and growth of the microbial cultures being
studied. For commercial products that are strictly microbial agents not
containing their own nutrients, a mineral nutrient solution is provided
if requested by the submitter; no further nutrients are added to
commercial products containing their own nutrients. To be listed on the
Schedule, bioremediation agents must demonstrate a statistically
significant difference between the average degradation of both total
alkanes and total aromatics in the oil achieved by the product after 28
days and the average degradation for the same compounds achieved by the
non-nutrient control in the same time period.
---------------------------------------------------------------------------

    \56\ Artificially distilled Alaska North Slope crude oil at
521[emsp14][deg]F (272[deg]C) to remove the low molecular weight
hydrocarbons to approximate natural weathering processes that occur
after a spill.
---------------------------------------------------------------------------

    Proposed Revisions: The proposal reflects a series of changes to
the current efficacy testing protocol for bioremediation agents. The
protocol includes freshwater testing in addition to the current
saltwater-based test, and uses artificial water for both fresh and
saltwater testing, replacing the natural seawater currently used. The
proposed protocol also eliminates several gravimetric and
microbiological analyses and testing endpoints not used in the proposed
listing determinations. Additionally, the proposed protocol limits the
levels at which external nutrients may be added, which allows the
addition for product formulations without nutrients, or for product
formulations that have nutrient concentrations at insufficient levels
for the experimental setup. Finally, the methodology streamlines the
statistical analysis. The proposed revisions address concerns with the
existing methodology as discussed below, expanding its application to
include freshwater environments, improving the consistency and
comparability of the test results, and generally streamlining the
protocol.
    Protocol. The proposed efficacy testing protocol is designed to
determine a bioremediation agent's ability to biodegrade weathered
crude oil in the exposure water (saltwater or freshwater) by
quantifying changes in the oil composition resulting from
biodegradation. It consists of a series of six product and control
flasks containing artificial seawater or artificial freshwater and
weathered crude oil in which biodegradation of the crude oil
hydrocarbons is monitored for 28 days. Product flasks at day 28 are
compared to product flasks at day 0 to determine if a specified
reduction both in total resolved alkanes and total resolved aromatics
was achieved in that time period. Product flasks contain exposure
water, weathered oil, and product in concentrations specified by the
manufacturer. Positive control flasks must contain exposure water, oil,
nutrients, and the standard culture supplied by the Agency. A negative
control, consisting of artificial exposure water, product, weathered
crude oil, nutrients, and a sterilant is also used to ensure that the
observed degradation of hydrocarbons was not caused by abiotic losses
or interaction with the product. The Agency is requesting comment on
whether an additional protocol specific to products containing enzymes
only would be appropriate; this would consist only of exposure water,
weathered oil and the enzymatic product in the concentrations specified
by the manufacturer. The proposed protocol quantifies the degradation
(or disappearance) of alkane hydrocarbons and aromatic hydrocarbons.
The sample preparation procedure extracts the oil phase into the
solvent dichloromethane (DCM; also known as methylene chloride) with a
subsequent solvent exchange into hexane. The test method targets the
relatively easy to degrade normal alkanes and the more resistant and
toxic aromatics. The analytical technique uses a high resolution GC/MS
because of its high degree of chemical separation and spectral
resolution. GC/MS has long been used to study the weathering and fate
of oil spilled into the environment. It gives unambiguous results for
determining biodegradation efficacy. For quantitative analyses, the
instrument is operated in the selected ion monitoring mode (SIM) of
detection at a scan rate of > 5 scans per second to maximize the linear
quantitative range and precision of the instrument.
    Fresh and Saltwater Environments. The existing bioremediation test
is exclusively for saline environments with no equivalent test for
freshwater environments. Further, the existing test uses natural
seawater and has been found to give variable results due to the
compositional variability of seawater both chemically and
microbiologically. The Agency proposes to replace the natural seawater
with a standardized artificial saltwater formula called GP2, whose
components and concentrations are generally recognized, and which is
easily made. The use of artificial saltwater allows for better test
reproducibility. Additionally, the Agency proposes to expand the
requirement for efficacy testing to include freshwater, which allows
for a better evaluation of the use of these agents in this environment.
Similarly to

the artificial saltwater, artificial minimal salts freshwater would be
used with known ingredients (Bushnell and Haas; Journal of
Bacteriology, Vol. 41: 653, 1941). Because the Agency is adding a
freshwater test, it is also allowing the submitter to test a product
for freshwater only, saltwater only, or both. The Schedule listing
would specify in which environment the product was tested and
authorized for use. Products could be listed for use on saltwater only,
on freshwater only, or for use on both environments, giving the option
to the submitter to market its products accordingly.
    GC/MS Testing Endpoints. GC/MS has long been used to study the
weathering and fate of oil spilled into the environment. However, GC/MS
being the primary tool used in the analysis makes this test expensive.
The current protocol includes several measured variables in both the
product flasks and the non-nutrient control flasks, including the
gravimetric residual oil weight analysis, a Most Probable Number
microbiological analysis, and the GC/MS analysis at 3 different time
points, days 0, 7, and 28. The Agency is proposing to eliminate all of
these analyses except the day 0 and 28 GC/MS analysis of both the non-
nutrient control and the product flasks. The Agency believes this is
appropriate because the other measurements are not used in determining
whether a product meets the listing criterion. Additionally, the
statistical analysis has been greatly simplified, and a new decision
rule is proposed for listing determinations rather than relying on a
statistical significance test.
     Gravimetric Weight Analysis: Originally, the gravimetric
weight analysis was used as a preliminary test to avoid having to
perform a GC/MS analysis. Products that failed to significantly reduce
the gravimetric weight of the oil within 28 days were considered not
effective, thereby eliminating the need to conduct the more expensive
GC/MS analysis. However, numerous compounds can give rise to positive
interferences with the gravimetric weight analysis, such as biomass
lipids and other biogenic materials, thereby rendering the gravimetric
analysis suspect. Furthermore, numerous factors can confound the
interpretation of gravimetric weight changes in oil over time. This has
led to confusion as some manufacturers have mistakenly concluded their
product passed the testing protocol simply by complying with the
gravimetric weight loss measurement. By eliminating the gravimetric
analysis altogether, EPA is streamlining the testing process, resulting
in less confusion and a modest analytical cost savings for the
manufacturer.
     Most Probable Number Enumeration (Microbiological
Analysis), Nutrient Control, and Day-Seven Sampling Event: Results of
these test endpoints, while currently required, would not be used in
determining whether a product meets the proposed listing requirements.
Therefore, the Agency is proposing to eliminate these test requirements
from the proposed protocol.
     28 day Sampling Event: Generally, results of
biodegradation may occur in less than 28 days, particularly for alkanes
for which biodegradation often takes place in a much shorter time
period. However, 28 days are needed to make sure that the aromatic
components, which biodegrade more slowly, have been reduced
significantly; testing protocols that accommodate aromatics are of
particular importance because of their potential ecological toxicity.
While the Agency could propose different time frames in determining
whether the product met the reduction criterion for alkanes and
aromatics, it believes that such an approach would be confusing.
Therefore, the 28 day time period is being proposed for both fractions
for simplicity and to provide sufficient time for degradation of the
aromatics.
    Protocol Verification. The Agency proposes to provide a standard
culture for performing laboratories to use as a positive control
benchmark. A positive control is needed as an indication that the test
was performed properly. The Agency is proposing to use as the standard
culture an oil-degrading bacteria isolated from Disk Island in Prince
William Sound in 1990. This culture is an excellent degrader of alkanes
and aromatics in saltwater and freshwater, although it performs better
in saltwater, especially in degrading the aromatics. This culture has
the ability to degrade ANS 521 oil, with known efficacy values for both
fresh and saltwater. The proposed positive control consists of
triplicate flasks containing sterile artificial seawater or freshwater,
nutrients (salts of nitrogen and phosphorus), the weathered ANS 521
oil, and the standard culture. The performing laboratory must achieve
the known reduction in alkane and aromatic fractions in these positive
control flasks in order to certify they successfully conducted the test
procedure. Additionally, data from the positive control are required to
be submitted with the product test results. The Agency is not
proposing, however, that the positive control be repeated every time a
product test is performed. Rather, the certifying laboratory would be
required to report the results of the positive control tests conducted
within a year prior to the product testing, as part of the product
submission package. Additionally, this positive control culture would
be used as a standard microbial inoculum to test abiotic products, such
as nutrients and enzymes.
    Added Nutrients. The current protocol allows the manufacturer to
request the addition of nutrients to support a culture's ability to
degrade the crude oil hydrocarbons. This addition is currently allowed
for commercial products that are strictly microbial agents and do not
contain any nutrients; the addition of nutrients is not allowed for
commercial products containing its own nutrients. A modified salt
solution of nitrogen and phosphorus is used as the mineral nutrient.
All microbial cultures need nutrients to survive and grow. In the
natural environment, biodegradation is not completely limited by
nutrient availability given that a low level flow of nutrients is
continuous. To maximize biodegradation rates, the addition of nutrients
is typically recommended in the field with a bioremediation product
unless nutrients are already high (i.e., >5 mg/L). However, in a closed
laboratory flask, the amount of nitrogen and phosphorus supplied by a
typical product might easily become limiting quickly as biodegradation
takes place because they are supplied only once at the beginning of the
test. If nutrient limitation occurs, further reduction of hydrocarbons
would likely be inhibited, and this may cause the product to fail the
listing criteria. To address this problem, the Agency proposes
modifying the protocol by allowing the addition of nutrients to any
product containing living microbes that does not contain said nutrients
in sufficient quantities to allow a fair evaluation. However, the
additional quantities allowed are limited to total concentrations of
nitrogen and phosphorus that do not to exceed the equivalent amounts
used in the positive control. Capping the amount of nutrients that can
be added to all products will yield more consistent results and more
effective comparisons among products.
    Efficacy Thresholds. The Agency is proposing to revise the listing
criteria by replacing the current ``statistically significant
difference'' test with defined values for the percent reduction of
total alkane and aromatic concentrations. For a bioremediation agent to
be listed on

the Schedule, the Agency proposes the percent reduction of the total
alkane fraction (sum of all alkane concentrations determined by GC/MS)
to be greater than 95% at day 28, and that the percent reduction of the
total aromatic fraction (sum of all aromatic concentrations determined
by GC/MS) must be greater than 70% at day 28, both based on the one-
tailed Upper 95% Confidence Limit (UCL95) for salt water.
For freshwater, the Agency proposes the percent reduction of the total
alkane fraction (sum of all alkane concentrations determined by GC/MS)
to be greater than 95% at day 28, and that the percent reduction of the
total aromatic fraction (sum of all aromatic concentrations determined
by GC/MS) must be greater than 40% at day 28, both based on the one-
tailed Upper 95% Confidence Limit (UCL95).
    Basis of Efficacy Thresholds. According to Haines et al.
(2005),\57\ the positive control culture was able to biodegrade total
alkanes in saltwater by 98.9% and total aromatics by 79.8% in 28 days,
based on the UCL90. In freshwater, the percent reduction
values were 97.9% and 37.8%, respectively, again based on the
UCL90. Thus, the proposed listing thresholds for the percent
reduction of total alkanes and total aromatics from the GC/MS analysis
are based on the findings of Haines et al. (95% for alkanes vs. 98.9%
in saltwater and 97.9% in freshwater, and 70% for aromatics in
saltwater and 40% in freshwater vs. 79.8% in saltwater and 37.8% in
freshwater). As for the positive control, the Agency believes a
reasonable target in saltwater would be 95% for total alkanes in both
types of exposure waters. For aromatics reduction, 70% is considered
reasonable in saltwater and 40% in freshwater, based on Haines et al.
EPA is using UCL95 values rather than the UCL90
values from Haines because EPA's latest research uses 6 replicates for
the test protocol which increases precision. The proposed criteria
demonstrate that the product can cause a substantial degradation of the
alkane and aromatic fractions of weathered crude oil compared to a
control, as determined solely by GC/MS analysis.
---------------------------------------------------------------------------

    \57\ Haines, J.R., E.J. Kleiner, K.A. McClellan, K.M. Koran,
E.L. Holder, D.W. King, and A.D. Venosa. 2005. ``Laboratory
evaluation of oil spill bioremediation products in salt and
freshwater systems.'' J. Ind. Micorbiol. Biotechnol. 32:171-185.
---------------------------------------------------------------------------

    Of note, these proposed thresholds for listing bioremediation
products on the Schedule are similar to those established for Canadian
efficacy testing, which are reductions of 30% for total aliphatics and
10% for total aromatics. The 30% reduction in total aliphatics
(including all resolvable and non-resolvable but GC-detectable
aliphatics) is approximately equivalent to an 80% reduction in total
GC/MS-resolvable target n-alkanes, based on Canadian data. The 10%
reduction in total aromatics is approximately equivalent to a 50%
reduction of the 5-aromatic homologue group consisting of naphthalene,
fluorene, dibenzothiophene, phenanthrene, and chrysene and their
alkylated homologs. The U.S. aromatic series includes 2 other 4-ring
aromatics in addition to those 5 aromatic series considered by
Blenkinsopp et al.\58\ Thus, the U.S. and Canadian protocols are
similar in terms of decision criteria. The Agency requests comments on
all the proposed changes and listing thresholds.
---------------------------------------------------------------------------

    \58\ Blenkinsopp, S, G Sergy, Z Wang, MF Fingas, J Foght and DWS
Westlake. 1995. Oil spill bioremediation agents-Canadian efficacy
test protocols. Proceedings of the 1995 International Oil Spill
Conference, Feb 27-March 2, Long Beach, CA. American Petroleum
Institute, Washington, DC. pp. 91-96.
---------------------------------------------------------------------------

(2) Bioremediation Agent Toxicity
    Current Requirements: The Agency currently has no bioremediation
agent toxicity testing requirements for purposes of listing these
agents on the Schedule. Section 5 of Appendix C is reserved for this
purpose. The Agency has, however, on a case-by-case basis, requested
manufacturers to test bioremediation agents for toxicity if the product
contains surfactants or other ingredients that may be harmful to the
environment.
    Proposed Revisions: The Agency is proposing an acute toxicity
testing protocol for bioremediation agents to include both fresh and
saltwater. The Agency will use these testing results to determine
listing eligibility on the Schedule. The proposed testing protocols for
bioremediation agents are detailed in Appendix C. The proposed acute
toxicity test protocol for bioremediation agents is based on EPA's
protocol, Methods for Measuring the Acute Toxicity of Effluents and
Receiving Waters for Freshwater and Marine Organisms. The Agency
proposes to require bioremediation agents be tested for acute toxicity
for the product alone using fresh water species Ceriodaphnia dubia and
Pimephales promelas, and saltwater species Americamysis bahia and
Menidia beryllina. The concentration of test product causing 50%
lethality to the test organisms (LC50) lower and upper 95%
confidence intervals (LCI95 and ULCI95) are
calculated at the end of the exposure period. To be listed on the
Schedule, bioremediation agents must demonstrate an acute lethal
concentration for 50% of the test species (LC50) at the
lower 95% confidence interval greater than 10 ppm in either fresh or
salt water, consistent with the acute toxicity thresholds proposed for
dispersants. EPA's toxicity classification scheme \59\ classifies
LC50 values ranging from 10 ppm to 100 ppm as slightly
toxic, and values above 100 ppm substances are considered practically
nontoxic to aquatic organisms. By proposing this threshold level the
Agency is establishing an adequate safety margin without being overly
restrictive. The Agency requests comments on the proposed acute
toxicity methods (or any others available) and thresholds for
bioremediation agents.
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    \59\ USEPA 2010. http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysiseco.htm#Ecotox.
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    Similarly to surface washing agents, the Agency is not proposing
provisions for conducting acute toxicity tests with bioremediation
agent-oil mixtures. The Agency is requesting comment on the need for
acute toxicity tests conducted with bioremediation agents-reference oil
mixtures. A protocol for preparation of product/oil mixtures for
toxicity testing is available for review in the docket.
(3) Listing of Non-Proprietary Nutrients
    The Agency recognizes there may be oil discharge situations where
it is determined that the addition of nutrients in the form of salts of
nitrogen, phosphorus and potassium (i.e., fertilizers) to stimulate or
enhance bioremediation may be the most effective and environmentally
favorable mitigation method. However, non-proprietary commercially
available formulations of nutrients are not specifically listed on the
Schedule, even though as nutrient additives they are subject to Subpart
J requirements. Currently, an OSC may only authorize the use of an
agent not listed on the Schedule when its use is necessary to prevent
or substantially reduce a hazard to human life. Further, RRTs are not
currently able to preauthorize the use of nutrients unless they are
listed on the Schedule. To address these concerns, the Agency proposes
to include on the Schedule a specific list of the following generic
non-proprietary nutrients: Ammonium nitrate, ammonium phosphate, sodium
nitrate, potassium nitrate, urea, sodium triphosphate (or
tripolyphosphate), sodium phosphate, potassium phosphate (mono- or
dibasic), triple super phosphate, or any combination thereof. For these
non-proprietary commercial nutrients, the Agency believes there is no
need for submission of readily available

information. Thus, the proposal requires no technical product data or
further action on the part of a manufacturer prior to authorizing their
use in response to a discharge event. However, this listing will be
limited to products commonly formulated entirely of those mineral
nutrients and synthetically-derived urea listed. For products that may
contain additional proprietary components or have unique proprietary
formulations, the requirement for the submitter to provide the toxicity
and efficacy data under the bioremediation agent category will apply.
    The Agency considered proposing a definition of ``fertilizer'' to
specifically capture the listed bioremediation agents proposed to be
exempted. However, fertilizer is a term commonly used to describe
organic nutrients, which may contain substances that do not play a role
in mitigating oil discharges, and that may have deleterious effects on
the environment. Some non-proprietary fertilizers, for example,
comprised of activated sewage sludge or manure, could contain unwanted
pathogens and trace metals that could further stress the environment if
used in response to an oil discharge. Thus, instead of an exemption
based on a fertilizer definition, EPA proposes to restrict the
exemption under the bioremediation category only to those nutrients
listed above in order to avoid any confusion. The Agency requests
comments on this approach.
(e) Solidifier Testing and Listing Requirements
    The proposal defines solidifiers as substances that cause oil to
become a coherent mass, preventing oil from dissolving or dispersing
into the water column, and which are collected and recovered from the
environment. For this agent category, the Agency proposes to revise the
toxicity testing protocol and to establish a listing threshold for
toxicity in Sec.  300.915(e). Although solidifiers are intended to be
removed from the environment, the proposed revisions and new toxicity
listing threshold respond to concerns regarding the general increase in
the use of chemical and biological agents as tools available for oil
discharge responses.
(1) Solidifier Efficacy
    There are currently no efficacy testing requirements in the NCP
Subpart J for solidifiers to determine listing eligibility on the
Schedule. These agents would have been captured by the current MOSCA
agent category, which currently has no efficacy testing requirements,
and which the Agency is proposing to eliminate. While the Agency is
aware of existing protocols to determine the effectiveness of
solidifiers, its focus has been on reviewing the protocols for
dispersants and bioremediation agents, given that their specific
process for affecting the oil allows them to be left in the
environment, whereas solidifiers are intended for removal from the
environment. Therefore, the Agency is not proposing an efficacy testing
methodology for solidifiers, but is requesting comment on available
methodologies and/or performance criteria (e.g., buoyancy) it can
consider.
(2) Solidifier Toxicity
    Current Requirements: The current NCP Subpart J requires
solidifiers to be tested for saltwater species toxicity. Solidifier
toxicity is tested following the dispersant toxicity testing protocols
in Appendix C to part 300 of the NCP.
    Proposed Revisions: The proposal revises the toxicity testing
requirements for solidifiers, including the testing protocol. While the
Agency currently provides the toxicity testing results to the OSC to
assist in authorization of use determinations, it is proposing to use
these results to determine listing eligibility on the Schedule.
    The proposed revisions to the testing protocols for solidifiers are
detailed in Appendix C to part 300. The proposed acute toxicity test
protocol for solidifiers is based on EPA's protocol, Methods for
Measuring the Acute Toxicity of Effluents and Receiving Waters for
Freshwater and Marine Organisms. The Agency proposes to require
solidifiers be tested for acute toxicity for the product alone using
fresh water species Ceriodaphnia dubia and Pimephales promelas, or
saltwater species Americamysis bahia and Menidia beryllina, or both,
depending on the intended product use. The concentration of test
product causing 50% lethality to the test organisms (LC50)
and lower and upper 95% confidence intervals (LCI95 and
ULCI95) are calculated at the end of the exposure period. To
be listed on the Schedule, solidifiers must demonstrate an acute lethal
concentration for 50% of the test species (LC50) at the
lower 95% confidence interval greater than 10 ppm in either fresh or
salt water, consistent with the acute toxicity thresholds proposed for
dispersants. EPA's toxicity classification scheme \60\ considers
LC50 values ranging from 10 ppm to 100 ppm as slightly toxic
and values above 100 ppm substances practically nontoxic to aquatic
organisms. By proposing this threshold level, the Agency is
establishing an adequate safety margin without being overly
restrictive. The Agency requests comments on the proposed acute
toxicity methods (or any others available) and thresholds for
solidifiers.
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    \60\ USEPA 2010. http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysis_eco.htm#Ecotox.
---------------------------------------------------------------------------

    Similarly to surface washing agents, the Agency is not proposing
provisions for conducting acute toxicity tests with solidifiers-oil
mixtures. The Agency is requesting comment on the need for acute
toxicity tests conducted with solidifiers-reference oil mixtures. A
protocol for preparation of product/oil mixtures for toxicity testing
is available for review in the docket.
(3) Limitations
    The Agency is proposing a conditional use listing for solidifiers.
The proposal specifies that the listing of these products is limited to
use only in those water environments for which the product was tested
and for which it met the listing threshold criteria. The Agency
recognizes that products may yield effective results in certain
environments and not in others. Products that may be effective in
freshwater may not necessarily be so in saltwater, and vice versa. The
Agency is proposing this limitation to allow product manufacturers the
flexibility to select which environment the product is to be tested and
could be authorized for use, either saltwater, fresh water, or both.
Therefore, the product would be listed and may only be authorized for
use in those water environments for which it was tested and for which
it met the listing criteria.
(f) Herding Agent Testing and Listing Requirements
    The proposal defines herding agents as substances that are used to
control the spreading of oil across the water surface. For this agent
category, the Agency proposes to revise the toxicity testing protocol
and to establish a listing threshold for toxicity in Sec.  300.915(f).
While these agents are intended to be removed from the environment, the
proposed revisions and new toxicity listing threshold respond to
concerns regarding the general increase in the use of chemical and
biological agents as tools available for oil discharge responses.
    Currently, there is a test requirement for distinguishing surface
collecting agents from other chemical agents (Sec.  300.915(c)(9), Test
to Distinguish Between Surface Collecting Agents and Other Chemical
Agents). Because the proposal eliminates surface collecting agents as a
category and redefines herding agents to better reflect its specific
process for affecting the oil, and

given that the agents will need to be identified in order for the
required testing to be submitted, the Agency is eliminating this
requirement.
(1) Herding Agent Efficacy
    There are currently no efficacy testing requirements in the NCP
Subpart J for herding agents to determine listing eligibility on the
Schedule. These agents would have been captured by the current surface
collecting agent category, which currently has no efficacy testing
requirements, and which the proposal eliminates. The Agency is not
proposing an efficacy testing methodology for herding agents, but is
requesting comment on available methodologies and/or performance
criteria it can consider.
(2) Herding Agent Toxicity
    Current Requirements: The current NCP Subpart J requires herding
agents to be tested for saltwater species toxicity. Herding agent
toxicity is tested following the dispersant toxicity testing protocols
in Appendix C to part 300 of the NCP.
    Proposed Revisions: The proposal revises the toxicity testing
requirements for herding agents, including the testing protocol. While
the Agency currently provides the toxicity testing results to the OSC
to assist in authorization of use determinations, we are proposing to
use these results to determine listing eligibility on the Schedule.
    The proposed revisions to the testing protocols for herding agents
follow the same procedures as described for surface washing agents and
are detailed in Appendix C to part 300. The acute toxicity test
protocol for herding agents is based on EPA's protocol, Methods for
Measuring the Acute Toxicity of Effluents and Receiving Waters for
Freshwater and Marine Organisms. The Agency proposes to require herding
agents to be tested for acute toxicity for the product alone using
fresh water species Ceriodaphnia dubia and Pimephales promelas, or
saltwater species Americamysis bahia and Menidia beryllina, or both,
depending on the intended product use. The concentration of test
product causing 50% lethality to the test organisms (LC50) and lower
and upper 95% confidence intervals (LCI95 and ULCI95) are calculated at
the end of the exposure period. To be listed on the Schedule, herding
agents must demonstrate an acute lethal concentration for 50% of the
test species (LC50) at the lower 95% confidence interval
greater than 10 ppm in either fresh or salt water, consistent with the
acute toxicity thresholds proposed for dispersants. EPA's toxicity
classification scheme \61\ considers LC50 values ranging
from 10 ppm to 100 ppm as slightly toxic and values above 100 ppm
substances practically nontoxic to aquatic organisms. By proposing this
threshold level, the Agency is establishing an adequate safety margin
without being overly restrictive. The Agency requests comments on the
proposed acute toxicity methods (or any others available) and
thresholds for herding agents.
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    \61\ USEPA 2010. http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysis_eco.htm#Ecotox.
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    Herding agents form a monolayer of surfactants on the water surface
that result in the contraction of the oil slick.62 63
Herding agent composition may include hydrocarbons, fluorosurfactants
and/or silicone-based surfactants, which suggests that a stock solution
prepared using a WAF procedure similar to solidifiers may be
appropriate. The Agency is requesting comment on the procedure for
preparing the stock solution for herding agents for the acute toxicity
tests proposed in Appendix C. Any alternative procedure for preparing
the stock solution must include an appropriate rationale in order for
the Agency to be able to consider it for final action.
---------------------------------------------------------------------------

    \62\ Buist, I., Potter, S., Nedwed, T., (2011) Herding Agents to
Thicken Oil Spills in Drift Ice for In Situ Burning: New
Developments, IOSC, http://ioscproceedings.org/doi/abs/10.7901/2169-3358-2011-1-230.
    \63\ Buist, I., Nedwed, T., (2011) Using Herders for Rapid In
Situ Burning Of Oil Spills on Open Water, IOSC, http://ioscproceedings.org/doi/abs/10.7901/2169-3358-2011-1-231.
---------------------------------------------------------------------------

    Similarly to surface washing agents, the Agency is not proposing
provisions for conducting acute toxicity tests with herding agents-oil
mixtures. The Agency is requesting comment on the need for acute
toxicity tests conducted with herding agents-reference oil mixtures. A
protocol for preparation of product/oil mixtures for toxicity testing
is available for review in the docket.
(3) Limitations
    The Agency is proposing a conditional use listing for herding
agents. The proposal specifies that these products may only be used in
those water environments for which the product was tested and for which
it met the listing threshold criteria. The Agency recognizes that
products may yield effective results in certain environments and not in
others. Products that may be effective in freshwater may not
necessarily be so in saltwater, and vice versa. The Agency is proposing
this limitation to allow product manufacturers the flexibility to
select which environment the product is to be tested and could be
authorized for use, either saltwater, fresh water, or both. Therefore,
the product would be listed and may only be authorized for use in those
water environments for which it was tested and for which it met the
listing criteria.
(g) Sorbent Requirements
    The proposal defines sorbents as inert, insoluble substances that
readily absorb and/or adsorb oil or hazardous substances. Sorbents
would exclude those contaminated with substances that would interact
with the environment beyond their absorption/adsorption capabilities
(e.g., an invasive species). The proposed definition states that
sorbents are generally collected and removed from the environment and
may be used in their natural bulk form, or as manufactured products in
particulate form, sheets, rolls, pillows, or booms. The list of sorbent