Sulfuryl Fluoride; Proposed Order Granting Objections to Tolerances and Denying Request for a Stay, 3422-3449 [2011-917]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 76, Number 12 (Wednesday, January 19, 2011)]
[Proposed Rules]
[Pages 3422-3449]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-917]



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Part V





Environmental Protection Agency





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40 CFR Part 180



Sulfuryl Fluoride; Proposed Order Granting Objections to Tolerances and 
Denying Request for a Stay; Proposed Rule

Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 / 
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2005-0174; FRL-8857-9]


Sulfuryl Fluoride; Proposed Order Granting Objections to 
Tolerances and Denying Request for a Stay

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed Order.

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SUMMARY: In this document, EPA is making available its proposed 
resolution of objections and a stay request with regard to sulfuryl 
fluoride and fluoride tolerances promulgated in 2004 and 2005 under 
section 408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA). The 
objections and stay request were filed by the Fluoride Action Network, 
the Environmental Working Group, and Beyond Pesticides. Notwithstanding 
the fact that this document is a proposed resolution, and regulatory 
assessment requirements do not apply, EPA is inviting public comment on 
all aspects of the proposed resolution of objections, including the 
underlying scientific evaluations.

DATES: Comments must be received on or before April 19, 2011.

ADDRESSES: Submit your comments, identified by docket identification 
(ID) number EPA-HQ-OPP-2005-0174, by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket Facility's normal hours of operation (8:30 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays). 
Special arrangements should be made for deliveries of boxed 
information. The Docket Facility telephone number is (703) 305-5805.
    Instructions: Direct your comments to docket ID number EPA-HQ-OPP-
2005-0174. EPA's policy is that all comments received will be included 
in the docket without change and may be made available on-line at 
https://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through regulations.gov or e-
mail. The regulations.gov Web site is an ``anonymous access'' system, 
which means EPA will not know your identity or contact information 
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through regulations.gov, 
your e-mail address will be automatically captured and included as part 
of the comment that is placed in the docket and made available on the 
Internet. If you submit an electronic comment, EPA recommends that you 
include your name and other contact information in the body of your 
comment and with any disk or CD-ROM you submit. If EPA cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, EPA may not be able to consider your comment. Electronic 
files should avoid the use of special characters, any form of 
encryption, and be free of any defects or viruses.
    Docket: All documents in the docket are listed in the docket index 
available at https://www.regulations.gov. Although listed in the index, 
some information is not publicly available, e.g., CBI or other 
information whose disclosure is restricted by statute. Certain other 
material, such as copyrighted material, is not placed on the Internet 
and will be publicly available only in hard copy form. Publicly 
available docket materials are available either in the electronic 
docket at https://www.regulations.gov, or, if only available in hard 
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac 
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The hours of 
operation of this Docket Facility are from 8:30 a.m. to 4 p.m., Monday 
through Friday, excluding legal holidays. The Docket Facility telephone 
number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Meredith Laws, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: 703-308-7038; e-mail address: laws.meredith@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this action apply to me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, pesticide manufacturer, or 
consumer. Potentially affected entities may include, but are not 
limited to:
     Food manufacturing (NAICS code 311), e.g., grain and 
oilseed milling; animal food manufacturing; flour milling; bread and 
bakery product manufacturing; cookie, cracker, and pasta manufacturing; 
snack food manufacturing.
     Pesticide manufacturing (NAICS code 32532), e.g., 
pesticide manufacturers; commercial applicators.
     Community Food Services (NAICS code 624210), e.g., food 
banks.
     Farm Product Warehousing and Storage (NAICS code 493130), 
e.g., grain elevators, private and public food warehousing and storage.
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. What should I consider as I prepare my comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
regulations.gov or e-mail. Clearly mark the part or all of the 
information that you claim to be CBI. For CBI information in a disk or 
CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as 
CBI and then identify electronically within the disk or CD-ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2.
    2. Tips for preparing your comments. When submitting comments, 
remember to:
    i. Identify the document by docket ID number and other identifying 
information (subject heading, Federal Register date and page number).
    ii. Follow directions. The Agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.

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    iii. Explain why you agree or disagree; suggest alternatives and 
substitute language for your requested changes.
    iv. Describe any assumptions and provide any technical information 
and/or data that you used.
    v. If you estimate potential costs or burdens, explain how you 
arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
    vi. Provide specific examples to illustrate your concerns and 
suggest alternatives.
    vii. Explain your views as clearly as possible, avoiding the use of 
profanity or personal threats.
    viii. Make sure to submit your comments by the comment period 
deadline identified.

C. What are the acronyms used in this order?

    The following is a list of acronyms used in this order:

CAA--Clean Air Act
CAAA--Clean Air Act Amendments of 1990
CSFII--Continuing Survey of Food Intakes by Individuals
CUE--Critical Use Exemption
EPA--Environmental Protection Agency
FACA--Federal Advisory Committee Act
FAN--Fluoride Action Network
FDA--Food and Drug Administration
FIFRA--Federal Insecticide, Fungicide, and Rodenticide Act
FFDCA--Federal Food, Drug, and Cosmetic Act
FQPA--Food Quality Protection Act of 1996
IOM--Institute of Medicine
L--liter
LOAEL--Lowest Observed Adverse Effect Level
MCL--Maximum contaminant level
MCLG--Maximum contaminant level goal
mg--milligram
MOE--Margin of Exposure
MRID--Master Record Identification
NAS--National Academy of Sciences
NOAEL--No Observed Adverse Effect Level
NPDWR--National Public Drinking Water Regulations
NRC--National Research Council
NRDC--Natural Resources Defense Council
OPP--EPA's Office of Pesticide Programs
OW--EPA's Office of Water
PAD--Population Adjusted Dose
ppm--parts per million
RED--Reregistration Eligibility Decision
RfD--Reference Dose
SDWA--Safe Drinking Water Act
SMCL--Secondary maximum contaminant level
SOP--Standard Operating Procedure
USDA--United States Department of Agriculture

II. Introduction

A. What action is the agency taking?

    In this document, EPA is making available for comment a proposed 
order granting objections and denying a stay request with regard to 
tolerances established for sulfuryl fluoride and fluoride in 2004 (69 
FR 3240, January 23, 2004) (FRL-7342-1) and 2005 (70 FR 40899, July 15, 
2005) (FRL-7723-7) under FFDCA section 408 (21 U.S.C. 346a). (See 40 
CFR 180.145(c); 180.575). These objections were first filed by the 
Fluoride Action Network (FAN) and Beyond Pesticides/National Coalition 
Against the Misuse of Pesticides. (Ref. 1). FAN and Beyond Pesticides 
also requested a hearing on their objections. At a later date, FAN and 
Beyond Pesticides were joined by the Environmental Working Group 
(hereinafter the three parties are referred to as ``the Objectors'') 
(Refs. 2 and 3). The Objectors argue that the sulfuryl fluoride and 
fluoride tolerances should not have been established by EPA because 
aggregate exposure to fluoride is unsafe under FFDCA section 408. The 
stay request as to the tolerances was filed by the Objectors in June, 
2006, following release of a report by the National Research Council 
(NRC) of the National Academy of Sciences (NAS) concerning the risk of 
fluoride. (71 FR 38125, July 5, 2006) (FRL-8075-6).
    After reviewing the objections and the NRC Report, EPA is proposing 
to grant the objections because it agrees that aggregate exposure to 
fluoride for certain major identifiable population subgroups does not 
meet the safety standard in FFDCA section 408. Because EPA is proposing 
to grant the Objectors' objections a hearing is not warranted. Finally, 
EPA is proposing to deny the Objectors' request for a stay because the 
risks from continued sulfuryl fluoride use in the short term is 
insignificant while the environmental and economic consequences from a 
sudden withdrawal of sulfuryl fluoride, a methyl bromide replacement, 
are considerable.

B. What is the agency's authority for taking this action?

    The procedure for filing objections to tolerance actions and EPA's 
authority for acting on such objections is contained in section 408(g) 
of FFDCA (21 U.S.C. 346a(g)) and regulations at 40 CFR part 178. That 
same authority governs hearing and stay requests.

III. Statutory and Regulatory Background

    In this Unit, EPA provides background on the relevant statutes and 
regulations governing the Objectors' objections, requests for hearing, 
and request for a stay as well as on pertinent Agency policies and 
practices.
    Unit III.A. summarizes the requirements and procedures in section 
408 of FFDCA and applicable regulations pertaining to pesticide 
tolerances, including the procedures for objecting to EPA tolerance 
actions and the substantive standards for evaluating the safety of 
pesticide tolerances. This unit also discusses the closely-related 
statute under which EPA regulates the sale, distribution, and use of 
pesticides, the Federal Insecticide, Fungicide, and Rodenticide Act 
(FIFRA) (7 U.S.C. 136 et seq.).
    Unit III.B. provides an overview of the risk assessment process 
followed by EPA's Office of Pesticide Programs (OPP). It contains an 
explanation of how EPA identifies the hazards posed by pesticides, how 
EPA determines the level of exposure to pesticides that pose a concern 
(level of concern), how EPA measures human exposure to pesticides, and 
how hazard, level of concern conclusions, and human exposure estimates 
are combined to evaluate risk. Further, this unit presents background 
information on two Agency policies with particular relevance to this 
action.
    Unit III.C. provides a brief overview of the Safe Drinking Water 
Act (SDWA) and the Montreal Protocol on Substances that Deplete the 
Ozone Layer (Montreal Protocol) and Title VI of the Clean Air Act (CAA) 
addressing Stratospheric Ozone Protection. These statutory schemes and 
international treaty are relevant to this proceeding because EPA 
regulates fluoride, a sulfuryl fluoride degradate, under SDWA, and 
because sulfuryl fluoride has played an important role in the United 
States fulfilling its obligations under the Montreal Protocol and CAA. 
Specifically, sulfuryl fluoride is a substitute for the ozone-depleting 
pesticide, methyl bromide.

A. FFDCA/FIFRA and Applicable Regulations

    1. In general. EPA establishes maximum residue limits, or 
``tolerances,'' for pesticide residues in food under section 408 of 
FFDCA. (21 U.S.C. 346a). Without such a tolerance or an exemption from 
the requirement of a tolerance, a food containing a pesticide residue 
is ``adulterated'' under section 402 of FFDCA and may not be legally 
moved in interstate commerce. (21 U.S.C. 331, 342). Monitoring and 
enforcement of pesticide tolerances are carried out by the U.S. Food 
and Drug Administration (FDA) and the U.S. Department of Agriculture 
(USDA). Section 408 was substantially rewritten by the Food Quality 
Protection Act of 1996 (FQPA), which added the provisions establishing 
a detailed safety standard for pesticides, additional protections for 
infants and children, and the estrogenic substances screening

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program. (Pub. L. 104-170, 110 Stat. 1489 (1996)).
    EPA also regulates pesticides under FIFRA (7 U.S.C. 136 et seq.). 
While FFDCA authorizes the establishment of legal limits for pesticide 
residues in food, FIFRA requires the approval of pesticides prior to 
their sale and distribution, (7 U.S.C. 136a(a)), and establishes a 
registration regime for regulating the use of pesticides. FIFRA 
regulates pesticide use in conjunction with its registration scheme by 
requiring EPA review and approval of pesticide labeling and specifying 
that use of a pesticide inconsistent with its labeling is a violation 
of Federal law. (7 U.S.C. 136j(a)(2)(G)). In the FQPA, Congress 
integrated action under the two statutes by requiring that the safety 
standard under FFDCA be used as a criterion in FIFRA registration 
actions as to pesticide uses which result in dietary risk from residues 
in or on food, (7 U.S.C. 136(bb)), and directing that EPA coordinate, 
to the extent practicable, revocations of tolerances with pesticide 
cancellations under FIFRA. (21 U.S.C. 346a(l)(1)).
    2. Safety standard for pesticide tolerances. A pesticide tolerance 
may only be promulgated by EPA if the tolerance is ``safe.'' (21 U.S.C. 
346a(b)(2)(A)(i)). ``Safe'' is defined by the statute 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.'' (21 U.S.C. 346a(b)(2)(A)(ii)). Section 
408(b)(2)(D) directs EPA, in making a safety determination, to:

Consider, among other relevant factors--* * *
* * *available information concerning the aggregate exposure levels 
of consumers (and major identifiable subgroups of consumers) to the 
pesticide chemical residue and to other related substances, 
including dietary exposure under the tolerance and all other 
tolerances in effect for the pesticide chemical residue, and 
exposure from other non-occupational sources.* * *

(21 U.S.C. 346a(b)(2)(D)(v), (vi) and (viii)). EPA must also consider, 
in evaluating the safety of tolerances, ``safety factors which * * * 
are generally recognized as appropriate for the use of animal 
experimentation data.'' (21 U.S.C. 346a(b)(2)(D)(ix).
    Risks to infants and children are given special consideration. 
Specifically, section 408(b)(2)(C)(i)(II) requires that EPA assess the 
risk to pesticides based on ``available information concerning the 
special susceptibility of infants and children to the pesticide 
chemical residues, including neurological differences between infants 
and children and adults, and effects of in utero exposure to pesticide 
chemicals.* * * '' (21 U.S.C. 346a(b)(2)(C)(i)(II)). This provision 
also creates a presumption that EPA will use an additional safety 
factor for the protection of infants and children. Specifically, it 
directs that ``[i]n the case of threshold effects, * * * an additional 
tenfold margin of safety for the pesticide chemical residue and other 
sources of exposure shall be applied for infants and children to take 
into account potential pre- and post-natal toxicity and completeness of 
the data with respect to exposure and toxicity to infants and 
children.'' (21 U.S.C. 346a(b)(2)(C)). EPA is permitted to ``use a 
different margin of safety for the pesticide chemical residue only if, 
on the basis of reliable data, such margin will be safe for infants and 
children.'' (Id.). The additional safety margin for infants and 
children is referred to throughout this Order as the ``children's 
safety factor.''
    3. Procedures for establishing, amending, or revoking tolerances. 
Tolerances are established, amended, or revoked by rulemaking under the 
unique procedural framework set forth in FFDCA. Generally, a tolerance 
rulemaking is initiated by the party seeking to establish, amend, or 
revoke a tolerance by means of filing a petition with EPA. (See 21 
U.S.C. 346a(d)(1)). EPA publishes in the Federal Register a notice of 
the petition filing and requests public comment. (21 U.S.C. 
346a(d)(3)). After reviewing the petition, and any comments received on 
it, EPA may issue a final rule establishing, amending, or revoking the 
tolerance, issue a proposed rule to do the same, or deny the petition. 
(21 U.S.C. 346a(d)(4)).
    Once EPA takes final action on the petition by either establishing, 
amending, or revoking the tolerance or denying the petition, any person 
may file objections with EPA and seek an evidentiary hearing on those 
objections. (21 U.S.C. 346a(g)(2)). Objections and hearing requests 
must be filed within 60 days. (Id.). The statute provides that EPA 
shall ``hold a public evidentiary hearing if and to the extent the 
Administrator determines that such a public hearing is necessary to 
receive factual evidence relevant to material issues of fact raised by 
the objections.'' (21 U.S.C. 346a(g)(2)(B)). EPA regulations make clear 
that hearings will only be granted where it is shown that there is ``a 
genuine and substantial issue of fact,'' the requestor has identified 
evidence ``which, if established, resolve one or more of such issues in 
favor of the requestor,'' and the issue is ``determinative'' with 
regard to the relief requested. (40 CFR 178.32(b)). EPA's final order 
on the objections and requests for hearing is subject to judicial 
review. (21 U.S.C. 346a(h)(1)). The statute directs that tolerance 
regulations shall take effect upon publication unless EPA specifies 
otherwise. (40 U.S.C. 346a(g)(1)). EPA is authorized to stay the 
effectiveness of the tolerance if objections are filed. (Id.).

B. EPA Risk Assessment for Tolerances--Policy and Practice

    1. The safety determination--risk assessment. To assess risk of a 
pesticide tolerance, EPA combines information on pesticide toxicity 
with information regarding the route, magnitude, and duration of 
exposure to the pesticide. The risk assessment process involves four 
distinct steps:
    (1) Identification of the toxicological hazards posed by a 
pesticide;
    (2) Determination of the ``level of concern'' with respect to human 
exposure to the pesticide;
    (3) Estimation of human exposure to the pesticide; and
    (4) Characterization of risk posed to humans by the pesticide based 
on comparison of human exposure to the level of concern.
    a. Hazard identification. In evaluating toxicity or hazard, EPA 
reviews toxicity data, typically from studies with laboratory animals, 
to identify any adverse effects on the test subjects. Where available 
and appropriate, EPA will also take into account studies involving 
humans, including human epidemiological studies. For most pesticides, 
the animal toxicity database usually consists of studies investigating 
a broad range of endpoints including gross and microscopic effects on 
organs and tissues, functional effects on bodily organs and systems, 
effects on blood parameters (such as red blood cell count, hemoglobin 
concentration, hematocrit, and a measure of clotting potential), 
effects on the concentrations of normal blood chemicals (including 
glucose, total cholesterol, urea nitrogen, creatinine, total protein, 
total bilirubin, albumin, hormones, and enzymes such as alkaline 
phosphatase, alanine aminotransfersase and cholinesterases), and 
behavioral or other gross effects identified through clinical 
observation and measurement. EPA examines whether adverse effects are 
caused by different durations of exposure ranging from short-term 
(acute) to long-term (chronic) pesticide exposure and different routes 
of exposure (oral, dermal, inhalation). Further, EPA evaluates 
potential adverse effects in

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different age groups (adults as well as fetuses and juveniles). (Ref. 4 
at 8-10).
    EPA also considers whether the adverse effect has a threshold--a 
level below which exposure has no appreciable chance of causing the 
adverse effect. For effects that have no threshold, EPA assumes that 
any exposure to the substance increases the risk that the adverse 
effect may occur.
    b. Level of concern/dose-response analysis. Once a pesticide's 
potential hazards are identified, EPA determines a toxicological level 
of concern for evaluating the risk posed by human exposure to the 
pesticide. In this step of the risk assessment process, EPA essentially 
evaluates the levels of exposure to the pesticide at which effects 
might occur. An important aspect of this determination is assessing the 
relationship between exposure (dose) and response (often referred to as 
the dose-response analysis). EPA follows differing approaches to 
identifying a level of concern for threshold and non-threshold hazards.
    i. Threshold effects. In examining the dose-response relationship 
for a pesticide's threshold effects, EPA evaluates an array of toxicity 
studies on the pesticide. In each of these studies, EPA attempts to 
identify the lowest observed adverse effect level (LOAEL) and the no 
observed adverse effect level (NOAEL), which by definition is the next 
lower tested dose level below the LOAEL. Generally, EPA will use the 
lowest NOAEL from the available studies as a starting point (called 
``the Point of Departure'') in estimating the level of concern for 
humans. (Ref. 4 at 9 (The Point of Departure ``is simply the toxic dose 
that serves as the `starting point' in extrapolating a risk to the 
human population.'')). At times, however, EPA will use a LOAEL from a 
study as the Point of Departure when no NOAEL is identified in that 
study and the LOAEL is close to, or lower than, other relevant NOAELs. 
The Point of Departure is in turn used in choosing a level of concern. 
EPA will make separate determinations as to the Points of Departure, 
and correspondingly levels of concern, for both short and long exposure 
periods as well as for the different routes of exposure (oral, dermal, 
and inhalation).
    In recent years, EPA has increasingly used a more scientifically 
sophisticated approach to choosing the Point of Departure. This 
approach, called a benchmark dose, or BMD, estimates a point along a 
dose-response curve that corresponds to a specific response level. 
(Ref. 5). For example, a BMD10 represents a 10% change from 
the background or typical value for the response of concern. In 
contrast to the NOAEL/LOAEL approach, a BMD is calculated using a range 
of dose response data and thus better accounts for the variability and 
uncertainty in the experimental results due to characteristics of the 
study design, such as dose selection, dose spacing, and sample size. In 
addition to a BMD, EPA generally also calculates a ``confidence limit'' 
in the BMD. Confidence limits express the uncertainty in a BMD that may 
be due to sampling and/or experimental error. The lower confidence 
limit on the dose used as the BMD is termed the BMDL, which the Agency 
often uses as the Point of Departure. Use of the BMDL for deriving the 
Point of Departure rewards better experimental design and procedures 
that provide more precise estimates of the BMD, resulting in tighter 
confidence intervals. It also provides a health protective conservative 
estimate of the safe dose. Numerous scientific peer review panels over 
the last decade have supported the Agency's application of the BMD 
approach as a scientifically supportable method for deriving Points of 
Departure in human health risk assessment, and as an improvement over 
the historically applied approach of using NOAELs or LOAELs. (Refs. 6 
and 7).
    In estimating and describing the level of concern, the Point of 
Departure is at times used differently depending on whether the risk 
assessment addresses dietary or non-dietary exposures. For dietary 
risks, EPA uses the Point of Departure to calculate an acceptable level 
of exposure or reference dose (RfD). The RfD is calculated by dividing 
the Point of Departure by all applicable safety or uncertainty factors. 
Typically, EPA uses a baseline safety/uncertainty factor of 100X in 
assessing pesticide risk. That value includes a factor of 10 (10X) 
where EPA is using data from laboratory animals to account for the 
possibility that humans potentially have greater sensitivity to the 
pesticide than animals and another factor of 10X to account for 
potential variations in sensitivity among members of the human 
population. Additional safety factors may be added to address data 
deficiencies or concerns raised by the existing data. Under the FQPA, 
an additional safety factor of 10X is presumptively applied to protect 
infants and children, unless reliable data support selection of a 
different factor. This FQPA additional safety factor largely replaces 
pre-FQPA EPA practice regarding additional safety factors. (Ref. 8 at 
4-11).
    In implementing FFDCA section 408, EPA's Office of Pesticide 
Programs, also calculates a variant of the RfD referred to as a 
Population Adjusted Dose (PAD). APAD is the RfD divided by any portion 
of the FQPA safety factor that does not correspond to one of the 
traditional additional safety factors used in general Agency risk 
assessments. (Id. at 13-16). The reason for calculating PADs is so that 
other parts of the Agency, which are not governed by FFDCA section 408, 
can, when evaluating the same or similar substances, easily identify 
which aspects of a pesticide risk assessment are a function of the 
particular statutory commands in FFDCA section 408. Today, RfDs and 
PADs are generally calculated for both acute and chronic dietary risks 
although traditionally RfDs and PADs were only calculated for chronic 
risks. Throughout this document general references to OPP's calculated 
safe dose are denoted as an RfD/PAD.
    For non-dietary, and combined dietary and non-dietary, risk 
assessments of threshold effects, the toxicological level of concern is 
not expressed as an RfD/PAD but rather in terms of an acceptable (or 
target) margin of exposure (MOE) between human exposure and the Point 
of Departure. The ``margin'' of interest is the ratio between human 
exposure and the Point of Departure which is calculated by dividing 
human exposure into the Point of Departure. An acceptable MOE is 
generally considered to be a margin at least as high as the product of 
all applicable safety factors for a pesticide. For example, if a 
pesticide needs a 10X factor to account for potential inter-species 
differences, 10X factor for potential intra-species differences, and 
10X factor for the FQPA children's safety provision, the safe or target 
MOE would be a MOE of at least 1,000. What that means is that for the 
pesticide in the example to meet the safety standard, human exposure to 
the pesticide would generally have to be at least 1,000 times smaller 
than the Point of Departure. Like RfD/PADs, specific target MOEs are 
selected for exposures of different durations. For non-dietary 
exposures, EPA typically examines short-term, intermediate-term, and 
long-term exposures. Additionally, target MOEs may be selected based on 
both the duration of exposure and the various routes of non-dietary 
exposure--dermal, inhalation, and oral.
    ii. Non-threshold effects. For risk assessments for non-threshold 
effects, EPA does not use the RfD/PAD or MOE approach to choose a level 
of concern if quantification of the risk is deemed appropriate. Rather, 
EPA calculates the slope of the dose-response curve for the non-
threshold effects from relevant

[[Page 3426]]

studies frequently using a linear, low-dose extrapolation model that 
assumes that any amount of exposure will lead to some degree of risk. 
This dose-response analysis will be used in the risk characterization 
stage to estimate the risk to humans of the non-threshold effect.
    c. Estimating human exposure. Risk is a function of both hazard and 
exposure. Thus, equally important to the risk assessment process as 
determining the hazards posed by a pesticide and the toxicological 
level of concern for those hazards is estimating human exposure. Under 
FFDCA section 408, EPA is concerned not only with exposure to pesticide 
residues in food but also exposure resulting from pesticide 
contamination of drinking water supplies and from use of pesticides in 
the home or other non-occupational settings. (See 21 U.S.C. 
346a(b)(2)(D)(vi)). Additionally, EPA must take into account non-
occupational exposure from ``other related substances.'' (Id.).
    i. Exposure from food. There are two critical variables in 
estimating exposure in food:
     The types and amount of food that is consumed; and
     The residue level in that food.

Consumption is estimated by EPA based on scientific surveys of 
individuals' food consumption in the United States conducted by the 
USDA. (Ref. 4 at 12). Information on residue values comes from a range 
of sources including crop field trials, data on pesticide reduction (or 
concentration) due to processing, cooking, and other practices, 
information on the extent of usage of the pesticide, and monitoring of 
the food supply. (Id. at 17).
    In assessing exposure from pesticide residues in food, EPA, for 
efficiency's sake, follows a tiered approach in which it, in the first 
instance, assesses exposure using the worst case assumptions that 100% 
of the crop or commodity in question is treated with, or exposed to, 
the pesticide and 100% of the food from that crop or commodity contains 
pesticide residues at the tolerance level. (Id. at 11). When such an 
assessment shows no risks of concern, a more complex risk assessment is 
unnecessary. By avoiding a more complex risk assessment, EPA's 
resources are conserved and regulated parties are spared the cost of 
any additional studies that may be needed. If, however, a first tier 
assessment suggests there could be a risk of concern, EPA then attempts 
to refine its exposure assumptions to yield a more realistic picture of 
residue values through use of data on the percent of the crop or 
commodity actually treated with, or exposed to, the pesticide and data 
on the level of residues that may be present on the treated crop or 
commodity. These latter data are used to estimate what has been 
traditionally referred to by EPA as ``anticipated residues.''
    Use of percent crop/commodity treated data and anticipated residue 
information is appropriate because EPA's worst-case assumptions of 100% 
treatment and residues at tolerance value significantly overstate 
residue values. There are several reasons why this is true. First, all 
growers of a particular crop would rarely choose to apply the same 
pesticide to that crop (some may apply no pesticide; some may apply an 
alternative pesticide); generally, the proportion of the crop treated 
with a particular pesticide is significantly below 100%. (70 FR 46706, 
46731, August 10, 2005) (FRL-7727-4). This is true with food and 
structural fumigants such as sulfuryl fluoride as well, especially with 
regard to the structural fumigant use in food processing facilities 
because such use incurs infrequently and only potentially affects a 
small portion of the food processed in the facility. Second, the 
tolerance value represents a high end or worst case value. Tolerance 
values are chosen only after EPA has evaluated data from experimental 
trials in which the pesticide has been used in a manner, consistent 
with the draft FIFRA label, that is likely to produce the highest 
residue in the crop or food in question (e.g., maximum application 
rate, maximum number of applications, minimum pre-harvest interval 
between last pesticide application and harvest). (Refs. 4 and 9). These 
experimental trials are generally conducted in several locations and 
involve multiple samples. (Id. at 5, 7 and Tables 1 and 5). The results 
from such experimental trials invariably show that the residue levels 
for a given pesticide use will vary from as low as non-detectable to 
measurable values in the parts per million (ppm) range with the 
majority of the values falling at the lower part of the range. (70 FR 
46731) (FRL-7727-4). EPA uses a statistical procedure to analyze the 
experimental trial results and identify the upper bound of expected 
residue values. This upper bound value is typically used as the 
tolerance value. (Ref. 10). There may be some commodities from a 
treated crop or commodity that approach the tolerance value where the 
maximum label rates are followed, but most generally fall significantly 
below the tolerance value. If less than the maximum legal rate is 
applied, residues will be even lower. Third, residue values measured at 
the time of treatment do not take into account the lowering of residue 
values that frequently occurs as a result of degradation over time and 
through food processing and cooking.
    EPA uses several techniques to refine residue value estimates. 
(Ref. 4 at 17-28). First, where appropriate, EPA will take into account 
all the residue values reported in the experimental trials, either 
through use of an average or individually. Second, EPA will consider 
data showing what portion of the crop or commodity is not treated with, 
or exposed to, the pesticide. Third, data can be produced showing 
pesticide degradation and decline over time, and the effect of 
commercial and consumer food handling and processing practices. 
Finally, EPA can consult monitoring data gathered by the FDA, the USDA, 
or pesticide registrants, on pesticide levels in food at points in the 
food distribution chain distant from the farm, including retail food 
establishments.
    Another critical component of the exposure assessment is how data 
on consumption patterns are combined with data on pesticide residue 
levels in food. Traditionally, EPA has calculated exposure by simply 
multiplying average consumption by average residue values for 
estimating chronic risks and high-end consumption by maximum residue 
values for estimating acute risks. Using average residues is a 
realistic approach for chronic risk assessment due to the fact that 
variations in residue levels and consumption amounts average out over 
time especially given the nationwide market for food in the United 
States. Using average values is inappropriate for acute risk 
assessments, however, because in assessing acute exposure situations it 
matters how much of each treated food a given consumer eats in the 
short-term and what the residue levels are in the particular foods 
consumed. Yet, using maximum residue values for acute risk assessment 
tends to greatly overstate exposure because it is unlikely that a 
person would consume at a single meal multiple food components bearing 
high-end residues. To take into account the variations in short-term 
consumption patterns and food residue values for acute risk 
assessments, EPA uses probabilistic modeling techniques for estimating 
exposure when more simplistic models appear to show risks of concerns.
    All of these refinements to the exposure assessment process, from 
use of food monitoring data through probabilistic modeling, can have 
dramatic effects on the level of exposure

[[Page 3427]]

predicted, typically reducing worst case estimates by at least 1 or 2 
orders of magnitude. (Ref. 11 at 16-17; 70 FR 46706, 46732, August 10, 
2005) (FRL-7727-4).
    ii. Exposure from water. EPA may use either or both field 
monitoring data and mathematical water exposure models to generate 
pesticide exposure estimates in drinking water. Monitoring and modeling 
are both important tools for estimating pesticide concentrations in 
water and can provide different types of information. Monitoring data 
can provide estimates of pesticide concentrations in water that are 
representative of specific agricultural or residential pesticide 
practices and under environmental conditions associated with a sampling 
design. Although monitoring data can provide a direct measure of the 
concentration of a pesticide in water, it does not always provide a 
reliable estimate of exposure because sampling may not occur in areas 
with the highest pesticide use, and/or the sampling may not occur when 
the pesticides are being used.
    In estimating pesticide exposure levels in drinking water, EPA most 
frequently uses mathematical water exposure models. EPA's models are 
based on extensive monitoring data and detailed information on soil 
properties, crop characteristics, and weather patterns. (69 FR 30042, 
30058-30065, May 26, 2004) (FRL-7355-7). These models calculate 
estimated environmental concentrations of pesticides using laboratory 
data that describe how fast the pesticide breaks down to other 
chemicals and how it moves in the environment. These concentrations can 
be estimated continuously over long periods of time, and for places 
that are of most interest for any particular pesticide. Modeling is a 
useful tool for characterizing vulnerable sites, and can be used to 
estimate peak concentrations from infrequent, large storms.
    Unlike assessments of exposure to pesticides in food, assessments 
of exposure to pesticides in drinking water conducted under FIFRA and 
FFDCA section 408 do not assume there is a nationwide market for 
drinking water. A person's source of drinking water is primarily local 
and often the pesticide use is quite localized as well. Thus, generally 
EPA assesses drinking water exposure to pesticides under FIFRA and 
FFDCA section 408 based on the most vulnerable watersheds and not on a 
national or even regional average. (See 74 FR 59608, 59618-59619, 
59658, November 18, 2009) (FRL-8797-6). Further, these assessments 
commonly use high-end residue estimates from models and assume average 
consumption levels.
    In the case of fluoride, however, the primary source of exposure is 
not from pesticide use. Additionally, as described in Unit V.A.2., EPA 
has an extensive monitoring database from across the United States on 
fluoride levels in drinking water. These factors have been taken into 
account in how EPA has conducted its FFDCA section 408 risk assessment 
for fluoride.
    d. Risk characterization. The final step in the risk assessment is 
risk characterization. In this step, EPA combines information from the 
first three steps (hazard identification, level of concern/dose-
response analysis, and human exposure assessment) to quantitatively 
estimate the risks posed by a pesticide. Separate characterizations of 
risk are conducted for different durations of exposure. Additionally, 
separate and, where appropriate, aggregate characterizations of risk 
are conducted for the different routes of exposure (dietary and non-
dietary).
    For threshold risks, EPA estimates risk in one of two ways. Where 
EPA has calculated a RfD/PAD, risk is estimated by expressing human 
exposure as a percentage of the RfD/PAD. Exposures lower than 100% of 
the RfD/PAD are generally not of concern. Alternatively, EPA may 
express risk by comparing the MOE between estimated human exposure and 
the Point of Departure with the acceptable or target MOE. As described 
previously, the acceptable or target MOE is the product of all 
applicable safety factors. To calculate the actual MOE for a pesticide, 
estimated human exposure to the pesticide is divided into the Point of 
Departure. In contrast to the RfD/PAD approach, higher MOEs denote 
lower risk. Accordingly, if the target MOE for a pesticide is 100, MOEs 
equal to or exceeding 100 would generally not be of concern.
    As a conceptual matter, the RfD/PAD and MOE approaches are 
fundamentally equivalent. For a given risk and given exposure of a 
pesticide, if exposure to a pesticide were found to be acceptable under 
an RfD/PAD analysis it would also pass under the MOE approach, and 
vice-versa. However, for any specific pesticide, risk assessments for 
different exposure durations or routes may yield different results. 
This is a function not of the choice of the RfD/PAD or MOE approach but 
of the fact that the levels of concern and the levels of exposure may 
differ depending on the duration and route of exposure.
    For non-threshold risks (generally, cancer risks), EPA uses the 
slope of the dose-response curve for a pesticide in conjunction with an 
estimation of human exposure to that pesticide to estimate the 
probability of occurrence of additional adverse effects. Under FFDCA 
section 408, for non-threshold cancer risks, EPA generally considers 
cancer risk to be negligible if the probability of increased cancer 
cases falls within the range of 1 in 1 million. EPA describes this 
quantitative standard as a ``range'' because it does not want to impart 
a false precision to numerical cancer risk estimates. EPA seeks to 
identify risks differing significantly from a 1 in 1 million risk and 
that involves both a quantitative as well as qualitative assessment of 
what a risk estimate represents.
    2. EPA policy on the children's safety factor. As the previous 
brief summary of EPA's risk assessment practice indicates, the use of 
safety factors plays a critical role in the process. This is true for 
traditional 10X safety factors to account for potential differences 
between animals and humans when relying on studies in animals (inter-
species safety factor) and potential differences among humans (intra-
species safety factor) as well as the FQPA's additional 10X children's 
safety factor.
    In applying the children's safety factor provision, EPA has 
interpreted it as imposing a presumption in favor of applying an 
additional 10X safety factor. (Ref. 8 at 4, 11). Thus, EPA generally 
refers to the additional 10X factor as a presumptive or default 10X 
factor. EPA has also made clear, however, that this presumption or 
default in favor of the additional 10X is only a presumption. The 
presumption can be overcome if reliable data demonstrate that a 
different factor is safe for children. (Id.). In determining whether a 
different factor is safe for children, EPA focuses on the three factors 
listed in section 408(b)(2)(C)--the completeness of the toxicity 
database, the completeness of the exposure database, and potential pre- 
and post-natal toxicity. In examining these factors, EPA strives to 
make sure that its choice of a safety factor, based on a weight-of-the-
evidence evaluation, does not understate the risk to children. (Id. at 
24-25, 35).

C. SDWA and the Montreal Protocol/CAA

    1. SDWA. SDWA (42 U.S.C. 300f et seq.) was enacted to assure that 
water supply systems serving the public meet minimum national standards 
for the protection of public health and to protect the underground 
sources of drinking water upon which the public

[[Page 3428]]

relies. (See generally A Legislative History of the Safe Drinking Water 
Act, Committee Print, 97th Cong., 2d Sess. (1982) at 533-541). Under 
SDWA, EPA is authorized to set ``National primary drinking water 
regulations'' (NPDWRs) governing contaminants which the Administrator 
determines may have an adverse effect on the health of persons. NPDWRs 
apply to ``public water systems'' nationwide and include monitoring and 
reporting requirements. (42 U.S.C. 300g-1).
    ``Public water systems'' are defined as systems that provide water 
to the public through pipes or other constructed conveyances for human 
consumption and that have at least 15 service connections or regularly 
serve at least 25 individuals. (42 U.S.C. 300f(4)(A)). By regulation, 
EPA has interpreted ``regularly serve at least 25 individuals'' to mean 
providing water to an average of at least 25 individuals daily at least 
60 days of the year. (40 CFR 141.2). There are over 160,000 public 
water systems in the United States. The vast majority of these systems 
(95%) are small (i.e. serve populations of 3,300 persons or less) and 
these systems only serve about 10% of the population. Many of these 
small systems rely on groundwater as a water source. The largest 2% of 
the public water systems serve 80% of the population and include the 
large metropolitan water systems such as in New York City, Washington, 
DC, Boston and Chicago. Most of these systems rely on surface waters as 
their primary water source. Public drinking water systems provide water 
to roughly 85 to 90% of the U.S. population.
    In promulgating a NPDWR for a contaminant, EPA must establish both 
a maximum contaminant level goal (MCLG) for that contaminant as well as 
either a maximum contaminant level (MCL) or a treatment technology 
requirement. (42 U.S.C. 300g-1(a)(3) and 300g-1(b)(4)(7)). MCLGs are 
not regulatory requirements and do not impose any obligations on public 
water systems. Rather, MCLGs are health goals that are to be set at a 
level at which, in the Administrator's judgment, ``no known or 
anticipated adverse effects on the health of persons occur and which 
allows for an adequate margin of safety.'' (42 U.S.C. 300g-1(b)(4)(A)).
    A MCL sets a level of the contaminant not to be exceeded by public 
water systems and, with some exceptions is to be set as close to the 
MCLG as is ``feasible.'' (42 U.S.C. 300g-1(b)(4)(B)). The Act defines 
feasible to mean ``feasible with the use of the best technology, 
treatment techniques or other means which the Administrator finds * * * 
are available (taking costs into consideration).'' (42 U.S.C. 300g-
(b)(4)(D)). The legislative history for this provision makes it clear 
that ``feasibility'' is to be defined relative to ``what may reasonably 
be afforded by large metropolitan or regional public water systems.'' 
(A Legislative History of the Safe Drinking Water Act, Committee Print, 
97th Cong., 2d Sess. (1982) at 550. MCLs appear at 40 CFR part 141, 
subparts B and G).
    A treatment technique requirement imposes an obligation on public 
water systems to use an identified treatment technology and it must 
``prevent known or anticipated adverse effects on the health of persons 
to the extent feasible.'' (42 U.S.C. 300g-1(b)(7)(A). EPA may establish 
treatment technique requirements in lieu of an MCL only if it is not 
economically or technologically feasible to ascertain the level of the 
contaminant. (Id.).
    SDWA also authorizes EPA to set ``secondary'' drinking water 
standards or ``SMCLs.'' Such standards specify levels which are 
necessary to protect ``the public welfare,'' (42 U.S.C. 300f(2)), but 
are not Federally enforceable (see A Legislative History of the Safe 
Drinking Water Act, Committee Print, 97th Cong., 2d Sess. (1982) at 
557). For example, such a contaminant level might be one which 
adversely affects the odor or appearance of water so that a large 
number of people discontinue using that source. SMCLs may vary by 
geography or other circumstances. EPA has established SMCLs for 15 
contaminants, which are intended to be guidelines for the States. (40 
CFR part 143).
    Every 6 years, EPA is required to review and revise ``as 
appropriate'' its existing drinking water standards. (42 U.S.C. 300g-
1(b)(9)).
    There is a long history of regulation of fluoride under SDWA. In 
1975, EPA established a MCL for fluoride at a level varying between 1.4 
milligrams (mg)/liter (L) and 2.4 mg/L depending on annual ambient air 
temperature. (40 FR 59566, December 24, 1975). These levels were set to 
prevent objectionable dental fluorosis. In 1981, South Carolina 
petitioned EPA to revoke the fluoride MCL arguing that dental fluorosis 
is merely a cosmetic effect not an adverse health effect. (See 50 FR 
20164, May 14, 1985). In response to that petition, EPA took a series 
of actions. First, in 1985, EPA established a MCLG for fluoride at 4 
mg/L. (50 FR 47142, November 14, 1985) (At that time MCLGs were termed 
``recommended maximum contaminant levels'' (RMCLs) under SDWA.). The 
MCLG was set to protect against crippling skeletal fluorosis, an 
adverse health effect associated with high levels of fluoride exposure. 
EPA concluded that dental fluorosis, which had formed the basis for the 
earlier MCL, was not an adverse health effect under SDWA but only a 
cosmetic effect. Second, in 1986, EPA established a MCL for fluoride at 
4 mg/L, again based on the crippling skeletal fluorosis endpoint. (51 
FR 11396, April 2, 1986). Finally, also in 1986, EPA established a SMCL 
for fluoride at 2 mg/L to protect against objectionable dental 
fluorosis. (Id.). Judicial review of the MCLG was sought by both the 
Natural Resources Defense Council (NRDC) and by South Carolina. (NRDC 
v. EPA, 812 F.2d 721 (DC Cir. 1987)). NRDC argued that the level was 
too high because, among other reasons, the MCLG should have been set on 
dental fluorosis. Taking the opposite position, South Carolina claimed 
that no MCLG at all was appropriate because the evidence did not 
support that fluoride caused any adverse health effects. The DC Circuit 
upheld EPA's regulation ruling that EPA had reasonably interpreted SDWA 
term adverse health effect to be limited to functional impairments and 
that EPA had reasonably concluded that effects of dental fluorosis were 
cosmetic in nature and did not result in functional impairment. South 
Carolina's challenge was dismissed based on the court's conclusion that 
EPA had made a ``permissible administrative judgment'' based on the 
evidence before it. (Id. at 725).
    Subsequent to these rulemakings, EPA has on two occasions asked NAS 
to reevaluate the potential risks of fluoride exposure in regard to the 
MCLG/MCL. The NRC Report on the second request is discussed extensively 
in Unit IV.D.
    2. The Montreal Protocol/CAA and methyl bromide. The Montreal 
Protocol is the international agreement aimed at reducing and 
eliminating the production and consumption of stratospheric ozone-
depleting substances. The stratospheric ozone layer protects humans 
from overexposure to harmful ultraviolet radiation. The United States 
was one of the original signatories to the 1987 Montreal Protocol and 
the United States ratified the Protocol in April, 1988. Congress then 
enacted the Clean Air Act Amendments (CAAA) of 1990 which included 
Title VI on Stratospheric Ozone Protection, codified as 42 U.S.C. 
Chapter 85, Subchapter VI, to ensure that the United States could 
satisfy its obligations under the Montreal Protocol. EPA issued 
regulations in 40 CFR part 82 to implement this legislation and has 
since modified and updated the regulations as needed. In 2009, the 
Montreal Protocol became the first

[[Page 3429]]

universally ratified international environmental treaty.
    Methyl bromide was added to the Montreal Protocol as an ozone-
depleting substance in 1992 through the Copenhagen Amendment to the 
Protocol. The Parties to the Montreal Protocol (Parties) agreed that 
each developed country's level of methyl bromide production and 
consumption in 1991 should be the baseline for establishing a freeze. 
Under the Montreal Protocol and Title VI of the CAAA the term 
``consumption'' is a calculated amount equal to production plus imports 
minus exports. EPA published a final rule in the Federal Register on 
December 10, 1993 (58 FR 65018), listing methyl bromide as a Class I, 
Group VI controlled substance, freezing U.S. production and consumption 
at this 1991 baseline level of 25,528,270 kilograms, and setting forth 
the percentage of baseline allowances for methyl bromide granted to 
companies in each control period (each calendar year) until 2001, when 
the complete phase-out would occur. This phase-out date was established 
in response to a petition filed in 1991 under sections 602(c)(3) and 
606(b) of CAAA of 1990, requesting that EPA list methyl bromide as a 
Class I substance and phase out its production and consumption. This 
date was consistent with section 602(d) of CAAA of 1990, which, for 
newly listed Class I ozone-depleting substances, provides that ``no 
extension [of the phase-out schedule in section 604] under this 
subsection may extend the date for termination of production of any 
class I substance to a date more than 7 years after January 1 of the 
year after the year in which the substance is added to the list of 
class I substances.''
    At the Seventh Meeting of the Parties (MOP) in 1995, the Parties 
made adjustments to the methyl bromide control measures and agreed to 
reduction steps and a 2010 phase-out date for industrialized countries 
with exemptions permitted for critical uses. At that time, the United 
States continued to have a 2001 phase-out date in accordance with 
section 602(d) of CAAA of 1990. At the Ninth MOP in 1997, the Parties 
agreed to further adjustments to the phase-out schedule for methyl 
bromide in industrialized countries, with reduction steps leading to a 
2005 phase-out.
    In October 1998, the U.S. Congress amended CAA to conform the U.S. 
schedule to the schedule specified under the Protocol for developed 
countries by requiring EPA to move the date for ending production to 
January 1, 2005 and authorizing EPA to provide certain exemptions. 
These amendments were contained in section 764 of the 1999 Omnibus 
Consolidated and Emergency Supplemental Appropriations Act (Pub. L. 
105-277, October 21, 1998) and were codified in section 604 of CAA. (42 
U.S.C. 7671c). The amendment that specifically addresses the critical 
use exemption (CUE) appears at section 604(d)(6), 42 U.S.C. 
7671c(d)(6). EPA revised the phase-out schedule for methyl bromide 
production and consumption in a direct final rulemaking on November 28, 
2000 (65 FR 70795) (FRL-6906-4), which allowed for the phased reduction 
in methyl bromide consumption specified under the Protocol and extended 
the phase-out to 2005. EPA again amended the regulations to allow for 
an exemption for quarantine and preshipment purposes with an interim 
final rule on July 19, 2001 (66 FR 37752)(FRL-7014-5) and with a final 
rule on January 2, 2003 (68 FR 238)(FRL-7434-1).
    On December 23, 2004 (69 FR 76982)(FRL-7850-8), EPA published a 
final rule that established the framework for the CUE; set forth a list 
of approved critical uses for 2005; and specified the amount of methyl 
bromide that could be supplied in 2005 from stocks and new production 
or import to meet the needs of approved critical uses. EPA subsequently 
published rules applying the CUE framework to the 2006, 2007, 2008, 
2009, and 2010 control periods.
    Since its introduction in 2004, sulfuryl fluoride has served as an 
alternative to methyl bromide with regard to methyl bromide's use as a 
post-harvest commodity fumigant and fumigant for food processing 
warehouses and facilities. Introduction of sulfuryl fluoride has played 
a significant role in the United States' reduction of the postharvest 
methyl bromide CUEs by almost 80% over the last 6 years.

IV. Regulatory History of Sulfuryl Fluoride

A. In General

    Sulfuryl fluoride is a fumigant that is used to kill insect pests, 
rodents, birds, and snakes. It is used both for the treatment of 
structures as well as stored food. Sulfuryl fluoride was initially 
registered under FIFRA as Vikane[supreg], a fumigant to treat drywood 
termites and other wood boring insects in 1959. More recently, sulfuryl 
fluoride was identified as a potential alternative for uses of methyl 
bromide as a food fumigant and as a fumigant of food processing 
facilities. It was registered under the name of ProFume[supreg] by Dow 
AgroSciences for these uses in 2004 and 2005. Sulfuryl fluoride has 
achieved significant penetration of several methyl bromide markets. EPA 
and Dow AgroSciences have concluded that sulfuryl fluoride is used in 
approximately 40% of mills and food processing facilities and is used 
on 100% of cocoa beans. More recently, sulfuryl fluoride has been used 
extensively in fumigating walnuts and dried fruit other than raisins.
    Sulfuryl fluoride rapidly breaks down to form sulfate and the 
fluoride anion.

B. 2004 Registration and Tolerances

    In 2004, EPA registered sulfuryl fluoride for use as a direct 
fumigant of various grains and dried fruits under FIFRA and established 
corresponding tolerances under FFDCA section 408. (69 FR 3240, January 
23, 2004)(FRL-7342-1). Tolerances were established for both the parent 
chemical, sulfuryl fluoride, and the breakdown product, fluoride. (For 
convenience, both the sulfuryl fluoride and fluoride tolerances 
established in association with the use of sulfuryl fluoride are, 
hereinafter, referred to in this document as sulfuryl fluoride 
tolerances.) Separate risk assessments were conducted for sulfuryl 
fluoride and fluoride.
    In assessing the risk of fluoride, EPA relied on the MCLG that had 
been established under SDWA to establish a RfD-like value for fluoride. 
Established in 1986, the fluoride MCLG is 4 mg/L and is based on the 
adverse effect of crippling skeletal fluorosis. (40 CFR 141.41). As was 
the case with the MCLG, EPA determined that dental fluorosis was not an 
adverse effect and thus was not an appropriate benchmark for evaluating 
the safety of fluoride under FFDCA. EPA also determined that, ``given 
the wealth of reliable human data on fluoride,'' the presumptive 
additional 10X children's safety factor could be removed. (69 FR 3253) 
(FRL-7342-1). Using the MCLG in combination with high-end water 
consumption information and body weights for age subgroups from infants 
through adults, EPA calculated safe fluoride levels on a milligram of 
fluoride per kilogram of body weight per day (mg/kg/day) basis. (69 FR 
3248) (FRL-7342-1). These RfD-like values were compared to estimated 
aggregate exposure levels to fluoride from numerous sources: From use 
of the pesticides sulfuryl fluoride and cryolite on food; from natural 
and artificial levels of fluoride in drinking water; from background 
levels of fluoride in beverages, food, and ambient air; and from 
fluoride in dental products. Because aggregate exposure for each of

[[Page 3430]]

the age-based population subgroups fell below the calculated RfD-like 
values, EPA concluded that the tolerances were safe.
    Although FAN did not submit comments on the notice announcing Dow 
AgroSciences' petition for tolerances, FAN had submitted objections to 
an earlier sulfuryl fluoride tolerance action. That earlier tolerance 
action was the establishment of temporary tolerances for sulfuryl 
fluoride on various grains and dried fruits in conjunction with an 
experimental use permit for sulfuryl fluoride under FIFRA section 5. (7 
U.S.C. 136c). Sulfuryl fluoride was never used under that experimental 
permit and the temporary tolerances were revoked with the establishment 
of the 2004 tolerances. However, EPA treated the FAN objections as 
comments on the petition for tolerances and responded to them in detail 
in promulgating the 2004 tolerances. (Refs. 13, 14 and 15). Because EPA 
recognized that the NAS was undertaking a comprehensive evaluation of 
the latest data on fluoride, EPA noted that its review of the data 
submitted by FAN was preliminary and subject to reevaluation once the 
NRC Report was complete. (Ref. 14).
    On March 23, 2004, FAN, joined by Beyond Pesticides, filed 
objections to the 2004 tolerances and requested a hearing on those 
objections. (See Unit IV.D.).

C. 2005 Registration and Tolerances

    In 2005, EPA registered sulfuryl fluoride for use as a direct 
fumigant on additional commodities and also as a structural fumigant 
for food processing facilities under FIFRA and established 
corresponding tolerances under FFDCA section 408. (70 FR 40899, July 
15, 2005) (FRL-7723-7). Again, EPA relied on the MCLG in assessing the 
aggregate risk to fluoride, taking into account the additional fluoride 
exposure from the new uses. (Id. at 40905). EPA also assessed fluoride 
risk using the Point of Departure suggested by NAS' Institute of 
Medicine for evaluating the risk of crippling skeletal fluorosis. (Id. 
at 40906). Under both approaches, EPA concluded that the tolerances 
were safe.
    FAN submitted comments on the notice announcing Dow AgroSciences' 
petition for tolerances. EPA prepared a detailed response to these 
comments. (Ref. 16).
    On September 13, 2005, FAN, joined by Beyond Pesticides and the 
Environmental Working Group, filed objections to the 2005 tolerances 
and requested a hearing on those objections. (See Unit IV.D.).

D. The 2006 NRC Report

    In 2003, EPA's Office of Water (OW) asked the NRC to review new 
research on fluoride to determine whether the MCLG and SMCL for 
fluoride established under SDWA adequately protect the public health. 
(Ref. 17 at xii). Specifically, EPA asked NRC ``to review toxicologic, 
epidemiologic, and clinical data on fluoride--particularly data 
published since NRC's previous (1993) report--and exposure data on 
orally ingested fluoride from drinking water and other sources * * *, 
'' and ``to evaluate independently the scientific basis of EPA's MCLG 
of 4 mg/L and SMCL of 2 mg/L in drinking water and the adequacy of 
those guidelines to protect children and others from adverse health 
effects.'' (Id. at 2). NRC was also asked to identify data gaps and to 
make recommendations for future research relevant to setting the MCLG 
and SMCL for fluoride.'' (Id.).
    NRC completed its report in March 2006. Its overall conclusions 
were that: (1) ``EPA's MCLG of 4 mg/L should be lowered;'' (2) further 
study was needed to assess the protectiveness of the SMCL of 2 mg/L; 
and (3) ``EPA should update the risk assessment of fluoride to include 
new data on health risks and better estimates of total exposure 
(relative source contribution) in individuals and to use current 
approaches to quantifying risk, considering susceptible subpopulations, 
and characterizing uncertainties and variability.'' (Id. at 352).
    NRC's decision as to the MCLG was driven by its concern regarding 
the fluoride exposure levels