Dimethyl Ether; Exemption from the Requirement of a Tolerance, 28436-28443 [05-9475]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 70, Number 95 (Wednesday, May 18, 2005)]
[Rules and Regulations]
[Pages 28436-28443]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-9475]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 80

[OPP -2005-0109; FRL-7711-4]


Dimethyl Ether; Exemption from the Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes an exemption from the requirement 
of a tolerance for residues of dimethyl ether or methane, oxybis- as an 
inert ingredient (propellant) in pesticide formulations applied to 
growing crops or to raw agricultural commodities (RAC) after harvest. 
The DuPont Company, DuPont Fluoroproducts submitted a petition to EPA 
under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by 
the Food Quality Protection Act of 1996 (FQPA), requesting an exemption 
from the requirement of a tolerance. This regulation eliminates the 
need to establish a maximum permissible level for residues of dimethyl 
ether.

DATES: This regulation is effective May 18, 2005. Objections and 
requests for hearings must be received on or before July 18, 2005.

ADDRESSES: To submit a written objection or hearing request follow the 
detailed instructions as provided in Unit XIV. of the SUPPLEMENTARY 
INFORMATION. EPA has established a docket for this action under Docket 
identification (ID) number OPP-2005-0109. All documents in the docket 
are listed in the EDOCKET index at https://www.epa.gov/edocket. Although 
listed in the index, some information is not publicly available, i.e., 
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 electronically 
in EDOCKET or in hard copy at the Public Information and Records 
Integrity Branch (PIRIB), Rm. 119, Crystal Mall 2, 1801 S. 
Bell St., Arlington, VA. This docket facility is open from 8:30 a.m. to 
4 p.m., Monday through Friday, excluding legal holidays. The docket 
telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Kathryn Boyle, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 305-6304; e-mail address: boyle.kathryn@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, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
     Crop production (NAICS 111)
     Animal production (NAICS 112)
     Food manufacturing (NAICS 311)
     Pesticide manufacturing (NAICS 32532)
    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

[[Page 28437]]

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. How Can I Get Electronic Documents and Other Related Information?

    In addition to using EDOCKET at (https://www.epa.gov/edocket/), you 
may access this Federal Register document electronically through the 
EPA Internet under the ``Federal Register'' listings at https://
www.epa.gov/fedrgstr/. A frequently updated electronic version of 40 
CFR part 180 is available at E-CFR Beta Site Two at https://
www.gpoaccess.gov/ecfr/.

II. Background and Statutory Findings

    In the Federal Register of September 27, 2000 (65 FR 58078) (FRL-
6742-4), EPA issued a notice pursuant to section 408(d)(3) of the 
FFDCA, 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide 
tolerance petition (6E4785) by the DuPont Company, DuPont 
Fluoroproducts, Chestnut Run Plaza, P.O. Box 80711, Wilmington, DE, 
19880-0711. This notice included a summary of the petition prepared by 
the petitioner.
    The petition requested that 40 CFR 180.1001(c) now redesignated as 
40 CFR 180.910 be amended by establishing an exemption from the 
requirement of a tolerance for residues of dimethyl ether (DME), also 
known as methane, oxybis, (CAS Reg. No. 115-10-6) as an inert 
ingredient (propellant) in pesticide formulations applied to growing 
crops or to RAC after harvest. There were no comments received in 
response to the notice of filing.
    Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish an 
exemption from the requirement for 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) of the FFDCA 
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) of the FFDCA 
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. First, EPA determines the 
toxicity of pesticides. Second, EPA examines exposure to the pesticide 
through food, drinking water, and through other exposures that occur as 
a result of pesticide use in residential settings.

III. Inert Ingredient Definition

    Inert ingredients are all ingredients that are not active 
ingredients as defined in 40 CFR 153.125 and include, but are not 
limited to, the following types of ingredients (except when they have a 
pesticidal efficacy of their own): Solvents such as alcohols and 
hydrocarbons; surfactants such as polyoxyethylene polymers and fatty 
acids; carriers such as clay and diatomaceous earth; thickeners such as 
carrageenan and modified cellulose; wetting, spreading, and dispersing 
agents; propellants in aerosol dispensers; microencapsulating agents; 
and emulsifiers. The term ``inert'' is not intended to imply 
nontoxicity; the ingredient may or may not be chemically active. 
Generally, EPA has exempted inert ingredients from the requirement of a 
tolerance based on the low toxicity of the individual inert 
ingredients.

IV. Physical/Chemical Properties

    The vapor pressure of DME is 4,450 mm Hg @ 25[deg]C. DME exists as 
a gas at room temperature, thus allowing it to spread and disperse 
rapidly. DME is soluble in water (7% by weight). The flash point of DME 
is -41[deg]C or -42[deg]C with flammable limits in air of 3.4% by 
volume in air (lower limit) and 18.0% (upper limit). DME is slightly 
heavier than air with a density of 1.92 grams/Liter @ 1 atmosphere and 
25[deg]C.

V. Toxicological Profile

    Consistent with section 408(b)(2)(D) of the FFDCA, EPA has reviewed 
the available scientific data and other relevant information in support 
of this action and considered its validity, completeness and 
reliability, and the relationship of this information 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 identified in DME toxicity studies are discussed in this unit.

A. Review and Evaluation of Five Inhalation Toxicity Studies

    The Agency reviewed and evaluated the following five inhalation 
toxicity studies conducted using DME.

          Table 1.--Dimethyl Ether Inhalation Toxicity Studies
------------------------------------------------------------------------
           Study Type (Species)                       Results
------------------------------------------------------------------------
Acute Inhalation (rat)                     Doses were 8.4, 12.1, 15.2,
                                            16.9, or 20.5% equivalent to
                                            84,000, 121,000, 152,000,
                                            169,000, or 205,000 part per
                                            million (ppm); or 158, 228,
                                            286, 318, or 386 mg/L.
                                           LC50 = 309 mg/L (Toxicity
                                            Category IV) (95% confidence
                                            limits of 268 - 382 mg/L)
                                           Whole-body inhalation
                                            exposure. Clinical signs
                                            during exposure included
                                            ataxia, anesthesia, coma,
                                            head bobbing, paw waving,
                                            and heavy or short jerky
                                            respirations.
------------------------------------------------------------------------
2-Week Inhalation (rat)                    Doses were 0, 1, or 5% (v/v)
                                            equivalent to 0, 18.8, or
                                            94.1 mg/L
                                           NOAEL = Not determined
                                           LOAEL = 1% or 18.8 mg/L
                                           Whole-body inhalation
                                            exposure. LOAEL based on red
                                            nasal and ocular discharge,
                                            sluggish behavior,
                                            salivation, lung noise, wet
                                            perineal area, decreased
                                            cumulative body weight
                                            gains, and decreased thymus
                                            and liver weights. Moderate
                                            sluggishness occurred
                                            briefly at 1% and was very
                                            common at 5%.
------------------------------------------------------------------------
13 Week Inhalation (rat and hamster)       Doses were 1, 1,000, 5,000,
                                            10,000, or 20,000 ppm
                                            equivalent to 0, 1.9, 9.4,
                                            18.8, or 37.7 mg/L.
                                           NOAEL = 37.7 mg/L
                                           LOAEL = Not Observed
                                           Whole body inhalation
                                            exposure in both species.
                                            There were no treatment-
                                            related effects.
------------------------------------------------------------------------

[[Page 28438]]

 
Chronic toxicity/carcinogenicity (rat)     Doses were 0, 0.2, 1.0, or
                                            2.5% equivalent to 0, 2,000,
                                            10,000, or 25,000 ppm; or 0,
                                            3.7, 18.6, and 46.4 mg/L
                                           NOAEL = 3.7 mg/L
                                            LOAEL = 1% or 18.6 mg/L
                                           Whole body inhalation
                                            exposure. LOAEL based on
                                            decreased survival towards
                                            the end of the study and
                                            liver angictasis in males.
                                            The Office of Pesticide
                                            Program Cancer Peer Review
                                            Committee concluded that DME
                                            should be classified as
                                            Group D (not classifiable as
                                            to human carcinogenicity)
                                            since chronic testing was
                                            performed in only one
                                            species.
------------------------------------------------------------------------
Cardiac sensitization (dog)                Doses were 10, 20, (16.7), or
                                            30 (33.3%) (v/v) equivalent
                                            to 100,000, 200,000, or
                                            300,000 ppm. The dogs
                                            received an intravenous
                                            injection of epinephrine
                                            prior to exposure to the DME
                                            and a second (challenge)
                                            injection after breathing
                                            the test compound for five
                                            minutes.
                                           NOAEL = 10%
                                           LOAEL = 16.7%
                                            Capable of sensitizing the
                                            mammalian heart to
                                            epinephrine (development of
                                            a cardiac arrhythmia after a
                                            challenge injection of
                                            epinephrine).
------------------------------------------------------------------------

B. Mutagenicity Study

    Dimethyl ether did not induce a genotoxic response in the five S. 
typhimurium strains tested with or without S9-activation.

C. Developmental Toxicity

    There are two inhalation developmental toxicity rat studies, both 
conducted in 1981. One study was conducted in Sprague-Dawley rats at 
concentrations of 0, 0.125, 0.5, and 2.0% and a second study was 
conducted in Wistar rats at concentrations of 0, 2.0 and 2.8%.
    In the study conducted using Sprague-Dawley rats, at 2.0%, 
decreased response to tapping on the glass wall of the inhalation 
chamber was identified by the study authors. This cage-side type 
evaluation was not well-characterized in the report. The observations 
in these studies may not have been conducted in a manner consistent 
with determining a true no observed adverse effect level (NOAEL) for 
neurotoxic effect in dams. The NOAEL for maternal toxicity is 0.5%.
    The developmental toxicity findings are remarkedly similar across 
both studies. The fetal observations were referred to by different 
names in the two laboratories. But, both laboratories were referring to 
skeletal variations. Combining the results of both studies, there is an 
unequivocal, statistically significant dose-related response for both 
fetuses and litters at 0.5, 2.0, and 2.8%. The NOAEL for this finding 
is 0.125%.
    The results of the two studies also indicated delays in 
ossification. The incidence is statistically significant at 2.0% in the 
first study and at 2.8% in the second study. Non-statistically 
significant increases in this finding occur at 0.5% in the first study 
and at 2.0% in the second study.
    Taken together, the results of the two developmental toxicity 
studies are:
     Developmental NOAEL = 0.125% (v/v) equivalent to 2.4 mg/L 
or 1,250 ppm.
     Developmental LOAEL = 0.5% (v/v) equivalent to 9 mg/L or 
5,000 ppm based on an increased incidence of ribs with extra 
ossification center.
     Maternal NOAEL = 0.5% (v/v) equivalent to 9 mg/L or 5,000 
ppm.
     Maternal LOAEL = 2.0% (v/v) equivalent to 37 mg/L or 
20,000 ppm based on decreased responsiveness.
    The fact that the developmental NOAEL is less than the maternal 
NOAEL is a possible indication of increased susceptibility. However, 
the maternal effects were not always well- characterized.

D. Conclusions

    Using the submitted studies and its typical procedures, the Agency 
classified DME as acute inhalation toxicity Category IV, which is the 
Agency's category of lowest acute toxicity. No treatment-related 
effects were noted in a 13-week inhalation study. In both the 2-week 
and the chronic inhalation studies the LOAELs were determined to be 1%. 
In a developmental toxicity study, exposure at levels of 0.5% (v/v) 
produced developmental effects (skeletal variations) but maternal 
toxicity, other than decreased responsiveness, was not noted. DME is 
not classifiable as to human carcinogenicity. It produces cardiac 
sensitization in dogs. For several reasons, the Agency has concerns 
about the doses at which the studies were conducted. DME's flammablity 
limits in air are 3.4% by volume (lower limit) and 18.0% (upper limit). 
Several of the studies were conducted with one or more dose levels 
greater than the lower limit of flammability.
    The Agency's limit concentration for inhalation studies is 2 mg/L, 
which was greatly exceeded in all studies. The limit concentration is a 
concept used in animal toxicity testing to establish an upper 
concentration level beyond which testing is not encouraged: 
Concentrations higher than the limit concentration represent very 
unrealistic scenarios. Testing above the limit concentration may not 
provide the appropriate information on adverse effects which could then 
support a NOAEL for use in risk assessment. It must be possible to 
differentiate between toxic effects due to the test substance and toxic 
effects due to other causes such as stress induced by breathing 
difficulties.

VI. Aggregate Exposures

    In examining aggregate exposure, section 408 of the FFDCA directs 
EPA to consider available information concerning exposures from the 
pesticide residue in food and all other non-occupational exposures, 
including drinking water from groundwater or surfacewater and exposure 
through pesticide use in gardens, lawns, or buildings (residential and 
other indoor uses).
    EPA establishes exemptions from the requirement of a tolerance only 
in those cases where it can be demonstrated that the risks from 
aggregate exposure to pesticide chemical residues under reasonably 
foreseeable circumstances will pose no appreciable risks to human 
health. In order to determine the risks from aggregate exposure to 
pesticide inert ingredients, the Agency considers the toxicity of the 
inert in conjunction with possible exposure to residues of the inert 
ingredient through food, drinking water, and through other exposures 
that occur as a result of pesticide use in residential settings. If EPA 
is able to determine that a finite tolerance is not necessary to ensure 
that there is a reasonable certainty that no harm will result from 
aggregate exposure to the inert ingredient, an exemption from the 
requirement of a tolerance may be established.

A. Dietary Exposure

    1. Food. DME is a gas at room temperature. Significant levels of 
residues from such a volatile gas are unlikely to be present in food or 
feed items.
    2. Drinking water exposure. Residues of a volatile gas such as 
dimethyl ether

[[Page 28439]]

are not likely to be present in any significant quantities in surface 
water. The estimated half-life in a river is 2.1 hours and in a lake 
2.7 days. DME is therefore, not expected to be present in drinking 
water.

B. Other Non-Occupational Exposure

    Dimethyl ether is sponsored under the High Production Volume 
Challenge Program. This is indicative of over 1 million pounds of DME 
either produced or imported per year.
    Dimethyl ether is used as a propellant in various personal care 
products such as hairsprays, shaving creams, mousses, deodorants, 
antiperspirants, baby care products, medical/pharmaceutical products 
and perfumes. Residential uses could also include air fresheners, 
disinfectants, furniture polishes, adhesives, insulating foams, paints, 
and insecticides.
    In 1990, an article (MRID 45772201) on simulated consumer exposures 
to DME was published. The report's authors simulated and then measured 
breathing zone concentrations of DME for typical hair spray exposures, 
for both domestic and salon conditions. To assure accuracy, repeated 
measurements were made, thus yielding the range of reported results. 
Some of the results were expressed as a time-weighted average 
concentration over 10 minutes (TWA10). TWA10s are calculated by 
averaging the peak concentration of DME (at initial release) with the 
lower concentrations that reflect the rapid dispersal of DME throughout 
the room over the 10 minute time-frame. Table 2 and Table 3 contain 
domestic simulated exposures to DME. The difference in the measurements 
is due solely to a closed door (Table 2) and an open door (Table 3). 
Examination of the data in the tables, indicates that the peak 
concentration of DME declines substantially from the initial (peak) 
spray, to the TWA10, to the residual 20-minute concentration whether 
the door is open or closed.

  Table 2.--Domestic DME Concentrations from Simulated Hairspray Uses in a Closed Room (all values expressed in
                                                      ppm)
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Peak concentration hairspray user)                                                                    Mean 1,310
                                                                                                   Maximum 1,577
                                                                                                   Minimum 1,043
----------------------------------------------------------------------------------------------------------------
Peak concentration (nearby child)                                                                       Mean 717
                                                                                                     Maximum 762
                                                                                                     Minimum 672
----------------------------------------------------------------------------------------------------------------
TWA10 (hairspray user)                                                                                  Mean 114
                                                                                                     Maximum 143
                                                                                                      Minimum 82
----------------------------------------------------------------------------------------------------------------
TWA10 (nearby child)                                                                                     Mean 89
                                                                                                      Maximum 97
                                                                                                      Minimum 86
----------------------------------------------------------------------------------------------------------------
Residual concentration in the breathing zone at 20                                                       Mean 62
 minute (hairspray user)                                                                              Maximum 78
                                                                                                      Minimum 42
----------------------------------------------------------------------------------------------------------------
Residual concentration in the breathing zone at 20                                                       Mean 56
 minute (nearby child)                                                                                Maximum 63
                                                                                                      Minimum 41
----------------------------------------------------------------------------------------------------------------

    With the door closed there is an order of magnitude reduction from 
peak concentration to TWA10 concentration, which is then reduced by 
half to a residual 20 minute concentration.

   Table 3.--Domestic DME Concentrations from Simulated Hairspray Uses in a Room with an Open Door (all values
                                                expressed in ppm)
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Peak concentration (hairspray user)                                                                     Mean 693
                                                                                                     Maximum 837
                                                                                                     Minimum 549
----------------------------------------------------------------------------------------------------------------
Peak concentration (nearby child)                                                                       Mean 530
                                                                                                     Maximum 954
                                                                                                     Minimum 105
----------------------------------------------------------------------------------------------------------------
TWA10 (hairspray user)                                                                                   Mean 84
                                                                                                     Maximum 107
                                                                                                      Minimum 67
----------------------------------------------------------------------------------------------------------------
TWA10 (nearby child)                                                                                     Mean 68
                                                                                                     Maximum 102
                                                                                                      Minimum 38
----------------------------------------------------------------------------------------------------------------

[[Page 28440]]

 
Residual concentration at 20 minutes                                                                     Mean 23
 (hairspray user)                                                                                     Maximum 41
                                                                                                       Minimum 8
----------------------------------------------------------------------------------------------------------------
Residual concentration at 20 minutes                                                                     Mean 24
 (nearby child)                                                                                       Maximum 42
                                                                                                       Minimum 7
----------------------------------------------------------------------------------------------------------------

    With an open door, the dispersion of the DME occurs so rapidly, 
that even the peak concentration (Table 3) is less than the peak 
concentration in Table 2 (door closed). Having an open door and the 
resultant more rapid dispersion means that DME concentrations are 25% 
lower.
    There is an additional factor that must also be considered in 
understanding the DME use pattern in the home. The above estimates 
considered that the user and the nearby child were perfectly still and 
did not move for 20 minutes. This is an unlikely possibility. It is 
more likely that the user and the nearby child would move away from the 
area where the spray occurred within that 20 minute time-frame.
    To examine use as an inert ingredient in pesticide products, the 
Agency examined a scenario likely to yield a higher exposure: Foggers. 
Release of DME occurs via activation of the fogger, as the propellant 
releases and fills the enclosed area. The average amount of DME found 
in a pesticide fogger product is 67.2 grams (g). If the 67.2 grams is 
suddenly released into a 136 m3 area, then the concentration 
in the room equals 67.2 g DME/136m3 = 0.49 g/m3 
or 490 mg/m3 at the time of release.
    Label directions for foggers indicate that no one is to be present 
during the application of the pesticide product and for a short period 
of time afterward. A standardized time-frame for re-entry is 2 hours. 
The concentration of DME in the room at the end of two hours can be 
estimated using a decrease of approximately 50% to account for the 
dispersion of DME from the residence. The 50% rate of decline was based 
on a study (MRID 45772401) that used a testing chamber with 
``ceilings'' that were 11 ft. high. The average measured concentration 
of DME in the chamber declined by approximately 50% over a period of 
two hours. The 245 (50% of 490) mg/m3 used as the starting 
point in Table 2 is an over-estimate since the testing chambers are 
usually designed to be airtight. DME would escape from a house much 
faster through the cracks and crevices around doors and windows.
    At the end of two hours, the homeowner re-enters the house, not to 
stay, but to open doors and windows for venting. Rapid venting occurs 
immediately as the doors and window are opened. (Labels indicate that 
venting should occur for at least 30 minutes.) Assuming, (1) that the 
above 136m3 area could have one door and three windows, 
depending on the layout, and (2) every 10 minutes the DME concentration 
drops 10% due to dispersal, 25% for a door and 10% for a window, then a 
65% reduction in DME concentration occurs every 10 minutes. Each line 
in Table 4 represents 10 minutes. Therefore, the initial concentration 
of 245 mg/m3 (Column 1) reduces to 86 mg/m3 
(Column 2). The next 10 minute time-frame (Line 2) begins with 86 mg/
m3 in Column 1.

                                      Table 4.--DME Concentration vs. Time
----------------------------------------------------------------------------------------------------------------
                                           Concentration Minutes Later (mg/    Total Elapsed Time Since Re-entry
  Starting Concentration of DME (mg/m3)                   m3)                              (minutes)
----------------------------------------------------------------------------------------------------------------
245                                                                       86                                  10
------------------------------------------------------------------------------
86                                                                        30                                  20
------------------------------------------------------------------------------
30                                                                        11                                  30
----------------------------------------------------------------------------------------------------------------

VII. Cumulative Effects

    Section 408(b)(2)(D)(v) of the FFDCA 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.''
    Unlike other pesticides for which EPA has followed a cumulative 
risk approach based on a common mechanism of toxicity, EPA has not made 
a common mechanism of toxicity finding as to DME. Dimethyl ether does 
not appear to produce a toxic metabolite produced by other substances. 
For the purposes of this action, therefore, EPA has not assumed that 
DME has a common mechanism of toxicity with other substances. For 
information regarding EPA's efforts to determine which chemicals have a 
common mechanism of toxicity and to evaluate the cumulative effects of 
such chemicals, see the policy statements released by EPA's Office of 
Pesticide Programs concerning common mechanism determinations and 
procedures for cumulating effects from substances found to have a 
common mechanism on EPA's website at https://www.epa.gov/pesticides/
cumulative/.

VIII. Safety Factor for Infants and Children

    Section 408 of the FFDCA provides that EPA shall apply an 
additional tenfold margin of safety for infants and children in the 
case of threshold effects to account for prenatal and postnatal 
toxicity and the completeness of the database on toxicity and exposure 
unless EPA determines that a different margin of safety will be safe 
for infants and children.
    The toxicity database for DME is adequate for the purpose of 
establishing

[[Page 28441]]

this tolerance exemption for use of DME as an inert ingredient 
(propellant) in a pesticide product. From that toxicity database, the 
Agency could select a toxicological endpoint to use in the Agency's 
risk assessment. In selecting an endpoint, EPA matches, as best 
possible, the time-frames of a potential user's exposure to the time-
frames of the toxicity study(ies). Selection of a developmental NOAEL 
for use in assessing short-term risk appears, at first glance, to be a 
good match. However, the test animals were confined in the test 
chambers for 6 hours/day for either 10 or 11 consecutive days, 
receiving an artificially maintained atmosphere to breathe. The 
concentrations of DME used in the toxicity studies considered in this 
final rule are maintained by enclosed test chambers and constant in-
flow of DME. Such concentrations cannot be maintained in any building 
such as greenhouses, apartments, single-family dwellings, or places of 
business, since any released DME will disperse from the structure via 
cracks and crevices. Unless, the DME is continually released in that 
environment, the DME concentration is always decreasing. Therefore, 
although these studies provide some information concerning potential 
toxicological hazards of DME, they do not provide useful information 
for quantitatively assessing the risks from human exposure to DME given 
the dissimilarity in duration between likely human exposure and the 
exposure patterns in the studies.
    Further, for DME, in the developmental toxicity study, the dose 
levels used in these inhalation toxicity studies routinely exceeded the 
limit concentration. It is also noted that dose concentrations in 
several of the toxicity studies exceed the DME flammable limits and 
routinely exceed the industrial time-weighted 8-hour day average 
acceptable exposure limit of 1,000 ppm recommended by DuPont and the 
American Industrial Hygiene Association. Effects appearing above the 
limit concentration may not indicate the toxicity of the chemical.
    Given the extreme testing conditions in these studies and the 
effects observed, EPA believes it has adequate data to evaluate the 
safety of DME. Further, when the hazard testing data is evaluated in 
light of exposure information, EPA has determined that a safety factor 
analysis is neither appropriate or needed to assess the risk. For the 
same reasons a tenfold safety factor is unnecessary.

IX. Determination of Safety for U.S. Population, and Infants and 
Children

    The NOAELs or LOAELs in any of the toxicological studies for DME 
are significantly higher than any concentration that could be 
reasonably expected in a home environment given the volatility of DME. 
The confined, artificially-maintained environment and a 6 hour exposure 
used in the toxicological studies are not readily comparable to the 
highly dispersive nature of DME and does not consider the massive 
reductions in concentration that occur in a 20 to 30 minute time-frame 
as shown in Tables 2, 3, and 4.
    DME is widely used in consumer products that are not regulated by 
EPA. Simulated consumer exposures for domestic hairspray use are 
presented in Tables 2 and 3. The magnitude of the EPA-regulated 
exposures expected from use in a pesticide product is not dissimilar to 
those of other consumer products. However, the possible number of 
products containing DME are dissimilar, as well as the use patterns. 
There is a wide-variety of consumer use patterns, including personal 
care products, which during use are aimed directly at the user, for 
example hair spray. Types of pesticide products containing DME are the 
spray can (which during use is not directed at the individual), and 
foggers (where the individual is directed to not be present). In most 
cases, the consumer use patterns and the pesticide use patterns are not 
likely to overlap. One is unlikely to use a consumer product in a house 
that is being fogged. One is unlikely to spray paint and apply 
hairspray at the same time. The activities would usually be separated 
by time and occur in different rooms.
    The exposure estimates presented by the Agency are considered to be 
over-estimates. It is very likely the DME will disperse more rapidly 
and/or an individual would remove themselves from the location of the 
peak concentration.
    Given the rapid dispersion of DME from a home via cracks around 
doors and windows, as well as via open doors and windows, and the 
likelihood of an exposed individual to move away from the peak 
concentration area, exposures to DME from use in a pesticide product, 
or any other product such as hair spray, are very small. Based on the 
available information on these very small exposures, the volatile 
nature of DME and its rapid dispersion, the use of dose levels in the 
toxicological studies which are greater than the limit concentration, 
toxicity studies that do not readily lend themselves to selection of an 
appropriate dose and endpoint for such a short duration, and effects 
that are occurring only at levels greater than the limit concentration, 
EPA finds that exempting DME, also known as methane, oxybis, (CAS Reg. 
No. 115-10-6) from the requirement of a tolerance will be safe for the 
general population including infants and children.

X. Other Considerations

A. Endocrine Disruptors

    FQPA requires EPA to develop a screening program to determine 
whether certain substances, including all pesticide chemicals (both 
inert and active ingredients), ``may have an effect in humans that is 
similar to an effect produced by a naturally occurring estrogen, or 
such other endocrine effect * * *'' EPA has been working with 
interested stakeholders to develop a screening and testing program as 
well as a priority setting scheme. As the Agency proceeds with 
implementation of this program, further testing of products containing 
DME, also known as methane, oxybis, (CAS Reg. No. 115-10-6) for 
endocrine effects may be required.

B. Analytical Method(s)

    An analytical method is not required for enforcement purposes since 
the Agency is establishing an exemption from the requirement of a 
tolerance without any numerical limitation.

C. Existing Tolerances

    There is an existing exemption from tolerance for DME when used as 
a propellant (40 CFR 180.930) in pesticide formulations applied to 
animals.

D. International Tolerances

    The Agency is not aware of any country requiring a tolerance for 
DME nor have any CODEX Maximum Residue Levels (MRL's) been established 
for any food crops at this time.

XI. Conclusion

    Therefore, an exemption from the requirement for a tolerance is 
established for DME, also known as methane, oxybis, (CAS Reg. 115-10-
6).

XII. Objections and Hearing Requests

    Under section 408(g) of the FFDCA, as amended by the FQPA, any 
person may file an objection to any aspect of this regulation and may 
also request a hearing on those objections. The EPA procedural 
regulations which govern the submission of objections and requests for 
hearings appear in 40 CFR part 178. Although the procedures in those 
regulations require some modification to

[[Page 28442]]

reflect the amendments made to the FFDCA by the FQPA, EPA will continue 
to use those procedures, with appropriate adjustments, until the 
necessary modifications can be made. The new section 408(g) of the 
FFDCA provides essentially the same process for persons to ``object'' 
to a regulation for an exemption from the requirement of a tolerance 
issued by EPA under new section 408(d) of the FFDCA, as was provided in 
the old FFDCA sections 408 and 409 of the FFDCA. However, the period 
for filing objections is now 60 days, rather than 30 days.

A. What Do I Need to Do to File an Objection or Request a Hearing?

    You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in this unit 
and in 40 CFR part 178. To ensure proper receipt by EPA, you must 
identify docket ID number OPP-2005-0109 in the subject line on the 
first page of your submission. All requests must be in writing, and 
must be mailed or delivered to the Hearing Clerk on or before July 18, 
2005.
    1. Filing the request. Your objection must specify the specific 
provisions in the regulation that you object to, and the grounds for 
the objections (40 CFR 178.25). If a hearing is requested, the 
objections must include a statement of the factual issues(s) on which a 
hearing is requested, the requestor's contentions on such issues, and a 
summary of any evidence relied upon by the objector (40 CFR 178.27). 
Information submitted in connection with an objection or hearing 
request may be claimed confidential by marking any part or all of that 
information as 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.
    Mail your written request to: Office of the Hearing Clerk (1900L), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001. You may also deliver your request to the 
Office of the Hearing Clerk in Suite 350, 1099 14th St., NW., 
Washington, DC 20005. The Office of the Hearing Clerk is open from 8 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The 
telephone number for the Office of the Hearing Clerk is (202) 564-6255.
    2. Copies for the Docket. In addition to filing an objection or 
hearing request with the Hearing Clerk as described in Unit XI.A., you 
should also send a copy of your request to the PIRIB for its inclusion 
in the official record that is described in ADDRESSES. Mail your 
copies, identified by docket ID number OPP-2005-0109, to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001. In person or by courier, bring a copy to the location of the 
PIRIB described in ADDRESSES. You may also send an electronic copy of 
your request via e-mail to: opp-docket@epa.gov. Please use an ASCII 
file format and avoid the use of special characters and any form of 
encryption. Copies of electronic objections and hearing requests will 
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format. 
Do not include any CBI in your electronic copy. You may also submit an 
electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

    A request for a hearing will be granted if the Administrator 
determines that the material submitted shows the following: There is a 
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(s) in the manner sought 
by the requestor would be adequate to justify the action requested (40 
CFR 178.32).

XIII. Statutory and Executive Order Reviews

    This final rule establishes an exemption from the tolerance 
requirement under section 408(d) of the FFDCA 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). Because this rule has been exempted from review under Executive 
Order 12866 due to its lack of significance, this rule is not subject 
to Executive Order 13211, Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, 
May 22, 2001). 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) (Public Law 104-4). Nor 
does it require any special considerations under Executive Order 12898, 
entitled Federal Actions to Address Environmental Justice in Minority 
Populations and Low-Income Populations (59 FR 7629, February 16, 1994); 
or OMB review or any Agency action under Executive Order 13045, 
entitled Protection of Children from Environmental Health Risks and 
Safety Risks (62 FR 19885, April 23, 1997). This action does not 
involve any technical standards that would require Agency consideration 
of voluntary consensus standards pursuant to section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (NTTAA), 
Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since 
tolerances and exemptions that are established on the basis of a 
petition under section 408(d) of the FFDCA, such as the exemption 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. In addition, the Agency has determined that this 
action will not have a substantial direct effect on States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132, entitled Federalism 
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' This final rule directly regulates growers, food 
processors, food handlers and food retailers, not States. This action 
does not alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of the FFDCA. For these same reasons, the Agency 
has determined that this rule does not have any ``tribal implications'' 
as described in Executive Order 13175, entitled Consultation and 
Coordination with Indian Tribal Governments (65 FR

[[Page 28443]]

67249, November 6, 2000). Executive Order 13175, requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by tribal officials in the development of regulatory policies that have 
tribal implications.'' ``Policies that have tribal implications'' is 
defined in the Executive Order to include regulations that have 
``substantial direct effects on one or more Indian tribes, on the 
relationship between the Federal Government and the Indian tribes, or 
on the distribution of power and responsibilities between the Federal 
Government and Indian tribes.'' This rule will not have substantial 
direct effects on tribal governments, on the relationship between the 
Federal Government and Indian tribes, or on the distribution of power 
and responsibilities between the Federal Government and Indian tribes, 
as specified in Executive Order 13175. Thus, Executive Order 13175 does 
not apply to this rule.

XIV. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement 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 this final rule in the Federal Register. This final 
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: April 27, 2005.
Betty Shackleford,
Director, Registration Division, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 180 --[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.910 is amended by adding alphabetically, the following 
entry.


Sec.  180.910  Insert ingredients used pre-harvest and post-harvest; 
Exemptions from the requirement of a tolerance.

* * * * *

------------------------------------------------------------------------
        Inert ingredient                Limit                 Use
------------------------------------------------------------------------
                               * * * * * *
Dimethyl ether (methane, oxybis- ...................  Propellant
 ) (CAS Reg. No. 115-10-06)       ..................
                                  ...........
                               * * * * * *
------------------------------------------------------------------------

 [FR Doc. 05-9475 Filed 5-17-05; 8:45 am]
BILLING CODE 6560-50-S