[Federal Register Volume 64, Number 3 (Wednesday, January 6, 1999)]
[Rules and Regulations]
[Pages 759-769]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-109]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300767; FRL-6049-2]
RIN 2070-AB78
Dicamba (3,6-dichloro-o-anisic acid); Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes, revises and revokes tolerances
for combined residues of Dicamba in or on various raw agricultural
commodities. BASF Corporation requested this tolerance under the
Federal Food, Drug and Cosmetic Act (FFDCA), as amended by the Food
Quality Protection Act of 1996 (Pub. L. 104-170).
DATES: This regulation is effective January 6, 1999. Objections and
requests for hearings must be received by EPA on or before March 8,
1999.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300767], must be submitted to: Hearing
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St.,
SW., Washington, DC 20460. Fees accompanying objections and hearing
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to:
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees),
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and
hearing requests filed with the Hearing Clerk identified by the docket
control number, [OPP-300767], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 119, Crystal
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1
file format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300767]. No Confidential Business Information (CBI) should
be submitted through e-mail. Electronic copies of objections and
hearing requests on this rule may be filed online at many Federal
Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Joanne I. Miller,
Registration Division (7505C), Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
Office location, telephone number, and e-mail address: Crystal Mall #2,
1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-6224, e-mail:
miller.joanne@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: In the Federal Register of November 20, 1998
(63 FR 64481)(FRL-6043-9), EPA issued a notice pursuant to section 408
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e)
announcing the filing of pesticide petitions (PP 6F4604, 4F3041 and FAP
4H5428) for tolerances by BASF Corporation. This notice included a
summary of the petitions prepared by BASF. There were no comments
received in response to the notice of filing.
These petitions requested that 40 CFR 180.40 CFR part 180.227 be
amended by establishing, revising and revoking tolerances for combined
residues of the herbicide dicamba (3,6-dichloro-o-anisic acid) and its
metabolites 3,6-dichloro-5-hydroxy-o-anisic acid and 3,6-dichloro-2-
hydroxybenzoic acid in or on the commodities listed in the summary of
this Final Rule
I. Risk Assessment and Statutory Findings
Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue. . . .''
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 and a complete description of
the risk assessment process, see the Final Rule on Bifenthrin Pesticide
Tolerances (62 FR 62961, November 26, 1997)(FRL-5754-7).
II. Aggregate Risk Assessment and Determination of Safety
Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant
[[Page 760]]
information in support of this action. EPA has sufficient data to
assess the hazards of Dicamba (3,6-dichloro-o-anisic acid) and to make
a determination on aggregate exposure, consistent with section
408(b)(2), for revising and establishing tolerances for combined
residues of Dicamba as described as follows:
1. Establishing new tolerances for residues of dicamba and its
metabolite 3,6-dichloro-5-hydroxy-o-anisic acid in or on: barley hay at
2 ppm, corn, field, forage at 3 ppm; corn, field, stover at 3 ppm,
corn, pop, stover at 3 ppm; cottonseed meal at 5 ppm; Crop Group 17
(grass forage, fodder, and hay) forage at 125 ppm and hay at 200 ppm;
oats forage at 80 ppm, oats hay at 20 ppm; wheat forage at 80 ppm,
wheat hay at 20 ppm.
2. Establishing new tolerances for residues of dicamba and its
metabolites 3,6-dichloro-2-hydroxybenzoic acid and 3,6-dichloro-5-
dichloro-5-hydroxy-o-anisic acid in or on aspirated grain fractions at
5100 ppm, and soybean hulls at 13 ppm.
3. Revising tolerances for residues of dicamba (3,6-dichloro-o-
anisic acid) and its metabolite 3,6-dichloro-5-hydroxy-o-anisic acid in
or on: barley grain to 6 ppm, barley straw at 15 ppm; cottonseed to 3
ppm; wheat grain to 2 ppm, wheat straw to 30 ppm.
4. Revising tolerances for residues of dicamba and its metabolite
3,6-dichloro-2-hydroxybenzoic acid in or on: asparagus to 4 ppm.
5. Revise tolerances for residues of dicamba and its metabolites
3,6-dichloro-2-hydroxybenzoic acid and 3,6-dichloro-5-hydroxy-o-anisic
acid in or on soybeans seed to 10 ppm, changing the name of the
commodity from soybean grain to soybean seed.
6. Revoking the following tolerances: grasses, hay at 40 ppm;
grasses, pasture at 40 ppm and grasses, rangeland at 40 ppm as these
tolerances are being replaced by Crop Group 17.
EPA's assessment of the dietary exposures and risks associated with
establishing the tolerance follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by Dicamba (3,6-
dichloro-o-anisic acid) are discussed below.
1. Acute toxicity. The following acute toxicity studies with
technical dicamba were submitted in support of this regulatory action:
\Acute oral in rats with an LD50 2,740 mg/kg
\Acute dermal in rabbits with an LD50 > 2,000 mg/kg
\Acute inhalation in rats with an LD50 > 5.3 mg/L
\Acute eye irritation in rabbits with mild to moderate eye
irritation
\Acute dermal irritation in rabbits with irritation
\Dermal Sensitization in guinea pigs with no dermal sensitization
The results from the eye irritation study and the dermal irritation
study placed technical in category II as an acute toxicant.
2. In a 13-week oral toxicity study, Charles River CD rats were
exposed to dicamba (86.8% a.i.) at 0, 5,000, 10,000, 12,500 or 15,000
ppm (approximately 500, 1,000, 1,250 or 1,500 mg/kg/day). At 10,000 ppm
and above, a reduction of cytoplasmic vacuolization of hepatocyte was
observed, along with slight decreases in body weight and food
consumption. The NOAEL = approximately 500 mg/kg/day, the LOAEL =
approximately 1,000 mg/kg/day based on body weight changes and liver
effects.
3. In a 21-day dermal study Dicamba was administered to New Zealand
white rabbits (5/sex/group) at levels of 0, 40, 200, or 1,000 mg/kg/day
for 3 weeks. Administration was 6 hr/day to an area approximately 10 x
15 cm (10% of body surface area). No systemic toxicity was observed at
any dose level. Dose-related dermal irritation was observed at the
application sites. Desquamation was seen predominantly in the 1,000 mg/
kg/day group while moderate erythema, moderate edema and atonia were
observed exclusively in the 1,000 mg/kg/day group. A dose-related
incidence of fissuring was noted in the 200 and 1,000 mg/kg/day groups.
The severity of acanthosis and the incidence of hyperkeratosis was
increased at these sites among rabbits in the 200 and 1,000 mg/kg
groups. Based on these findings, the systemic NOAEL for males and
females is 1,000 mg/kg/day. A systemic LOAEL could not be established.
The NOAEL for dermal irritation is 40 mg/kg/day and the LOAEL is 200
mg/kg/day.
4. In the combined chronic toxicity/carcinogenicity study in rats,
Dicamba 86.8% a.i. was administered to 50 Charles River CD rats/sex/
dose via the diet at dose levels of 0, 50, 250 or 2,500 ppm/day
(approximately 2.5, 12.5, or 125 mg/kg/day) for 24 months. There were
no effects of dosing on clinical signs of toxicity, survival, mean body
weights or weight gains, food consumption, and hematologic, clinical
chemistry, or urinary parameters. Organ weights, macroscopic findings,
and non-neoplastic histologic findings were similar among dosed and
control groups.The NOAEL is approximately 125 mg/kg/day, the highest
dose level tested. A LOAEL was not established. As an effect level was
not achieved, it is possible that the animals may have tolerated a
higher dose.
5. In the carcinogenicity study in mice, dicamba 86.8% a.i. was
administered to 52 CD-1 mice/sex/dose via the diet at dose levels of 0,
50, 150, 1,000, and 3,000 ppm (approximately 0, 6, 18, 115 or 361 mg/
kg/day) for 24 months. There was no significant biological evidence of
oncogenicity from ingestion of dicamba. A statistically significant
increase (p<0.05) in="" the="" mortality="" rate="" (-31%)="" in="" 3,000="" ppm="" males="" could="" not="" clearly="" be="" associated="" with="" treatment="" because="" a="" statistically="" significant="" increase="" was="" also="" observed="" in="" males="" at="" 150="" ppm.="" also,="" decreased="" body="" weight="" gain="" and="" an="" increased="" ratio="" of="" lymphocytes="" to="" neutrophils="" in="" high-dose="" females="" could="" not="" be="" related="" to="" treatment="" with="" any="" degree="" of="" certainty.the="" loael="" is="" 3,000="" ppm="" (approximately="" 360="" mg/="" kg/day)="" based="" on="" increased="" mortalities="" in="" males="" and="" decreased="" body="" weight="" gain="" in="" females.="" the="" noael="" is="" 1,000="" ppm="" (approximately="" 115="" mg/="" kg/day.="" there="" was="" no="" evidence="" of="" a="" treatment="" related="" oncogenic="" response.="" 6.="" in="" a="" 1-year="" chronic="" feeding="" study,="" dicamba="" 86.8%="" a.i.="" was="" administered="" to="" beagle="" dogs="" (4/sex/group)="" in="" the="" diet="" at="" 0,="" 10,="" 500="" or="" 2,500="" ppm="" (0,="" 2,="" 11="" or="" 52="" mg/kg/day)="" for="" 12="" months.="" no="" adverse="" effects="" were="" observed="" at="" any="" dose="" level.="" no="" abnormalities="" in="" clinical="" signs,="" hematology,="" clinical="" chemistry="" or="" urinalysis="" were="" reported.="" no="" abnormal="" findings="" were="" made="" at="" necropsy,="" nor="" were="" there="" any="" significant="" changes="" in="" food="" consumption="" or="" body="" weight.="" the="" noael="" for="" this="" study="" is="" 52="" mg/="" kg/day,="" the="" highest="" dose="" level="" tested.="" the="" loael="" could="" not="" be="" established.="" 7.="" in="" a="" developmental="" toxicity="" study="" cd="" (charles="" river)="" pregnant="" rats="" (25/dose="" group)="" were="" administered="" dicamba="" (85.8%="" a.i.)="" at="" oral="" dose="" levels="" of="" 0,="" 64,="" 160="" or="" 400="" mg/kg/day="" in="" corn="" oil="" on="" days="" 6="" through="" 19="" of="" gestation.="" maternal="" toxicity,="" limited="" to="" the="" high-dose="" group,="" was="" characterized="" by="" mortality="" in="" three="" gravid="" and="" one="" non-="" gravid="" dams="" that="" exhibited="" neurotoxic="" signs="" prior="" to="" death;="" clinical="" signs="" of="" nervous="" system="" toxicity="" that="" included="" ataxia,="" salivation,="" stiffening="" of="" the="" body="" when="" held,="" and="" decreased="" motor="" activity;="" statistically="" [[page="" 761]]="" significant="">0.05) decreases in body weight gain during the
dosing period (days 0 to 20); and concomitant decreases in food
consumption. Dicamba had no effect on any of the cesarean parameters.
The maternal LOAEL is 400 mg/kg/day, based on mortality, clinical
signs, body weight changes and decreases in food consumption. The
maternal NOAEL is 160 mg/kg/day. No treatment-related fetal gross
external, skeletal or visceral anomalies (malformations or variations)
were seen at any dose level. The developmental LOAEL is not
established. The developmental NOAEL is > 400 mg/kg/day, the highest
dose level tested.
8. In a developmental toxicity study inseminated New Zealand White
rabbits (19 or 20/dose group) were administered dicamba (90.5% a.i.) at
oral (capsule) dose levels of 0, 30, 150, or 300 mg/kg/day on days 6
through 18 of gestation.No maternal toxicity was observed at 30 mg/kg/
day. At 150 mg/kg/day maternal toxicity was characterized by abortion
(5%) and clinical signs such as ataxia, rales, decreased motor
activity. At 300 mg/kg/day maternal toxicity was manifested by
abortions, clinical signs, decreased body.
9. In a 2-generation reproduction study, Sprague-Dawley rats (32 or
28/group) received dicamba technical (86.5% a.i.) in the diet at dose
levels of 0, 500, 1,500, or 5,000 ppm (0, 40, 122, or 419 mg/kg/day
(male) and 0, 45, 136 or 450 mg/kg/day (female). Systemic toxicity was
observed at 5,000 ppm, manifested as clinical signs in dams from both
generations during lactation (tense/stiff body tone and slow righting
reflex) and significantly increased relative liver to body weights
ratios (112% of control) in both generations and sexes, adults as well
as weanlings. Relative kidney to body weights (107%) at 1,500 and/or
5,000 ppm were not considered to be toxicologically relevant since
there were no gross or histopathological findings. Based on these
results, the NOAEL for systemic toxicity was 1,500 ppm (122 and 136 mg/
kg/day for males and females (M/F), respectively). The LOAEL was 5,000
ppm (M/F: 419/450 mg/kg/day) based on clinical signs of neurotoxicity.
Reproductive and/or offspring toxicity was observed at 1,500 and 5,000
ppm, manifested as significantly decreased pup growth (decreased body
weight gain) in all generations and matings at 1,500 ppm (86 - 90% of
control) and at 5,000 ppm (74 - 94% of control). In addition, delayed
sexual maturation was noted in F1 males at 5,000 ppm. Based on these
results, the NOAEL for reproductive toxicity was 500 ppm (45 mg/kg/day)
and the LOAEL was 1,500 ppm (136 mg/kg/day based on decreased pup
growth. Lastly, the NOAEL for offspring toxicity was 45 mg/kg/day and
the LOAEL was 136 mg/kg/day, based on significantly decreased pup
growth.
10. In an acute neurotoxicity study in rats, Dicamba was
administered by gavage in a single dose to Crl: CD BR rats at doses of
0, 300, 600, or 1,200 mg/kg. Vehicle controls received corn oil only.
Positive controls received acrylamide at 50 mg/kg/day by i.p. injection
on seven consecutive days. At 300 mg/kg, transiently impaired
respiration; rigidity upon handling, prodding or dropping; freezing of
movement when touched; decreased arousal and fewer rears/minute
compared to controls; impaired of gait and righting reflex were
observed in both sexes. In addition, males showed decreased forelimb
grip strength. With the exception of the decrease in forelimb grip
strength, which persisted until day seven, these effects were observed
only on the day of dosing. In addition, at 600 mg/kg, both sexes showed
decreases in locomotor activity and males showed significant decreases
in tail flick reflex and a raised posture when placed in an open field.
These effects were also observed only on the day of dosing. At the
highest dose level tested (1,200 mg/kg), both males and females showed
an impaired startle response to an auditory stimulus. The effect was
significant in males on day seven and in females on the day of dosing.
In addition, males showed decreases in body weight (5 - 9%), body
weight gain (24%) and food consumption (13% between days 0 and 7. The
LOAEL for this study was 300 mg/kg based on the several neurologic
signs listed above; the NOAEL was < 300="" mg/kg/day.="" 11.="" in="" a="" subchronic="" neurotoxicity="" study="" sprague-dawley="" rats="" (10/="" sex/dose)="" were="" fed="" test="" diets="" containing="" 0,="" 3,000,="" 6,000,="" or="" 12,000="" ppm="" (0,="" 197.1,="" 401.4,="" 767.9="" mg/kg/d="" (m)="" and="" 0,="" 253.4,="" 472.0="" or="" 1,028.9="" mg/="" kg/day="" (f))="" dicamba="" (86.9%="" a.i.)="" for="" 13="" weeks.="" neurobehavioral="" evaluations,="" consisting="" of="" fob,="" locomotor="" activity,="" and="" auditory="" startle="" response,="" were="" conducted="" at="" prestudy="" and="" during="" weeks="" 4,="" 8="" and="" 13.="" no="" toxicologically="" significant="" differences="" were="" noted="" in="" either="" the="" mean="" body="" weights="" or="" food="" consumption="" of="" the="" treated="" animals.="" neurobehavioral="" evaluations="" at="" the="" 4-,="" 8-,="" and="" 13-week="" evaluations="" revealed="" abnormal="" fob="" observations="" consisting="" of="" rigid="" body="" tone,="" slightly="" impaired="" righting="" reflex="" and="" impaired="" gait.="" at="" week="" 13="" the="" incidences="" of="" these="" findings="" were="" decreased.="" rigid="" body="" tone="" was="" also="" noted="" during="" evaluation="" of="" the="" righting="" reflex="" and="" landing="" foot="" splay.="" the="" noael="" is="" 401.4/472.0="" mg/kg/day="" (m/f),="" and="" the="" loael="" is="" 767.9/="" 1,028.9="" mg/kg/day="" (m/f)="" based="" on="" rigid="" body="" tone,="" slightly="" impaired="" righting="" reflex="" and="" impaired="" gait.="" 12.="" in="" a="" microbial="" mutagenicity="" assay,="" salmonella="" typhimurium="" strains="" ta98,="" ta100,="" ta1535,="" ta1537,="" or="" ta1538="" were="" exposed="" to="" the="" dimethylamine="" (dma)="" salt="" of="" dicamba="" (40.3%="" a.i.)="" in="" deionized="" distilled="" water="" at="" concentrations="" of="" 100,="" 333,="" 1,000,="" 3,333,="" or="" 5,000="">g/
plate in the presence and absence of mammalian metabolic activation.
Preparations for metabolic activation were made from induced rat
livers. The DMA salt of dicamba was tested up to the limit
concentration of 5,000 g/plate and no cytotoxicity was
observed. The positive controls induced the appropriate responses in
the corresponding strains. There was no evidence of induced mutant
colonies over background (reversion to prototrophy).
13. In a microbial mutagenicity assay, Salmonella typhimurium
strains TA98, TA100, TA1535, TA1537, or TA1538 were exposed to the
diglycolamine (DGA) salt of dicamba (39.7% a.i.) in deionized distilled
water at concentrations of 100, 333, 1,000, 3,333, or 5,000 g/
plate in the presence and absence of mammalian metabolic activation.
Preparations for metabolic activation were made from induced rat
livers. The DGA salt of dicamba was tested up to the limit
concentration of 5,000 g/plate, but no cytotoxicity was
observed. The positive controls induced the appropriate responses in
the corresponding corresponding strains. There was no evidence of
induced mutant colonies over background (reversion to prototrophy).
14. In a microbial mutagenicity assay, Salmonella typhimurium
strains TA98, TA100, TA1535, TA1537, or TA1538 were exposed to the
isopropylamine (IPA) salt of dicamba (32.3% a.i.) in deionized
distilled water at concentrations of 100, 333, 1,000, 3,333, or 5,000
g/plate in the presence and absence of mammalian metabolic
activation. Preparations for metabolic activation were made from
induced rat livers. The IPA salt of dicamba was tested up to the limit
concentration of 5,000 g/plate and no cytotoxicity was
observed. The positive controls induced the appropriate responses in
the corresponding strains. There was no evidence of induced mutant
colonies over background (reversion to prototrophy).
[[Page 762]]
15. In a mammalian cell gene mutation assay at the thymidine kinase
locus, L5178Y mouse lymphoma cells cultured in vitro were exposed to
dicamba dimethylamine (DMA) salt (40.3% a.i.) in distilled water at
concentrations of 900, 1,000, 1,500, 2,000, 2,500, 3,000, 3,500, 4,000,
4,500, and 5,000 g/mL in the presence and absence of S9
mammalian metabolic activation. Dicamba DMA salt was tested up to the
limit dose. Under nonactivation conditions, the percent total growth
values over the evaluated dose range were from 69-109% (initial assay)
and 65-111% (confirmatory assay). The mutation frequencies (MFs) for
all of the treated cultures were <2x the="" solvent="" controls;="" the="" exception="" was="" the="" 4,500="">g/mL dose, which had a MF of
approximately 2x background in the confirmatory trial. However, the
4,500 g/mL response was not reproducible. The S9-activation
assay confirmed the findings of the nonactivation assay. The percent
total growth values were 26-109% (initial assay) and 23-113%
(confirmatory assay). The MFs for all of the treated cultures were <2x the="" solvent="" controls="" with="" the="" exception="" of="" the="" 3,000="">g/mL dose
in the confirmatory trial which had a MF of approximately 2x
background; this result was not reproducible. It was determined that
dicamba DMA salt was not mutagenic under either nonactivation or S9-
activation conditions. In both the nonactivated and activated
conditions, the positive controls induced the appropriate response.
16. In a mammalian cell gene mutation assay at the thymidine kinase
locus (MRID 43310305), L5178Y mouse lymphoma cells cultured in vitro
were exposed to dicamba diglycolamine (DGA) salt (39.7% a.i.) in
distilled water at concentrations of 900, 1,000, 1,500, 2,000, 2,500,
3,000, 3,500, 4,000, 4,500, and 5,000 g/mL in the presence and
absence of S9 mammalian metabolic activation. Dicamba DGA salt was
tested up to the limit dose. Under nonactivation conditions, the
percent total growth values over the evaluated dose range were from 68-
116% (initial assay) and 72-105% (confirmatory assay). The mutation
frequencies (MFs) forall of the treated cultures were <2x the="" solvent="" controls.="" the="" s9-activation="" assay="" confirmed="" the="" findings="" of="" the="" nonactivation="" assay.="" the="" percent="" total="" growth="" values="" were="" 43-102%="" (initial="" assay)="" and="" 46-99%="" (confirmatory="" assay).="" the="" mfs="" for="" all="" of="" the="" treated="" cultures="" were=""><2x the="" solvent="" controls="" with="" the="" exception="" of="" the="" 4,500="">g/mL dose in the initial trial, which had a MF of
approximately 2x background. However, this result was not reproducible.
Therefore, it was determined that dicamba DGA salt was not mutagenic
under either nonactivation or S9-activation conditions. In both the
nonactivated and activated conditions, the positive controls induced
the appropriate response.
17. In a mammalian cell gene mutation assay at the thymidine kinase
locus, L5178Y mouse lymphoma cells cultured in vitro were exposed to
dicamba isopropyl amine (IPA) salt (32.3% a.i.) in distilled water at
concentrations of 900, 1,000, 1,500, 2,000, 2,500, 3,000, 3,500, 4,000,
4,500, and 5,000 g/mL in the presence and absence of S9
mammalian metabolic activation. Dicamba IPA salt was tested up to the
limit dose. Under nonactivation conditions, the percent total growth
values over the evaluated dose range were from 92-101% (initial assay)
and 51-107% (confirmatory assay). The mutation frequencies (MFs) for
all of the treated cultures were <2x the="" solvent="" controls.="" the="" s9-="" activation="" assay="" confirmed="" the="" findings="" of="" the="" nonactivation="" assay.="" the="" percent="" total="" growth="" values="" were="" 75-126%="" (initial="" assay)="" and="" 49-114%="" (confirmatory="" assay).="" the="" mfs="" for="" all="" of="" the="" treated="" cultures="" were=""><2x the="" solvent="" controls.="" therefore,="" it="" was="" determined="" that="" dicamba="" ipa="" salt="" was="" not="" mutagenic="" under="" either="" nonactivation="" or="" s9-activation="" conditions.="" in="" both="" the="" nonactivated="" and="" activated="" conditions,="" the="" positive="" controls="" induced="" the="" appropriate="" response.="" 18.="" in="" an="" in="" vivo="" mouse="" bone="" marrow="" micronucleus="" assay,="" groups="" of="" five="" icr="" mice/sex="" received="" a="" single="" ip="" injection="" of="" 525,="" 1,050,="" or="" 2,100="" mg/kg="" of="" the="" diglycolamine="" dga="" salt="" formulation="" of="" dicamba="" (39.7%="" a.i.).="" bone="" marrow="" cells="" were="" harvested="" at="" 24,="" 48,="" or="" 72="" hours="" post="" treatment="" and="" scored="" for="" micronucleated="" polychromatic="" erythrocytes="" (mpces).="" mortality="" occurred="" in="" 3/20="" male="" and="" 1/20="" female="" mice="" dosed="" at="" 2,100="" mg/kg.="" lethargy="" was="" observed="" in="" male="" and="" female="" mice="" at="" all="" dose="" levels.="" cytotoxicity="" by="" the="" dga="" salt="" formulation="" was="" observed="" by="" a="" reduction="" in="" the="" ratio="" of="" pces="" to="" total="" erythrocytes="" in="" males="" dosed="" at="" 2,100="" mg/kg="" 48="" and="" 72="" hours="" following="" dosing.="" the="" positive="" control="" induced="" significant="" increases="" in="" mpces="" in="" both="" sexes.="" the="" dga="" salt="" of="" dicamba="" was="" non-mutagenic.="" there="" was="" no="" significant="" increase="" in="" the="" frequency="" of="" mpces="" in="" bone="" marrow="" after="" any="" treatment="" time.="" 19.="" in="" an="" in="" vivo="" mouse="" bone="" marrow="" micronucleus="" assay,="" groups="" of="" five="" icr="" mice/sex="" received="" a="" single="" ip="" injection="" of="" 500,="" 1,000,="" or="" 2,000="" mg/kg="" of="" the="" isopropylamine="" (ipa)="" salt="" formulation="" of="" dicamba="" (32.3%="" a.i.).="" bone="" marrow="" cells="" were="" harvested="" at="" 24,="" 48,="" or="" 72="" hours="" post-treatment="" and="" scored="" for="" micronucleated="" polychromatic="" erythrocytes="" (mpces).="" mortality="" occurred="" in="" 2/20="" male="" and="" 0/20="" female="" mice="" dosed="" at="" 2,000="" mg/kg.="" lethargy="" was="" observed="" in="" male="" and="" female="" mice="" at="" all="" dose="" levels.="" the="" ipa="" salt="" formulation="" of="" dicamba="" was="" not="" cytotoxic="" to="" the="" target="" cell.="" the="" positive="" control="" induced="" significant="" increases="" in="" mpces="" in="" both="" sexes.="" the="" ipa="" salt="" of="" dicamba="" was="" non-mutagenic.="" there="" was="" no="" significant="" increase="" in="" the="" frequency="" of="" mpces="" in="" bone="" marrow="" after="" any="" treatment="" time.="" 20.="" in="" a="" metabolism,="" distribution="" and="" excretion="" study,="" (1)="" groups="" of="" four="" males="" and="" eight="" females="" per="" dose="" of="" charles="" river="" cd="" rats="" received="" a="" single="" oral="" dose="" (0.1="" or="" 0.93="" gm/kg)="" in="" peanut="" oil="" by="" esophageal="" intubation.="" the="" rats="" were="" sacrificed="" at="" intervals="" ranging="" from="" one="" hour="" to="" 72="" hours="" after="" dosing.="" tissues,="" urine="" and="" blood="" were="" retained="" for="" subsequent="" analysis.="" (2)="" one="" male="" and="" one="" female="" each="" received="" a="" single="" injection="" subcutaneously="" of="">14 labeled
dicamba. The rats were sacrificed at 72 hours. (3) Groups of five male
and five female rates per dose housed in individual metabolic cages
were fed C14 labeled dicamba at 10, 100, 1,000, 10,000 and
20,000 ppm for 24 days. Rats were sacrificed at 1, 3, 6, 13 and 24
days. Dietary ingestion resulted in 96% urinary excretion in 48 hours
and 4% via the feces. Fairly equal tissue distribution occurred
initially but tissue levels did not persist beyond a few hours,
indicating no bioaccumulation. It was concluded that when administered
orally to rats, C14 labeled dicamba is rapidly absorbed and
excreted. Over 95% is excreted in the urine and the compound is not
metabolized or appreciable accumulated by the tissues. A fraction of
the dicamba in the urine (ca. 13%) is conjugated to the glucuronide.
B. Toxicological Endpoints
1. Acute dietary (1-day). In an acute neurotoxicity study in rats
groups of Crl: CD BR rats (10/sex/dose) received a single oral (gavage)
administration of Dicamba (86.9%) in corn oil at doses of 0, 300, 600,
or 1,200 mg/kg. Vehicle controls received corn oil only. Positive
controls received Acrylamide at 50 mg/kg/day by intra peritoneal
injection on seven consecutive days. At 300 mg/kg, transiently impaired
respiration; rigidity upon handling, prodding or dropping; freezing of
movement when touched; decreased arousal and fewer rears/
[[Page 763]]
minute compared to controls; impairment of gait and righting reflex
were observed in both sexes. In addition, males showed decreased
forelimb grip strength. With the exception of the decrease in forelimb
grip strength, which persisted until day seven, these effects were
observed only on the day of dosing. In addition, at 600 mg/kg, both
sexes showed decreases in locomotor activity and males showed
significant decreases in tail flick reflex and a raised posture when
placed in an open field. These effects were also observed only on the
day of dosing. At the highest dose level tested (1,200 mg/kg), both
males and females showed an impaired startle response to an auditory
stimulus. The effect was significant in males on day seven and in
females on the day of dosing. In addition, males showed decreases in
body weight (5 - 9%), body weight gain (24%) and food consumption (13%
between days 0 and 7). The LOAEL was 300 mg/kg based on the several
neurologic signs listed above; a NOAEL was not established.
i. Dose and Endpoint for Risk Assessment: LOAEL=300 mg/kg/day based
on severe neurologic signs described above.
ii. Comments about Study and Endpoint: Neurotoxicity was seen in
both sexes at the lowest dose tested. With the exception of the
decrease in forelimb grip strength, which persisted until day seven,
the other neurologic signs were seen only on the day of dosing. The
Acute Dietary RfD is 0.10 mg/kg/day, based on the LOAEL of 300 mg/kg/
day and an uncertainty factor of 3,000 for infants and children (10x
for intra species variations, 10x for inter species variations, 10x
because a LOAEL was used instead of a NOAEL, and 3x for FQPA
considerations). The EPA used 10x because a LOAEL was used, not 3x,
because of the severity of neurotoxic signs exhibited by all animals in
both sexes at the lowest dose level used.
2. Chronic dietary Reference Dose (RfD). In a 2-generation
reproduction study, Sprague-Dawley rats (32 or 28/group) received
Dicamba technical (86.5%) in the diet at dose levels of 0, 500, 1,500,
or 5,000 ppm (0, 40, 122, or 419 mg/kg/day for males and 0, 45, 136 or
450 mg/kg/day for females, respectively) for two generations. Systemic
toxicity was observed at 5,000 ppm, manifested as clinical signs in
dams from both generations during lactation (tense/stiff body tone and
slow righting reflex) and significantly increased relative liver to
body weights (112% of control) in both generations and sexes, adults as
well as weanlings. The increase (107%) in relative kidney weights
observed at 1,500 and/or 5,000 ppm were not considered to be
toxicologically significant due to lack of corroborative gross or
histopathological lesions in the kidneys. For parental systemic
toxicity, the NOAEL was 122 and 136 mg/kg/day for males and females,
respectively and the LOAEL was 419 and 450 mg/kg/day in males and
females based on clinical signs of neurotoxicity. Reproductive toxicity
at 1,500 and 5,000 ppm, manifested as significantly decreased pup
growth in all generations and matings at 1,500 ppm (86 - 90% of
control) and at 5,000 ppm (74 - 94% of control). In addition, delayed
sexual maturation was noted in F1 males at 5,000 ppm. For offspring
toxicity, the NOAEL was 45 mg/kg/day and the LOAEL was 136 mg/kg/day
based on significantly decreased pup growth.
i. Dose and endpoint for establishing the RfD. NOAEL = 45 mg/kg/day
based on significant decreases in pup growth in all generations and
mating at 136 mg/kg/day (LOAEL).
ii. Comments about study and endpoint. The NOAEL/LOAEL in the two-
generation study is supported by the maternal NOAEL of 30 mg/kg/day and
the LOAEL of 150 mg/kg/day established in the developmental toxicity
study in rabbits; the maternal LOAEL was based on abortions (5%) and
clinical signs of neurotoxicity (ataxia, rales, and decreased motor
activity) Uncertainty Factor (UF): An UF of 1,000 was applied to
account for inter (10x)-and intra-(10x) species variation and 10 for F
PA.
RfD = 45 mg/kg/day (NOAEL)/1,000 (UF) = 0.045 mg/kg/day
3. Occupational and residential exposure (dermal). Short-Term (1 -
7 days) Dermal In a 21-day dermal study (MRID No. 40547901) New Zealand
white rabbits (5/sex/group) received 15 repeated dermal applications of
dicamba in deionized water at dose levels of 0, 40, 200, or 1,000 mg/
kg/day, 6 hours/day, 5 days/week over a 3-week period. No systemic
toxicity was observed at any dose level. Dose-related dermal irritation
was observed at the application sites. Desquamation was seen
predominantly in the 1,000 mg/kg/day group while moderate erythema,
moderate edema and atonia were observed exclusively in the 1,000 mg/kg/
day group. A dose-related incidence of fissuring was noted in the 200
and 1,000 mg/kg/day groups. The severity of acanthosis and the
incidence of hyperkeratosis was increased at these sites in rabbits at
200 and 1,000 mg/kg. For systemic toxicity, the NOAEL was 1,000 mg/kg/
day (HDT); a systemic LOAEL was not established. For dermal irritation,
the NOAEL was 40 mg/kg/day and the LOAEL was 200 mg/kg/day.
i. Dose and endpoint for risk assessment. Systemic NOAEL = 1,000
mg/kg/day, the highest dose tested.
ii. Comments about study and endpoint. Although no systemic
toxicity was observed at the Limit-Dose, the EPA recommended this dose
for risk assessment because:
a. Dicamba is used in residential lawns and thus there is potential
exposure by children and infants.
b. Increased sensitivity to offspring was demonstrated in the 2-
generation reproduction study. A systemic toxicological end point was
not determined from the study; however, for the risk assessment for the
exposures involving these tolerance actions, a conservative default
NOAEL of 1,000 was used.
4. Intermediate-term (7 days to several months) dermal. Summarized
under short term in Unit above. Dose and Endpoint for Risk Assessment:
Systemic NOAEL = 1,000 mg/kg/day, the highest dose tested. Comments
about Study and Endpoint: Although no systemic toxicity was observed at
the Limit-Dose, the EPA recommended this dose for risk assessment
because (1) Dicamba is used in residential lawns and thus there is
potential exposure by children and infants and (2) increased
sensitivity to offspring was demonstrated in the 2-generation
reproduction study.
5. Long term (Several months to life-time) dermal. Based on the
current use pattern, long-term dermal exposure is not anticipated.
Therefore, a dose and endpoint was not identified.
6. Inhalation exposure (Any-time period). Based on the
LC50 of >5.3 mg/L, Dicamba is placed in Toxicity Category
IV. The EPA determined that a risk assessment via the inhalation route
is not required because of the low acute inhalation toxicity and the
use pattern/application method does not indicate high exposure via this
route.
7. Margin of exposure for residential exposures. For Short-and
Intermediate Term dermal exposures a MOE of 300 is required for
residential exposures because: (a) Although developmental toxicity
studies showed no increased sensitivity in fetuses as compared to
maternal animals following in utero exposures in rats and rabbits,
increased sensitivity to offspring, however, was demonstrated in the 2-
generation reproduction toxicity study in rats (See Section III.2).
(b) There is evidence of neurotoxicity in the following studies:
acute and subchronic neurotoxicity, combined chronic toxicity/
carcinogenicity,
[[Page 764]]
developmental toxicity (rats and rabbits) and the 2-generation
reproduction (See Section III.1).
(c) A weight-of-the-evidence evaluation of the data base indicates
the need for a developmental neurotoxicity study.
C. Exposures and Risks
1. Food and feed. Tolerances have been established (40 CFR 180.227)
for the combined residues of Dicamba, in or on a variety of raw
agricultural commodities, including meat, milk and poultry and eggs.
Risk assessments were conducted by EPA to assessed dietary exposures
from Dicamba (3,6-dichloro-o-anisic acid) as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a one day or single exposure. The endpoint selected by EPA for
assessment of acute dietary risk is severe neurological effects in both
sexes at 300 mg/kg/day (LOAEL, a NOAEL was not established) in a rat
acute neurotoxicity study. Thus, this risk assessment is required for
all population subgroups. This acute dietary (food) risk assessment
used the Dietary Exposure Evaluation Model (DEEM). This program
utilizes individual food consumption as reported by respondents in the
USDA 1989-1991 nationwide Continuing Surveys for Food Intake by
Individuals (CSFII) and food residue levels to estimate possible
exposure levels of various population subgroups. Regulating at the 95th
percentile, acute dietary exposure values and percent of the acute RfD
are shown in following table:
Acute Dietary Exposure and Risks
------------------------------------------------------------------------
Acute High-end
Population Subgroup RfD\1\ (mg/ Exposure % Acute RfD
kg/day) (mg/kg/day)
------------------------------------------------------------------------
US Population.................... 0.1 0.02860 28.6
Nursing Infants (<1 yr="" old)......="" 0.1="" 0.02610="" 26.1="" non-nursing="" infants=""><1 yr="" old)..="" 0.1="" 0.06315="" 63.2="" children="" (1-6)...................="" 0.1="" 0.04581="" 45.8="" children="" (7-12)..................="" 0.1="" 0.03116="" 31.2="" ------------------------------------------------------------------------="" \1\="" based="" on="" loael="" of="" 300="" mg/kg/day="" and="" an="" uncertainty="" factor="" of="" 3,000.="" adjusted="" for="" fqpa.="" these="" estimates="" indicate="" that="" risks="" from="" acute="" dietary="" exposures="" to="" dicamba="" do="" not="" exceed="" epa's="" level="" of="" concern.="" ii.="" chronic="" exposure="" and="" risk.="" the="" chronic="" dietary="" exposure="" analysis="" from="" food="" sources="" was="" conducted="" using="" the="" reference="" dose="" (rfd)="" of="" 0.045="" mg/kg/day.="" the="" rfd="" is="" based="" on="" the="" noael="" of="" 45="" mg/kg/day,="" which="" in="" turn="" is="" based="" on="" reduced="" pup="" weights="" in="" all="" generations="" and="" matings="" at="" 136="" mg/kg/day="" in="" a="" multi-generation="" reproduction="" study="" in="" rats;="" and="" an="" uncertainty="" factor="" of="" 1,000="" applicable="" to="" all="" populations="" which="" include="" infants="" and="" children.="" in="" conducting="" this="" chronic="" dietary="" risk="" assessment,="" epa="" has="" made="" very="" conservative="" assumptions:="" 100%="" of="" racs="" having="" dicamba="" tolerances="" will="" contain="" dicamba="" residues="" and="" those="" residues="" will="" be="" at="" the="" level="" of="" the="" established="" tolerance.="" this="" results="" in="" an="" overestimate="" of="" human="" dietary="" exposure.="" thus,="" in="" making="" a="" safety="" determination="" for="" this="" tolerance,="" epa="" is="" taking="" into="" account="" this="" conservative="" exposure="" assessment.="" the="" dietary="" exposure="" evaluation="" model="" (deem)="" analysis="" evaluated="" the="" individual="" food="" consumption="" as="" reported="" by="" respondents="" in="" the="" usda="" 1989-91="" nationwide="" continuing="" surveys="" for="" food="" intake="" by="" individuals="" (csfii)="" and="" accumulated="" exposure="" to="" the="" chemical="" for="" each="" commodity.="" the="" chronic="" deem="" analysis="" used="" mean="" consumption="" (3="" day="" average)="" data="" and="" gave="" the="" results="" listed="" below:="" ------------------------------------------------------------------------="" subgroups="" %rfd="" ------------------------------------------------------------------------="" u.s.="" population="" (48="" states)..........................="" 23.9="" nursing="" infants="">< 1="" year="" old).......................="" 16.5="" non-nursing="" infants="">< 1="" year="" old)...................="" 71.1="" children="" (6="" years="" old)...............................="" 54.8="" children="" (7-12="" years="" old)............................="" 36.8="" non-hispanic="" whites..................................="" 24.1="" males="" (13-19="" years="" old)..............................="" 25.6="" ------------------------------------------------------------------------="" the="" subgroups="" listed="" above="" are:="" (1)="" the="" u.s.="" population="" (48="" states);="" (2)="" those="" for="" infants="" and="" children;="" and="" (3)="" the="" other="" subgroups="" for="" which="" the="" percentage="" of="" the="" rfd="" occupied="" is="" greater="" than="" that="" occupied="" by="" the="" subgroup="" u.s.="" population="" (48="" states).="" these="" estimates="" indicate="" that="" risks="" from="" chronic="" dietary="" exposures="" to="" dicamba="" do="" not="" exceed="" epa's="" level="" of="" concern.="" iii.="" carcinogenic="" risk.="" in="" the="" chronic="" toxicity/carcinogenicity="" study="" in="" rats="" there="" were="" no="" observed="" clinical="" signs="" of="" toxicity,="" including="" survival,="" mean="" body="" weights="" or="" body="" gains,="" food="" consumption,="" hematologic="" clinical="" chemistry,="" urinary="" parameters,="" organ="" weights,="" macroscopic="" findings,="" and="" non-neoplastic="" histology="" findings="" at="" 125="" mg/="" kg/day,="" the="" highest="" dose="" tested.="" a="" loael="" was="" not="" established.="" in="" the="" mouse="" carcinogenicity="" study="" at="" the="" highest="" dose="" tested,="" 361="" mg/kg/day,="" there="" were="" no="" clinical="" signs="" of="" carcinogenicity.="" a="" noael="" of="" 115="" mg/kg/="" day="" was="" determined="" for="" increased="" mortalities="" in="" males="" and="" decreased="" body="" weight="" gains="" in="" females.="" based="" on="" these="" studies,="" a="" finding="" of="" carcinogenicity="" in="" rats="" or="" mice="" would="" not="" change="" the="" rfd="" previously="" stated.="" in="" accordance="" with="" the="" epa="" proposed="" guidelines="" for="" carcinogen="" risk="" assessment="" (10-apr-1996),="" the="" epa="" classified="" dicamba="" as="" a="" ``not="" classifiable''="" human="" carcinogen.="" this="" was="" based="" on="" the="" mouse="" carcinogenicity="" study="" and="" the="" rat="" combined="" chronic="" toxicity/="" carcinogenicity="" study,="" being="" classified="" as="" supplemental="" because="" an="" mtd="" was="" not="" achieved="" in="" both="" studies.="" however,="" these="" studies="" were="" adequate="" to="" indicate="" that="" dicamba="" has="" either="" a="" low="" or="" no="" cancer="" potential="" in="" mammals.="" a="" pharmacokinetics="" study="" pending="" epa="" review="" indicates="" that="" the="" mtd="" for="" both="" the="" rat="" and="" mouse="" studies="" was="" reached.="" if="" this="" is="" corroborated="" by="" epa's="" review,="" a="" quantitative="" cancer="" risk="" will="" not="" be="" made="" for="" dicamba="" and="" its="" metabolites,="" on="" the="" other="" hand,="" if="" the="" review="" does="" not="" corroborate="" this="" indication,="" replacement="" studies="" will="" be="" required.="" 2.="" from="" drinking="" water.="" epa="" does="" not="" have="" monitoring="" data="" available="" to="" perform="" a="" quantitative="" drinking="" water="" risk="" assessment="" for="" dicamba="" at="" this="" time.="" a="" tier="" 1="" drinking="" water="" assessment="" of="" dicamba="" is="" given="" below..="" this="" assessment="" utilized="" the="" geneec="" and="" sci-grow="" screening="" models="" to="" provide="" estimates="" of="" ground="" and="" surface="" water="" contamination="" from="" dicamba="" and="" its="" metabolite,="" 3,6-dichlorosalicylic="" acid="" (dcsa).="" concentrations="" of="" the="" 5-hydroxy="" metabolite="" of="" dicamba="" (3,6-="" [[page="" 765]]="" dichloro-5-hydroxy-o-anisic="" acid)="" in="" surface="" and="" ground="" water="" could="" not="" be="" estimated;="" however,="" based="" on="" the="" available="" environmental="" fate="" data,="" it="" is="" not="" likely="" that="" this="" metabolite="" would="" be="" found="" in="" surface="" and="" ground="" water.="" epa="" followed="" an="" interim="" approach="" for="" addressing="" drinking="" water="" exposure="" in="" tolerance="" decision="" making="" issued="" on="" 17-nov-1997.="" thus,="" the="" geneec="" model="" and="" the="" sci-grow="" model="" were="" run="" to="" produce="" estimates="" of="" dicamba="" concentrations="" in="" surface="" and="" ground="" water="" respectively.="" the="" primary="" use="" of="" these="" models="" is="" to="" provide="" a="" coarse="" screen="" for="" sorting="" out="" pesticides="" for="" which="" opp="" has="" a="" high="" degree="" of="" confidence="" that="" the="" true="" levels="" of="" the="" pesticide="" in="" drinking="" water="" will="" be="" less="" than="" the="" human="" health="" drinking="" water="" levels="" of="" concern="" (dwlocs).="" a="" human="" health="" dwloc="" is="" the="" concentration="" of="" a="" pesticide="" in="" drinking="" water="" which="" would="" result="" in="" unacceptable="" aggregate="" risk,="" after="" having="" already="" factored="" in="" all="" food="" exposures="" and="" other="" non-occupational="" exposures.="">acute = [acute water exposure (mg/kg/day) x (body
weight)]/[consumption (L) x 10-3 mg/g]
where acute water exposure (mg/kg/day) = acute RfD - acute food
exposure (mg/kg/day)
DWLOCchronic = [chronic water exposure (mg/kg/day) x
(body weight)]/[consumption (L) x 10-3 mg/g]
where chronic water exposure (mg/kg/day) = [RfD - (chronic food
exposure + chronic residential exposure) (mg/kg/day)].
There is no chronic residential exposure for dicamba. The
DWLOCchronic is the concentration in drinking water as part
of the aggregate chronic exposure that results in a negligible cancer
risk. The Agency's default body weights and consumption values used to
calculate DWLOCs are as follows: 70 kg/2L (adult male), 60 kg/2L (adult
female), and 10 kg/1L (child).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acute Scenario Chronic Scenario
-------------------------------------------------------------------------------------------------------
Ground Surface
Water SCI- Water SCI-GROW2 GENEEC EEC
Population Subgroup\1\ Acute DWLOC GROW2 EEC GENEEC EEC RfD2 mg/kg/ DWLOC EEC in in g/ in g/ g/ m>g/L
kg/day L m>g/L m>g/L L L
--------------------------------------------------------------------------------------------------------------------------------------------------------
U.S. Population................................. 0.10 25000 0.013 98 0.045 1200 0.013 66
Children (1-6 yrs).............................. 0.10 540 0.013 98 0.045 200 0.013 66
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ DEEM TMRCs in mg/kg/day: U.S. Population = 0.01075, children (1-6 yrs) = 0.02465
\2\ Adjusted for FQPA
For chronic (non-cancer) exposure to dicamba in surface and ground
water, the drinking water levels of concern are 1,200 g/L for
U.S. population, and 200 g/L for children (1-6 yrs). To
calculate the DWLOC for chronic (non-cancer) exposure relative to a
chronic toxicity endpoint, the chronic dietary food exposure (from
DEEM) was subtracted from the RfD to obtain the acceptable chronic
(non-cancer) exposure to dicamba in drinking water. DWLOCs were then
calculated using default body weights and drinking consumption figures.
Estimated maximum concentrations of dicamba in surface and ground
water are 98 and 0.013 ppb, respectively. The estimated concentrations
of dicamba in surface and ground water are less than OPP's level of
concern for dicamba in drinking water as a contribution to chronic
aggregate exposure. Therefore, taking into account present uses and
uses proposed in this action, EPA concludes with reasonable certainty
that residues of dicamba in drinking water (when considered along with
other sources of exposure for which there are reliable data) would not
result in unacceptable levels of aggregate human health risk at this
time.
The dietary (food and water) exposure database for dicamba is
adequate to assess infants' and children's exposure.
3. From non-dietary exposure. Dicamba (3,6-dichloro-o-anisic acid)
is currently registered for use on outdoor residential and recreational
turf. Application is made by both homeowners and professional
applicators. There is a potential oral, inhalation, eye and dermal
exposure to infants and children to dicamba from the registered uses
for lawn and turfgrass weed control These exposures are considered to
be very low. Currently there are no inhalation or eye exposure data
required for post-application of pesticides to lawns and turf. As
inhalation exposure for mixer/loaders is acceptable, the risk to
infants and children from inhalation exposure under a much lower
exposure scenario is characterized qualitatively as being extremely
low. Exposure data are required for hand to mouth movements of infants
and children. As there are no chemical-specific or site-specific data
available to determine the potential risks associated with residential
exposures, the EPA has determined that residential exposure and risk
are acceptable for dosages of 0.5 lb/A, based on a dermal NOAEL of
1,000 mg/kg/day and exposures of 0.051 mg/kg/day for low pressure hand
wand, liquid formulations; and 0.079 mg/kg/day for granular
formulations. For residential post-application exposure and risk
assessment, EPA determined that the potential residential post-
application risks for short-term and intermediate exposures did not
exceed their level of concern. In this analysis both oral and dermal
exposures and risks for adults and infants from post-applications were
determined. This analysis was based on assumptions and generic data
from the Draft HED Standard Operating Procedures (SOPs) for Residential
Exposure Assessments (December 18, l997. These SOPs rely on what are
considered to be upper-percentile assumptions and intended to represent
Tier 1 assessments.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.'' The Agency believes that ``available
information'' in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that
[[Page 766]]
EPA will be able to develop and apply scientific principles for better
determining which chemicals have a common mechanism of toxicity and
evaluating the cumulative effects of such chemicals. The Agency
anticipates, however, that even as its understanding of the science of
common mechanisms increases, decisions on specific classes of chemicals
will be heavily dependent on chemical specific data, much of which may
not be presently available.
Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
case the Agency can conclude that it is unlikely that a pesticide
shares a common mechanism of activity with other substances) and
pesticides that produce a common toxic metabolite (in which case common
mechanism of activity will be assumed).
EPA does not have, at this time, available data to determine
whether dicamba and its metabolites (3,6-dichloro-5-hydroxy-o-anisic
acid and 3,6-dichloro-o-2-hydroxybenzoic acid) have a common mechanism
of toxicity with other substances or how to include this pesticide or
its metabolites in a cumulative risk assessment. For the purposes of
this tolerance action, therefore, EPA has not assumed that dicamba and
its metabolites have a common mechanism of toxicity with other
substances.
D. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. Under Unit II.C.1.i of this preamble an acute risk
assessment using a high-end exposure estimate for dicamba was
determined for the general U.S. population, infants (<1 year),="" children="" (1-6="" years),="" children="" (7="" -12)="" years).="" none="" of="" the="" population="" subgroups="" yielded="" percent="" rfds="" (adjusted="" for="" fqpa)="" above="" 100.="" based="" on="" the="" drinking="" water="" risk="" assessment="" under="" unit="" ii.c.2="" of="" this="" preamble,="" the="" maximum="" estimated="" concentrations="" of="" dicamba="" in="" surface="" and="" ground="" water="" are="" less="" than="" levels="" of="" concern="" in="" drinking="" water="" as="" a="" contribution="" to="" acute="" aggregate="" exposure.="" 2.="" chronic="" risk.="" using="" the="" exposure="" assumptions="" described="" unit="" ii.c.1.ii="" of="" this="" preamble,="" epa="" has="" concluded="" that="" aggregate="" exposure="" to="" dicamba="" from="" food="" will="" utilize="" 23.9%="" of="" the="" rfd="" for="" the="" u.s.="" population.="" the="" major="" identifiable="" subgroup="" with="" the="" highest="" aggregate="" exposure="" is="" children="" (1-6="" years="" old).="" the="" percent="" of="" the="" rfd="" utilized="" by="" this="" subgroup="" was="" determined="" to="" be="" 71.1%.="" epa="" generally="" has="" no="" concern="" for="" exposures="" below="" 100%="" of="" the="" rfd="" because="" the="" rfd="" represents="" the="" level="" at="" or="" below="" which="" daily="" aggregate="" dietary="" exposure="" over="" a="" lifetime="" will="" not="" pose="" appreciable="" risks="" to="" human="" health.="" despite="" the="" potential="" for="" exposure="" to="" dicamba="" in="" drinking="" water="" and="" from="" non-="" dietary,="" non-occupational="" exposure,="" epa="" does="" not="" expect="" the="" aggregate="" exposure="" to="" exceed="" 100%="" of="" the="" rfd.="" 3.="" short="" and="" intermediate-term="" aggregate="" risk.="" dicamba="" is="" currently="" registered="" for="" use="" on="" turfgrass="" including="" sod="" production,="" commercial="" and="" residential="" turf.="" short-="" or="" intermediate-term="" dermal="" toxicity="" endpoints="" have="" been="" identified="" for="" dicamba,="" and="" was="" quantified="" at="" 1,000="" mg/kg/day.="" using="" epa="" standard="" operating="" procedures="" for="" residential="" exposure="" assessments,="" including="" post-application="" exposures="" and="" risk="" assessments;="" the="" margin="" of="" exposure="" (moe)="" did="" not="" exceed="" 300="" the="" level="" of="" concern.="" 4.="" aggregate="" cancer="" risk="" for="" u.s.="" population.="" epa="" has="" classified="" dicamba="" as="" a="" ``not="" classifiable''="" human="" carcinogen.="" available="" oncogenicity="" studies="" have="" been="" classified="" as="" supplemental="" because="" the="" studies="" did="" not="" achieve="" an="" mtd.="" however,="" the="" studies="" indicate="" no="" carcinogenicity="" potential="" at="" the="" highest="" dose="" tested,="" 2,500="" ppm="" (rat)="" and="" 3,000="" ppm="" (mice).="" a="" quantitative="" cancer="" risk="" can="" not="" be="" made="" based="" on="" the="" supplemental="" rat="" and="" mouse="" carcinogenicity="" studies.="" however,="" these="" studies="" were="" adequate="" to="" indicate="" that="" dicamba="" has="" either="" a="" low="" cancer="" risk="" or="" no="" cancer="" risk.="" a="" pharmacokinetics="" study="" presently="" pending="" review="" by="" epa="" indicates="" that="" the="" mtd="" of="" these="" carcinogenicity="" studies="" was="" reached,="" thus="" changing="" these="" carcinogenicity="" studies="" to="" be="" acceptable="" studies.="" no="" quantitative="" cancer="" risk="" will="" be="" made="" for="" dicamba="" and="" its="" metabolites="" if="" the="" pending="" study="" is="" corroborated="" by="" epa's="" review.="" alternatively,="" if="" the="" study="" is="" not="" corroborated,="" replacement="" carcinogenicity="" studies="" will="" be="" required.="" 5.="" determination="" of="" safety.="" based="" on="" these="" risk="" assessments,="" epa="" concludes="" that="" there="" is="" a="" reasonable="" certainty="" that="" no="" harm="" will="" result="" from="" aggregate="" exposure="" to="" dicamba="" residues.="" e.="" aggregate="" risks="" and="" determination="" of="" safety="" for="" infants="" and="" children="" 1.="" safety="" factor="" for="" infants="" and="" children--="" i.="" in="" general.="" in="" assessing="" the="" potential="" for="" additional="" sensitivity="" of="" infants="" and="" children="" to="" residues="" of="" dicamba,="" epa="" considered="" data="" from="" developmental="" toxicity="" studies="" in="" the="" rat="" and="" rabbit="" and="" a="" two-generation="" reproduction="" study="" in="" the="" rat.="" the="" developmental="" toxicity="" studies="" are="" designed="" to="" evaluate="" adverse="" effects="" on="" the="" developing="" organism="" resulting="" from="" maternal="" pesticide="" exposure="" gestation.="" reproduction="" studies="" provide="" information="" relating="" to="" effects="" from="" exposure="" to="" the="" pesticide="" on="" the="" reproductive="" capability="" of="" mating="" animals="" and="" data="" on="" systemic="" toxicity.="" ffdca="" section="" 408="" provides="" that="" epa="" shall="" apply="" an="" additional="" tenfold="" margin="" of="" safety="" for="" infants="" and="" children="" in="" the="" case="" of="" threshold="" effects="" to="" account="" for="" pre-and="" post-natal="" toxicity="" and="" the="" completeness="" of="" the="" database="" unless="" epa="" determines="" that="" a="" different="" margin="" of="" safety="" will="" be="" safe="" for="" infants="" and="" children.="" margins="" of="" safety="" are="" incorporated="" into="" epa="" risk="" assessments="" either="" directly="" through="" use="" of="" a="" margin="" of="" exposure="" (moe)="" analysis="" or="" through="" using="" uncertainty="" (safety)="" factors="" in="" calculating="" a="" dose="" level="" that="" poses="" no="" appreciable="" risk="" to="" humans.="" epa="" believes="" that="" reliable="" data="" support="" using="" the="" standard="" uncertainty="" factor="" (usually="" 100="" for="" combined="" inter-="" and="" intra-species="" variability)="" and="" not="" the="" additional="" tenfold="" moe/="" uncertainty="" factor="" when="" epa="" has="" a="" complete="" data="" base="" under="" existing="" guidelines="" and="" when="" the="" severity="" of="" the="" effect="" in="" infants="" or="" children="" or="" the="" potency="" or="" unusual="" toxic="" properties="" of="" a="" compound="" do="" not="" raise="" concerns="" regarding="" the="" adequacy="" of="" the="" standard="" moe/safety="" factor.="" ii.="" pre-="" and="" post-natal="" sensitivity.="" there="" was="" evidence="" of="" increased="" susceptibility="" to="" the="" offspring="" following="" pre-="" and/or="" postnatal="" exposure="" in="" the="" 2-generation="" reproduction="" study="" in="" rat.="" in="" this="" study,="" offspring="" toxicity="" was="" manifested="" as="" significantly="" decreased="" pup="" growth="" in="" all="" generations="" and="" mating="" at="" a="" dose="" lower="" than="" that="" which="" caused="" parental="" systemic="" toxicity(abortions="" and="" clinical="" signs="" of="" neurotoxicity).="" available="" studies="" indicated="" no="" increase="" susceptibility="" of="" rats="" or="" rabbits="" in="" in="" utero="" exposure="" to="" dicamba.="" in="" a="" prenatal="" developmental="" toxicity="" study="" in="" rats,="" there="" was="" no="" evidence="" of="" developmental="" toxicity="" at="" the="" highest="" dose="" tested.="" in="" a="" prenatal="" developmental="" toxicity="" study="" in="" rabbits,="" developmental="" toxicity="" (irregular="" ossification="" of="" internasal="" bones)="" were="" only="" seen="" at="" the="" dose="" that="" caused="" maternal="" toxicity="" (abortions="" and="" neurotoxic="" clinical="" signs).="" iii.="" conclusion.="" there="" is="" a="" adequate="" toxicity="" database="" for="" dicamba="" and="" exposure="" data="" is="" complete="" or="" is="" estimated="" based="" on="" data="" that="" reasonably="" accounts="" for="" potential="" exposures.="" a="" ten-="" [[page="" 767]]="" fold="" safety="" factor="" for="" increased="" susceptibility="" of="" infants="" and="" children="" was="" applied="" for="" chronic="" (long-term)="" exposure,="" and="" a="" three-fold="" safety="" factor="" was="" applied="" for="" acute="" (short-="" and="" intermediate-term)="" exposures="" to="" dicamba,="" due="" to="" evidence="" of="" increased="" susceptibility="" to="" the="" offspring="" following="" pre-="" and/or="" postnatal="" exposure="" in="" the="" 2-generation="" reproduction="" study="" in="" rats.="" the="" uncertainty="" factor="" (fqpa="" safety="" factor)="" of="" ten-fold="" was="" reduced="" for="" acute="" dietary="" and="" short-="" and="" intermediate-="" term="" residential="" exposures="" because="" the="" increased="" susceptibility="" was="" only="" observed="" in="" the="" reproduction="" study="" and="" not="" in="" the="" prenatal="" developmental="" studies.="" the="" fqpa="" safety="" factor="" was="" reduced="" to="" 3x="" for="" acute="" dietary="" risk="" assessment="" for="" all="" populations,="" including="" infants="" and="" children,="" because:="" (1)="" the="" endpoint="" of="" concern="" is="" clinical="" signs="" of="" neurotoxicity="" (in="" the="" absence="" of="" neuropathology)="" observed="" following="" a="" single="" oral="" exposure="" in="" an="" acute="" neurotoxicity="" study;="" (2)="" the="" increased="" susceptibility="" was="" seen="" in="" the="" offspring="" of="" parental="" animals="" receiving="" repeated="" oral="" exposures="" in="" a="" 2-generation="" reproduction="" toxicity="" study;="" (3)="" no="" increased="" susceptibility="" was="" observed="" following="" in="" utero="" exposures="" to="" rats="" or="" rabbits="" in="" the="" developmental="" studies;="" and="" (4)="" a="" developmental="" neurotoxicity="" study="" in="" rats="" is="" required.="" 2.="" acute="" risk.="" acute="" dietary="" risks="" were="" discussed="" under="">1 above. As stated there, an acute dietary RfD was
determined to be 0.10 mg/kg/day, based on the LOAEL of 300 mg/kg/day
and and uncertainty factor of 3,000 for infants and children. The
assessment made by EPA included only exposure from food. Based on high-
end exposures, the percent of the RfD occupied for the U.S population,
Nursing Infants, Non-nursing Infants, Children (ages 1-6 years) and
Children (ages 7-12 years) were less than 100%. The subgroup with the
highest exposure was the Non-nursing Infants which occupied 63.2% of
the RfD. The EPA concluded that with reasonable certainty the residues
of dicamba in food and water do not contribute significantly to the
aggregate acute human health risk at the present time considering the
present uses and uses proposed in this Final Rule.
3. Chronic risk. Using the exposure assumptions described above,
EPA has concluded that aggregate exposure to dicamba from food will
utilize 16.5% of the RfD for nursing infants, 71.1% for non-nursing
infants, 54.8% for children (1-6 years old ), and 36.8% for children
(7-12 years old). EPA generally has no concern for exposures below 100%
of the RfD because the RfD represents the level at or below which daily
aggregate dietary exposure over a lifetime will not pose appreciable
risks to human health. Despite the potential for exposure to
dicamba.... in drinking water and from non-dietary, non-occupational
exposure, EPA does not expect the aggregate exposure to exceed 100% of
the RfD
4. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to infants and children from aggregate exposure to dicamba residues.
III. Other Considerations
A. Endocrine Disrupter Effects
EPA is required to develop a screening program to determine whether
certain substances (including all pesticides and inerts) ``may have an
effect in humans that is similar to an effect produced by a naturally
occurring estrogen, or such other endocrine effect....'' The Agency is
currently working with interested stakeholders, including other
government agencies, public interest groups, industry and research
scientists in developing a screening and testing program and a priority
setting scheme to implement this program. Congress has allowed 3 years
from the passage of FQPA (August 3, l999) to implement this program. At
that time, EPA may require further testing of this active ingredient
and end use products for endocrine disrupter effects.
B. Analytical Enforcement Methodology.
An adequate analytical method for determining the magnitude of
residues in the raw agricultural commodities listed in this Final Rule
has been evaluated by EPA and is published in the Pesticide Analytical
Manual (PAM II). The method may be requested from: Calvin Furlow,
Public Information Branch, Field Operations Division (7502C), Office of
Pesticide Programs, Environmental Protection Agency, 401 M St., SW.,
Washington, DC 20460. Office location and telephone number: Room 1130A,
CM #2, 1921 Jefferson Davis Highway, Arlington, VA 22202, (703-305-
5937).
C. Magnitude of Residues.
The nature of the residue in plants is adequately understood for
the purposes of this time-limited tolerance.
D. International Residue Limits
No CODEX Maximum Residue Levels (MRLs) have been established for
dicamba in or on wheat, barley, soybeans, corn, cotton or asparagus.
Compatibility cannot be achieved with the Canadian, Mexican, German or
Australian tolerances because their levels are expressed in terms of
parent compound only.
IV. Conclusion
The scientific evaluation of data supporting dicamba using 100%
crop treated and anticipated residues for all population subgroups
examined by EPA shows the use on the raw agricultural commodities for
which tolerances are established or revised by this Final Rule will not
cause exposure at which the Agency believes there is an appreciable
risk and thus EPA concludes there is a reasonable certainty of no harm
from aggregate exposure to dicamba. Based on the information cited
above, EPA has determined that the tolerances for residues of dicamba
in the raw agricultural commodities listed in this Final Rule will be
safe; therefore, the tolerances are established as set forth below.
V. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by March 8, 1999, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the
[[Page 768]]
material submitted shows the following: There is genuine and
substantial issue of fact; there is a reasonable possibility that
available evidence identified by the requestor would, if established,
resolve one or more of such issues in favor of the requestor, taking
into account uncontested claims or facts to the contrary; and
resolution of the factual issues in the manner sought by the requestor
would be adequate to justify the action requested (40 CFR 178.32).
Information submitted in connection with an objection or hearing
request may be claimed confidential by marking any part or all of that
information as Confidential Business Information (CBI). Information so
marked will not be disclosed except in accordance with procedures set
forth in 40 CFR part 2. A copy of the information 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.
VI. Public Record and Electronic Submissions
EPA has established a record for this rulemaking under docket
control number [OPP-300767] (including any comments and data submitted
electronically). 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 public
record is located in Room 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in ``ADDRESSES'' at the beginning of this document.
VII. Regulatory Assessment Requirements
A. Certain Acts and Executive Orders
This final rule establishes tolerances under FFDCA section 408(d)
in response to a petition submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive Order 12866, entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993). This final rule does not contain
any information collections subject to OMB approval under the Paperwork
Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose any enforceable
duty or contain any unfunded mandate as described under Title II of the
Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does
it require any special considerations as required by Executive Order
12898, entitled Federal Actions to Address Environmental Justice in
Minority Populations and Low-Income Populations (59 FR 7629, February
16, 1994), or require OMB review in accordance with Executive Order
13045, entitled Protection of Children from Environmental Health Risks
and Safety Risks (62 FR 19885, April 23, 1997).
In addition, since tolerances and exemptions that are established
on the basis of a petition under FFDCA section 408(d), such as the
tolerances in this final rule, do not require the issuance of a
proposed rule, the requirements of the Regulatory Flexibility Act (RFA)
(5 U.S.C. 601 et seq.) do not apply. Nevertheless, the Agency has
previously assessed whether establishing tolerances, exemptions from
tolerances, raising tolerance levels or expanding exemptions might
adversely impact small entities and concluded, as a generic matter,
that there is no adverse economic impact. The factual basis for the
Agency's generic certification for tolerance actions published on May
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.
B. Executive Order 12875
Under Executive Order 12875, entitled Enhancing the
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may
not issue a regulation that is not required by statute and that creates
a mandate upon a State, local, or tribal government, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by those governments. If the mandate is unfunded, EPA
must provide to OMB a description of the extent of EPA's prior
consultation with representatives of affected State, local, and tribal
governments, the nature of their concerns, copies of any written
communications from the governments, and a statement supporting the
need to issue the regulation. In addition, Executive Order 12875
requires EPA to develop an effective process permitting elected
officials and other representatives of State, local, and tribal
governments ``to provide meaningful and timely input in the development
of regulatory proposals containing significant unfunded mandates.''
Today's rule does not create an unfunded Federal mandate on State,
local, or tribal governments. The rule does not impose any enforceable
duties on these entities. Accordingly, the requirements of section 1(a)
of Executive Order 12875 do not apply to this rule.
C. Executive Order 13084
Under Executive Order 13084, entitled Consultation and Coordination
with Indian Tribal Governments (63 FR 27655, May 19,1998), EPA may not
issue a regulation that is not required by statute, that significantly
or uniquely affects the communities of Indian tribal governments, and
that imposes substantial direct compliance costs on those communities,
unless the Federal government provides the funds necessary to pay the
direct compliance costs incurred by the tribal governments. If the
mandate is unfunded, EPA must provide to OMB, in a separately
identified section of the preamble to the rule, a description of the
extent of EPA's prior consultation with representatives of affected
tribal governments, a summary of the nature of their concerns, and a
statement supporting the need to issue the regulation. In addition,
Executive Order 13084 requires EPA to develop an effective process
permitting elected officials and other representatives of Indian tribal
governments ``to provide meaningful and timely input in the development
of regulatory policies on matters that significantly or uniquely affect
their communities.''
Today's rule does not significantly or uniquely affect the
communities of Indian tribal governments. This action does not involve
or impose any requirements that affect Indian tribes. Accordingly, the
requirements of section 3(b) of Executive Order 13084 do not apply to
this rule.
VIII. Submission to Congress and the Comptroller General
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement
[[Page 769]]
Fairness Act of 1996, generally provides that before a rule may take
effect, the agency promulgating the rule must submit a rule report,
which includes a copy of the rule, to each House of the Congress and to
the Comptroller General of the United States. EPA will submit a report
containing this rule and other required information to the U.S. Senate,
the U.S. House of Representatives, and the Comptroller General of the
United States prior to publication of the rule in the Federal Register.
This rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: December 22, 1998.
James Jones,
Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180-[AMENDED]
1. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a and 371.
2. Section 180.227 is amended by adding a paragraph heading to
paragraph (a), designating the text following the paragraph heading as
paragraph (a)(1), redesignating paragraphs (b) and (c) as paragraphs
(a)(2) and (a)(3), respectively, and by adding and reserving with
paragraph headings new paragraphs (b), (c) and (d).
3. Section 180.227 is further amended as follows:
i. In newly designated paragraph (a)(1), by revising the entries
for the following commodities: barley, grain; barley, straw; wheat,
grain; and wheat, straw; by adding alphabetically entries for barley,
hay; corn, field, forage; corn, field, stover; corn, pop stover;
cottonseed; cottonseed, meal; crop Group 17 (grass, forage, fodder and
hay); grass, forage; grass, hay; oats, forage; oats, hay; wheat,
forage; and wheat, hay; and by removing the entries for asparagus;
grasses, pasture; and grasses, rangeland.
ii. In newly designated paragraph (a)(2) by removing the entries
for soybeans; soybeans, forage; and soybeans, hay; and by adding an
entry in alphabetical order for asparagus.
iii. By revising newly designated paragraph (a)(3).
The added and revised text reads as follows:
Sec. 180.227 Dicamba; tolerances for residues.
(a) General. (1) * * *
------------------------------------------------------------------------
Commodity Parts per million
------------------------------------------------------------------------
Barley, grain............................. 6.0
Barley, hay............................... 2.0
Barley, straw............................. 15.0
* * * * *
Corn, field, forage....................... 3.0
Corn, field, stover....................... 3.0
* * * * *
Corn, pop, stover......................... 3.0
Cottonseed................................ 3.0
Cottonseed, meal.......................... 5.0
Crop Group 17 (grass, forage, fodder and
hay).
Grass, forage............................. 125.0
Grass, hay................................ 200.0
* * * * *
Oats, forage.............................. 80.0
* * * * *
Oats, hay................................. 20.0
* * * * *
Wheat, forage............................. 80.0
Wheat, grain.............................. 2.0
Wheat, hay................................ 20.0
Wheat, straw.............................. 30.0
------------------------------------------------------------------------
(2) * * *
------------------------------------------------------------------------
Parts Per
Commodity million
------------------------------------------------------------------------
Asparagus.................................................. 4.0
* * * * *
------------------------------------------------------------------------
(3) Tolerances are established for the combined residues of dicamba
(3,6-dichloro-o-anisic and its metablites 3,6-dichloro-5-hydroxy-o-
anisic acid and 3,6-dichloro-o-2-hydroxy-benzoic acid in or on the raw
agricultural commodities as follows:
------------------------------------------------------------------------
Parts Per
Commodity million
------------------------------------------------------------------------
Aspirated grain fractions.................................. 5100.0
Soybean, hulls............................................. 13.0
Soybean, seed.............................................. 10.0
------------------------------------------------------------------------
(b) Section 18 emergency exemptions. [Reserved]
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 99-109 Filed 1-5-99; 8:45 am]
BILLING CODE 6560-50-F
