[Federal Register Volume 63, Number 82 (Wednesday, April 29, 1998)]
[Notices]
[Pages 23438-23444]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10840]
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ENVIRONMENTAL PROTECTION AGENCY
[PF-803; FRL-5783-4]
Notice of Filing of Pesticide Petitions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice announces the initial filing of pesticide
petitions proposing the establishment of
[[Page 23439]]
regulations for residues of certain pesticide chemicals in or on
various food commodities.
DATES: Comments, identified by the docket control number PF-803, must
be received on or before May 29, 1998.
ADDRESSES: By mail submit written comments to: Public Information and
Records Integrity Branch, Information Resources and Services Division
(7502C), Office of Pesticides Programs, Environmental Protection
Agency, 401 M St., SW., Washington, DC 20460. In person bring comments
to: Rm. 1132, CM #2, 1921 Jefferson Davis Highway, Arlington, VA.
Comments and data may also be submitted electronically by following
the instructions under ``SUPPLEMENTARY INFORMATION.'' No confidential
business information should be submitted through e-mail.
Information submitted as a comment concerning this document may be
claimed confidential by marking any part or all of that information as
``Confidential Business Information'' (CBI). CBI should not be
submitted through e-mail. Information marked as CBI will not be
disclosed except in accordance with procedures set forth in 40 CFR part
2. A copy of the comment that does not contain CBI must be submitted
for inclusion in the public record. Information not marked confidential
may be disclosed publicly by EPA without prior notice. All written
comments will be available for public inspection in Rm. 1132 at the
address given above, from 8:30 a.m. to 4 p.m., Monday through Friday,
excluding legal holidays.
FOR FURTHER INFORMATION CONTACT: The product manager listed in the
table below:
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Office location/
Product Manager telephone number Address
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Bipin Gandhi (PM-5)........... Rm. 4W53, CS #1, 703- 1921 Jefferson
308-8380, e- Davis Hwy,
mail:[email protected] Arlington, VA
mail.epa.gov.
Indira Gairola................ Rm. 4W57, CS #1, 703- Do.
308-8371, e-mail:
gairola.indira@epamai.
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SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions as
follows proposing the establishment and/or amendment of regulations for
residues of certain pesticide chemicals in or on various food
commodities under section 408 of the Federal Food, Drug, and Comestic
Act (FFDCA), 21 U.S.C. 346a. EPA has determined that these petitions
contain data or information regarding the elements set forth in section
408(d)(2); however, EPA has not fully evaluated the sufficiency of the
submitted data at this time or whether the data supports granting of
the petition. Additional data may be needed before EPA rules on the
petition.
The official record for this notice of filing, as well as the
public version, has been established for this notice of filing under
docket control number [PF-803] (including comments and data submitted
electronically as described below). A public version of this record,
including printed, paper versions of electronic comments, which does
not include any information claimed as CBI, is available for inspection
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal
holidays. The official record is located at the address in
``ADDRESSES'' at the beginning of this document.
Electronic comments can be sent directly to EPA at:
opp-docket@epamail.epa.gov
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption. Comment and data
will also be accepted on disks in Wordperfect 5.1 file format or ASCII
file format. All comments and data in electronic form must be
identified by the docket number (PF-803) and appropriate petition
number. Electronic comments on notice may be filed online at many
Federal Depository Libraries.
List of Subjects
Environmental protection, Agricultural commodities, Food additives,
Feed additives, Pesticides and pests, Reporting and recordkeeping
requirements.
Dated: April 13, 1998
Susan Lewis,
Acting Director, Registration Division, Office of Pesticide Programs.
Summaries of Petitions
Petitioner summaries of the pesticide petitions are printed below
as required by section 408(d)(3) of the FFDCA. The summaries of the
petitions were prepared by the petitioners and represent the views of
the petitioners. EPA is publishing the petition summaries verbatim
without editing them in any way. The petition summary announces the
availability of a description of the analytical methods available to
EPA for the detection and measurement of the pesticide chemical
residues or an explanation of why no such method is needed.
1. BFGoodrich Specialty Chemicals
PP 8E4958, 8E4961, 8E4962
EPA has received a pesticide petition (PP 8E4958,8E4961,8E4962)
from BFGoodrich Specialty Chemicals, 9911 Brecksville Road, Cleveland,
OH 44141, proposing pursuant to section 408(d) of the Federal Food,
Drug and Cosmetic Act, 21 U.S.C. 346a(d), to amend 40 CFR part 180 to
establish an exemption from the requirement of a tolerance for acrylic
acid terpolymer, partial sodium salt in or on raw agricultural
commodities when used as inert ingredients in the pesticide
formulations applied to growing crops, raw agricultural commodities
after harvest or to animals, under 40 CFR 180.1001(c) and (e). EPA has
determined that the petition contains data or information regarding the
elements set forth in section 408(d)(2) of the FFDCA; however, EPA has
not fully evaluated the sufficiency of the submitted data at this time
or whether the data supports granting of the petition. Additional data
may be needed before EPA rules on the petition.
A. Toxicological Profile
The Acrylate Terpolymers Good-RiteK-781,K-797, and K-798
conform to the definition of polymer given in 40 CFR 723.250(b) and
meets the following criteria that are used to identify low risk
polymers:
1. The Acrylate Terpolymers are not cationic polymers, nor are they
reasonably anticipated to become cationic polymers in a natural aquatic
environment.
2. The Acrylate Terpolymers contain as an integral part of their
composition the atomic elements carbon, hydrogen, oxygen, sulfur and
nitrogen. It also contains the monatomic counterion Na+.
3. The Acrylate Terpolymers do not contain as an integral part of
their composition, except as impurities, any elements other than those
listed in 40 CFR 723.250(d)(2)(ii).
4. The Acrylate Terpolymers are not designed, nor are they
reasonably anticipated to substantially degrade, decompose, or
depolymerize.
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5. The Acrylate Terpolymers are not manufactured or imported from
monomers and/or other reactants that are not already included on the
Toxic Substances Control Act (TSCA) Chemical Substance Inventory or
manufactured under an applicable TSCA Section 5 exemption.
6. The Acrylate Terpolymers are not water absorbing polymers.
7. The only reactive functional groups the Acrylate Terpolymers
contain is a carboxylic acid.
8. The Acrylate Terpolymers have a number average molecular weight
greater than 1,000 and less than 10,000 Daltons (and oligomer content
less than 10 percent below MW 500 and less than 25 percent below MW
1,000).
B. Aggregate Exposure
In the past decade Acrylate copolymers and terpolymers have been
used in a variety of applications, most notably water treatment
including boiler and retort waters, cooling waters, membrane
separations systems and are now de rigor in these applications. In
these and similar applications, reasonable levels of incidental
exposure to the neat polymer is expected and accepted without regard.
ANSI/NSF Standard 60 Drinking Water Treatment Chemical Additives
listing has been extended to similar acrylate co-and ter-polymers. The
chemical characteristics of these polymers and the published health and
safety data indicates that aggregate exposure to Acrylate terpolymers,
as listed in the current petitions, as inert ingredients in the
preparation and application of pesticide formulations for use on
growing crops, raw agricultural commodities after harvest or to animals
poses no harm.
C. Cumulative Effects
At this time there is no information to indicate that any toxic
effects produced by the Acrylate terpolymers would be cumulative with
those of any other chemical. Given the terpolymers' categorization as
``low risk polymers'' (40 CFR 723.250) and their proposed use an inert
ingredients in pesticide formulations, there is no reasonable
expectations of increased risk due to cumulative exposure to the
Acrylate terpolymers.
D. International Tolerances
BFGoodrich is petitioning that the Acrylate terpolymers be exempt
from the requirement of a tolerance based upon their status as low risk
polymers as per 40 CFR 723.250. Therefore, an analytical method to
determine residues of the Acrylate terpolymers in raw agricultural
commodities treated with pesticide forumlations containing the Acrylate
terpolymers has not been proposed.
There are no Codex maximum residue levels(MRLs) established for the
Acrylate terpolymers. (Bipin Gandhi)
2. Platte Chemical Company
PP 6E4742
EPA has received a pesticide petition (PP 6E4742) from Platte
Chemical Company, 419 18th Street, P.O. Box 667, Greeley, CO 80632,
proposing pursuant to section 408(d) of the Federal Food, Drug and
Cosmetic Act, 21 U.S.C. 346a(d), to amend 40 CFR part 80 to establish
an exemption from the requirement of a tolerance for residues of the
inert ingredient Modal Alder Bark (MAB) alder bark flour (ABF) when
used in pesticide formulations applied to growing crops, or in or on
raw agricultural commodities after harvest. EPA has determined that the
petition contains data or information regarding the elements set forth
in section 408(d)(2) of the FFDCA; however, EPA has not fully evaluated
the sufficiency of the submitted data at this time or whether the data
supports granting of the petition. Additional data may be needed before
EPA rules on the petition.
A. Residue Chemistry
1. Plant metabolism. MAB is not absorbed or metabolized by plants.
The ABF remains on the treated surface, where it decomposes to its
natural constituents including, cellulose, hemicelluloses, lignin and
various compounds such as suberins and phenolic acids. These
decomposition products are further degraded by various bacteria and
fungi to simple sugars, carbohydrates, gases and other molecular
compounds. Eventually ABF will be completely decomposed by natural
processes to nutrients which can be utilized by other plants.
2. Analytical method. No analytical method is available for
determining MAB, per se. Although various methods are available to
determine the various components of alder bark (e.g., content of
cellulose, lignin, polysaccharides, etc.), these methods are not
specific to MAB and can not distinguish whether the components are
derived from ABF or from other plant or soil sources.
3. Magnitude of residues. Since ABF is not absorbed or metabolized
by plants, no residues of MAB are expected to result in or on raw
agricultural commodities. For example, potato commodities grown from
seed potato pieces treated with formulations containing MAB do not have
residues of the inert ingredient. Furthermore, any residues would be
associated with the potato seed pieces, which shrivel as the daughter
plants withdraw nutrients during ``seedling''growth. Consequently, the
spent seed pieces are not harvested and will not be eaten. Finally, any
MAB adhering to the harvested potatoes would be removed by brushing and
washing.
B. Toxicological Profile
1. Acute toxicity. The use of MAB (ABF) as an inert ingredient in
pesticide formulations is not expected to result in adverse effects due
to its non-hazardous character, minimal potential for exposure, and
projected absence of dietary exposure. There is a wealth of available
information about the absence of, or minor health effects from,
exposure to various wood flours, dusts, shavings, and other wood/bark
components. Ingestion of wood flour, sawdust or wood shavings is
neither lethal, nor toxic, and is even considered to be a source of
non-nutritive dietary fiber. Dermal contact with wood or bark flour is
not associated with death or toxicity, although dermal allergies
(contact dermatitis) have been reported in certain sensitive
individuals. Acute inhalation exposure to wood dusts for a limited time
is not considered to be an occupational hazard if dust levels are below
established Permissible Exposure Levels (PEL) for non-toxic particulate
matter (i.e., unspecified dust particles). MAB is not expected to
produce any more eye irritation than any chemically inert particulate,
such as clay or wheat flour. In persons who may have a specific alder
wood allergy, eye irritation or conjunctivitis is possible even though
there are no known reports of such incidences. Alder wood dust is not a
sensitizer nor is ABF expected to be a sensitizer.
2. Genotoxicity. Evidence from studies with wood-related compounds
indicate that MAB is not genotoxic. ABF is composed mostly of
cellulose, hemicelluloses and lignins, which are not mutagenic.
3. Reproductive and developmental toxicity. MAB is not expected to
be a developmental or reproductive toxin, based on extensive testing of
the three principle components (cellulose, hemicelluloses and lignins)
of ABF. Additionally, wood flours have been used for numerous years to
increase dietary fiber in animal feeds and human diets with no known
adverse reproductive or developmental toxicity.
4. Subchronic toxicity. There is no subchronic exposure to MAB from
its use as a pesticidally inert ingredient. However, chronic toxicity
data adequately address possible
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toxicological effects that may result from subchronic exposure to ABF.
5. Chronic toxicity. There is minimal-to-no chronic toxicological
risk from the use of MAB as an inert ingredient in pesticide
formulations. There are no known adverse reactions to chronic
consumption or ingestion of wood flour. Ingestion of wood flour,
sawdust or wood shavings for extended periods of time is not hazardous.
Instead, it is considered to be a non-nutritive dietary supplement. In
fact, the Food and Drug Administration (FDA) has allowed the use of
wood flours in various prepared foods, such as bread, to increase
dietary fiber levels and reduce caloric intake.
Adverse effects of exposure to wood dust are limited to allergic
reactions, such as rhinitis and contact dermatitis, and from chronic
(lifetime) occupational exposure (via inhalation) to high
concentrations of wood dust. Based on the absence of chronic effects
from ingestion, the limited irritant and allergic effects from dermal
contact, limited exposure to ABF from seed potato treatment, and the
absence of chronic exposure by any route, Platte Chemical Company
concludes that there is minimal-to-no chronic toxicological risk from
the use of MAB in pesticide products.
6. Animal metabolism. There is no known human metabolism or
metabolic products from human ingestion of non-nutritive dietary fiber
from wood products. In humans, the polymers of plants such as cellulose
from plant cell walls (linkages), some pectins, hemicellulose, gums,
mucilages and lignin, are not easily digested and are passed through
the gastrointestinal tract as non-nutritive dietary fiber. Wood flour
and sawdust are commonly used in animal feeds. In ruminants, such wood
products are reduced to cellulose, hemicelluloses and lignins by
endogenous bacterial/microbial populations in the gut. These wood
product degradates are further reduced to simple sugars, carbohydrates,
carbon dioxide and indigestible biomass. The indigestible biomass is
readily excreted.
7. Metabolite toxicology. There is no known evidence of metabolite
toxicity from the ingestion of wood or ABF by either livestock or
humans. In humans, no metabolites are produced after ingestion of non-
nutritive dietary fiber such as ABF.
8. Endocrine disruption. No endocrine or estrogenic effects are
expected from the use of MAB for the following reasons:
i. The production of MAB includes oven drying the bark, which
removes moisture and volatile organic compounds.
ii. ABF does not penetrate and will not be absorbed by skin.
iii. Alder bark is primarily composed of naturally-occurring, non-
digestible cellulose, hemicelluloses and lignin; and most importantly.
iv. There is no non-occupational exposure to MAB when used as a
pesticidally inert ingredient.
C. Aggregate Exposure
1. Dietary exposure. Ingestion of MAB or its residues would simply
increase the level of non-nutritive fiber in the diet, which has been
shown to have beneficial health effects by reducing the incidence of
diverticulosis, cancer of the colon and coronary heart disease as well
as facilitating weight loss. Also, health claims for fiber-containing
foods have been made for more than a century and the effects of fiber
in promoting bowel evacuation are widely recognized.
2. Food. The use of MAB in potato seed piece pesticides does not
result in any significant dietary exposure to ABF. Residues, if any,
surround the potato seed pieces, which shrivel as the daughter plants
withdraw nutrients during ``seedling'' growth. Consequentially, the
spent seed pieces are not harvested and will not be eaten. Brushing and
washing potatoes to remove particulates, such as soil, would
simultaneously remove any residues of MAB. However, should ABF residues
adhere to harvested potatoes, the only effect would be to increase the
level of non-nutritive dietary fiber. Were this to be the case,
ingestion of MAB residues would be beneficial and of no toxicological
concern since MAB can be considered to be a non-nutritive source of
dietary fiber, which has been shown to improve health and lessen the
incidence of diverticulosis, colon cancer and coronary heart disease.
3. Drinking water . The use of MAB as an inert ingredient in
pesticide formulations does not lead to alder bark particles in the
drinking water. Wood and bark particles do not leach into the
groundwater. Any particles that may be transported into water bodies
will absorb moisture and either sediment out of the water column or be
removed with other particulate matter during drinking water treatment.
Similarly, any natural water-extractable components (humic acids,
fulvic acids, etc.) of MAB are natural products that will also be
removed during drinking water treatment.
4. Non-dietary exposure. The only anticipated human exposure to MAB
from non-dietary sources would be through occupational exposure during
product use.
D. Cumulative Effects
The use of MAB as an inert ingredient in pesticide formulations
does not result in any cumulative effects, since there is no non-
occupational exposure to MAB.
E. Safety Determination
1. U.S. population. The use of MAB does not pose a safety concern
for the US human population due to the non-toxic nature of ABF (oral,
dermal and acute exposure) and the absence of non-occupational
exposure.
2. Infants and children. Infants and children are not exposed to
MAB from its use in pesticide formulations or the treatment of potato
seed pieces.
F. International Tolerances
No international tolerances have been established for ABF, wood
flour or wood cellulose.
3. Wheelabrator Water Technologies, Inc.
PP 6E4732
EPA has received a pesticide petition (PP 6E4732) from Wheelabrator
Water Technologies, Inc., 8201 Eastern Boulevard, Baltimore, Maryland
21224. proposing pursuant to section 408(d) of the Federal Food, Drug
and Cosmetic Act, 21 U.S.C. 346a(d), to amend 40 CFR part 180 to
establish an exemption from the requirement of a tolerance for
biosolids in or on the raw agricultural commodity Granulite. EPA has
determined that the petition contains data or information regarding the
elements set forth in section 408(d)(2) of the FFDCA; however, EPA has
not fully evaluated the sufficiency of the submitted data at this time
or whether the data supports granting of the petition. Additional data
may be needed before EPA rules on the petition.
A. Residue Chemistry
1. Residues in the raw agricultural commodity and processed food/
feed. A tolerance for substances potentially present in biosolids for
raw or processed foods is not anticipated to be needed, based on the
very low risk posed by residues in raw food/feed, as discussed
throughout this application for a tolerance exemption for Granulite
heat-dried biosolids.
2. Background information and use profile. Granulite is a heat-
dried biosolids (sewage sludge) product. Biosolids are the solid, semi-
solid, or liquid residue generated from domestic wastewater treatment,
and have been used for centuries as a soil conditioner and fertilizer.
Regulations regarding the use and disposal of biosolids have been
introduced over the years to protect
[[Page 23442]]
human health and the environment, culminating in the 40 CFR part 503
rule promulgated in 1992, which regulates biosolids based on a
comprehensive risk assessment consucted by EPA. This rule has since
undergone relatively minor revisions, including the deletion of
chromium from the regulation; changes to the limits for molybdenum and
selenium; and a narrowing of a focus of future biosolids rulemaking to
dioxins/furans and polychlorinated biphenyls (PCBs). Land application
of biosolids enhances soil conditions and plant growth on agricultural,
forest, reclaimed, and public use (e.g., recreational, highway) lands.
Over 5 million dry metric tons of biosolids are generated annually in
the U.S. at publicly owned treatment works. A minimum of 33% of the
biosolids generated annually are land applied (this percentage has
probably increased significantly in recent years), while the remaining
are incinerated or disposed of using surface disposal. Of the biosolids
that are land applied, an estimated 67% are applies to agricultural
lands, 3% to forests, 9% to reclamation sites, and 9% to public use
sites. Biosolids are land applied by either incorporating or injecting
the biosolids into the soil or spreading the biosolids on the soil
surface.
B. Toxicological Profile
EPA has determined that the limits for inorganic pollutants
(metals) calculated in the EPA biosolids risk assessment protect humans
(including children), animals, and plants from reasonably anticipated
adverse effects via the 14 different exposure pathways evaluated. The
40 CFR part 503 rule regulates metals based on these risk assessment
limits, and regulates pathogens based on an operational standard
requiring certain pathogen and vector controls that reduce pathogens to
low levels (as described in ``Safety Determination: U.S. General
Population'' below). For biosolids that meet the most stringent
pollutant limits and pathogen controls of part 503, as Granulite does,
only minimal additional part 503 requirements need to be met because of
the low risk associated with these biosolids, which therefore are
allowed to be used as freely as any other soil conditioner. Research
indicates that risks associated with the bioavailability of metals in
biosolids are low when biosolids are land applied at rates commonly
used in agriculture and when good management practices commonly
implemented (e.g., soil pH above 5.0) are followed.
1. Acute toxicity. EPA initially submitted a list of 200 pollutants
potentially found in biosolids for review by a panel of experts; this
panel recommended that 50 of these pollutants be studies further, based
on avaliable toxicity and exposure data. EPA then developed hazard for
each of these 50 pollutants, derived by dividing a pollutant's
estimated concentration in soil, plant or animal tissue, or air by the
lowest concertration of the pollutants found in the scientific
literature to be toxic to the organism being evaluated via the most
sensetive route of exposure and dassuming maximum toxic effect. A
hazard index of less than 1 indicated that the pollutant was not toxic
to the organism (via that particular exposure pathway), and thus was
not analyzed further. EPA further evaluated pollutants with a hazard
index value of 1 or greater in the biosolids risk assestment (except
for pollutants deferred of deleted due to insufficient or limited
data). EPA also evaluated several additional pollutants based in the
addition of four exposure pathways. This process resulted in EPA
evaluating 23 pollutants in its biosolids risk assestment for land
application (see Table 1).
2. Reproductive and developmental toxicity. The ingestion of lead
by children, which is associated with developmental effects (e.g.,
learning disabilities), was addressed by the EPA biosolids risk
assessment in a conservative manner. EPA evaluated the risk to pica
children (children who regularly eat soil) because it is possible that
children might ingest soil to which biosolids has been land applied.
However, only a small number of children are likely to ingest biosolids
in gardens or lawns, especially on a regular basis, and thus this
evaluation is more conservative than dietary or drinking water
exposures. In addition to lead, limits for arsenic, cadmium, mercury,
and selenium are also included in the part 503 rule, based on a child
ingesting biosolids that potentially contain these pollutants.
Granulite meets all of these limits. For more details, see ``Safety
Determination: Infants and Children'' below.
3. Chronic toxicity. EPA's risk assessment for the land application
of biosolids included the evaluation of chronic effects based on RfDs
or RfCs for metals and organic substances potentially found in
biosolids. RDAs were used when RfDs were unavailable, or analogous no
adverse effect levels were used. Acceptable doses of a substance were
estimated for animals, using the most sensitive or most exposed
species. The RfDs, RfCs, or analogous levels were combined with other
variables to calculate the concentrations of pollutants in biosolids
that are reasonably protective against adverse impacts. For the
ingestion (dietary) pathways, RfDs were combined with a relative
effectiveness RE variable. The RE of exposure accounts for differences
in bioavailability depending on the route of exposure (e.g., ingestion
or inhalation); because of limited available data, the RE was
conservatively set at 1, which assumes 100% bioavailability intake, and
thus underestimates the allowable dose of biosolids pollutants and
reflects conservative pollutant limits. The pollutant concentrations
calculated in the risk assessment were used to develop the most
stringent limits in the 40 CFR part 503 rule, which Granulite meets.
4. Carcinogenicity. EPA's risk assessment for the land application
of biosolids included evaluation of carcinogenicity based on q1*s for
metals and organic substances potentially found in biosolids. The q1*s
were used with other variables to calculate the concentrations of
pollutants in biosolids that are reasonably protective against adverse
impacts; these calculated concentrations were used to develop the most
stringent pollutant limits in 40 CFR part 503 rule, which Granulite
meets. EPA also conducted a population-based risk assessment which
indicated that prior to the part 503 rule, biosolids use and disposal
practices (including land application, incineration, and surface
disposal) could have contributed 0.9 to 5 cancer cases annually; the
part 503 rule reduced cancer cases by 0.09 to 0.7 annually. This
analysis included exposure to pollutants potentially found in biosolids
from all sources, including food, drinking water, residential, and
other non-occupational sources.
5. Endocrine disruption. The EPA biosolids risk assessment
considered all adverse effects identified in the scientific literature,
including endocrine effects, if any, and used these to identify no
observed adverse effect levels (NOAEL) for the pollutants evaluated.
Future research may include additional impacts on wildlife due to
limited available field data. Although not specific to endocrine
effects, interactive (synergistic) effects observed with biosolids
reduce (rather than increase) adverse risks to potential receptors.
Interactions between certain elements typically found in biosolids
hinder the uptake of metals by plants and the bioavailability of metals
to animals and humans. See ``Cumulative Risk'' below for more
information on these interactive effects.
[[Page 23443]]
C. Aggregate Exposure
The 14 exposure pathways that EPA evaluated in its biosolids risk
assessment included: children ingesting biosolids/soil directly (the
pica child); adults ingesting plants grown in soils amended with
biosolids or drinking ground-water or surface-water containing
substances present in biosolids; adults ingesting fish from surface-
water containing substances in biosolids; adults ingesting animal
products derived from animals that ingested biosolids; animals
ingesting biosolids or plants grown in biosolids-amended soils; and
plants grown in biosolids-amended soils. Thus, the EPA risk assessment
for the land application of biosolids addressed exposures from dietary,
drinking water, and non-occupational sources. The most conservative
estimate from the 14 exposure pathways was then selected as the limit
for each of the pollutants potentially found in biosolids, thus
representing protection based on aggregate exposure. Granulite meets
these limits.
In addition, the EPA risk assessment calculations for all 14
pathways initially included pollutant exposure from sources other than
biosolids (food, air, and water). Exposures from sources other than
biosolids were then subtracted from the total allowable dose, yielding
a result that represented the allowable dose of a pollutant from
biosolids only. This value was then combined with other variables to
derive a pollutant limit.
1. Dietary exposure. Parameters for human, animal, or plant health
(e.g., based on RfDs, q1*s, etc., as described above in ``Chronic
Effects'' and (``Carcinogenicity'') were combined with pollutant intake
information (e.g., the amount of a particular food type consumed) to
derive pollutant limits in the EPA biosolids risk assessment. Several
pollutant limits were based on a dietary exposure pathway (for the
inorganic chemical molybdenum and for several organic chemicals).
However, the limits for molybdenum were re-evaluated and new limits are
expected to be less stringent, and limits for organics were not
included in the part 503 rule, as discussed in ``Other Considerations''
below. For other pollutants, exposure pathways other than dietary
exposure posed more risks, and pollutant limits were based on these
higher-risk pathways.
2. Drinking water. The part 503 rule requires that biosolids be
land applied at the agronomic rate (the rate that provides the amount
of nitrogen needed by a crop or vegetation to attain a desired yield
while minimizing the amount of nitrogen that will pass below the root
zone of the crop or vegetation to ground-water), thus protecting
ground-water from biosolids with nitrogen levels in excess of estimated
crop needs. In addition, for ground-water, the EPA risk assessment
analyzed the pathway involving: the land application of biosolids; the
leaching (mobility) of pollutants from soil into ground-water; and the
subsequent drinking of well water containing these pollutants by
humans. The ground-water pathway evaluation included: a mass balance
(between erosion, leaching, volatilization, and degradation
persistence); a reference water concentration (based on the q1* or
MCL); and use of the VADOFT (from RUSTIC) and the AT123D models. For
surface-water exposure, EPA analyzed the pathway involving: the land
application of biosolids; the erosion (mobility) of soil containing
pollutants in biosolids; the transfer of the pollutants contained in
the eroded soil to surface-water; and the ingestion of the surface-
water and fish living in the surface-water by humans. The surface-water
pathway evaluation included: a mass balance (as described above for
ground-water); a reference intake (based on the q1* or RfD); acute or
chronic freshwater criteria for aquatic life; a bioconcentration
factor; a food chain multiplier; and a dilution factor, among other
parameters. No pollutant limit was based on the ground-water pathway
because other exposure pathways resulted in more restrictive limits.
Only one pollutant limit, for DDT/DDD/DDE, was based on the surface-
water pathway; however, organics, including DDT, were deleted from part
503 regulation because they met at least one of three criteria set by
EPA (see ``Other Considerations'' below).
While metals potentially present in biosolids may be persistent,
they are bound in the biosolids-soil matrix for long periods of time,
as discussed in ``Environmental Fate Data Summary'' below. Also, the
dry characteristics of Granulite, which is heat-dried, minimize water
content and leachability of metals.
3. Non-dietary exposure. EPA's biosolids risk assessment evaluated
exposure to pollutants potentially found in biosolids that are land
applied to gardens, lawns, and other residential and non-occupational
settings in non-dietary pathways.
D. Cumulative Effects
Extensive field data used in EPA's risk assessment for biosolids
show no adverse effects of low levels of metals in land-applied
biosolids. Some metals are not transferred into edible plant parts
(even when their concentrations are greatly increased in the biosolids/
soil mixture) because these metals (e.g., chromium) are insoluble or
strongly bound to the biosolids-soil matrix (by iron or certain other
oxides, organic matter, or phosphates in biosolids) or to plant roots
(e.g., lead). Or, if other substances commonly found in biosolids, such
as zinc, calcium, and iron, are present, these substances will inhibit
absorption of some metals (e.g., selenium, molybdenum, and cadmium)
from the ingested food into the organism's intestines and blood stream.
Also, the EPA biosolids risk assessment included bioavailability and
bioaccumulation factors to account for uptake of pollutants by animals
(e.g., fish) and subsequently by humans.
E. Safety Determination
1. U.S. population. The EPA biosolids risk assessment as well as
field data show that certain biosolids that meet low pollutant limits
for metals can be considered NOAEL biosolids that have no observed
adverse effects on public health and the environment. Granulite meets
these limits. Human and animal health protection from pathogens are
addressed in the part 503 regulation through technology-based
requirements that minimize pathogen densities and reduce vector
attraction. Granulite meets the most stringent ``Class A'' part 503
requirements that pathogen densities be reduced to low levels.
2. Infants and children. For several of the metals evaluated in
EPA's biosolids risk assessment, the pollutant limit identified was
based on the exposure pathway for a pica child ingesting biosolids/
soil. These limits are conservative because they go beyond expected
dietary and drinking water exposures (i.e., a very small percentage of
children are expected to consume biosolids in gardens or on lawns).
Also, the limit for lead in biosolids in the part 503 regulation is 300
ppm, based on animal data. This number provides an additional margin of
safety for growing children because it is lower than the 500 ppm limit
for lead derived using EPA's Integrated Exposure Uptake Biokinetic
(IEUBK) model. In addition, animal (rat) studies show that the
bioavailability of lead in biosolids is 12-fold lower than that assumed
in the IEUBK model calculations used; thus the 300 ppm lead limit
provides even more of a margin of safety. The limits identified for the
other metals (arsenic, cadmium, mercury, and selenium) based on a child
ingesting biosolids/soil were calculated in algorithms developed
[[Page 23444]]
specifically for the EPA biosolids risk assessment. The most stringent
part 503 pollutant limits for metals in biosolids that are land applied
are based on these figures; Granulite meets these limits.
F. Other Considerations
Organic chemicals were evaluated in the EPA biosolids risk
assessment. However, the part 503 rule did not set limits for organic
chemicals because all the organic chemicals analyzed met one or more of
the following criteria:
i. The pollutant has been banned or restricted for use in the U.S.
or is no longer manufactured in the U.S.
ii. The pollutant is infrequently found in biosolids (e.g.,
detected less than 5% of the time).
iii. The limit for the pollutant identified in the EPA biosolids
risk assessment is not expected to be exceeded in biosolids that are
used or disposed.
iv. Nearly all of the organic chemicals evaluated met two or more
of these criteria.
G. Practical Analytical Method
Numerous analytical methods were used in the hundreds of research
studies on which the EPA risk assessment for the land application of
biosolids was based. Examples of analytical methods used for analyzing
metals concentrations in plant and animal tissue include atomic
absorption, X-ray fluorescence spectroscopy, and autoradiography.
H. List of All Pending Tolerances and Exemptions
The only known exemption from tolerance being proposed for
biosolids as an inert ingredient is this application, which is based on
the health and environmental protection identified in EPA's part 503
risk assessment for the land application of biosolids, as discussed
throughout this application.
I. Environmental Fate Data Summary
Studies have shown that metals are bound in the biosolids-soil
matrix over the long-term and that the binding properties of biosolids
are environmentally stable. The binding of metals by biosolids renders
the metals less bioavailable to plants, animals, and humans, and
studies have shown no adverse effects when biosolids containing metals
meeting the part 503 pollutant limits, which includes Granulite, are
land applied.
The EPA risk assessment for the land application of biosolids
included analysis of ecological risks through ground-water, surface-
water, plants, livestock, and wildlife (as well as to humans, including
children). Low risks were found to be associated with the ground-water
pathway and to wildlife, and thus pollutant limits for chemicals of
concern for these pathways or endpoints were based on other, more
restrictive risk assessment limits for other pathways/endpoints.
Granulite meets all of these limits. The one organic pollutant of
concern identified for the surface-water pathway was deleted from
regulation, as discussed in ``Other Considerations'' above.
J. International Tolerances
None known. Compatibility with any existing MRLs should be
possible, based on the low risk of adverse effects identified in EPA's
risk assessment for the land application of biosolids. (Bipin Gandhi)
[FR Doc. 98-10840 Filed 4-28-98; 8:45 am]
BILLING CODE 6560-50-F
