1512 Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations 

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, 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) or Executive Order 13045, 

entitled Protection of Children from 

Environmental Health Risks and Safety 

Risks (62 FR 19885, April 23, 1997). 

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., 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). 

Since tolerances and exemptions that 

are established on the basis of a petition 

under section 408(d) of FFDCA, such as 

the tolerance 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. 

This final rule directly regulates 

growers, food processors, food handlers, 

and food retailers, not States or tribes, 

nor does this action alter the 

relationships or distribution of power 

and responsibilities established by 

Congress in the preemption provisions 

of section 408(n)(4) of FFDCA. As such, 

the Agency has determined that this 

action will not have a substantial direct 

effect on States or tribal governments, 

on the relationship between the national 

government and the States or tribal 

governments, or on the distribution of 

power and responsibilities among the 

various levels of government or between 

the Federal Government and Indian 

tribes. Thus, the Agency has determined 

that Executive Order 13132, entitled 

Federalism (64 FR 43255, August 10, 

1999) and Executive Order 13175, 

entitled Consultation and Coordination 

with Indian Tribal Governments (65 FR 

67249, November 6, 2000) do not apply 

to this rule. In addition, This rule does 

not 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). 

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). 

VII. Congressional Review Act 

The Congressional Review Act, 5 

U.S.C. 801 et seq., generally provides 

that before a rule may take effect, the 

agency promulgating the rule must 

submit a rule report 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: December 28, 2007. 

Lois Rossi, 

Director, Registration Division, Office of 

Pesticide Programs. 

■ Therefore, 40 CFR chapter I is 

amended as follows: 

PART 180—[AMENDED] 

■ 1. The authority citation for part 180 

continues to read as follows: 

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

■ 2. Section 180.571 is amended by 

alphabetically adding the following 

commodities in the table in paragraph 

(a) to read as follows: 

§ 180.571 Mesotrione; tolerances for 

residues. 

(a) * * * 

Commodity Parts per million 

Berry, group 13 ............... 0.01 

* * * * * 

Cranberry ........................ 0.02 

Flax, seed ....................... 0.01 

Lingonberry ..................... 0.01 

Millet, grain ..................... 0.01 

Millet, forage ................... 0.01 

Millet, hay ....................... 0.02 

Millet, straw ..................... 0.02 

* * * * * 

[FR Doc. E8–181 Filed 1–8–08; 8:45 am] 

BILLING CODE 6560–50–S 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 180 

[EPA–HQ–OPP–2005–0268; FRL–8345–8] 

Poly(hexamethylenebiguanide) 

hydrochloride (PHMB); Exemption 

from the Requirement of a Tolerance 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: This regulation establishes an 

exemption from the requirement of a 

tolerance for residues of the insecticide, 

Poly(hexamethylenebiguanide) 

hydrochloride (PHMB) on all food when 

residues are the result of lawful 

application of a food contact surface 

sanitizer containing PHMB as a sanitizer 

solution in food handling 

establishments when applied as a 

sanitizer. Arch Chemicals Inc. 

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 PHMB. 

DATES: This regulation is effective 

January 9, 2008. Objections and requests 

for hearings must be received on or 

before March 10, 2008, and must be 

filed in accordance with the instructions 

provided in 40 CFR part 178 (see also 

Unit I.C. of the SUPPLEMENTARY

INFORMATION. 

ADDRESSES: EPA has established a 

docket for this action under docket 

identification (ID) number EPA–HQ–

OPP–2005–0268. To access the 

electronic docket, go to http:// 

www.regulations.gov, select ‘‘Advanced 

Search,’’ then ‘‘Docket Search.’’ Insert 

the docket ID number where indicated 

and select the ‘‘Submit’’ button. Follow 

the instructions on the regulations.gov 

website to view the docket index or 

access available documents. All 

documents in the docket are listed in 

the docket index available in 

regulations.gov. Although listed in the 

index, some information is not publicly 

available, e.g., Confidential Business 

Information (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 http://www.regulations.gov, or, if only 


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Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations 1513 

available in hard copy, at the Office of 

Pesticide Programs (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: 

Adam Heyward, Antimicrobials 

Division (7510P), Environmental 

Protection Agency, 1200 Pennsylvania 

Ave., NW., Washington, DC 20460–

0001; telephone number: (703) 308–

6422; e-mail address: 

heyward.adam@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 code 111). 

• Animal production (NAICS code 

112). 

• Food manufacturing (NAICS code 

311). 

• Pesticide manufacturing (NAICS 

code 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 

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. To determine whether 

you or your business may be affected by 

this action, you should carefully 

examine the applicability provisions in 

40 CFR 180.940(a) Tolerance 

exemptions for active and inert 

ingredients for use in antimicrobial 

formulations (Food-contact surface 

sanitizing solutions. 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 Access Electronic Copies 

of this Document? 

In addition to accessing an electronic 

copy of this Federal Register document 

through the electronic docket at http:// 

www.regulations.gov, you may access 

this Federal Register document 

electronically through the EPA Internet 

under the ‘‘Federal Register’’ listings at 

http://www.epa.gov/fedrgstr. You may 

also access a frequently updated 

electronic version of 40 CFR part 180 

through the Government Printing 

Office’s pilot e-CFR site at http:// 

www.gpoaccess.gov/ecfr. 

C. Can I File an Objection or Hearing 

Request? 

Under section 408(g) of FFDCA, as 

amended by 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. 

You must file your objection or request 

a hearing on this regulation in 

accordance with the instructions 

provided in 40 CFR part 178. To ensure 

proper receipt by EPA, you must 

identify docket ID number EPA–HQ–

OPP–2005–0268 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 March 10, 2008. 

In addition to filing an objection or 

hearing request with the Hearing Clerk 

as described in 40 CFR part 178, please 

submit a copy of the filing that does not 

contain any CBI for inclusion in the 

public docket that is described in 

ADDRESSES. Information not marked 

confidential pursuant to 40 CFR part 2 

may be disclosed publicly by EPA 

without prior notice. Submit your 

copies, identified by docket ID number 

EPA–HQ–OPP–2005–0268, by one of 

the following methods: 

• Federal eRulemaking Portal: http:// 

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’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. 

II. Background and Statutory Findings 

In the Federal Register of December 

21, 2005 (70 FR 75805) (FRL–7745-8), 

EPA issued a notice pursuant to section 

408(d)(3) of FFDCA, 21 U.S.C. 

346a(d)(3), announcing the filing of a 

pesticide tolerance petition (PP 5F6975) 

by Arch Chemical Inc.,1955 Lake Park 

Drive, Suite 100, Smyrna, GA 30080. 

The petition requested that 40 CFR part 

180 be amended by establishing an 

exemption from the requirement of a 

tolerance for residues of 

Poly(hexamethylenebiguanide) 

hydrochloride. This notice included a 

summary of the petition prepared by the 

petitioner Arch Chemical Inc. There 

were no comments received in response 

to the notice of filing. 

Section 408(c)(2)(A)(i) of 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(c)(2)(A)(ii) of 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. Pursuant to 

section 408(c)(2)(B) of FFDCA, in 

establishing or maintaining in effect an 

exemption from the requirement of a 

tolerance, EPA must take into account 

the factors set forth in section 

408(b)(2)(C) of FFDCA, which 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. Toxicological Profile 

A. Toxic Effects 

Consistent with section 408(b)(2)(D) 

of 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 


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1514 Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations 

nature of the toxic effects are discussed 

in this unit. 

There are adequate toxicology data 

available to characterize the toxicity of 

PHMB. PHMB is a severe eye irritant 

and is a moderate dermal irritant and 

sensitizer. Acute oral, inhalation and 

dermal toxicity are acute toxicity, 

category III, which requires the signal 

word caution to appear on the product 

label as defined in 40 CFR 156.64(3). 

B. Toxic Endpoints 

For hazards that have a threshold 

below which there is no appreciable 

risk, the dose at which no adverse 

effects are observed (NOAEL) from the 

toxicology study identified as 

appropriate for the risk assessment is 

used to estimate the toxicological level 

of concern (LOC). 

The Agency’s level of concern for 

residential PHMB dermal, inhalation 

and oral exposures is 100 (i.e. a margin 

of exposure (MOE) less than 100 

exceeds the Agency’s level of concern). 

The level of concern is based on 10x for 

interspecies extrapolation and 10x for 

intraspecies variability. A summary of 

the toxic endpoints for PHMB is listed 

in the following table. 

TABLE 1—TOXICOLOGICAL ENDPOINTS FOR ASSESSING OCCUPATIONAL AND RESIDENTIAL EXPOSURES/RISK* 

ExposureScenario Dose Used in Risk Assessment, UF 

Special FQPA SF 

and Level of Concern for Risk Assessment 

Study and Toxicological Effects 

Acute Dietary (Females 13-50 

years of age) 

NOAEL = 20 mg/kg/day 

UF = 100 

Acute RfD = 0.2 mg/kg/ 

day 

FQPA SF = 1 

aPAD = acute RfD 

÷ FQPA SF= 0.2 

mg/kg/day 

Rabbit Developmental Study (MRID 42865901) 

LOAEL = 40 mg/kg/day based on a reduced number of 

litters and skeletal abnormalities. 

Acute Dietary (General population including infants and 

children) 

No appropriate single dose effect was identified for the general population. 

Chronic Dietary (All populations) NOAEL = 20 mg/kg/day 

UF = 100 

Chronic RfD = 0.2 mg/kg/ 

day 

FQPA SF = 1 

cPAD = chronic 

RfD ÷ FQPA 

SF= 0.2 mg/kg/ 

day 

Rabbit Developmental Study (MRID 42865901) 

LOAEL = 40 mg/kg/day Based on increased mortality, reduced food consumption, and clinical toxicity; 

Mouse Developmental Study (Report No. CTL/P/335, 

1977 (cited in Report No. 003810, 1978. Section C-9)) 

LOAEL = 40 mg/kg/day Based on reduced body weight 

gain; and 

Rat Developmental Study (Report No. CTL/P/1262, 1976 

(cited in Report No. 003810, 1978. Section C-11)) 

LOAEL = 50 mg/kg/day Based on reduced food consumption. 

Short-Term Incidental Oral (1-30 

days) 

NOAEL = 20 mg/kg/day 

UF = 100 

Residential LOC 

for MOE = 100 

Rabbit Developmental Study (MRID 42865901) 

LOAEL = 40 mg/kg/day Based on the increased mortality, 

reduced food consumption, and clinical toxicity; 

Mouse Developmental Study (Report No. CTL/P/335, 

1977 (cited in Report No. 003810, 1978. Section C-9)) 

LOAEL = 40 mg/kg/day;Based on reduced body weight 

gain; and 

Rat Developmental Study (Report No. CTL/P/1262, 1976 

(cited in Report No. 003810, 1978. Section C-11)) 

LOAEL = 50 mg/kg/day Based on reduced food consumption. 

Intermediate-Term Incidental 

Oral (1 - 6 months) 

NOAEL = 20 mg/kg/day 

UF = 100 

Residential LOC 

for MOE = 100 

See Short-Term Incidental Oral Endpoint 

Short-Term, Intermediate-Term 

and Long-Term Dermal Exposure 

Dermal (or oral) study 

NOAEL= 150 mg/kg/day 

UF = 100 

(Relative dermal absorption rate =100%) 

Residential LOC 

for MOE = 100 

80-Week Skin Painting Study – Mouse (MRIDs 00066475 

and 00104796) 

LOAEL = 750 mg/kg/day based on decreased body 

weight and liver tumors. 

Short-Term, Intermediate-Term 

and Long-Term Inhalation Exposure 

An appropriate route-specific inhalation study is not available. The oral endpoint of 20 mg/kg/day with a target MOE of 100 (10x inter-species extrapolation, 10x intra-species variation) is used. An additional 10x 

route-to-route extrapolation is used to determine if a confirmatory inhalation toxicity study is warranted. 

Cancer (oral, dermal) EPA has classified PHMB as having suggestive evidence of carcinogenicity but the evidence was too weak 

to warrant quantification of human cancer risk 

*UF = uncertainty factor, FQPA SF = FQPA safety factor, NOAEL = no observed adverse effect level, LOAEL = lowest observed adverse effect level, PAD = acute population adjusted dose (a = acute, c = chronic) RfD = reference dose, LOC = level of concern, MOE = margin of 

exposure 


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Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations 1515 

IV. Aggregate Exposures 

In examining aggregate exposure, 

FFDCA section 408 directs EPA to 

consider available information 

concerning exposures from the pesticide 

residue in food and all other nonoccupational exposures, including 

drinking water from ground water or 

surface water and exposure through 

pesticide use in gardens, lawns, or 

buildings (residential and other indoor 

uses). 

A. Dietary Exposure 

PHMB is an antimicrobial that is used 

as a hard surface sanitizer and may be 

in or on food processing equipment, 

premises of food processing plants, milk 

processing equipment, milk processing 

plants, eating establishments, food 

contact surfaces, adhesives, and slurries. 

The use of PHMB as an antimicrobial 

product on these various surfaces may 

result in pesticide residues in human 

food. Residues from treated surfaces can 

migrate to food that comes into contact 

with the treated surfaces which then can 

result in human ingestion. 

1. Food. The Agency assessed acute 

and chronic dietary exposure from the 

use of PHMB as a disinfectant and food 

contact sanitizer on direct and indirect 

food-contact surfaces. This assessment 

calculated the Daily Dietary Dose (DDD) 

and the Estimated Daily Intake (EDI) 

using an FDA model (‘‘Sanitizing 

Solutions: Chemical Guidelines for 

Food Additives Petition, January 

1993’’). The FDA model takes into 

account application rates, residual 

solution, area of the treated surface 

which comes into contact with food, 

pesticide migration fraction, and body 

weight of the population exposed. 

To calculate the EDI (estimated daily 

intake) values for PHMB when it is used 

as a sanitizer in public eating spaces, it 

was assumed that PHMB would be used 

at a concentration of 550 parts per 

million (ppm), the thickness of the 

PHMB residues on surfaces would be 1 

mg per square centimeter of treated 

surface, and the surface area of the food 

contact surface being sanitized to which 

a person would be exposed on a daily 

basis is 4,000 cm2 (which includes 

contact with treated silverware, china, 

and glass used by an individual who 

regularly eats three meals per day at an 

institutional or public facility). It was 

also assumed that 100% of the pesticide 

would migrate to food. 

To calculate the EDI (estimated daily 

intake) values for PHMB when it is used 

in the food processing industry, it was 

also assumed to be used at a 

concentration of 550 ppm. However, 

specific to this scenario, the exposure 

estimates were calculated using the milk 

truck model that is described in the 

FDA document, ‘‘Sanitizing Solutions: 

Chemistry Guidelines For Food 

Additive Petitions.’’ This includes the 

assumption that estimates of sanitary 

exposure from use in dairy processing 

plants significantly exceed estimates 

based on other uses with food 

processing equipment and utensils. For 

the purpose of assessing risks stemming 

from food processing uses, parameters 

assuming a sanitized milk truck were 

used as the worst case scenario. The 

various input parameters, such as the 

size of the truck, internal surface area, 

residual thickness, and application rate 

of PHMB were used to calculate 

potential residues present in the truck 

per liter of food (i.e. milk). 

For each dietary exposure assessment 

it was assumed that adults (both male 

and female) consume 3,000 grams of 

food a day and a child, 1,500 grams. 

This allowed for an estimation of the 

amount of PHMB that is anticipated to 

be present in an average adult’s or 

child’s daily intake from these uses, and 

in turn, the calculation of a daily dietary 

dose. 

2. Drinking water exposure. The uses 

of PHMB are not expected to 

significantly contaminate drinking 

water sources. As provided in the 

PHMB Reregistration Eligibility 

Document, ‘‘none of the uses associated 

with PHMB are expected to impact 

either surface or ground water 

resources.’’ Therefore, the PHMB 

contributions for drinking water 

exposure are considered to be negligible 

and are not quantified. 

B. Other Non-Occupational Exposure 

The residential exposure assessment 

considers all potential non-occupational 

pesticide exposure, other than exposure 

due to residues in food or in drinking 

water. Exposures may occur during and 

after application as a hard surface 

disinfectant (e.g. walls, floors, tables, 

fixtures) and to swimming pools. Each 

route of exposure is assessed, where 

appropriate, and risk is expressed as a 

margin of exposure (MOE), which is the 

ratio of estimated exposure to an 

appropriate NOAEL. 

Residential exposure may occur 

during application of PHMB to indoor 

hard surfaces (e.g., mopping, wiping, 

trigger pump sprays) and to swimming 

pools. The residential handler scenarios 

were assessed to determine dermal and 

inhalation exposures. Surrogate dermal 

and inhalation unit exposure values 

were estimated using Pesticide Handler 

Exposure Database (PHED) data and the 

Chemical Manufactures Association 

Anitmicrobial Exposure Assessment 

Study (USEPA, 1999) and the 

SWIMODEL 3.0 was utilized to conduct 

exposure assessments of pesticides 

found in swimming pools and spas 

(Versar, 2003). Note that for this 

assessment, EPA assumed that 

residential users complete all elements 

of an application (mix/load/apply) 

without the use of personal protective 

equipment. 

The duration for most residential 

exposures is believed to be best 

represented by short-term duration (1 to 

30 days). The short-term duration was 

chosen for this assessment because the 

residential handler and post-application 

scenarios are assumed to be performed 

on an episodic, not a daily basis. 

Based on toxicological criteria and the 

potential for exposure, the Agency has 

conducted incidental oral, dermal and 

inhalation exposure assessments for 

PHMB residential use. As noted 

previously, MOEs greater than or equal 

to 100 are considered adequately 

protective for the residential exposure 

assessment. 

Specific information on the 

residential exposure for PHMB can be 

found at http://www.regulations.gov, 

docket ID No. EPA–HQ–OPP–2005–

0268. 

V. 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 

PHMB and any other substances and 

PHMB does not appear to produce a 

toxic metabolite produced by other 

substances. For the purposes of this 

tolerance action, therefore, EPA has not 

assumed that PHMB 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 EPA’s website at http:// 

www.epa.gov/pesticides/cumulative. 

VI. Safety Factor for Infants and 

Children 

1. In general. Section 408 of FFDCA 

provides that EPA shall apply an 

additional (‘‘10x’’) tenfold margin of 

safety for infants and children in the 


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1516 Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations 

case of threshold effects to account for 

prenatal and postnatal toxicity and the 

completeness of the data base on 

toxicity and exposure unless EPA 

determines based on reliable data that a 

different margin of safety will be safe for 

infants and children. This additional 

margin of safety is commonly referred to 

as the FQPA safety factor. In applying 

this provision, EPA either retains the 

default value of 10x when reliable data 

do not support the choice of a different 

factor, or, if reliable data are available, 

EPA uses a different additional FQPA 

safety factor value based on the use of 

traditional uncertainty/safety factors 

and/or special FQPA safety factors, as 

appropriate. 

2. Prenatal and postnatal sensitivity. 

There is no quantitative or qualitative 

evidence of increased susceptibility to 

the fetus following in utero exposure to 

PHMB in the prenatal developmental 

toxicity studies, and no quantitative or 

qualitative evidence of increased 

susceptibility to the offspring when 

adults are exposed to PHMB in the twogeneration reproductive study. In each 

study, any development/reproductive 

effect observed occurred at doses equal 

to or higher than the doses at which 

maternal toxicity was observed. This, 

together with the nature of the effects 

seen in the studies has led the Agency 

to conclude that there is no evidence of 

increased susceptibility. 

EPA has determined that reliable data 

show that it would be safe for infants 

and children to reduce the FQPA safety 

factor to 1x. That decision is based on 

the following findings: 

i. The toxicity database for 

Poly(hexamethylenebiguanide) 

hydrochloride (PHMB) is complete for 

assessing risk to infants and children 

under the FFDCA. 

ii. There is no indication that PHMB 

is a neurotoxic chemical and there is no 

need for a developmental neurotoxicity 

study or additional uncertainty factors 

to account for neurotoxicity. 

iii. There is no evidence that PHMB 

results in increased susceptibility in in 

utero rats or rabbits in the prenatal 

developmental studies or in young rats 

in the two-generation reproduction 

study. 

iv. There are no residual uncertainties 

identified in the exposure databases. 

The dietary food exposure assessments 

were performed based on 100% crop 

treated (CT) and tolerance-level residues 

and will not underestimate the exposure 

and risk. Conservative ground and 

surface water modeling estimates were 

used. Similarly conservative Residential 

SOPs were used to assess postapplication exposure to children as well 

as incidental oral exposure of toddlers. 

These assessments will not 

underestimate the exposure and risks 

posed by PHMB. 

VII. Determination of Safety for U.S. 

Population, Infants and Children 

Safety is assessed for acute and 

chronic risks by comparing aggregate 

exposure to the pesticide to the acute 

population adjusted dose (‘‘aPAD’’) and 

chronic population adjusted dose 

(‘‘cPAD’’). The aPAD and cPAD are 

calculated by dividing the LOC by all 

applicable uncertainty/safety factors. 

For linear cancer risks, EPA calculates 

the probability of additional cancer 

cases given aggregate exposure. Short-, 

intermediate-, and long-term risks are 

evaluated by comparing aggregate 

exposure to the LOC to ensure that the 

MOE called for by the product of all 

applicable uncertainty/safety factors is 

not exceeded. 

1. Acute and chronic risk. EPA 

compares the estimated dietary 

exposures to an aPAD and a cPAD, both 

of which are 0.2 mg/kg/day for PHMB. 

Generally, a dietary exposure estimate 

that is less than 100% of the aPAD or 

cPAD does not exceed the Agency’s 

levels of concern. 

The antimicrobial indirect food use 

acute/chronic risk estimates from 

exposure to treated utensils and 

countertops as well as from food 

processing facility sanitation are below 

the Agency’s level of concern. For 

adults females of child bearing age (13 

to 49 years old), the cumulative (food 

utensils and food processing) acute and 

chronic dietary exposure risk estimates 

are 18.8% of the acute and chronic 

PADs. For children ages 3 to 5 years old, 

the most highly exposed population 

subgroup, the cumulative chronic 

dietary risk estimates are 37.2% of 

chronic PAD (there are no effects 

anticipated for the acute exposures). 

Therefore, dietary exposure estimates 

are below the Agency’s level of concern 

for all population subgroups. Based on 

the information in this preamble, EPA 

concludes that there is a reasonable 

certainty of no harm from aggregate 

exposure to residues. Accordingly, EPA 

finds that exempting from the 

requirement of a tolerance will be safe. 

2. Non-occupational risk. Aggregate 

exposure takes into account residential 

exposure plus chronic exposure to food 

and water (considered to be a 

background exposure level). 

Using the exposure assumptions 

described in this unit for other nonoccupational exposures, EPA has 

concluded that food, water, and 

residential exposures aggregated result 

in aggregate MOEs greater than or equal 

to 100 for the inhalation route of 

exposure and 100 for dermal exposure. 

Therefore, these levels of exposure are 

not of concern. 

3. Aggregate cancer risk for U.S. 

population. EPA has classified PHMB as 

having no greater than suggestive 

evidence of carcinogenicity. The weightof-the-evidence considerations for this 

classification are as follows: 

i. A treatment-related statistically 

significant increase (trend and pairwise) in vascular tumors (mainly 

benign) was seen in female rats at an 

oral dose that was considered to be 

adequate, but not excessive. This was 

considered the strongest evidence on 

the Agency’s evaluation of PHMB. 

ii. Oral exposure to male and female 

mice also resulted in treatment-related 

vascular tumors seen at an excessive 

dose. However, at the next highest dose 

level, which was considered adequate 

but not excessive, there was a slight, but 

not statistically significant, increase in 

this same tumor, which added to the 

Agency’s concern for this tumor type. 

iii. It is noted that dermal exposure to 

female mice resulted in an equivocal 

increase in vascular tumors seen at only 

an excessive dose. 

iv. No treatment-related increase in 

any tumors was seen in male rats via the 

oral route or in male mice via the 

dermal route of exposure. 

Based on the findings above, the 

Agency has determined that PHMB 

posed no greater than a negligible 

cancer risk. 

4. Determination of safety. Based on 

these risk assessments, EPA concludes 

that there is a reasonable certainty that 

no harm will result to the general 

population or to infants and children 

from aggregate exposure to PHMB. 

Accordingly, EPA finds that exempting 

PHMB from the requirement of a 

tolerance will be safe. 

VII. Other Considerations 

A. Endocrine Disruptors 

EPA is required under the FFDCA, as 

amended by FQPA, to develop a 

screening program to determine whether 

certain substances (including all 

pesticide active and other ingredients) 

‘‘may have an effect in humans that is 

similar to an effect produced by a 

naturally occurring estrogen, or other 

such endocrine effects as the 

Administrator may designate.’’

Following the recommendations of its 

Endocrine Disruptor Screening and 

Testing Advisory Committee (EDSTAC), 

EPA determined that there was 

scientific basis for including, as part of 

the program, the androgen and thyroid 

hormone systems, in addition to the 

estrogen hormone system. EPA also 


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Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations 1517 

adopted EDSTAC’s recommendation 

that the Program include evaluations of 

potential effects in wildlife. For 

pesticide chemicals, EPA will use the 

Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA), and, to the 

extent that effects in wildlife may help 

determine whether a substance may 

have an effect in humans, FFDCA has 

authority to require the wildlife 

evaluations. As the science develops 

and resources allow, screening of 

additional hormone systems may be 

added to the Endocrine Disruptor 

Screening Program (EDSP). 

When the appropriate screening and/ 

or testing protocols being considered 

under the Agency’s EDSP have been 

developed, PHMB may be subjected to 

additional screening and/or testing to 

better characterize effects related to 

endocrine disruption. 

B. Analytical Method(s) 

An analytical method for food is not 

needed. Food contact sanitizers are 

typically regulated by state health 

departments to ensure that the food 

industry is using these products in 

compliance with regulations in 40 CFR 

180.940. The end use solution that is 

applied to the food contact surface is 

analyzed not food items that may come 

into contact with the treated surface. An 

analytical method is available to analyze 

the use dilution that is applied to food 

contact surfaces. The solution can be 

analyzed by use of the 

spectrophotometric method. 

C. Existing Tolerances 

There is no existing tolerance or 

exemption from tolerance for PHMB. 

D. International Tolerances 

No Codex, Canadian, or Mexican 

maximum residue limits (MRLs) have 

been established for any food uses at 

this time. 

VIII. Statutory and Executive Order 

Reviews 

This final rule establishes a tolerance 

under section 408(d) of 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 final rule 

has been exempted from review under 

Executive Order 12866, 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) or Executive Order 13045, 

entitled Protection of Children from 

Environmental Health Risks and Safety 

Risks (62 FR 19885, April 23, 1997). 

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., 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). 

Since tolerances and exemptions that 

are established on the basis of a petition 

under section 408(d) of FFDCA, such as 

the tolerance 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. 

This final rule directly regulates 

growers, food processors, food handlers, 

and food retailers, not States or tribes, 

nor does this action alter the 

relationships or distribution of power 

and responsibilities established by 

Congress in the preemption provisions 

of section 408(n)(4) of FFDCA. As such, 

the Agency has determined that this 

action will not have a substantial direct 

effect on States or tribal governments, 

on the relationship between the national 

government and the States or tribal 

governments, or on the distribution of 

power and responsibilities among the 

various levels of government or between 

the Federal Government and Indian 

tribes. Thus, the Agency has determined 

that Executive Order 13132, entitled 

Federalism (64 FR 43255, August 10, 

1999) and Executive Order 13175, 

entitled Consultation and Coordination 

with Indian Tribal Governments (65 FR 

67249, November 6, 2000) do not apply 

to this final rule. In addition, this final 

rule does not 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). 

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). 

IX. Congressional Review Act 

The Congressional Review Act, 5 

U.S.C. 801 et seq., generally provides 

that before a rule may take effect, the 

agency promulgating the rule must 

submit a rule report 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: December 18, 2007. 

Betty Shackleford, 

Acting Director, Antimicrobials Division, 

Office of Pesticide Programs. 

■ Therefore, 40 CFR chapter I is 

amended as follows: 

PART 180—[AMENDED] 

■ 1. The authority citation for part 180 

continues to read as follows: 

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

■ 2. Section 180.1280 is added to 

subpart D to read as follows: 

§ 180.1280 Poly(hexamethylenebiguanide) 

hydrochloride (PHMB) exemption from the 

requirement of a tolerance. 

Poly(hexamethylenebiguanide) 

hydrochloride (PHMB)(CAS Reg. No. 

32289–58–0) is exempt from the 

requirement of a tolerance for residues 

of the antimicrobial in or on all food 

commodities when the residues are the 

result of the lawful application of a food 

contact surface sanitizer containing 

PHMB at 550 parts per million (ppm). 

[FR Doc. E8–189 Filed 1–8–08; 8:45 am] 

BILLING CODE 6560–50–S 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 180 

[EPA–HQ–OPP–2007–0300; FRL–8346–3] 

Zeta-cypermethrin; Pesticide 

Tolerance 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: This regulation establishes 

tolerances for combined residues of 

zeta-cypermethrin and its inactive Risomers in or on Citrus (dried pulp, fruit 

and oil); oilseed commodities (seeds of 

borage, castor oil plant, Chinese tallow 

tree, crambe, cuphea, echium, 

euphorbia, evening primrose, flax, gold 

of pleasure, hare’s-ear mustard, jojoba, 


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