Document ID: EPA-HQ-OPPT-2013-0443-0001
Agency: epa
Document Type: Proposed Rule
Title: Toxic Substances Control Act Petitions: Hydrofluorosilicic Acid in Drinking Water
Posted Date: 2013-08-12T04:00Z

[Federal Register Volume 78, Number 155 (Monday, August 12, 2013)]
[Proposed Rules]
[Pages 48845-48848]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-19486]

[[Page 48845]]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Chapter I

[EPA-HQ-OPPT-2013-0443; FRL-9395-3]

Hydrofluorosilicic Acid in Drinking Water; TSCA Section 21 
Petition; Reasons for Agency Response

AGENCY: Environmental Protection Agency (EPA).

ACTION: Petition; reasons for Agency response.

-----------------------------------------------------------------------

SUMMARY: This document announces the availability of EPA's response to 
a petition received by EPA under the Toxic Substances Control Act 
(TSCA). The TSCA section 21 petition, dated May 9, 2013, was submitted 
by American University students, alumni, and faculty. The petitioners 
requested EPA to take action to prohibit the use of hydrofluorosilicic 
acid (HFSA) as a water fluoridation agent. After careful consideration, 
EPA denied the TSCA section 21 petition for the reasons discussed in 
this document.

DATES: EPA's response to this TSCA section 21 petition was signed 
August 6, 2013.

FOR FURTHER INFORMATION CONTACT: For technical information contact: 
Toni Krasnic, Chemical Control Division (7405M), Office of Pollution 
Prevention and Toxics, Environmental Protection Agency, 1200 
Pennsylvania Ave. NW., Washington, DC 20460-0001; telephone number: 
(202) 564-0984; fax number: (202) 564-4775; email address: 
krasnic.toni@epa.gov.
    For general information contact: The TSCA-Hotline, ABVI-Goodwill, 
422 South Clinton Ave., Rochester, NY 14620; telephone number: (202) 
554-1404; email address: TSCA-Hotline@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this action apply to me?

    This action is directed to the public in general. Operators and 
customers of public water systems may have particular interest in this 
action. This action also might be of interest to those persons who 
manufacture (including import) or process HFSA or other fluoridation 
agents.

B. How can I access information about this petition?

    The docket for this TSCA section 21 petition, identified by docket 
identification (ID) number EPA-HQ-OPPT-2013-0443, is available at 
http://www.regulations.gov or at the Office of Pollution Prevention and 
Toxics Docket (OPPT Docket), Environmental Protection Agency Docket 
Center (EPA/DC), EPA West Bldg., Rm. 3334, 1301 Constitution Ave. NW., 
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744, and the telephone 
number for the OPPT Docket is (202) 566-0280. Please review the visitor 
instructions and additional information about the docket available at 
http://www.epa.gov/dockets.

II. TSCA Section 21

A. What is a TSCA Section 21 Petition?

    Under TSCA section 21 (15 U.S.C. 2620), any person can petition EPA 
to initiate a rulemaking proceeding for the issuance, amendment, or 
repeal of a rule under TSCA section 4, 6, or 8 or an order under TSCA 
section 5(e) or 6(b)(2). A TSCA section 21 petition must set forth the 
facts that are claimed to establish that it is necessary to take the 
requested action. EPA must grant or deny the petition within 90 days of 
its filing. If EPA grants the petition, the Agency must promptly 
commence an appropriate proceeding. If EPA denies the petition, the 
Agency must publish its reasons for the denial in the Federal Register. 
15 U.S.C. 2620(b)(3). A petitioner may commence a civil action in a 
U.S. district court to compel initiation of the requested rulemaking 
proceeding within 60 days of either a denial or the expiration of the 
90-day period. 15 U.S.C. 2620(b)(4).

B. What criteria apply to a decision on a TSCA section 21 petition?

    Section 21(b)(1) of TSCA requires that the petition ``set forth the 
facts which it is claimed establish that it is necessary'' to issue the 
rule or order requested. 15 U.S.C. 2620(b)(1). Thus, TSCA section 21 
implicitly incorporates the statutory standards that apply to the 
requested actions. In addition, TSCA section 21 establishes standards a 
court must use to decide whether to order EPA to initiate rulemaking in 
the event of a lawsuit filed by the petitioner after denial of a TSCA 
section 21 petition. 15 U.S.C. 2620(b)(4)(B). Accordingly, EPA has 
relied on the standards in TSCA section 21 and in the provision under 
which the action has been requested to evaluate this TSCA section 21 
petition.
    Of particular relevance here is the legal standard regarding TSCA 
section 6 rules. In order to promulgate a rule under TSCA section 6, 
the EPA Administrator must find that ``there is a reasonable basis to 
conclude that the manufacture, processing, distribution in commerce, 
use, or disposal of a chemical substance or mixture . . . presents or 
will present an unreasonable risk.'' 15 U.S.C. 2605(a). This finding 
cannot be made considering risk alone. Under TSCA section 6, a finding 
of ``unreasonable risk'' requires the consideration of costs and 
benefits. Specifically, in promulgating any rule under TSCA section 
6(a), the statute (15 U.S.C. 2605(c)(1)) requires that the EPA 
Administrator consider:
     The effects of such chemical substance or mixture on 
health and the magnitude of the exposure of human beings to such 
chemical substance or mixture.
     The effects of such chemical substance or mixture on the 
environment and the magnitude of the exposure of the environment to 
such chemical substance or mixture.
     The benefits of such chemical substance or mixture for 
various uses and the availability of substitutes for such uses.
     The reasonably ascertainable economic consequences of the 
rule, after consideration of the effect on the national economy, small 
business, technological innovation, the environment, and public health.

Furthermore, the control measure adopted is to be the ``least 
burdensome requirement'' that adequately protects against the 
unreasonable risk. 15 U.S.C. 2605(a).
    In addition, TSCA section 21(b)(4)(B) provides the standard for 
judicial review should EPA deny a request for rulemaking under TSCA 
section 6(a): ``If the petitioner demonstrates to the satisfaction of 
the court by a preponderance of the evidence that . . . there is a 
reasonable basis to conclude that the issuance of such a rule . . . is 
necessary to protect health or the environment against an unreasonable 
risk of injury,'' the court shall order the EPA Administrator to 
initiate the requested action. 15 U.S.C. 2620(b)(4)(B).
    Finally, TSCA section 9(b) directs EPA to take regulatory action on 
a chemical substance or mixture under other statutes administered by 
the Agency if the EPA Administrator determines that actions under those 
statutes could eliminate or reduce to a sufficient extent the risks 
posed by the chemical substance or mixture. If this is the case, the 
regulation can be promulgated under TSCA only if the EPA determines 
that it is in the ``public interest'' to protect against that risk 
under TSCA rather than the alternative authority. 15 U.S.C. 2608(b).

[[Page 48846]]

III. Summary of the TSCA Section 21 Petition

A. What action was requested?

    In the petition, dated May 9, 2013, American University students, 
alumni, and faculty seek to have EPA take action under TSCA section 6 
to prohibit the use of HFSA as a water fluoridation agent (Ref. 1).

B. What support do the petitioners offer?

    The petitioners claim that HFSA leads to the contamination of 
drinking water with arsenic, lead, and radionuclides. In addition, the 
petitioners claim that an existing alternative source of fluoride for 
water fluoridation, pharmaceutical grade sodium fluoride (NaF), would 
not contribute to drinking water levels of arsenic, lead, or 
radionuclides comparable to those in HFSA. The following is a summary 
of major claims by the petitioners:
    1. Arsenic. Petitioners claim that an alternate source of fluoride, 
pharmaceutical grade NaF, delivers at least 100-fold lower levels of 
arsenic than does HFSA when water authorities choose to adjust their 
water supply to contain about 0.7 milligram per liter (mg/L) of 
fluoride. The petitioners cite an analysis that purports to show that 
for typical levels of arsenic in HFSA and pharmaceutical grade NaF, use 
of pharmaceutical grade NaF as a fluoridation agent produces about 100-
fold fewer lung and bladder cancer cases than HFSA (3.4 versus 320 
cases) (Ref. 2). That analysis also purports to show that use of 
typical pharmaceutical grade NaF, rather than HFSA (delivering an 
average level of arsenic as determined by National Sanitation 
Foundation (NSF) tests), results in over 500-fold fewer lung and 
bladder cancer cases (3.4 versus 1,800 cases). Based on this analysis, 
the petitioners assert that the net cost to the citizens of the United 
States of using HFSA is at least $1,011 million (M) to $6,191M more per 
year than using the pharmaceutical grade NaF (Ref. 2; see Tables 1-3, 
case 1 and case 4).
    2. Lead. Petitioners claim that HFSA contains lead and that the use 
of HFSA results in leaching of lead from lead-containing water piping 
systems into water. The petitioners also claim that when chloramine is 
used in conjunction with silicofluorides (chemical substances composed 
of silicon and fluorine), such as HFSA, enhanced leaching of lead into 
water occurs (Refs. 3, 4, and 5). Petitioners further claim that when 
pharmaceutical grade NaF is used as the fluoridating agent, rather than 
HFSA, leaching of lead is greatly reduced or eliminated altogether. The 
petitioners assert children drinking water fluoridated with 
silicofluorides are at increased risk of having elevated blood lead 
levels (Refs. 6 and 7).
    3. Radionuclides. Petitioners also expressed concerns about 
radionuclides impurities in HFSA and increased risk of cancer as a 
common concern for all radionuclides (Refs. 1 and 8).

IV. Disposition of TSCA Section 21 Petition

A. What is EPA's response?

    After careful consideration, EPA denied the TSCA section 21 
petition primarily because EPA concluded that petitioners have not set 
forth sufficient facts to establish that HFSA presents or will present 
an unreasonable risk and that it is necessary to initiate a TSCA 
section 6(a) rulemaking to protect adequately against such risk. A copy 
of the Agency's response, which consists of a letter to the 
petitioners, is available in the docket for this TSCA section 21 
petition.

B. What is EPA's reason for this response?

    For the purpose of making its decision, EPA evaluated the 
information presented or referenced in the petition as well as the 
Agency's authority and requirements under TSCA sections 6, 9, and 21. 
After careful consideration, EPA denied the TSCA section 21 petition 
because the evidence presented by the petitioners does not adequately 
support a conclusion that HFSA, when used as a fluoridation agent, 
presents or will present an unreasonable risk to health or the 
environment and that a TSCA section 6 rulemaking is necessary to 
protect adequately against such risk. More specifically:
    1. Arsenic. EPA evaluated the cost-benefit analysis submitted by 
the petitioners and determined that the petitioners miscalculated net 
benefits for pharmaceutical grade NaF compared to HFSA. Specifically, 
it appears that the petitioners failed to convert their estimates of 
lifetime cancer risk to estimates of annual cancer risk for the purpose 
of calculating annual net benefits. This error alone results in a 70-
fold overestimation of the number of annual cancer cases due to 
arsenic. That is, for the analysis in which the petitioners evaluate 
arsenic concentrations of 0.078 parts per billion (ppb) due to HFSA and 
0.00084 ppb due to pharmaceutical grade NaF, the estimated numbers of 
cancer cases, when corrected, decrease from 320 to 4.6 per year for 
HFSA and from 3.4 to 0.05 per year for pharmaceutical grade NaF (Refs. 
2 and 9). Similarly, for the analysis in which the petitioners evaluate 
an arsenic concentration of 0.43 ppb due to HFSA and 0.00084 due to 
pharmaceutical grade NaF, the estimated numbers of cancer cases, when 
corrected, decrease from 1,800 to 25 per year for HFSA and from 3.4 to 
0.05 per year for pharmaceutical grade NaF (Refs. 2 and 9). After 
making the correction (i.e., annualizing the lifetime cancer risk), and 
retaining all other assumptions of the petitioners analysis, the 
analysis actually indicates that the cost-benefit ratio is in favor of 
using HFSA over pharmaceutical grade NaF (-$81M/year to -$8M/year, 
respectively) rather than pharmaceutical grade NaF over HFSA (Ref. 9). 
As a result, the information submitted by petitioners does not support 
the petitioners' claim that there are net benefits in switching from 
HFSA to pharmaceutical grade NaF. Given that the petition is based upon 
the premise that the benefits of using pharmaceutical grade NaF as a 
fluoridation agent significantly exceed the costs relative to the use 
of HFSA as a fluoridation agent, EPA concludes that petitioners have 
not set forth sufficient facts to establish that HFSA presents or will 
present an unreasonable risk of injury to health or the environment 
with respect to arsenic or that it is necessary to initiate a TSCA 
section 6(a) rulemaking to protect adequately against such risk.
    2. Lead. Petitioners assert that HFSA contains lead but provided no 
data to support this assertion. Petitioners also assert that the use of 
HFSA in lead-containing water piping systems results in leaching of 
lead from lead-containing water piping systems into water (Ref. 5), and 
that when chloramine is used in conjunction with silicofluorides 
greatly enhanced leaching of lead into water occurs (Ref. 3). However, 
multiple other studies concluded that the fluoridation of drinking 
water with HFSA has little impact on corrosivity and/or release of 
metals from plumbing materials (Refs. 10, 11, 12, and 13). For example, 
the Centers for Disease Control and Prevention (CDC) conducted a study 
of the relationship between the additives used for fluoridation (i.e., 
HFSA, sodium silicofluoride, and sodium fluoride) and blood lead 
concentrations among a nationally representative sample of >9,000 U.S. 
children, aged 1-16 years (Ref. 10). The study analysis did not offer 
support for the hypothesis that silicofluorides in community water 
systems increase blood lead concentrations in children. Based on the 
available evidence, EPA cannot conclude that the use of HFSA, with or

[[Page 48847]]

without the presence of chloramine, results in enhanced leaching of 
lead.
    Further, and as discussed in this unit, as petitioners seeking that 
EPA initiate a TSCA section 6 rulemaking banning HFSA pursuant to TSCA 
section 21, petitioners must provide facts that establish it is 
necessary to issue a TSCA section 6 rulemaking, including that there is 
a reasonable basis to conclude that the manufacture, processing, 
distribution in commerce, use, or disposal of a chemical substance or 
mixture (in this case HFSA), or that any combination of those 
activities, presents or will present an unreasonable risk of injury to 
health or the environment. Here, petitioners have not provided 
information specific to the costs and benefits of using pharmaceutical 
grade NaF as compared to HFSA with respect to lead. In sum, with 
respect to concerns about lead, petitioners have not demonstrated that 
the use of HFSA presents or will present an unreasonable risk of injury 
to health or the environment or that it is necessary to initiate a TSCA 
section 6(a) rulemaking to protect adequately against such risk.
    3. TSCA section 9(b). TSCA section 9(b) directs EPA to take 
regulatory action on a chemical substance or mixture under other 
statutes administered by the Agency if the EPA Administrator determines 
that actions under those statutes could eliminate or reduce to a 
sufficient extent the risks posed by the chemical substance or mixture. 
If that is the case, the regulation can be promulgated under TSCA only 
if EPA determines that it is in the ``public interest'' to protect 
against that risk under TSCA rather than the alternative authority. 15 
U.S.C. 2608(b).
    In 1974, Congress passed the Safe Drinking Water Act (SDWA). That 
law requires EPA to determine the level of contaminants in drinking 
water at which no adverse health effects are likely to occur with an 
adequate margin of safety. These non-enforceable health goals, based 
solely on possible health risks, are called maximum contaminant level 
goals (MCLG). The MCLGs for both arsenic and lead are zero. EPA has set 
these levels based on the best available science, which indicates there 
is no safe level of exposure to arsenic or lead. However, for most 
contaminants, EPA sets an enforceable regulation called a maximum 
contaminant level (MCL) based on the MCLG. The MCLs are set as close to 
the MCLGs as possible, considering cost, benefits, and the ability of 
public water systems to detect and remove contaminants using suitable 
treatment technologies.
    In 2001, EPA amended the arsenic standard for drinking water, 
lowering it to 0.010 parts per million (ppm) (10 ppb) to protect 
consumers served by public water systems from the effects of long-term, 
chronic exposure to arsenic (Ref. 16). As part of that rulemaking, EPA 
performed an extensive review--including review by EPA's Science 
Advisory Board--of both the costs and benefits to determine what the 
appropriate achievable MCL should be. The MCL established by EPA was 
one that maximizes health risk reduction benefits at a cost that is 
justified by the benefits. 42 U.S.C. 300g-1(b)(6)(A). As a result, EPA 
has already weighed costs, benefits, and risk reduction relating to 
arsenic in drinking water as part of its rulemaking efforts under SDWA. 
The petition provides no information that would cause EPA to question 
the conclusions reached in that rulemaking. That rulemaking, as with 
other drinking water standards under SDWA, is reviewed every 6 years to 
determine whether revisions are appropriate. 42 U.S.C. 300(g)-1(b)(9). 
EPA believes, therefore, that the SDWA standard-setting process 
provides the most appropriate regulatory authority to eliminate or 
reduce to a sufficient extent the health risks from arsenic in drinking 
water systems.
    While arsenic levels in HFSA are higher than in pharmaceutical 
grade NaF, the arsenic levels in drinking water due to HFSA use 
presented in the cost-benefit analysis submitted by petitioners (at 
0.078 ppb and 0.00084 ppb respectively (Ref. 2)), are lower than the 
arsenic MCL of 10 ppb. In addition, these levels are also lower than 
the NSF International/American National Standards Institute Standard 
60-2012 Drinking Water Treatment Chemicals--Health Effects (NSF/ANSI 
60-2012) for drinking water treatment chemicals (i.e., single product 
allowable concentration (SPAC)) of 1 ppb (Refs. 14 and 15). When the 
Agency established the arsenic MCL in 2001, the Agency noted that the 
lung and bladder cancer risks at the 10 ppb level were within the 
Agency's target risk range of 10-4 to 10-6 (Ref. 
16). Therefore, the excess cancer risk attributable to HFSA at the 
0.078 ppb arsenic concentration (128 times lower than the arsenic 10 
ppb MCL) would be consistent with the Agency's acceptable excess 
lifetime cancer risk range of 10-4 to 10-6.
    NSF compiled data from initial and annual monitoring tests for 
fluoridation products that NSF certified to NSF/ANSI 60 between 2007 
and 2011 (216 samples) and between 2000 and 2006 (245 samples). Arsenic 
was detected in 50% of the 216 samples analyzed between 2007 and 2011. 
The mean arsenic concentration was 0.15 ppb (non-detects were estimated 
at \1/2\ the detection limit) and the maximum was 0.6 ppb. Arsenic was 
detected in 43% of the 245 samples analyzed between 2000 and 2006. The 
mean arsenic concentration was 0.12 ppb (non-detects were estimated at 
\1/2\ the detection limit) and the maximum was 0.6 ppb. In both sets of 
data, the mean and the maximum values were less than the NSF/ANSI 60 
SPAC of 1 ppb (Ref. 15). Fluoridation additive dosing was at the 
highest optimal level (i.e., 1.2 mg/L of fluoride). At the newly 
proposed optimal fluoride dosing of 0.7 mg/L (Ref. 17), the 
concentration of arsenic would be approximately 40% lower.
    To address lead in drinking water, EPA promulgated the Lead and 
Copper Rule under SDWA in 1991 (Ref. 11) and revised the regulation in 
2000 and 2007 (see 40 CFR Parts 141 and 142) . The rule is undergoing a 
longer-term revision at this time. Because lead contamination of 
drinking water often results from corrosion of the plumbing materials 
in the distribution system, EPA established a treatment technique, 
rather than an MCL, for lead. A treatment technique is an enforceable 
procedure or level of technological performance that water systems must 
follow to ensure control of a contaminant. The regulation requires 
systems to collect tap samples from sites served by the system that are 
more likely to have plumbing materials containing lead. If more than 
10% of tap water samples exceed the lead action level of 15 ppb, then 
water systems are required to take additional actions to control the 
corrosivity of the water including:
     Taking further steps to optimize their corrosion control 
treatment (for water systems serving 50,000 people that have not fully 
optimized their corrosion control).
     Educating the public about lead in drinking water and 
actions consumers can take to reduce their exposure to lead.
     Replacing the portions of lead service lines (lines that 
connect distribution mains to customers) under the water system's 
control.
    In sum, EPA's Lead and Copper Rule under SDWA already directly 
addresses lead leaching in drinking water distribution systems and the 
rule is subjected to periodic review and revision to incorporate the 
latest scientific studies. Like the arsenic rule under SDWA, EPA's 
requirements under SDWA related to lead in drinking water distribution 
systems already address and balance risks, costs, and

[[Page 48848]]

benefits, and, as with arsenic, the petition provides no information 
that would cause EPA to question the current approach. EPA believes, 
therefore, that the SDWA provides the most appropriate authority (and 
in fact has been used) to eliminate or reduce to a sufficient extent 
the health risks identified by petitioners as being associated with 
HFSA when used as a fluoridation agent.
    4. Radionuclides. Although the petitioners mention ``concern'' 
about radionuclides, the petitioners present limited information to 
support a claim that HFSA presents or will present and unreasonable 
risk with respect to radionuclides. NSF compiled data from initial and 
annual monitoring tests for fluoridation products that NSF certified to 
NSF/ANSI 60 between 2007 and 2011 (216 samples) and between 2000 and 
2006 (245 samples). Alpha emitters (type of radioactive decay in which 
an atomic nucleus emits an alpha particle) were detected in less than 
1% of the 216 samples analyzed between 2007 and 2011. The mean (non-
detects were estimated at \1/2\ the detection limit) and maximum values 
were less than the MCL of 15 picoCuries per liter (pCi/L) and were less 
than the NSF/ANSI 60 SPAC of 1.5 pCi/L (Ref. 15). Beta photon emitters 
(another type of radioactive decay in which an atomic nucleus emits a 
beta particle) also were detected in less than 1% of the 216 samples 
analyzed between 2007 and 2011. The mean (non-detects were estimated at 
\1/2\ the detection limit) and maximum values were less than the MCL of 
4 millirems per year (mrem/y) and were less than the NSF/ANSI 60 SPAC 
of 0.4 mrem/y (Ref. 15). Radionuclides (alpha or beta) were not 
detected in any (0%) of the 245 samples analyzed between 2000 and 2006 
(Ref. 11). The concentrations reported represent contaminant levels 
expected when the fluoridation products are dosed into water at the 
allowable maximum use levels for NSF/ANSI 60-2012 (see Refs. 14 and 
15). NSF notes that lower product use levels would produce 
proportionately lower contaminant concentrations.
    Thus, the petition has failed to present facts that establish that 
HFSA presents or will present an unreasonable risk of injury to health 
or the environment with respect to radionuclides, or that it is 
necessary to issue a TSCA section 6 rulemaking to protect health and 
the environment from such risk.
    For the reasons set forth in this document, EPA denied the TSCA 
section 21 petition.

V. References

    As indicated under ADDRESSES, a docket has been established for 
this document under docket ID number EPA-HQ-OPPT-2013-0443. The 
following is a listing of the documents that are specifically 
referenced in this action. The docket includes these documents and 
other information considered by EPA, including documents that are 
referenced within the documents that are included in the docket, even 
if the referenced document is not physically located in the docket. For 
assistance in locating these other documents, please consult the 
technical person listed under FOR FURTHER INFORMATION CONTACT.

1. American University students, alumni, and faculty. Letter from J. 
William Hirzy to EPA Acting Administrator Robert Perciasepe, ``Re: 
Citizen Petition Under Toxic Substances Control Act Regarding the 
Hydrofluorosilicic Acid (HFSA) in Drinking Water.'' May 9, 2013.
2. Hirzy, J.W.; Carton, R.J.; Bonanni, C.D.; Montanero, C.M.; and 
Nagle, M.F. Comparison of hydrofluorosilicic acid and pharmaceutical 
sodium fluoride as fluoridating agents--a cost-benefit analysis. 
Environmental Science & Policy. Vol. 29, pp. 81-86. 2013.
3. Maas, R.P.; Patch, S.C.; Christian, A-M.; and Coplan, M.J. 
Effects of fluoridation and disinfection agent combinations on lead 
leaching from leaded-brass part. Neurotoxicology. Vol. 28, pp. 1023-
1031. 2007.
4. Coplan, M.J.; Patch, S.C., Masters, R.D; and Bachman, M.S. 
Confirmation of and explanations for elevated blood lead and other 
disorders in children exposed to water disinfection and fluoridation 
chemicals. Neurotoxicology. Vol. 28, pp. 1032-1042. 2007.
5. Edwards, M.; Triantafyllidou, S.; and Best, D. Elevated blood 
lead in young children due to contaminated drinking water: 
Washington, DC 2001-2004. Environmental Science & Technology. Vol. 
43, pp. 1618-1623. 2007.
6. Masters, R.D. and Coplan, M.J. Water treatment with 
silicofluorides and lead toxicity. International Journal of 
Environmental Studies. Vol. 56, pp. 435-449. 1999.
7. Masters, R.D.; Coplan, M.J.; Hone, B.T.; and Dykes, J.E. 
Association of silicofluoride treated water with elevated blood 
lead. Neurotoxicology. Vol. 21, pp. 1091-1099. 2000.
8. Stein, M.; Starinsky, A.; and Kolodny, Y. Behaviour of uranium 
during phosphate ore calcination. Journal of Chemical Technology and 
Biotechnology. Vol. 32, pp. 834-847. 1982.
9. EPA. EPA Correction of the ``Comparison of hydrofluorosilicic 
acid and pharmaceutical sodium fluoride as fluoridating agents--a 
cost-benefit analysis'' by Hirzy et al. 2013.
10. Macek, M.D.; Matte, T.D.; Sinks, T.; and Malvitz, D.M. Blood 
lead concentrations in children and method of water fluoridation in 
the United States, 1988-1994. Environmental Health Perspectives. 
Vol. 114, pp. 130-134. 2006.
11. EPA. Drinking Water Regulations, Maximum Contaminant Level Goals 
and National Primary Drinking Water Regulations for Lead and Copper; 
Final Rule. Federal Register (56 FR 26460, June 7, 1991).
12. American Water Works Association (AWWA). Water Fluoridation 
Principles and Practices. AWWA Manual M4. Fifth Ed. Denver: AWWA. 
2004.
13. Urbansky, E.T. and Schock, M. R. Can fluoridation affect lead 
(II) in potable water? Hexafluorosilicate and fluoride equilibria in 
aqueous solution. International Journal Environmental Studies. Vol. 
57, pp. 597-637.
14. NSF International. June 7, 2013. Available at http://www.nsf.org/business/standards_and_publications.
15. NSF International. NSF Fact Sheet on Fluoridation Products. June 
7, 2013. Available at http://www.nsf.org/business/water_distribution/pdf/NSF_Fact_Sheet_flouride.pdf.
16. EPA. National Primary Drinking Water Regulation; Arsenic and 
Clarifications to Compliance and New Source Contaminants Monitoring; 
Final Rule. Federal Register (66 FR 6976, January 22, 2001).
17. Health and Human Services Department (HHS). Proposed HHS 
Recommendation for Fluoride Concentration in Drinking Water for 
Prevention of Dental Caries; Notice. Federal Register (76 FR 2383, 
January 13, 2011).

List of Subjects in 40 CFR Chapter I

    Environmental protection, Hydrofluorosilicic acid (HFSA), Drinking 
water, Toxic Substances Control Act (TSCA).

    Dated: August 6, 2013.
James Jones,
Assistant Administrator, Office of Chemical Safety and Pollution 
Prevention.
[FR Doc. 2013-19486 Filed 8-9-13; 8:45 am]
BILLING CODE 6560-50-P