[MEMORANDUM]{.underline}

DATE: April 18, 2006

SUBJECT: **Orthophenylphenol and orthophenylphenol salts**: AD DRAFT
Risk Assessment for the Reregistration Eligibility Decision (RED)
Document. Case No. **2575**, PC Codes: **064103, 064104, 064108,
064116.**

# FROM: Tim McMahon, Ph.D., Senior Toxicologist

Najm Shamim, Ph.D., Chemist

Kathryn Montague, Biologist

Talia Milano, Chemist

Cassi Walls, Ph.D., Chemist

Bob Quick, Chemist

Antimicrobials Division (7510C)

TO: Rebecca Miller, Chemical Review Manager

Regulatory Management Branch II

Antimicrobials Division (7510C)

Attached is the Preliminary Risk Assessment for orthophenylphenol and
orthophenylphenol salts (OPP/NA-OPP) for the purpose of issuing a
Reregistration Eligibility (RED) Decision. The disciplinary science
chapters and other supporting documents for the OPP/NA-OPP RED are also
included as attachments as follows:

Toxicology Science Chapter for the Reregistration Eligibility Decision
Document, T. McMahon, October 2005

Revised Occupational and Residential Exposure Chapter for
Ortho-phenylphenol & Ortho-phenylphenol Salts. From

T.Milano and C. Walls, Chemists, to Rebecca Miller, Chemical Review
Manager. April 2006.

Inert Ingredient Dietary and Non-dietary Risk Assessments for
O-Phenylphenol and Salts Reregistration Eligibility

Document (RED). From T. Milano and C. Walls, Chemists, to Rebecca
Miller, Chemical Review Manager,

February 2006.

Ortho Phenylphenol, and its Sodium and Potassium Salts**.** Dietary
Exposure Assessments for the Reregistration Eligibility Decision
Memorandum from Bob Quick, Chemist. to Michelle Centra, August 2005

Product Chemistry of Orthophenylphenol. From Najm Shamim, Ph.D. to T.
McMahon, Ph.D. , April 2005

Science Chapter on: Environmental Fate Studies and Environmental Fate
Assessment of Orthophenylphenol. From Najm Shamim, Ph.D. Chemist, to
Michelle Centra, September 2005,

Ecological Hazard and Environmental Risk Assessment: 2-Phenylphenol and
Salts From Kathryn V. Montague, M.S. , December, 2005.

Epidemiology Assessment based on Incident Reports. From J. Chen, Ph.D.
Toxicologist, to Tim McMahon, Ph.D. Toxicologist, December 2005

+-------------------------------------------------------------------+---+
| **TABLE OF CONTENTS**                                             | 4 |
|                                                                   |   |
| **1.0 EXECUTIVE SUMMARY**                                         | 1 |
|                                                                   | 4 |
| **2.0 PHYSICAL/CHEMICAL PROPERTIES**                              |   |
|                                                                   | 1 |
| **3.0 HAZARD CHARACTERIZATION**                                   | 6 |
|                                                                   |   |
| > 3.1 Hazard Profile                                              | 1 |
| >                                                                 | 6 |
| > 3.2 Dose-Response Assessment                                    |   |
| >                                                                 | 1 |
| > 3.3 FQPA Considerations                                         | 8 |
| >                                                                 |   |
| > 3.4 Endocrine Disruption                                        | 2 |
|                                                                   | 0 |
| **4.0 EXPOSURE ASSESSMENT AND CHARACTERIZATION**                  |   |
|                                                                   | 2 |
| > 4.1 Summary of Registered Antimicrobial Uses                    | 1 |
| >                                                                 |   |
| > 4.1.1 Residential Exposure and Risk for antimicrobial uses      | 2 |
| >                                                                 | 1 |
| > 4.2 Dietary Exposure and Risk for Antimicrobial uses            |   |
| >                                                                 | 2 |
| > 4.2.1 Mushroom houses                                           | 1 |
| >                                                                 |   |
| > 4.2.2 Poultry uses                                              | 2 |
| >                                                                 | 3 |
| > 4.2.3 Greenhouse uses                                           |   |
| >                                                                 | 3 |
| > 4.2.4 Polymer and Plastic uses                                  | 0 |
| >                                                                 |   |
| > 4.2.5 Wood and wood products                                    | 3 |
| >                                                                 | 2 |
| > 4.2.6 Paper adhesive uses                                       |   |
| >                                                                 | 3 |
| > 4.3 Dietary Exposure and Risk from agricultural uses            | 2 |
|                                                                   |   |
| **5.0 AGGREGATE RISK ASSESSMENT AND RISK CHARACTERIZATION**       | 3 |
|                                                                   | 3 |
| > 5.1 Acute and Chronic Dietary Aggregate Risk                    |   |
| >                                                                 | 3 |
| > 5.2 Short- and Intermediate-Term Aggregate Risk                 | 3 |
|                                                                   |   |
| **6.0 CUMULATIVE RISK**                                           | 3 |
|                                                                   | 3 |
| **7.0 OCCUPATIONAL EXPOSURE**                                     |   |
|                                                                   | 3 |
| > 7.1 Occupational Postapplication Exposure                       | 3 |
| >                                                                 |   |
| > 7.1.1 Fogging Exposure                                          | 3 |
| >                                                                 | 4 |
| > 7.1.2 Metalworking fluid use                                    |   |
| >                                                                 | 3 |
| > 7.2 Wood Preservation                                           | 6 |
| >                                                                 |   |
| > 7.3 Summary of registered conventional (agricultural) uses      | 3 |
| >                                                                 | 7 |
| > 7.3.1 Occupational Handler Exposure Scenarios                   |   |
|                                                                   | 3 |
| 7.3.2 Occupational Postapplication exposure and risk              | 8 |
|                                                                   |   |
| **8.0 ENVIRONMENTAL RISK**                                        | 4 |
|                                                                   | 0 |
| > 8.1 Ecological Hazard                                           |   |
| >                                                                 | 4 |
| > 8.2 Environmental fate and transport                            | 1 |
| >                                                                 |   |
| > 8.3 Environmental exposure and Risk                             | 4 |
| >                                                                 | 2 |
| > 8.4 Endangered Species                                          |   |
|                                                                   | 4 |
| 8.  **INCIDENT REPORT ASSESSMENT**                                | 2 |
|                                                                   |   |
| > 9.1 OPP Incident Data System                                    | 4 |
| >                                                                 | 2 |
| > 9.2 Poison Control Center                                       |   |
| >                                                                 | 4 |
| > 9.3 California Data 1982-2003                                   | 3 |
| >                                                                 |   |
| > 9.4 National Telecommunication Pesticide Network                | 4 |
| >                                                                 | 4 |
| > 9.5 Hazardous Substances Data Bank                              |   |
| >                                                                 | 4 |
| > 9.6 Conclusions                                                 | 4 |
|                                                                   |   |
| **10.0 REFERENCES**                                               | 4 |
|                                                                   | 6 |
|                                                                   |   |
|                                                                   | 4 |
|                                                                   | 7 |
|                                                                   |   |
|                                                                   | 4 |
|                                                                   | 7 |
|                                                                   |   |
|                                                                   | 4 |
|                                                                   | 9 |
|                                                                   |   |
|                                                                   | 5 |
|                                                                   | 0 |
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|                                                                   | 5 |
|                                                                   | 0 |
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|                                                                   | 5 |
|                                                                   | 1 |
|                                                                   |   |
|                                                                   | 5 |
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|                                                                   | 5 |
|                                                                   | 1 |
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|                                                                   | 5 |
|                                                                   | 2 |
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|                                                                   | 5 |
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|                                                                   | 5 |
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|                                                                   | 5 |
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|                                                                   | 4 |
+-------------------------------------------------------------------+---+

**Executive Summary**

Orthophenylphenol (hence forth 2-phenylphenol or OPP) is a white flaky
crystal and is sparingly soluble in water but soluble in alcohols and
ethers. However, its sodium and potassium salts are highly water
soluble. Due to the close chemical similarities between OPP and its
sodium and potassium salts (NA-OPP and K-OPP), the hazard
characterization is a composite of the three chemicals. Currently, there
are 124 active registrations for 2-phenylphenol and salts. Of these 124,
seven are manufacturing use/technical grade active ingredient (MUP/TGAI)
products.

OPP is a bacteriostat, microbiostat, nematicide, fumigant, and
bactericide chemical. As a fungicide, tolerances have been established
(40 CFR 180.129) for the combined residues of OPP and Na-OPP from
postharvest application on apples, cantaloupes, carrots, cherries,
citrus, cucumbers, grapefruits, kiwifruits, kumquats, lemons, limes,
nectarines oranges, bell peppers, peaches, pears, pineapples, plums, and
prunes, sweet potatoes, tangerines, and tomatoes. In addition, OPP is
used in applications to hard surfaces, (walls, floors, barns)
agricultural premises and equipment, air deodorization, commercial and
institutional premises, medical premises, residential and public access
premises (carpet, hard surfaces, crack and crevice treatment), and
material preservatives (stains, and paints, metal working fluids,
textiles, paper slurries and cement mixtures, glues, and adhesives, and
consumer, household and institutional cleaning products).

Sodium o-phenylphenate (Na-OPP) is the only chemical in the RED case
that is formulated as inert ingredient. Sodium o-phenylphenate is
formulated as inert ingredient in approximately 123 registered end-use
products. The types of products that contain sodium o-phenylphenate as
an inert ingredient include: turf insecticides and herbicides; garden
and ornamental insecticides and herbicides; insect repellant for pets;
and indoor/outdoor crack and crevice insecticides. These products are
formulated as soluble concentrates, gels, flowable concentrates, ready
to use liquids, granular, and bait traps. The vast majority of these
products contain sodium o-phenylphenate as an inert ingredient in
amounts less than 2% of the formulation. In these cases, the residues on
food have an exemption from the requirement of a tolerance under the 40
CFR §180.920 when used as an inert ingredient in pesticide formulations
that are applied to growing crops.

**Hazard Characterization**

The toxicology database for OPP is complete, with the exception of acute
dermal toxicity (870.1200), acute inhalation toxicity (870.1300), and
primary eye irritation (870.2400). Acceptable acute toxicity studies for
these guidelines must be submitted. A complete toxicology profile for
OPP can be found in the toxicology disciplinary chapter for OPP.

The Health Effects Division's Carcinogenicity Assessment Review
Committee (CARC) classified OPP and NA-OPP as **"Not Likely to be
Carcinogenic to Humans"** below a defined dose range, based on
convincing evidence that carcinogenic effects are not likely below 200
mg/kg/day in experimental animal studies. This classification is based
on convincing evidence of a non-linear mode of action for development of
bladder tumors in carcinogenicity studies in rats. High doses of OPP (\>
200 mg/kg/day) lead to saturation of phase II detoxification enzyme
pathways, resulting in increased amounts of the oxidative metabolites
phenylhydroquinone (PHQ) and/or phenylbenzoquinone (PBQ). The generation
of PBQ is considered dose-dependent, appearing in increased quantity
only at higher doses of OPP (\>200 mg/kg/day). The shift in
biotransformation products with increased dose of OPP has been
postulated to be associated with the non-linear response observed in
tumorigenicity of the urinary bladder, involving oxidative damage to
cells and subsequent regenerative hyperplasia. With continued exposure,
this process leads to development of tumors. Evidence suggests that a
non-genotoxic mode of action is operative.

OPP and NA-OPP were also classified by the CARC as **"Likely to be
Carcinogenic to Humans,"** based on the presence of urinary bladder
tumors in rats and the presence of liver tumors in mice at doses above
200 mg/kg/day. This classification is based on the fact that
insufficient data were provided to support a mode of action for the
mouse liver tumors. Although the tumors were benign and observed only in
one sex at high doses, more data are required for any conclusion to be
drawn regarding the mode of action for these tumors.

The CARC noted that although OPP and NA-OPP are classified as "Likely to
be Carcinogenic to Humans" above a defined dose range, quantification of
cancer risk is not required since the NOAEL selected for the chronic
Reference Dose (39 mg/kg/day, selected from the combined chronic
toxicity/carcinogenicity study in rats \[MRIDs 43954301, 44852701,
44832201\] based on decreased body weight gains, decreased food
consumption and reduced food efficiency, and increased clinical and
gross pathological signs of toxicity at the LOAEL of 200 mg/kg/day) is
sufficiently protective of the key events involved in the carcinogenic
mode of action, which are not present at doses below 200 mg/kg/day in
the rat and is also protective of liver adenomas occurring at 500
mg/kg/day in the mouse. Thus, the precursor events leading to
development of bladder and liver tumors are not likely to occur using
the NOAEL selected for the chronic RfD value and this value is thus
protective against development of tumors.

**Dose-Response Assessment**

On October 20, 2004, the Antimicrobials Division Toxicology Endpoint
Selection Committee (ADTC) reviewed the available toxicology data for
OPP and selected endpoints for use as appropriate in
occupational/residential exposure risk assessments. The potential for
increased susceptibility of infants and children from exposure to OPP
was also evaluated by the committee in order to meet the statutory
requirements of the Food Quality Protection Act (FQPA) of 1996. The
committee concluded that:

an acute dietary risk assessment is not required for OPP, because a
single dose effect from OPP was not identified. For chronic dietary risk
assessment, a NOAEL value of 39 mg/kg/day from the combined chronic
toxicity/carcinogenicity study in rats (MRIDs 43954301, 44852701,
44832201) was identified, based on decreased body weight, body weight
gain, food consumption and food efficiency, increased clinical and gross
pathological signs of toxicity at a dose of 200 mg/kg/day. For dietary
risk assessments, an uncertainty factor of 100 is assigned (10x
inter-species extrapolation, 10x intra-species variation). As the FQPA
factor was reduced to 1x, the resulting chronic reference dose is 0.39
mg/kg/day.

For short-term incidental oral risk assessments (1-30 days), a NOAEL
value of 100 mg/kg/day was selected from the developmental toxicity
study in rats (MRIDs 00067616 and 92154037), based on clinical
observations of toxicity, decreased weight gain, food consumption and
food efficiency observed at the next higher dose of 300 mg/kg/day. An
uncertainty factor of 100 was assigned to this endpoint (10x
inter-species extrapolation, 10x intra-species variation). For
intermediate-term incidental oral risk assessments, a NOAEL value of 39
mg/kg/day was selected from the combined chronic
toxicity/carcinogenicity stud in rats. (MRIDs 43954301, 44852701,
44832201), based on decreased body weight, body weight gain, food
consumption and food efficiency, increased clinical and gross
pathological signs of toxicity at a dose of 200 mg/kg/day. For risk
assessments, an uncertainty factor of 100 was selected (10x
inter-species extrapolation, 10x intra-species variation).

For short-term dermal risk assessment (1-30 days), a NOAEL of 100
mg/kg/day was selected from the 21-day dermal toxicity study in rats
(MRID 42881901), based on dermal irritation (erythema, scaling) at the
site of test substance application at the next highest dose of 500
mg/kg/day. This is a route-specific study and is also appropriate for
the time frame of the risk assessment. For risk assessments, an
uncertainty factor of 100 was assigned (10x inter-species extrapolation,
10x intra-species variation).

For intermediate-term and long-term dermal risk assessments, a NOAEL
value of 39 mg/kg/day was selected from the combined chronic
toxicity/carcinogenicity stud in rats. (MRIDs 43954301, 44852701,
44832201), based on decreased body weight, body weight gain, food
consumption and food efficiency, increased clinical and gross
pathological signs of toxicity at a dose of 200 mg/kg/day. For risk
assessments, an uncertainty factor of 100 was assigned (10x
inter-species extrapolation, 10x intra-species variation).

There are no repeated dose inhalation toxicity studies available for
OPP. Thus, oral endpoints were used. For assessment of short-term
inhalation risk, a NOAEL value of 100 mg/kg/day was selected from the
developmental toxicity study in rats (MRIDs 00067616 and 92154037),
based on clinical observations of toxicity, decreased weight gain, food
consumption and food efficiency observed at the next higher dose of 300
mg/kg/day. An uncertainty factor of 100 was assigned (10x inter-species
extrapolation, 10x intra-species variation). An additional database
uncertainty factor of 10x was assigned in addition to determine the need
for a confirmatory inhalation toxicity study.

For intermediate- and long-term inhalation risk assessments, a NOAEL
value of 39 mg/kg/day was selected from the combined oral chronic
toxicity/carcinogenicity stud in rats. (MRIDs 43954301, 44852701,
44832201), based on decreased body weight, body weight gain, food
consumption and food efficiency, increased clinical and gross
pathological signs of toxicity at a dose of 200 mg/kg/day. An
uncertainty factor of 100 was assigned (10x inter-species extrapolation,
10x intra-species variation). An additional database uncertainty factor
of 10x was assigned in addition to determine the need for a confirmatory
inhalation toxicity study. If estimated MOEs fall below 1000 for
intermediate and long-term inhalation risk, a confirmatory
route-specific inhalation toxicity study may be required.

**FQPA Considerations**

The ADTC recommended that the special hazard-based FQPA safety factor be
**reduced to 1x** for OPP. There are available developmental toxicity
and reproductive toxicity studies for OPP that are considered acceptable
and that show no evidence of increased toxicity to offspring at the same
or lower doses as those causing parental/systemic toxicity or evidence
of more severe toxicity relative to parental/systemic toxicity.

**Dietary Exposure and Risk**

Exposure from the direct and indirect food uses for OPP as well as the
inert uses of OPP that result in dietary exposure have been assessed.
Exposure estimates from direct food uses were developed using the
Dietary Exposure Evaluation Model software with the Food Commodity
Intake Database (DEEM-FCID), Version 2.00, which incorporates
consumption data from USDA's Continuing Surveys of Food Intakes by
Individuals (CSFII), 1994-1996 and 1998. Exposure estimates from
indirect food uses of OPP in counter top disinfectants, dishwashing
disinfectants, paper slimicides, paper coatings, and paper adhesives
were developed using FDA methodology. Exposure estimates from inert uses
of Na-OPP were developed using DEEM-FCID.

Results of direct food exposure showed that for the adult U.S.
population, 7.1% of the chronic Population Adjusted Dose (cPAD) was
occupied from this exposure, while for children, 19.9% of the cPAD was
occupied for children ages 1-6, the highest exposed subpopulation. From
indirect food exposure, aggregate dietary exposure occupied 20% and 29%
of the cPAD for adults and children respectively. From the inert uses of
Na-OPP, 1.5% of the cPAD was occupied from adult exposure, while 5.4%
was occupied from the highest exposed subpopulation of children (ages
1-2). These percentages are all below 100% of the cPAD and are thus do
not pose a risk of concern.

**Drinking Water Exposure and Risk**

Residues of OPP are not expected to significantly impact surface or
ground water, as OPP and its salts are known to breakdown in soils,
under aerobic as well as anaerobic conditions within a few hours to
weeks and therefore a drinking water assessment is not needed.

**Residential Handler Exposure and Risk**

Several residential handler exposure scenarios were assessed for OPP,
including use on indoor and outdoor hard surfaces, air deodorization,
fogging, treated plastics, and treated paint. Exposures were assessed
using either CMA (Chemical Manufacturers Association, now the American
Chemistry Council) data, PHED data presented in HED's Residential SOPs,
or (for inhalation) EPA's Wall Paint Exposure Model. The duration of
exposure assessed was primarily short-term exposures, because the
residential uses are expected to be episodic in nature and not daily.
The resulting short-term exposures and MOEs for the representative
residential handler scenarios were above the target dermal and
inhalation MOE of 100 for all scenarios. Furthermore, all short-term
inhalation MOEs for exposure to aerosolized paint are above the target
MOE of 100. Results of exposure to chemical vapor exposure from treated
paint using the Wall Paint Exposure Model showed that the inhalation
(vapor) MOE for the short-term exposure for the homeowner painter is
above the target MOE of 100.

For residential post-application assessment, scenarios were developed
that encompass multiple products, but still represent a high end
exposure scenario for all products represented for purposes of a
screening-level assessment. Representative postapplication scenarios
assessed include contacting treated hard surfaces/floors (dermal and
incidental oral exposure to children), wearing treated clothing (dermal
exposure to adults and children), wearing treated diapers (dermal
exposure to infants), mouthing treated textiles such as clothing and
blankets (incidental oral exposure to children), and mouthing treated
plastic toys (incidental oral exposure to infants). Additionally,
postapplication/bystander inhalation exposures were assessed for use of
the disinfecting/deodorizing products (vapor exposure to adults and
children) and paints (vapor exposure to adults and children). As with
residential handler scenarios, most exposures were assessed for
short-term duration only. However, it is believed that intermediate-term
exposure to children may occur in day care centers where disinfecting
products are used more frequently. Additionally, it is believed that
exposures will occur on a continuous basis for infants wearing treated
diapers. Therefore, short-, intermediate- and long-term (\> 6 months)
exposures were necessary to assess this scenario.

Results of the post-application residential assessment showed that for
short- and intermediate-term dermal exposures of children contacting
treated floors, dermal MOEs for short-term (150) and intermediate-term
(930) were above the target level of 100 and thus not of concern. Short-
and intermediate-term incidental oral exposures of children contacting
treated floors were also above the target MOE of 100 (1,200 and 6,900
respectively) and thus are not of concern.

For short-term dermal exposure of adults and children wearing treated
clothing, the dermal MOEs for children were below the target MOE of 100
using the 100% transfer factor (MOE \< 1) and using the 5% transfer
factor (MOE = 16). For adults, the dermal MOEs were also below the
target MOE of 100 using both the 100% transfer factor (MOE = 1) and the
5% transfer factor (MOE = 25) and thus present risks of concern for this
scenario. In addition to treated clothing, there is the potential for
dermal exposure to infants wearing cloth diapers treated with a
trigger-pump spray product containing OPP. Though it is likely that the
diapers treated with this product would be washed prior to use, the
label does not provide specific use instructions pertaining to washing.
Therefore, a post-application assessment assuming no laundering was
conducted as a conservative measure. Calculation of short-,
intermediate-, and long-term dermal doses and MOE for infants wearing
treated cloth diapers showed all MOEs below the target of 100 using a
transfer factor of either 100% or 5%.

For incidental oral exposures of children mouthing treated textiles or
treated toys, calculation of incidental oral MOEs showed no risks of
concern from these exposures (MOEs of 300 and 2,400 respectively).

Inhalation exposures of adults and children from exposure to air
deodorizers containing OPP were assessed using the Multi-Chamber
Concentration and Exposure Model (MCCEM v1.2) to present a
screening-level estimate of the potential inhalation risk. For both
adults and children, the calculated inhalation MOEs are greater than the
target MOE of 100. Furthermore, these MOEs are also greater than 1,000
therefore; an additional inhalation toxicity study is **not** warranted
based on the results of this scenario. The MCCEM model was also used to
assess post-application inhalation exposures for entry into a room after
a fogging application. All of the adult and child inhalation MOEs were
above the target MOE of 100. All of the MOEs for children were below
1,000. However, the ST vapor inhalation exposures to adults for a 0-hr
REI and a 4- and 24- hour exposure duration along with the ST vapor
inhalation exposure to adults for a 4-hr REI and 24 hour exposure
duration were below 1,000. Therefore, the based on the results of these
scenarios for which the calculated MOEs are below 1,000, the Agency may
request that a confirmatory inhalation toxicity study be conducted.

Post-application inhalation exposure to OPP from use in paint was
estimated using the Wall Paint Exposure Model (WPEM) version 3.2. Both
the child and adult inhalation MOEs are above the target MOE of 100, but
below a value of 1,000. Since the MOEs are below 1,000, the Agency may
request that a confirmatory inhalation toxicity study be conducted.

**Aggregate Exposure and Risk**

[Acute and Chronic Dietary Aggregate Risk]{.underline}: Aggregate
dietary risk includes exposure from direct food uses, indirect food
uses, inert uses, and exposure from drinking water. As an acute dietary
endpoint of concern was not identified for OPP, and as there are no
concerns for surface or ground water residues of OPP, the aggregate
dietary risk can be addressed from the direct and indirect food uses of
OPP. Dietary exposure from conventional uses of OPP is detailed in a
separate memorandum from the Health Effects Division of the Office of
Pesticide Programs (D319639), while dietary exposure from the indirect
food uses of OPP have been detailed in a separate memorandum ( A Memo
from Bob Quick, to Najm Shamim, 2006). Dietary exposure from the inert
uses of NA-OPP is detailed in a separate memorandum as well (Talia
Milano and Cassi Walls, Ph.D., February 2006). Aggregate dietary risk
from these sources occupy 31.5% of the cPAD for adults and 68.7% of the
cPAD for children. These aggregate risk estimates are all below 100% of
the cPAD for OPP and thus there is no risk of concern.

[Short- and Intermediate-term aggregate risk:]{.underline} Short- and
intermediate-term aggregate exposures and risks include food and/or
water exposures in conjunction with relevant residential exposures from
both the active and inert uses of OPP and NA-OPP. In the case of OPP,
short- and intermediate-term aggregate risks were assessed for adults
and children that could be exposed to OPP and OPP salt residues from the
use of products in non-occupational environments. Since the short-term
dermal toxicity endpoint (NOAEL of 100 mg/kg/day from a 21-day dermal
toxicity study) was based on skin irritation, in comparison to a
different effect from the short-term oral and inhalation end points
(NOAEL of 100 mg/kg/day from developmental toxicity studies), short-term
dermal exposures were not aggregated with the short-term inhalation and
oral exposures. Intermediate-term toxicity endpoints for all of the
routes of exposure (oral, dermal and inhalation) are based on the same
study and same toxic effect (NOAEL of 39 mg/kg/day from a
chronic/carcinogenicity study); therefore, all intermediate-term routes
were aggregated together. The Total MOE method was employed to assess
aggregate risk. This method is found at
http://www.epa.gov/pesticides/trac/science/aggregate.pdf. When dietary
exposures were aggregated with oral and inhalation residential exposure
scenarios, the aggregate short-term Margin of Exposure (MOE) for adults
was 333, and the aggregate short-term MOE for children was 355.
Intermediate-term aggregate risk (children only) was calculated to be
247. Aggregate dermal risk (MOE) for adults was calculated to be 141,
and the aggregate MOE for children was 111. These values are above the
target MOE of 100 and are thus not of concern.

#### Occupational Exposure

Occupational handler exposures were assessed for numerous scenarios
under the Use Site Categories (USC) of agricultural premises, food
handling premises, commercial/institutional/industrial premises, and
medical premises. Additionally, occupational exposure can occur during
the preservation of materials that are used for household,
institutional, and industrial uses, along with the preservation of wood.
A detailed analysis is presented in the occupational and residential
exposure chapter for OPP (D320537). In summary, the results of
occupational handler analysis indicated no risks of concern with the
exception of the following MOEs are slightly below the target MOE of
100:

-   Agricultural premises, fogging: intermediate-term PPE Total MOE
    = 98. The IT inhalation MOE = 880, and is below 1,000 so that the
    Agency may request a confirmatory inhalation toxicity study.

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-   Commercial/Institutional premises, wiping: short-term baseline
    dermal MOE= 74, intermediate-term baseline dermal MOE = 68, and
    intermediate-term baseline Total MOE = 64.

-   Medical premises, mopping: short-term baseline dermal MOE= 93,
    intermediate-term baseline dermal MOE = 84, and intermediate-term
    baseline Total MOE = 78.

-   Materials Preservatives, liquid pour preservation of textiles:
    short-term PPE dermal MOE= 92, intermediate-term PPE dermal MOE =
    83, and intermediate-term Total MOE = 78.

-   Materials Preservatives, painter (applying paint post-preservation),
    airless sprayer: baseline dermal short-term MOE = 66.

-   Professional Painters: short term inhalation exposure MOE = 43,
    which is below the target MOE of 100.

An occupational post-application assessment was only conducted for
inhalation exposures as a result of entry into a building after a
fogging application, because dermal post application is presumed to be
negligible. The inhalation exposure assessment was conducted using the
Multi-Chamber Concentration and Exposure Model (MCCEM v1.2). Both the
short-term MOE (690) and the intermediate-term MOE (270) were above the
target MOE of 100 but below 1,000. Therefore, the Agency may request
that a confirmatory inhalation toxicity study be submitted since the
current inhalation endpoint is based on an oral toxicity study.

In addition, there are also occupational exposure risks as a result of
using materials that have been already treated with OPP and OPP Salt
products. These include metalworking fluids and wood.

There is a potential for dermal and inhalation exposure when a worker
handles treated metalworking fluids. This route of exposure occurs after
the chemical has been incorporated into the metalworking fluid and a
machinist is using/handling this treated end-product. The short-term
dermal MOE = 54 shows a risk of concern for exposure to metalworking
fluid treated with OPP, and there is no concern with the inhalation
risks associated with exposure to already treated fluids.

OPP and OPP salts are used in products that are intended to preserve
wood (non-pressure treatment). There is the worker function of
incorporating the wood preservative into the slurry. For this liquid
pump treatment when workers add the preservative to the wood slurry, the
MOEs are above the target MOE of 100 and therefore do not pose a
concern. However, the IT inhalation MOE (840) for the blender/spray
operators adding the chemical via closed-liquid pumping is less than
1,000 and therefore a confirmatory inhalation toxicity study is
warranted based on these results.

There are also several other job functions that pose a risk for handlers
to come into contact with OPP or OPP Salt preserved wood. For all worker
functions, which include, chemical operators, graders, millwrights,
clean-up crews, trim saw operators and dip tank operators, the dermal,
inhalation and total MOEs are not of concern.

**Environmental Fate Assessment**

Orthophenylphenol is stable and persistent in abiotic aqueous medium at
pHs 5, 7 and 9. It degrades completely in 14 days when exposed to
sunlight and is therefore, photolytically unstable in neutral aqueous
medium. When exposed to UV light (253.7 nm), it degrades into
phenylbenzoquinone, pehnylhydroquinone, and 2-hydroxy benzofuran. Its
half-life is (measured against hydroxyl radical) 14 hours and is
unstable in the atmosphere. It has a high K~OC~ value of 10,000 and is
immobile in soils and is likely to remain on the soil surfaces. It is
not likely to migrate into ground water. Its major degradation pathway
appears to be through biodegradation under aerobic and anaerobic
conditions. The observed half lives vary from a few hours to three
weeks. Hence even though it is likely to stay on soil surfaces, it
biodegrades under aerobic and aerobic soil conditions. Thus it is not
likely to contaminate surface water (drinking water). The sodium salt of
OPP (applied as an antisapstain wood treatment) has been shown to leach
out up to 58% within first day after treatment highest leach rate: 71
µg/cm^2^ /day on day one) and up to 82 % within 14 days after treatment
(maximum application rate is 4% of NA-OPP). The exposure from the
leaching of OPP/NA-OPP from wood treated for antisapstain purposes
cannot be addressed at this time due to a lack of leaching information.
The registrants have completed an antisapstain leaching study from the
treated wood. The wooden blocks were treated with 1% and 4% DOWICIDE A.
Since the DOWICIDE A contains 71.1% actives, actual dosings of SOPP were
0.71 and 2.84%, respectively). The study showed that under experimental
conditions, 1% and 4 % solutions of SOPP leached 52 to 58% from the
treated wooden blocks within the first day; after 14 days, 78-82 % of
SOPP leached out from the treated wooden blocks.

Leach rates were: 1% solution 71 µg SOPP/cm^2^ /day and for 4% solution:
192µg/ SOPP/cm^2^ /day for the first day; after 14 days, leach rates
were: 0.5 to 2.0µg/cm^2^ /day for both solutions. Maximum leaching
occurred within the first day and attained pseudo equilibrium after 14
days. At the end of the experiment 20-24% SOPP was extracted from the
wooden blocks. (Orthophenylphenol: Determination of the leaching rate
from Wood following a simulated Sapstain Treatment, The Dow Chemical
Company, Study ID#: 051089, 2005, DP Barcode: 319656)

**Ecological/Environmental Risk Assessment**

2-phenylphenol and its salts demonstrate low toxicity to birds, and
moderate toxicity to mammals, freshwater fish, freshwater invertebrates,
and algae.

The low exposure potential from the indoor uses of 2-phenylphenol and
salts, coupled with the tendency for the compounds to degrade under
environmental conditions, result in low likelihood of adverse acute
effects to wildlife and aquatic organisms from the indoor uses. Based on
the results of the antisapstain modeling, runoff from antisapstain
treating facilities will exceed acute high risk, restricted use, and
endangered species LOCs for freshwater fish, freshwater invertebrates,
and aquatic plants. Chronic risks cannot be assessed at this time due to
a lack of chronic toxicity data.

The model used to estimate exposure from antisapstain uses is intended
as a Tier I screening model, and, as such, has inherent assumptions and
uncertainties that may result in over- or under-estimation of exposure
levels. Since the model is only intended as a screening-level model,
further refinement of the model is recommended to more accurately assess
risks from the antisapstain uses of 2-phenylphenol.

[]{.mark}

Methods to reduce the amount of 2-phenylphenol potentially released from
antisapstain-treated wood could potentially mitigate the risks. Possible
mitigation methods might include, but are not limited to, lowering the
application rate or requiring specific storage conditions to prevent
exposure of recently treated wood to weather (e.g., full covering)
and/or prevent the release of any associated runoff into aquatic
habitats (e.g., drip pads). 2-phenylphenol is not very mobile in soils,
so any 2-phenylphenol leached outdoors will likely bind to soils and not
reach aquatic habitats as free 2-phenylphenol. An environmental
monitoring study of runoff from antisapstain facilities is needed to
address the potential risks of concern and provide estimated
environmental concentrations (EEC) to use in a refined risk assessment.
In the interim, precautions to limit leaching and runoff from
antisapstain treatment facilities areas (see Label Hazard Statements and
Use Recommendations section, below) should prevent exposure to aquatic
organisms.

**Endocrine Disruption**

Laboratory studies indicate that 2-phenylphenol (aka 2-hydroxybiphenol)
demonstrates some potential to act as an endocrine disruptor. When the
appropriate screening and/or testing protocols being considered under
the Agency's Endocrine Disruptor Screening and Testing Advisory
Committee (EDSTAC)'s Endocrine Disruptor Screening Program (EDSP) have
been developed, 2-phenylphenol may be subjected to additional screening
and/or testing to better characterize effects related to endocrine
disruption.

**Endangered Species**

For certain use categories, the Agency assumes there will be minimal
environmental exposure, and only a minimal toxicity data set is required
(Overview of the Ecological Risk Assessment Process in the Office of
Pesticide Programs U.S. Environmental Protection Agency - Endangered and
Threatened Species Effects Determinations, 1/23/04, Appendix A, Section
IIB, pg.81). Chemicals in these categories therefore do not undergo a
full screening-level risk assessment, and are considered to fall under a
Ano effect@ determination. The active ingredient uses of 2-phenylphenol,
with the exception of the antisapstain wood preservation use, fall into
this category. Using Tier I screening modeling to assess potential
exposure from antisapstain wood preservation uses of 2-phenylphenol,
risks to Listed Species are indicated. Since the model is only intended
as a screening-level model, and, as such, has inherent uncertainties and
limitations which may result in inaccurate exposure estimations, further
refinement of the model is recommended before any regulatory action is
taken regarding the antisapstain uses of 2-phenylphenol . Additionally,
impacts from the antisapstain use could potentially be mitigated with
precautions to prevent leaching and runoff when wood is stored outdoors
(see Label Hazard Statements/Use Recommendations, below). Due to these
circumstances, the Agency defers making a determination for the
antisapstain uses of 2-phenylphenol until additional data and modeling
refinements are available. At that time, the environmental exposure
assessment of the antisapstain use of 2-phenylphenol will be revised,
and the risks to Listed Species will be reconsidered.

**[Data Gaps]{.underline}**:

The following ecological effects data gaps exist for the registered uses
of 2-phenylphenol and salts:

Marine/estuarine organism acute testing (72-3/850.1075, 850.1035/1045,
and 850.1025/1055) (*These studies have recently been submitted to the
Agency and are currently undergoing review*).

Aquatic organism chronic toxicity testing (72-4a/850.1300 and
72-4b/850.1400**)**

Terrestrial plant toxicity testing using rice (123-1/850.4225 and
850.4250) (*These studies have recently been submitted to the Agency and
are currently undergoing review*).

Aquatic plant toxicity testing on four species (123-2/850.4400 and
850.5400) (*These studies have recently been submitted to the Agency and
are currently undergoing review*).

Monitoring study of runoff from antisapstain facilities to establish
EEC\'s for risk assessment

**[Label Hazard Statements/Use Recommendations]{.underline}**

2-phenylphenol and salts labels must state**:**

\"Do not discharge effluent containing this product into lakes, streams,
ponds, estuaries,

oceans, or other waters unless in accordance with the requirements of a
National Pollutant Discharge Elimination System (NPDES) permit and the
permitting authority has been notified in writing prior to discharge. Do
not discharge effluent containing this product to sewer systems without
previously notifying the local sewage treatment plant authority. For
guidance contact your State Water Board or Regional Office of the EPA.\"

Antisapstain labels must state: "Treated lumber must not be stored
outdoors without precautions to prevent to prevent leaching by rainfall
to the environment. Suitable precautions include: covering wood with
plastic or other impervious covering, installation of berms and
placement of plastic under the wood to prevent surface water runoff away
from the storage area."

##### Incident Reports

For assessment of human incidents, several databases were searched for
available information, including the Office of Pesticides Programs (OPP)
Incident Data System (IDS), Poison Control Centers, the California
Department of Pesticide Regulation, the National Pesticide
Telecommunications Network (NPTN), and the published scientific
peer-reviewed literature. From examination of these databases, OPP and
salts appear to cause dermal effects which are perhaps due to
irritation. Inhalation is another route which shows some symptoms.
However, it is clear that all the databases and published literature
show that specific chemical toxic effects can not be attributed
specifically to OPP or NA-OPP or K-OPP only, as most of the symptoms
appear in a mixture of active ingredients, one of them OPP or its salts.

**2.0 PHYSICAL/CHEMICAL PROPERTIES AND CHARACTERIZATION**

**Chemical Identity:**

Chemical Name: Orthophenylphenol (or 2-phenylphenol)

Chemical Family: Phenol

Common/Trade Name: Dowcide1, Preventol O extra

CAS Number: 90-43-7

Molecular Formula: C~12~H~20~O

Chemical Structure:

![](media/image1.wmf)

Table 2-1 Chemical Characteristics for Technical Grade Active OPP

  --------------------------------------- -------------------------------
  Molecular Weight                        170.2

  Color                                   Colorless

  Physical State                          Solid (flakes)

  Specific Gravity                        1.2

  Dissociation Constant                   9.9 at 25 ^o^ C

  pH                                      6.1 in aqueous solution at 22.7
                                          ^o^ C

  Stability                               Stable at normal conditions

  Melting Point                           56-58 ^o^ C

  Boiling Point                           286 ^o^ C

  Water Solubility                        700 mg/L at 25 ^o^ C

  Octanol-Water Partition constant        3.3
  (LogK~OW~)                              

  Vapor Pressure                          2 x 10^-3^ mm Hg at 25 ^o^ C
  --------------------------------------- -------------------------------

> **Chemical Identity**
>
> Chemical Name: Sodium orthophenylphenol (NA-OPP)
>
> Chemical Family: Phenol
>
> Common/Trade Names: Dowcide A, Preventol ON Extra
>
> CAS Number: 132-27-4
>
> Molecular Formula: C~12~H~19~NaO
>
> Molecular Structure:
>
> ![](media/image2.png){width="2.15625in" height="1.2291666666666667in"}
>
> Na-OPP (Sodium orthophenylphenate)

**Table 2-2 Chemical Characteristics for Technical Grade NA-OPP**

  ---------------------------------------- ------------------------------
  Molecular Weight                         192.19

  Color                                    White to light buff

  Physical State                           Solid (flakes)

  Specific Gravity                         1.36

  Dissociation Constant                    10 at 20 ^o^ C

  pH                                       12\. 13.5

  Stability                                Stable under controlled
                                           conditions

  Melting Point                            298.5 ^o^ C

  Boiling Point                            N/A

  Octanol-Water Partition Coefficient (Log 0.59
  K~OW~)                                   

  Water Solubility                         60.6 g/100 mL, 53.37 % (w/w)

  Vapor Pressure                           1.8 x 10^-9^ mm Hg at 25 ^o^ C
  ---------------------------------------- ------------------------------

> **Chemical Identity**
>
> Chemical Name: Potassium Orthophenylphenate (K-OPP)
>
> Chemical Family: Phenol
>
> Common/Trade Name: Potassium salt
>
> CAS Number: 13707-65-8
>
> Molecular Formula: C~12~H~19~KO
>
> Chemical Structure:

![](media/image3.png){width="2.0416666666666665in" height="1.125in"}

K-OPP (Potassium Orthophenylphenate)

**Table 2-3 Chemical Characteristics for Technical Grade Active
Potassium-o-Phenylphenate (K-OPP)**

  ---------------------------------------- ------------------------------
  Molecular Weight                         208.30

  Color                                    White

  Physical State                           Solid

  Specific Gravity                         n/a

  Dissociation Constant                    n/a

  PH                                       n/a

  Stability                                n/a

  Melting Point                            230.7 C

  Boiling Point                            n/a

  Octanol-Water Partition Coefficient (Log 0.59
  K~OW~)                                   

  Water Solubility                         Highly water soluble

  Vapor Pressure                           1.91 x 10^-11^ mm Hg at 25 C
  ---------------------------------------- ------------------------------

**3.0 HAZARD CHARACTERIZATION**

**3.1 Hazard Profile**

**Acute Toxicity**

The acute toxicity database for 2-phenylphenol and salts is incomplete.
Acute dermal toxicity (870.1200), acute inhalation toxicity (870.1300),
and primary eye irritation (870.2400) studies must be submitted.
2-phenylphenol has a moderate order of acute toxicity via the oral route
of exposure (Toxicity Category III). For dermal irritation,
2-phenylphenol and its sodium salt are severe (Toxicity Category I) and
moderate to severe (Toxicity Category II) irritants, respectively.
2-phenylphenol and its sodium salt are not dermal sensitizers. The acute
toxicity profile is presented in Table 3-1.

+--------+-------------------+-------------+-----------------+--------+
| ## T   |                   |             |                 |        |
| able 3 |                   |             |                 |        |
| -1 Acu |                   |             |                 |        |
| te Tox |                   |             |                 |        |
| icity  |                   |             |                 |        |
| Profil |                   |             |                 |        |
| e for  |                   |             |                 |        |
| 2-Phen |                   |             |                 |        |
| ylphen |                   |             |                 |        |
| ol and |                   |             |                 |        |
|  Salts |                   |             |                 |        |
+========+===================+=============+=================+========+
| #      | ##                | ## M        | ## Results      | ##     |
| # Guid | Study Type/Test s | RID Number/ |                 |  Toxic |
| eline  | ubstance (% a.i.) |             |                 | ity Ca |
| Number |                   | ## Citation |                 | tegory |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Acute Oral- Rat   | 43334201    | LD~50~ = 2733   | III    |
| 0.1100 |                   |             | mg/kg           |        |
|        | 2-phenylphenol    |             |                 |        |
| (      | purity 99.9%      |             |                 |        |
| §81-1) |                   |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Acute Oral- Rat   | 43334204    | LD~50~ = 846    | III    |
| 0.1100 |                   |             | mg/kg (male)    |        |
|        | 2-phenylphenol,   |             |                 |        |
| (      | sodium salt       |             | LD~50~ = 591    |        |
| §81-1) | purity 99.1%      |             | mg/kg (female)  |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Acute Dermal-Rat  | 00078779    | LD~50~ \> 5000  | IV     |
| 0.1200 |                   |             | mg/kg           |        |
|        | OPP 99.73% a.i.   |             |                 |        |
| (      |                   |             |                 |        |
| §81-2) |                   |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Acute             | 42333101    | Unacceptable    | NA     |
| 0.1300 | Inhalation-Rat    |             | Study           |        |
|        |                   |             |                 |        |
| (      | OPP 99.75% a.i.   |             |                 |        |
| §81-3) |                   |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Primary Eye       | 00139884    | Unacceptable    | NA     |
| 0.2400 | Irritation-Rabbit |             | Study           |        |
|        |                   |             |                 |        |
| (      | Dowicide ® 1      |             |                 |        |
| §81-4) |                   |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Primary Dermal    | 43334202    | Primary         | I      |
| 0.2500 | Irritation-       |             | Irritant        |        |
|        | Rabbit            |             |                 |        |
| (      |                   |             |                 |        |
| §81-5) | 2-phenylphenol    |             |                 |        |
|        | purity 99.9%      |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Dermal            | 43334203    | Not a           | No     |
| 0.2600 | Sensitization -   |             | sensitizer.     |        |
|        | Guinea pig        |             |                 |        |
| (      |                   |             |                 |        |
| §81-6) | 2-phenylphenol    |             |                 |        |
|        | purity 99.9%      |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Dermal            | 43334205    | Not a           | No     |
| 0.2600 | Sensitization -   |             | sensitizer.     |        |
|        | Guinea pig        |             |                 |        |
| (      |                   |             |                 |        |
| §81-6) | 2-phenylphenol,   |             |                 |        |
|        | sodium salt       |             |                 |        |
|        | purity 99.1%      |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+

#### 

#### In accordance with the EPA Final Guidelines for Carcinogen Risk Assessment (March 29, 2005), the Health Effects Division's Carcinogenicity Assessment Review Committee (CARC) used multiple descriptors for the classification of orthophenylphenol and sodium orthophenylphenol in its meeting of June 8, 2005. 

OPP and NA-OPP were classified as **"Not Likely to be Carcinogenic to
Humans"** based on convincing evidence that carcinogenic effects are not
likely below a defined dose range (i.e, below 200 mg/kg/day). This
classification is based on the following: convincing evidence that a
non-linear mode of action for bladder tumors was established in rats.
High doses of OPP lead to saturation of phase II detoxification enzyme
pathways, resulting in increased amounts of the oxidative metabolites
PHQ and/or PBQ. The generation of PBQ is considered dose-dependent,
appearing in increased quantity only at higher doses of OPP (\>200
mg/kg/day). The shift in biotransformation products with increased dose
of OPP has been postulated to be associated with the non-linear response
observed in tumorigenicity of the urinary bladder, involving oxidative
damage to cells and subsequent regenerative hyperplasia. With continued
exposure, this process leads to development of tumors. Evidence suggests
that a non-genotoxic mode of action is operative.

OPP and NA-OPP were also classified as **"Likely to be Carcinogenic to
Humans,"** based on the presence of urinary bladder tumors in rats and
the presence of liver tumors in mice at doses above 200 mg/kg/day. This
classification is based on the fact that insufficient data were provided
to support a mode of action for the mouse liver tumors. Although the
tumors were benign and observed only in one sex at high doses, more data
are required for any conclusion to be drawn regarding the mode of action
for these tumors.

The CARC noted that although both chemicals are classified as "Likely to
be Carcinogenic to Humans" above a defined dose range, quantification of
cancer risk is not required since the NOAEL selected for the chronic
Reference Dose (39 mg/kg/day) is protective of the precursor events
leading to development of bladder tumors that occur at doses above 200
mg/kg/day and liver tumors that occur above 500 mg/kg/day**.**

2.  **Dose-Response Assessment**

On October 20, 2004, the Antimicrobials Division Toxicology Endpoint
Selection Committee (ADTC) reviewed the available toxicology data for
OPP and selected endpoints for use as appropriate in
occupational/residential exposure risk assessments. The potential for
increased susceptibility of infants and children from exposure to OPP
was also evaluated by the committee in order to meet the statutory
requirements of the Food Quality Protection Act (FQPA) of 1996. A
summary of the results are presented in Table 3-2.

+------------+--------------+-------------+--------------------------+
| **Table    |              |             |                          |
| 3-2        |              |             |                          |
| Summary of |              |             |                          |
| Tox        |              |             |                          |
| icological |              |             |                          |
| Doses and  |              |             |                          |
| Endpoints  |              |             |                          |
| for        |              |             |                          |
| Orthoph    |              |             |                          |
| enylphenol |              |             |                          |
| for Use in |              |             |                          |
| Human Risk |              |             |                          |
| Ass        |              |             |                          |
| essments** |              |             |                          |
+============+==============+=============+==========================+
| Exposure   | Dose Used in | Target MOE, | Study and Toxicological  |
|            | Risk         | UF, Special | Effects                  |
| Scenario   | Assessment   | FQPA SF,    |                          |
|            |              | for Risk    |                          |
|            | (mg/kg/day)  | Assessment  |                          |
+------------+--------------+-------------+--------------------------+
| **Dietary  |              |             |                          |
| Risk       |              |             |                          |
| Ass        |              |             |                          |
| essments** |              |             |                          |
+------------+--------------+-------------+--------------------------+
| **Acute    | No           |             |                          |
| Dietary**  | appropriate  |             |                          |
|            | endpoints    |             |                          |
| (general   | were         |             |                          |
| population | identified   |             |                          |
| and        | that         |             |                          |
| females    | represent a  |             |                          |
| 13-49)     | single dose  |             |                          |
|            | effect.      |             |                          |
|            | Therefore,   |             |                          |
|            | this risk    |             |                          |
|            | assessment   |             |                          |
|            | is not       |             |                          |
|            | required.    |             |                          |
+------------+--------------+-------------+--------------------------+
| **Chronic  | **NOAEL** =  | **FQPA SF** | Combined oral            |
| Dietary**  |              | = 1         | toxicity/carcinogenicity |
|            | 39 mg/kg/day |             | study in rats (MRID      |
| (all       |              | **UF** =    | 43954301, 44852701,      |
| po         | (43% dermal  | 100 (10x    | 44832201)                |
| pulations) | absorption)  | in          |                          |
|            |              | ter-species | LOAEL of 200 mg/kg/day   |
|            |              | ext         | based upon decreased     |
|            |              | rapolation, | body weight, body weight |
|            |              | 10x         | gain, food consumption   |
|            |              | in          | and food efficiency,     |
|            |              | tra-species | increased clinical and   |
|            |              | variation)  | gross pathological signs |
|            |              |             | of toxicity.             |
|            |              | **Chronic   |                          |
|            |              | RfD** =     |                          |
|            |              |             |                          |
|            |              | 0.39        |                          |
|            |              | mg/kg/day   |                          |
|            |              |             |                          |
|            |              | **Chronic   |                          |
|            |              | PAD** =     |                          |
|            |              |             |                          |
|            |              | 0.39        |                          |
|            |              | mg/kg/day   |                          |
+------------+--------------+-------------+--------------------------+
| **N        |              |             |                          |
| on-Dietary |              |             |                          |
| Risk       |              |             |                          |
| Ass        |              |             |                          |
| essments** |              |             |                          |
+------------+--------------+-------------+--------------------------+
| **         | **NOAEL      | **Target    | Developmental (gavage)   |
| Incidental | (maternal)** | MOE** = 100 | toxicity studies in rats |
| Oral**     | = 100        |             | (MRID 00067616,          |
|            | mg/kg/day    | **FQPA SF** | 92154037) and rabbits    |
| Short-Term |              | = 1         | (MRID 41925003;          |
|            |              |             | co-critical              |
| (1 - 30    |              | **UF** =    | developmental toxicity   |
| days)      |              | 100 (10x    | study)                   |
|            |              | in          |                          |
|            |              | ter-species | Maternal LOAEL of 300    |
|            |              | ext         | mg/kg/day based upon     |
|            |              | rapolation, | clinical observations of |
|            |              | 10x         | toxicity, decreased      |
|            |              | in          | weight gain, food        |
|            |              | tra-species | consumption and food     |
|            |              | variation)  | efficiency observed in   |
|            |              |             | the rat developmental    |
|            |              |             | toxicity study.          |
+------------+--------------+-------------+--------------------------+
| **         | **NOAEL** =  | **Target    | Combined oral            |
| Incidental |              | MOE** = 100 | toxicity/carcinogenicity |
| Oral**     | 39 mg/kg/day |             | study in rats (MRID      |
|            |              | **FQPA SF** | 43954301, 44852701,      |
| Interme    |              | = 1         | 44832201)                |
| diate-Term |              |             |                          |
|            |              | **UF** =    | LOAEL of 200 mg/kg/day   |
| (1 - 6     |              | 100 (10x    | based upon decreased     |
| months)    |              | in          | body weight, body weight |
|            |              | ter-species | gain, food consumption   |
|            |              | ext         | and food efficiency,     |
|            |              | rapolation, | increased clinical and   |
|            |              | 10x         | gross pathological signs |
|            |              | in          | of toxicity.             |
|            |              | tra-species |                          |
|            |              | variation)  |                          |
+------------+--------------+-------------+--------------------------+
| **Dermal** | **NOAEL      | **Target    | 21-Day Dermal toxicity   |
|            | (dermal)** = | MOE** = 100 | study in rats (MRID      |
| Short-Term | 100          |             | 42881901)                |
|            | mg/kg/day    | **FQPA SF** |                          |
| (1 - 30    |              | = 1         | LOAEL (dermal) of 500    |
| days)      | (200         |             | mg/kg/day based upon     |
|            | µg/cm^2^)^a^ | **UF** =    | dermal irritation        |
| (r         |              | 100 (10x    | (erythema, scaling) at   |
| esidential |              | in          | the site of test         |
| and        |              | ter-species | substance application.   |
| occ        |              | ext         |                          |
| upational) |              | rapolation, |                          |
|            |              | 10x         |                          |
|            |              | in          |                          |
|            |              | tra-species |                          |
|            |              | variation)  |                          |
+------------+--------------+-------------+--------------------------+
| **Dermal** | **NOAEL** =  | **Target    | Combined oral            |
|            |              | MOE** = 100 | toxicity/carcinogenicity |
| Int        | 39           |             | study in rats (MRID      |
| ermediate- | mg/kg/day^b^ | **FQPA SF** | 43954301, 44852701,      |
| and        |              | = 1         | 44832201)                |
| Long-Term  |              |             |                          |
| (1 - 6     |              | **UF** =    | LOAEL of 200 mg/kg/day   |
| months and |              | 100 (10x    | based upon decreased     |
| \>6        |              | in          | body weight, body weight |
| months)    |              | ter-species | gain, food consumption   |
|            |              | ext         | and food efficiency      |
| (r         |              | rapolation, | (effects observed as     |
| esidential |              | 10x         | early as 13 weeks in     |
| and        |              | in          | this study), increased   |
| occ        |              | tra-species | clinical and gross       |
| upational) |              | variation)  | pathological signs of    |
|            |              |             | toxicity.                |
+------------+--------------+-------------+--------------------------+
| **In       | **NOAEL      | **Target    | Developmental (gavage)   |
| halation** | (maternal)** | MOE** =     | toxicity studies in rats |
|            | =            |             | (MRID 00067616,          |
| Short-Term |              | 100         | 92154037) and rabbits    |
|            | 100          |             | (MRID 41925003;          |
| (1 - 30    | mg/kg/day^c^ | **FQPA SF** | co-critical              |
| days)      |              | = 1         | developmental toxicity   |
|            |              |             | study)                   |
| (r         |              | **UF** =    |                          |
| esidential |              | 100 (10x    | Maternal LOAEL of 300    |
| and        |              | in          | mg/kg/day based upon     |
| occ        |              | ter-species | clinical observations of |
| upational) |              | ext         | toxicity, decreased      |
|            |              | rapolation, | weight gain, food        |
|            |              | 10x         | consumption and food     |
|            |              | in          | efficiency observed in   |
|            |              | tra-species | the rat developmental    |
|            |              | variation)  | toxicity study.          |
|            |              |             |                          |
|            |              | **Note:**   |                          |
|            |              | an          |                          |
|            |              | additional  |                          |
|            |              | 10x is      |                          |
|            |              | necessary   |                          |
|            |              | for route   |                          |
|            |              | ext         |                          |
|            |              | rapolation. |                          |
|            |              | If results  |                          |
|            |              | are below a |                          |
|            |              | MOE of      |                          |
|            |              | 1,000, a    |                          |
|            |              | c           |                          |
|            |              | onfirmatory |                          |
|            |              | inhalation  |                          |
|            |              | study may   |                          |
|            |              | be required |                          |
+------------+--------------+-------------+--------------------------+
| **In       | **NOAEL** =  | **Target    | Combined oral            |
| halation** |              | MOE** =     | toxicity/carcinogenicity |
|            | 39           |             | study in rats (MRID      |
| Int        | mg/kg/day^c^ | 100         | 43954301, 44852701,      |
| ermediate- |              |             | 44832201)                |
| and        |              | **FQPA SF** |                          |
| Long-Term  |              | = 1         | LOAEL of 200 mg/kg/day   |
| (1 - 6     |              |             | based upon decreased     |
| months and |              | **UF** =    | body weight, body weight |
| \>6        |              | 100 (10x    | gain, food consumption   |
| months)    |              | in          | and food efficiency      |
|            |              | ter-species | (effects observed as     |
| (r         |              | ext         | early as 13 weeks in     |
| esidential |              | rapolation, | this study), increased   |
| and        |              | 10x         | clinical and gross       |
| occ        |              | in          | pathological signs of    |
| upational) |              | tra-species | toxicity.                |
|            |              | variation)  |                          |
|            |              |             |                          |
|            |              | **Note:**   |                          |
|            |              | an          |                          |
|            |              | additional  |                          |
|            |              | 10x is      |                          |
|            |              | necessary   |                          |
|            |              | for route   |                          |
|            |              | ext         |                          |
|            |              | rapolation. |                          |
|            |              | If results  |                          |
|            |              | are below a |                          |
|            |              | MOE of      |                          |
|            |              | 1,000, a    |                          |
|            |              | c           |                          |
|            |              | onfirmatory |                          |
|            |              | inhalation  |                          |
|            |              | study may   |                          |
|            |              | be required |                          |
+------------+--------------+-------------+--------------------------+
| **Cancer** | **Class      |             |                          |
| (oral,     | ification:** |             |                          |
| dermal,    | Ortho        |             |                          |
| i          | phenylphenol |             |                          |
| nhalation) | is           |             |                          |
|            | classified   |             |                          |
|            | as ANot      |             |                          |
|            | likely to be |             |                          |
|            | carcinogenic |             |                          |
|            | below a      |             |                          |
|            | specific     |             |                          |
|            | dose range@, |             |                          |
|            | without      |             |                          |
|            | qu           |             |                          |
|            | antification |             |                          |
|            | of risk.     |             |                          |
+------------+--------------+-------------+--------------------------+

UF = uncertainty factor, DB UF = data base uncertainty factor, FQPA SF =
special FQPA safety factor, NOAEL = no observed adverse effect level,
LOAEL = lowest observed adverse effect level, PAD = population adjusted
dose (a = acute, c = chronic), RfD = reference dose, MOE = margin of
exposure

^a^ ([100mg]{.underline} x [0.200 kg rat]{.underline} x [1000
µg]{.underline} ) / 100 cm^2^ area of rat dose = 200 µg/cm^2^

Kg rat mg

^b^ A dermal absorption factor of 43% was chosen based on the results of
a submitted study (Timchalk et al., 1996) in humans.

^c^ The inhalation absorption factor of 100% (default value, assuming
oral and inhalation absorption are equivalent) is used as an assumption
since an oral endpoint was selected for the inhalation exposure
scenarios.

3.  **FQPA Considerations**

Developmental toxicity studies for orthophenylphenol are available in
both the rat and rabbit, as summarized in this toxicology chapter. Both
studies were well conducted and considered acceptable by the Agency. The
examination of these studies shows that adverse effects in offspring
occurred at doses higher than those producing maternal toxicity. In
addition, the effects on offspring were not considered more severe than
those occurring in maternal animals. Therefore, there is no increased
concern for developmental toxicity of orthophenylphenol when comparing
effects in adult animals with those in offspring. This conclusion is
similar to that reached by the Department for Environment, Food and
Rural Affairs of the Pesticides Safety Directorate in their 1993
publication on the evaluation of 2-phenylphenol.

An acceptable two-generation reproduction toxicity study conducted
according to Agency guidelines is available for orthophenylphenol. There
were no toxicologically significant effects on reproductive parameters
in this study. Therefore, there is no increased concern for potential
reproductive toxicity of orthophenylphenol.

Based on the above, the ADTC recommended that the special hazard-based
FQPA safety factor be **reduced to 1x** for OPP. There are available
developmental toxicity and reproductive toxicity studies for OPP that
are considered acceptable and that show no evidence of increased
toxicity to offspring at the same or lower doses as those causing
parental/systemic toxicity or evidence of more severe toxicity relative
to parental/systemic toxicity.

4.  **Endocrine Disruption**

EPA is required under the Federal Food Drug and Cosmetic Act (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
adopted EDSTAC's recommendation that the Program include evaluations of
potential effects in wildlife. For pesticide chemicals, EPA will use
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, OPP may be subjected to
additional screening and/or testing to better characterize effects
related to endocrine disruption.

4.  **EXPOSURE ASSESSMENT AND CHARACTERIZATION**

    1.  **Summary of Registered Antimicrobial Uses**

Table 4-1 presents the uses of OPP and OPP salts that represent the high
end exposures and risks associated with the labeled uses. Some OPP and
OPP salts are registered for residential uses such as disinfectants and
deodorizers. The use patterns for these include indoor and outdoor hard
surfaces (e.g., floors, bathroom fixtures, trash cans, household
contents), textiles (e.g., clothing, diapers, and bedding) and carpets.
Additional uses include fogging and air deodorizing and also as material
preservative for homeowner-type products (e.g., plastics and paints,
metalworking fluids, sapstain, glues, paper, polymers, and paper). The
percentage of OPP and OPP salts in various products range from 0.0137%
to 99.5%.

The routes of exposure evaluated in the present assessment are:
short-term (ST), intermediate-term (IT), and long-term (LT) dermal and
inhalation exposures, and short-term (ST) and intermediate-term (IT)
oral exposures. Specific routes and durations are also presented in
Table 4-1.

+---------------+--------------+--------+-----------+-----------------+
| **Table 4-1   |              |        |           |                 |
| R             |              |        |           |                 |
| epresentative |              |        |           |                 |
| Uses          |              |        |           |                 |
| Associated    |              |        |           |                 |
| with          |              |        |           |                 |
| Residential   |              |        |           |                 |
| Exposure**    |              |        |           |                 |
+===============+==============+========+===========+=================+
| R             | Exposure     | Appli  | Reg       | Application     |
| epresentative | Scenario     | cation | istration | Rate            |
| Use           |              | Method | \#        |                 |
+---------------+--------------+--------+-----------+-----------------+
| Indoor Hard   | ST Handler:  | M      | 40510-5   | 0.126 lb        |
| Surfaces      | Dermal and   | opping |           | a.i./diluted    |
|               | Inhalation;  |        | (OPP      | gal             |
|               |              |        | Salt)     |                 |
|               | ST and IT    |        |           | (8 oz. product  |
|               |              |        |           | / 4 gal water x |
|               | Po           |        |           | 97% a.i. x 8.34 |
|               | st-app^1,9^: |        |           | lb/gal x 1      |
|               | child        |        |           | gal/128 oz)     |
|               | incidental   |        |           |                 |
|               | ingestion    |        |           |                 |
|               | and dermal   |        |           |                 |
+---------------+--------------+--------+-----------+-----------------+
|               | ST Handler:  | Wiping |           |                 |
|               | Dermal and   |        |           |                 |
|               | Inhalation   |        |           |                 |
+---------------+--------------+--------+-----------+-----------------+
|               | ST Handler:  | A      | 777-27    | 0.42% a.i. by   |
|               | Dermal and   | erosol | (OPP)     | weight          |
|               | Inhalation   | foam   |           |                 |
|               |              | sp     |           |                 |
|               |              | ray^3^ |           |                 |
+---------------+--------------+--------+-----------+-----------------+
| Outdoor Hard  | ST Loader    | Tank   | 71240-1   | 0.00104 lb      |
| Surfaces      | and Handler: | type   |           | a.i./gal        |
| (i.e.         | Dermal and   | garden | (OPP      |                 |
| exterior      | Inhalation   | s      | Salt)     | (0.25 gal       |
| house         |              | prayer |           | product / 5 gal |
| cleaner)      |              | (i.e.  |           | water x 0.25%   |
|               |              | low    |           | a.i. x 8.34     |
|               |              | pr     |           | lb/gal:         |
|               |              | essure |           | assuming        |
|               |              | sp     |           | product has the |
|               |              | rayer) |           | density of      |
|               |              |        |           | water)          |
+---------------+--------------+--------+-----------+-----------------+
|               |              |        |           |                 |
+---------------+--------------+--------+-----------+-----------------+
| Textiles      | ST Handler:  | T      | 10088-105 | 0.0208 lb       |
| (i.e.,        | Dermal and   | rigger | (OPP)     | ai/gal          |
| clothing and  | Inhalation   | pump   |           |                 |
| cloth         |              | sp     |           | (0.249% ai x    |
| diapers)      | ST Post-app: | ray^3^ |           | 8.34 lb/gal)    |
|               | adult        |        |           |                 |
|               | dermal;      |        |           |                 |
|               | child        |        |           |                 |
|               | incidental   |        |           |                 |
|               | ingestion    |        |           |                 |
|               | and dermal   |        |           |                 |
|               |              |        |           |                 |
|               | IT/LT        |        |           |                 |
|               | Post-app:    |        |           |                 |
|               | child dermal |        |           |                 |
|               | (diaper)     |        |           |                 |
+---------------+--------------+--------+-----------+-----------------+
| Air           | ST Handler:  | A      | 44446-67  | 0.199% a.i. by  |
| Deodorization | Dermal and   | erosol | (OPP)     | weight          |
|               | Inhalation   | spray  |           |                 |
|               |              |        |           |                 |
|               | Post-app:    |        |           |                 |
|               | adult (ST)   |        |           |                 |
|               | and child    |        |           |                 |
|               | (ST and      |        |           |                 |
|               | IT)^1^       |        |           |                 |
|               | inhalation   |        |           |                 |
|               | ^2^          |        |           |                 |
+---------------+--------------+--------+-----------+-----------------+
| Fogging       | ST Post-app: | Fogger | 70263-3   | 0.019 lb a.i./  |
|               | adult and    |        | ^5^ (OPP) | 6000 ft^2^      |
|               | child        |        |           |                 |
|               | inhalation   |        |           | (0.22% a.i. x 1 |
|               | (vapor)^8^   |        |           | gal             |
|               |              |        |           | product/6000    |
|               |              |        |           | ft^2^ x 8.34    |
|               |              |        |           | lb/gal)         |
+---------------+--------------+--------+-----------+-----------------+
| Using Treated | ST Post-app: | NA     | 67869-24  | 0.34% a.i. by   |
| Pl            | child        |        | (OPP      | weight of       |
| astic/polymer | incidental   |        | salt)     | material to be  |
| products      | ingestion    |        |           | preserved       |
| (i.e., toys)  |              |        |           |                 |
+---------------+--------------+--------+-----------+-----------------+
| Using Treated | ST Handler:  | Paint  | 67869-24  | 0.56% a.i. by   |
| Paint         | Dermal and   | brush, |           | weight of       |
|               | Inhalation   |        | (OPP      | material to be  |
|               | (aerosol and | ro     | salt)     | preserved       |
|               | vapor)^6^    | llers, |           |                 |
|               |              |        | and       | 0.5% a.i. by    |
|               | ST Post-app: | a      |           | weight of       |
|               | adult and    | irless | 464-126   | material to be  |
|               | child        | s      | (OPP)     | preserved       |
|               | inhalation   | prayer |           |                 |
|               | (vapor) ^7^  |        |           |                 |
+---------------+--------------+--------+-----------+-----------------+

ST = Short-term exposure, IT = Intermediate-term exposure

^1^IT post-application exposures for children were assessed because that
this product could be used in a commercial day care facility.

^2^ Since this application rate is for OPP, which has a relatively high
vapor pressure, it was necessary to assess post-application inhalation
exposure to the vapor. OPP salts have a much lower vapor pressure and
will not readily volatilize.

^3^ The aerosol spray was chosen to represent the aerosol foam product
and trigger pump spray product because it is expected that they have
similar unit exposures.

^4^ The post-app exposure is represented by the post-app exposure
scenario for air deodorization.

^5^ Label Reg \# 70263-3 can be used in household settings by commercial
applicators; therefore, a postapplication scenario was assessed using
the %ai from this product. However, the application rate from another
label (#65020-7) for lack of better data. Note: Reg \# 65020-7 also can
be used in schools.

^6^ Handler dermal and inhalation (to the particulates) exposure were
assessed for OPP salts using PHED unit exposures. WPEM (Wall Paint
Exposure Model) was also used to assess the vapors of OPP for
residential handlers because of the high vapor pressure of OPP.

^7^ Post-application inhalation exposures to the vapor were assessed for
only the OPP product because of its high vapor pressure.

^8^ For the fogging scenario, child post-application incidental
ingestion or dermal exposures were not assessed because they were
assessed for the mopping application. The mopping application has a much
higher application rate (in terms of lb ai/ft^2^) than the fogging
application. It should also be noted that although the fogging
application can occur in child care facilities, the intermediate-term
duration was not assessed because it was assumed that the fogging
application would be used primarily in areas damaged by smoke, fire,
floods, or sewage backups and these incidents do not occur on a
continuous basis.

^9^This label, \# 40510-5 states that the product can be used for
"housekeeping santization" and to "sanitize latrine: buckets, urinals,
toilet bowls, walls, shower stalls, garbage cans, and garbage
platforms." This is why it is assumed to not be used in daycares. It
does not specifically say "commercial and institutional premises."

**4.1.1 Residential Exposure/Risk**

The residential handler scenarios shown in Table 4-2 were assessed to
determine dermal and inhalation exposures. The majority of the scenarios
were assessed using CMA data. However, for handlers using paint, two
approaches were used to determine inhalation exposure. First, the
Pesticides Handler Exposure Database (PHED) was used to determine
inhalation exposure to aerosolized particles of paint (assessed below).
Secondly, to assess the inhalation exposure to OPP vapor, EPA's Wall
Paint Exposure Model (WPEM) was used. For specific assumptions used in
this analysis, consult the Occupational and Residential Exposure chapter
for OPP.

**Handlers**

The resulting short-term dermal and aerosol portion of the inhalation
exposures and MOEs for the representative residential handler scenarios
are presented in Table 4-2. The calculated MOEs were above the target
dermal and inhalation MOE of 100 for all scenarios. Furthermore, all
short-term inhalation MOEs exceeded 1,000 therefore, a confirmatory
inhalation toxicity study is **not** warranted based on the results of
these exposure scenarios.

<table>
<colgroup>
<col style="width: 12%" />
<col style="width: 12%" />
<col style="width: 7%" />
<col style="width: 9%" />
<col style="width: 10%" />
<col style="width: 8%" />
<col style="width: 8%" />
<col style="width: 10%" />
<col style="width: 7%" />
<col style="width: 10%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="10"><strong>Table 4-2 Short-Term OPP &amp; Salts
Residential Handlers Exposures and MOEs</strong></td>
</tr>
<tr class="even">
<td rowspan="2">Exposure Scenario</td>
<td rowspan="2">Method of Application</td>
<td colspan="2"><p>Unit Exposure</p>
<p>(mg/lb ai)</p></td>
<td rowspan="2">Application Rate</td>
<td rowspan="2">Quantity Handled/ Treated per day</td>
<td colspan="2">Absorbed Daily Dose (mg/kg/day)</td>
<td colspan="2">MOE (ST)</td>
</tr>
<tr class="odd">
<td>Dermal<sup>a</sup></td>
<td>Inhalation</td>
<td>Dermal<sup>b</sup></td>
<td>Inhalation<sup>c</sup></td>
<td>Dermal (Target = 100)<sup>d</sup></td>
<td>Inhalation (Target = 100)<sup>e</sup></td>
</tr>
<tr class="even">
<td rowspan="3">Application to indoor hard surfaces</td>
<td>Mopping</td>
<td>71.6</td>
<td>2.38</td>
<td>0.126 lb ai/gallon</td>
<td>1 gallons</td>
<td>0.1289</td>
<td>0.0043</td>
<td>780</td>
<td>23,000</td>
</tr>
<tr class="odd">
<td>Wiping</td>
<td>2870</td>
<td>67.3</td>
<td>0.126 lb ai/gallon</td>
<td>0.13 gallons</td>
<td>0.6716</td>
<td>0.0157</td>
<td>150</td>
<td>6,300</td>
</tr>
<tr class="even">
<td>Aerosol Foam Spray</td>
<td>220</td>
<td>2.4</td>
<td>0.42 % ai by weight</td>
<td>0.875 lbs</td>
<td>0.0116</td>
<td>0.0001</td>
<td>8,700</td>
<td>7.90x10<sup>5</sup></td>
</tr>
<tr class="odd">
<td>Application to outdoor hard surfaces (i.e. exterior of homes)</td>
<td>Tank Type Low Pressure Garden Sprayer</td>
<td>100</td>
<td>0.03</td>
<td>0.00104 lb ai/gallon</td>
<td>5 gallons</td>
<td>0.01</td>
<td>0.00016</td>
<td>13,000</td>
<td>4.5x10<sup>7</sup></td>
</tr>
<tr class="even">
<td>Application to textiles</td>
<td>Trigger Pump Spray</td>
<td>220</td>
<td>2.4</td>
<td>0.0208 lb ai/gallon</td>
<td>0.13 gallons</td>
<td>0.085</td>
<td>0.0065</td>
<td>12,000</td>
<td>1.10x10<sup>6</sup></td>
</tr>
<tr class="odd">
<td>Air deodorization</td>
<td>Aerosol Spray</td>
<td>220</td>
<td>2.4</td>
<td>0.199% ai by weight</td>
<td>1.03 lbs</td>
<td>0.0064</td>
<td>7.5 x 10<sup>-5</sup></td>
<td>16,000</td>
<td>1.4 x10<sup>6</sup></td>
</tr>
<tr class="even">
<td rowspan="2">Painting</td>
<td>Brush/roller</td>
<td>230</td>
<td>0.284</td>
<td>0.56% ai by weight</td>
<td>20 lb s (2 gal)</td>
<td>0.368</td>
<td>0.0005</td>
<td>270</td>
<td>220,000</td>
</tr>
<tr class="odd">
<td>Airless sprayer</td>
<td>79</td>
<td>0.83</td>
<td>0.56% ai by weight</td>
<td>150 lbs (15 gal)</td>
<td>0.948</td>
<td>0.01</td>
<td>110</td>
<td>10,000</td>
</tr>
</tbody>
</table>

a All dermal unit exposures represent ungloved replicates. The aerosol
spray, tank-type garden sprayer (i.e., low pressure sprayer), trigger
pump sprayer, brush/roller, and airless sprayer unit exposures represent
short sleeve and short pant replicates. The mopping, wiping, and liquid
pour represent long pant and long shirt replicates.

b Dermal Daily Dose (mg/kg/day) = \[dermal unit exposure (mg/lb ai) \*
application rate \* quantity handled / body weight (70 kg).

c Inhalation Daily Dose (mg/kg/day) = \[inhalation unit exposure (mg/lb
ai) \* application rate \* quantity handled / body weight (70 kg).

d Dermal MOE = NOAEL (100 mg/kg/day) / Daily Dose. Target dermal MOE is
100.

e Inhalation MOE = NOAEL (100 mg/kg/day) / Daily Dose. Target inhalation
MOE is 100.

**Residential Painter Inhalation Exposure and Risk**

For assessment of the vapor portion of the inhalation exposure of
residential painters, AD utilized EPA's Wall Paint Exposure Model (WPEM)
version 3.2 to estimate air concentrations resulting from the use of
paint preserved with OPP. WPEM was developed under a contract by Geomet
Technologies for EPA OPPT to provide estimates of potential air
concentrations and consumer/worker exposures to chemicals emitted from
wall paint which is applied using a roller or a brush. WPEM uses
mathematical models developed from small chamber data to estimate the
emissions of chemicals from oil-based (alkyd) and latex wall paint. The
emission data can then be combined with detailed use, workload and
occupancy data (e.g., amount of time spent in the painted room, etc,) to
estimate exposure. Specific input parameters include: the type of paint
(latex or alkyd) being assessed, density of the paint (default values
available), and the chemical weight fraction, molecular weight, and
vapor pressure. Detailed information and the executable model can be
downloaded from
[http://www.epa.gov/opptintr/exposure/docs/wpem.htm.]{.underline}

Results of the WPEM model calculated the short-term vapor inhalation MOE
as 2,000, which does not present a risk of concern for inhalation
exposure of residential painters.

**Residential Post-Application**

For the purposes of this screening level assessment, post-application
scenarios have been developed that encompass multiple products, but
still represent a high end exposure scenario for all products
represented. As shown in Table 4-1, representative post-application
scenarios assessed include contacting treated hard surfaces/floors
(dermal and incidental oral exposure to children), wearing treated
clothing (dermal exposure to adults and children), wearing treated
diapers (dermal exposure to infants), mouthing treated textiles such as
clothing and blankets (incidental oral exposure to children), and
mouthing treated plastic toys (incidental oral exposure to infants).
Additionally, post-application/bystander inhalation exposures were
assessed for use of the disinfecting/deodorizing products (vapor
exposure to adults and children) and paints (vapor exposure to adults
and children). Typically, most products used in a residential setting
result in exposures occurring over a short-term time duration (1 to 30
days).

There is the potential for dermal exposure to toddlers crawling on hard
floors after mopping with OPP and OPP salts products. Exposures and MOEs
were calculated for children contacting treated hard surface floors in
residential homes (short-term exposure) and in commercial daycare
centers (intermediate-term exposure). The dermal MOEs for the
residential settings (short-term MOE) and institutional settings
(intermediate-term MOE) are above the target MOE of 100. In addition to
the dermal exposure, toddlers crawling on treated hard floors will also
be exposed to OPP and OPP salts residues via incidental oral exposure
through hand-to-mouth activity. To calculate incidental ingestion
exposure to these chemicals due to hand-to-mouth transfer, the
methodologies established in the *Standard Operating Procedures (SOPs)
for Residential Exposure Assessments* (USEPA 2000 and, 2001) were used.
These use assumptions that are similar to those used in calculating
dermal exposures for toddlers crawling on treated hard floors. Exposures
were calculated for children contacting treated floors in residential
homes and in commercial day care centers. The oral MOEs are above the
target MOE of 100 for residential settings and institutional settings,
and thus do not present a risk.

The calculation of the short- and intermediate-term dermal and oral
doses and the dermal and oral MOEs are shown in Table 4-3 and 4-4
respectively.

+------------+--------+----------+-------+----------+---------+-----+
| **Table    |        |          |       |          |         |     |
| 4-3.       |        |          |       |          |         |     |
| Short- and |        |          |       |          |         |     |
| Interme    |        |          |       |          |         |     |
| diate-term |        |          |       |          |         |     |
| Post-a     |        |          |       |          |         |     |
| pplication |        |          |       |          |         |     |
| Dermal     |        |          |       |          |         |     |
| Exposures  |        |          |       |          |         |     |
| and MOEs   |        |          |       |          |         |     |
| for        |        |          |       |          |         |     |
| Children   |        |          |       |          |         |     |
| Contacting |        |          |       |          |         |     |
| Treated    |        |          |       |          |         |     |
| Floors**   |        |          |       |          |         |     |
+------------+--------+----------+-------+----------+---------+-----+
| Exposure   | Appli  | Product  | Pe    | Body     | A       | Der |
| Scenario   | cation | r        | rcent | Area in  | bsorbed | mal |
|            | Rate   | emaining | T     | contact  | po      | MOE |
|            |        | after    | rans. | with     | tential | ^b^ |
|            | (lb    | mopping  | Re    | floor    | daily   |     |
|            | ai/sq  |          | sidue | (m^2^)   | dose^a^ |     |
|            | ft)    |          |       |          | (mg/    |     |
|            |        |          |       |          | kg/day) |     |
+------------+--------+----------+-------+----------+---------+-----+
| Hard       | 1.26x  | 25%      | 10%   | 0.657    | 0.674   | 150 |
| surfaces - | 10^-4^ |          |       |          |         | (   |
| r          |        |          |       |          |         | ST) |
| esidential |        |          |       |          |         |     |
| setting    |        |          |       |          |         |     |
+------------+--------+----------+-------+----------+---------+-----+
| Hard       | 1.83x  | 25%      | 10%   | 0.657    | 0.0421  | 930 |
| surfaces - | 10^-5^ |          |       |          |         | (   |
| daycare    |        |          |       |          |         | IT) |
| center     |        |          |       |          |         |     |
+------------+--------+----------+-------+----------+---------+-----+

a Absorbed Potential Daily Dose(mg/kg/day) = \[(Application rate, lb
ai/ft^2^)\*(conversion factor, 454 g/lb)\* (conversion factor, 1,000
mg/g) \* (conversion factor, 1 ft^2^/0.093 m^2^) \* (product remaining
after mopping, 25%) \* (dermal transfer factor, 10%) \* (body surface
area in contact with floor, 0.657 m^2^) \* (dermal absorption , 0.43 for
IT exposure and not applicable for ST exposures) \] / (body weight, 15
kg)

b Dermal MOE = NOAEL (mg/kg/day) / Absorbed Potential Daily Dose
(mg/kg/day) \[Where short-term

dermal NOAEL = 100 mg/kg/day and intermediate-term dermal NOAEL = 39
mg/kg/day\]. Target MOE = 100

**Table 4-4. Short- and Intermediate-term Incidental Oral
Post-application Exposures and MOEs for Children Contacting Treated
Floors**

<table>
<colgroup>
<col style="width: 9%" />
<col style="width: 10%" />
<col style="width: 8%" />
<col style="width: 8%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 8%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 10%" />
<col style="width: 8%" />
</colgroup>
<thead>
<tr class="header">
<th>Exposure Scenario</th>
<th><p>Appl. Rate</p>
<p>(lb ai/</p>
<p>sq ft)</p></th>
<th>Product remaining after mopping</th>
<th>Surface Residue<sup>a</sup> (µg/cm<sup>2</sup>)</th>
<th>Percent transferable residue</th>
<th>Surface area mouthed (cm<sup>2</sup>/event)</th>
<th>Exposure Frequency (events/hr)</th>
<th>Saliva Extraction Factor</th>
<th>Exp. Time (hrs/day)</th>
<th>Absorbed Potential Daily Dose<sup>b</sup> (mg/kg/day)</th>
<th>Oral MOE<sup>c</sup></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td>Hard surfaces - residential setting</td>
<td>1.26x10<sup>-4</sup></td>
<td>25%</td>
<td>15.45</td>
<td>10%</td>
<td>20</td>
<td>20</td>
<td>50%</td>
<td>4</td>
<td>0.0824</td>
<td>1,200 (ST)</td>
</tr>
<tr class="even">
<td>Hard surfaces - daycare center</td>
<td>1.83x10<sup>-5</sup></td>
<td>25%</td>
<td>2.24</td>
<td>10%</td>
<td>20</td>
<td>9.5</td>
<td>50%</td>
<td>4</td>
<td>0.0057</td>
<td>6,900 (IT)</td>
</tr>
</tbody>
</table>

a Surface residue (µg/cm^2^) = (application rate, lb
ai/ft^2^)\*(Disinfectant fraction remaining on floor, 0.25)\*(conversion
factor to convert lb to µg, 4.54E+08 µg/lb)\*(conversion factor to
convert ft^2^ to cm^2^, 1.08E-03 ft^2^/cm^2^)

b Absorbed Potential Daily Dose (mg/kg/day) = \[(Surface residue,
µg/cm^2^)\*(transferable residue, 0.10)\*(exposure time, 4
hrs/day)\*(surface area of hands, 20 cm^2^/event)\*(frequency of
hand-to-mouth activity, 20 events/hr, and 9.5 event for intermediate
term)\*(extraction by saliva, 50 %)\*(conversion factor to convert µg to
mg, 0.001 mg/µg)\]/(body weight, 15 kg)

c MOE = NOAEL (mg/kg/day) / absorbed potential daily dose(mg/kg/day)
\[Where short-term oral NOAEL = 100 mg/kg/day and intermediate-term
NOAEL = 39 mg/kg/day\]. Target MOE = 100.

For the intermediate-term exposures to the treated floors, it was
necessary to determine Total MOEs since the toxicity effects are the
same for the dermal and oral routes. The intermediate-term Total MOE for
children contacting treated floors in day care facilities was 820 and is
greater than the target MOE of 100.

**Dermal exposure from treated clothing**

There is the potential for dermal exposure to adults and children from
wearing clothing treated with a trigger-pump spray product containing
OPP or treatment via factory impregnation of the chemical as a
preservative. Even as there is anticipated exposure to result from an
already preserved textile, the trigger-pump use was identified to be the
high end, and ultimately was the one assessed. (See Table 4-5)

**Table 4-5. Dermal Post-application Exposures and MOEs for Children
and**

**Adults Contacting Treated Textiles**

<table>
<colgroup>
<col style="width: 7%" />
<col style="width: 10%" />
<col style="width: 12%" />
<col style="width: 10%" />
<col style="width: 11%" />
<col style="width: 14%" />
<col style="width: 8%" />
<col style="width: 9%" />
<col style="width: 6%" />
<col style="width: 8%" />
</colgroup>
<thead>
<tr class="header">
<th>% a.i.</th>
<th>Product absorption rate (mg/cm<sup>2</sup>)</th>
<th><p>Conc. on clothing<sup>a</sup></p>
<p>(mg ai/cm<sup>2</sup>)</p></th>
<th>Surface area covered by textile (cm<sup>2</sup>/day)</th>
<th>Percent transferred</th>
<th>Exposure time</th>
<th colspan="2">Potential daily dose<sup>b</sup> (mg/kg/day)</th>
<th colspan="2">Dermal MOE<sup>c</sup></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td colspan="10"><strong>Short-Term Wearing Treated Clothing -
Children</strong></td>
</tr>
<tr class="even">
<td rowspan="2">0.249</td>
<td rowspan="2">198</td>
<td rowspan="2">0.493</td>
<td rowspan="2">5,670</td>
<td>100%</td>
<td>16 (hours/day)</td>
<td colspan="2">124.24</td>
<td colspan="2"><strong>&lt;1</strong></td>
</tr>
<tr class="odd">
<td>5%</td>
<td>16 (hours/day)</td>
<td colspan="2">6.21</td>
<td colspan="2"><strong>16</strong></td>
</tr>
<tr class="even">
<td colspan="10"><strong>Short-Term Wearing Treated Clothing –
Adults</strong></td>
</tr>
<tr class="odd">
<td rowspan="2">0.249</td>
<td rowspan="2">198</td>
<td rowspan="2">0.493</td>
<td rowspan="2">16,900</td>
<td>100%</td>
<td>16 (hours/day)</td>
<td colspan="2">79.34</td>
<td colspan="2"><strong>1</strong></td>
</tr>
<tr class="even">
<td>5%</td>
<td>16 (hours/day)</td>
<td colspan="2">3.97</td>
<td colspan="2"><strong>25</strong></td>
</tr>
<tr class="odd">
<td colspan="10"><strong>Wearing Treated Diapers - &lt;1 year
old</strong></td>
</tr>
<tr class="even">
<td rowspan="2">0.249</td>
<td rowspan="2">198</td>
<td rowspan="2">0.493</td>
<td rowspan="2">462</td>
<td>100%</td>
<td>8 diapers/day</td>
<td>182.2 (ST)</td>
<td>78.35 (IT/LT)</td>
<td><strong>&lt;1</strong> (ST)</td>
<td><p><strong>&lt;1</strong></p>
<p>(IT/LT)</p></td>
</tr>
<tr class="odd">
<td>5%</td>
<td>8 diapers/day</td>
<td>9.11 (ST)</td>
<td><p>3.92</p>
<p>(IT/LT)</p></td>
<td><strong>11</strong> (ST)</td>
<td><p><strong>10</strong></p>
<p>(IT/LT)</p></td>
</tr>
</tbody>
</table>

a Concentration on clothing (mg/cm^2^) = % active ingredient / 100 \*
Product absorption rate (198 mg/cm^2^)

b Potential Daily Dose for clothing (mg/kg/day) = \[(concentration on
clothing, mg/cm^2^) \* (surface area of skin covered by clothing,
cm^2^/day) \* (percent transferable residue from textile) \* (exposure
time, hrs/day) \* (conversion factor, 1 day/24 hours)\] / (body weight,
kg).

Potential Daily Dose for diapers (mg/kg/day) = \[(concentration on
diapers, mg/cm^2^) \* (surface area covered by diaper, cm^2^/diaper) \*
(exposure frequency, diapers/day) \* (dermal absorption factor, 0.43 for
IT, not applicable for ST) \* (percent transferable residue from
diapers)\] / (body weight, kg)

c MOE = NOAEL (mg/kg/day) / absorbed potential daily dose \[Where
short-term dermal NOAEL = 100 mg/kg/day and IT/LT dermal NOAEL = 39
mg/kg/day\]. Target MOEs = 100.

The dermal MOEs for children are below the target MOE of 100 using the
100% transfer factor (MOE \< 1) and using the 5% transfer factor (MOE =
16). For adults, the dermal MOEs are also below the target MOE of 100
using both the 100% transfer factor (MOE = 1) and the 5% transfer factor
(MOE = 25).

For infants wearing treated cloth diapers, all MOEs were below the
target MOE of 100 when using a transfer factor of either 100% or 5%, and
therefore, are of concern.

***Incidental Oral Exposure to Children Mouthing Treated Textiles***

There is the potential for incidental oral exposure to children from
mouthing textiles treated with a trigger-pump spray product containing
OPP. The calculation of the oral dose and oral MOE for children mouthing
treated textiles shows that the MOE value is above the target MOE of 100
(MOE = 300). The results are presented in Table 4-6.

**Table 4-6. Short-term Post-application Incidental Oral Exposures and
MOEs for Children Contacting Treated Textiles**

  --------- ------------ --------------- ------------- ------------ ------------- ------------
  \% a.i.   Product      Concentration   Area mouthed  Saliva       Potential     Incidental
            absorption   on clothing^a^  (cm^2^/day)   Extraction   daily dose    Oral MOE^c^
            rate         (mg/cm^2^)                    Factor       (mg/kg/day)   
            (mg/cm^2^)                                                            

  0.249     198          0.493           20            50%          0.329         300
  --------- ------------ --------------- ------------- ------------ ------------- ------------

a Concentration on clothing (mg ai/cm^2^) = % active ingredient \*
Product absorption rate (198 mg/cm^2^)

b Potential Daily Dose (mg/kg/day) = (Concentration on clothing,
mg/cm^2^) \* (area mouthed, cm^2^/day) \* (saliva extraction factor,
unitless fraction) / (body weight, kg).

c MOE = NOAEL (mg/kg/day) / absorbed potential daily dose \[Where
short-term oral NOAEL = 100 mg/kg/day\]. Target MOE = 100.

***Incidental Oral Exposure to Children from Mouthing Treated Plastic
Toys***

The exposure estimates for children mouthing treated toys are based on
the methodology used for Microban Additive "B" assessment (USEPA 1997b),
which assessed risks to 12 month old infants playing with treated toys,
and exposure assumptions from HED's Residential SOPs (USEPA, 2000 and
2001). The calculations of the oral dose and MOE for children mouthing
treated toys are presented in Table 4-7. The MOE is above the target MOE
of 100 (MOE = 2400) and thus present no risk of concern.

Table 4-7 Short-term Incidental Oral Exposures and MOEs for Infants
Mouthing Treated Toys

+-----+------+-------+------+-------+-------+-------+--------+------+
| \%  | We   | Pe    | Sur  | Su    | S     | Su    | Ab     | In   |
| ai  | ight | rcent | face | rface | aliva | rface | sorbed | cide |
|     | of   | add   | area | Re    | Extra | area  | pot    | ntal |
|     | toy  | itive | of   | sidue | ction | of    | ential | Oral |
|     | (g)  | avai  | toy  | ^a^   | F     | toy   | Daily  | MOE  |
|     |      | lable | (cm  | (mg   | actor | mo    | Dose   | ^c^  |
|     |      | at    | ^2^) | ai/c  |       | uthed | ^b^    |      |
|     |      | su    |      | m^2^) |       |       | (mg/k  |      |
|     |      | rface |      |       |       | (     | g/day) |      |
|     |      | of    |      |       |       | cm^2^ |        |      |
|     |      | the   |      |       |       | /day) |        |      |
|     |      | toy   |      |       |       |       |        |      |
|     |      | (%)   |      |       |       |       |        |      |
+-----+------+-------+------+-------+-------+-------+--------+------+
| 0.  | 50   | 0.5%  | 500  | 0     | 50%   | 500   | 0.0425 | 2400 |
| 34% |      |       |      | .0017 |       |       |        |      |
+-----+------+-------+------+-------+-------+-------+--------+------+

a Surface Reside (mg ai for a 500 cm^2^ toy) = (% ai) \* (Weight of toy,
50 g) \* (Conversion factor, 1000 mg/g) \* (Additive available at
surface of toy, 0.5%) / (Surface area of toy, 500 cm^2^)

b Potential Daily Dose (mg/kg/day) = Surface residue (0.0017 mg
ai/cm^2^) \* (toy area mouthed, 500 cm2/day) \* (saliva extraction)
/(body weight, 15 kg)

c MOE = NOAEL (mg/kg/day) / potential daily dose (mg/kg/day) \[Where
short-term oral NOAEL = 100 mg/kg/day\]. Target MOE = 100.

**Air Deodorizers**

No post-application air concentration data have been submitted for OPP
products to determine potential vapor inhalation risk. Therefore, the
Multi-Chamber Concentration and Exposure Model (MCCEM v1.2) was used to
present a screening-level estimate of the potential inhalation risk to
adults and children. Results of the MCCEM calculation are shown in Table
4-8. For both adults and children, the calculated inhalation MOEs are
greater than 100 and thus present no risk of concern. Furthermore, these
MOEs are also greater than 1,000 therefore; an additional inhalation
toxicity study is **not** warranted based on the results of this
scenario.

**Table 4-8 Short-and Intermediate-term Post-application Inhalation
Exposures and MOEs for Adults and Children in Areas Treated With Air
Deodorizers**

+----------------------+----------+----------+-----------------------+
| Parameter            | Value    |          | Rationale             |
+----------------------+----------+----------+-----------------------+
|                      | Adult    | Child    |                       |
+----------------------+----------+----------+-----------------------+
| House^\*^            | Generic  |          | MCCEM default         |
|                      | House    |          |                       |
|                      | (2-c     |          |                       |
|                      | hambers: |          |                       |
|                      | 35 m^3^  |          |                       |
|                      | bedroom, |          |                       |
|                      | 373 m^3^ |          |                       |
|                      | other    |          |                       |
|                      | rooms)   |          |                       |
+----------------------+----------+----------+-----------------------+
| Activity             | In       |          | EPA Assumption        |
| Schedule^\*^         | bedroom  |          |                       |
|                      | at start |          |                       |
|                      | of       |          |                       |
|                      | m        |          |                       |
|                      | odeling, |          |                       |
|                      | out      |          |                       |
|                      | after 8  |          |                       |
|                      | hours    |          |                       |
+----------------------+----------+----------+-----------------------+
| Concentration of     | 0.199%   |          | Product label         |
| product              | OPP by   |          | #44446-67             |
|                      | weight   |          |                       |
+----------------------+----------+----------+-----------------------+
| Quantity in Can      | 168 g    |          | Product label         |
|                      | product  |          | #44446-67             |
+----------------------+----------+----------+-----------------------+
| Quantity Used per    | 1.15 g   |          | Based on rate of 1    |
| Day                  | product  |          | can per 6,000 m^3^    |
|                      | (2.5     |          | for 30 days, and a    |
|                      | 4x10^-3^ |          | bedroom size of 35    |
|                      | lb       |          | m^3^                  |
|                      | product) |          |                       |
+----------------------+----------+----------+-----------------------+
| Quantity ai Used per | 5.0      |          | (Quantity per day) \* |
| Day                  | 6x10^-6^ |          | (Concentration)       |
|                      | lb       |          |                       |
|                      | ai/day   |          |                       |
|                      |          |          |                       |
|                      | (2.3     |          |                       |
|                      | 0x10^-3^ |          |                       |
|                      | g/day)   |          |                       |
+----------------------+----------+----------+-----------------------+
| Concentration in     | 6.5      |          | (Quantity ai per day) |
| Bedroom after        | 6x10^-5^ |          | / (Bedroom volume)    |
| spraying (Initial    | g        |          |                       |
| Concentration in     | a        |          |                       |
| Bedroom)^\*^         | .i./m^3^ |          |                       |
|                      |          |          |                       |
|                      | (65.6 µg |          |                       |
|                      | a.       |          |                       |
|                      | i./m^3^) |          |                       |
+----------------------+----------+----------+-----------------------+
| Body Weight^\*^      | 70 kg    | 15 kg    | Average body weights  |
|                      |          |          | for adults and young  |
|                      |          |          | children              |
+----------------------+----------+----------+-----------------------+
| Inhalation Rate^\*^  | 11.6     | 8.88     | Average resting rate  |
|                      | m^3^/day | m^3^/day | for adults and young  |
|                      |          |          | children (USEPA,      |
|                      |          |          | 1997)                 |
+----------------------+----------+----------+-----------------------+
| MCCEM Outputs        |          |          |                       |
+----------------------+----------+----------+-----------------------+
| Dose                 | 2.6      | 9.5      | MCCEM Output          |
|                      | 7x10^-4^ | 3x10^-4^ |                       |
|                      | m        | m        |                       |
|                      | g/kg/day | g/kg/day |                       |
+----------------------+----------+----------+-----------------------+
| Inhalation           | 370,000  | 100,000  | NOAEL (100            |
| short-term MOE       |          |          | mg/kg/day)/Dose       |
+----------------------+----------+----------+-----------------------+
| Inhalation           | NA       | 41,000   | NOAEL (39             |
| intermediate-term    |          |          | mg/kg/day)/Dose       |
| MOE                  |          |          |                       |
|                      |          |          |                       |
| (day care            |          |          |                       |
| facilities)          |          |          |                       |
+----------------------+----------+----------+-----------------------+

**Paints**

AD utilized EPA's Wall Paint Exposure Model (WPEM) version 3.2 to
estimate air concentrations resulting from the use of paint preserved
with OPP. For this exposure assessment, WPEM default scenarios were used
to determine exposure to adults (RESADULT) and children (RESCHILD). In
these scenarios, an adult and child are located in a non-painted part of
the house while a bedroom is being painted by a professional painter.
For a detailed description of the RESADULT and RESCHILD scenarios, see
the WPEM User's Guide. Both the child and adult inhalation MOEs are
above the target MOE of 100, but below a value of 1,000. Since the MOEs
are below 1,000, the Agency may request that a confirmatory inhalation
toxicity study be conducted.

Table 4-9 Short-term Post-application Inhalation (vapor) Exposures and
MOEs for Adult and Children in Areas Painted with Preserved Paint

+---------+-----------+----------+--------+------------+-------------+
| Exposed | 24-hr TWA | Exposure | Inhal. | Inhalation | ST Inhal.   |
| Ind     | (mg       | Duration | Rate   | Dose       |             |
| ividual | /m^3^)^a^ | (        | (m^3^/ | (mg/       | MOE^d^      |
|         |           | hrs/day) | hr)^b^ | kg/day)^c^ |             |
+---------+-----------+----------+--------+------------+-------------+
| Adult   | 0.98      | 24       | 0.5    | 0.168      | 600         |
+---------+-----------+----------+--------+------------+-------------+
| Child   | 1.35      | 24       | 0.4    | 0.867      | 120         |
+---------+-----------+----------+--------+------------+-------------+

**Foggers**

Post-application inhalation exposures were assessed for entry into a
room after a fogging application was conducted using MCCEM v1.2. Results
are shown in the following Table 4-10. This table represents results for
various exposure durations immediately after the fogging (0 hours) and 4
hours after starting treatment. All of the adult and child inhalation
MOEs were above the target MOE of 100. All of the inhalation MOEs for
children were below 1,000. In addition, ST vapor inhalation exposures to
adults for a 0-hr REI and a 4- and 24- hour exposure duration along with
the ST vapor inhalation exposure to adults for a 4-hr REI and 24 hour
exposure duration were below 1,000. Therefore, the based on the results
of these scenarios for which the calculated MOEs are below 1,000, the
Agency may request that a confirmatory inhalation toxicity study be
conducted.

**Table 4-10.** **Short-term Post-application Inhalation Exposures and
MOEs for Adults and Children in Fogged Houses**

+--------------+-------------+------------+--------+--------+--------+
| Re-Entry     | Exposure    | TWA Air    | Inha   | Inha   | ST     |
| Interval     | Duration    | Conc.      | lation | lation | Inhal. |
|              | (hrs/day)   | (m         | Rate   | Dose   | MOE^d^ |
| (hrs)        |             | g/m^3^)^a^ | (m^3^/ | (      |        |
|              |             |            | hr)^b^ | mg/kg/ |        |
|              |             |            |        |        |        |
|              |             |            |        | d      |        |
|              |             |            |        | ay)^c^ |        |
+==============+=============+============+========+========+========+
| **Adults**   |             |            |        |        |        |
+--------------+-------------+------------+--------+--------+--------+
| 0            | 2           | 5.25       | 0.5    | 0.075  | 1,300  |
+--------------+-------------+------------+--------+--------+--------+
|              | 4           | 4.45       | 0.5    | 0.127  | 790    |
+--------------+-------------+------------+--------+--------+--------+
|              | 24          | 1.43       | 0.5    | 0.245  | 410    |
+--------------+-------------+------------+--------+--------+--------+
| 4            | 2           | 2.56       | 0.5    | 0.037  | 2,700  |
+--------------+-------------+------------+--------+--------+--------+
|              | 4           | 2.17       | 0.5    | 0.062  | 1,600  |
+--------------+-------------+------------+--------+--------+--------+
|              | 24          | 0.695      | 0.5    | 0.119  | 840    |
+--------------+-------------+------------+--------+--------+--------+
| **Child**    |             |            |        |        |        |
+--------------+-------------+------------+--------+--------+--------+
| 0            | 2           | 5.25       | 0.4    | 0.280  | 360    |
+--------------+-------------+------------+--------+--------+--------+
|              | 4           | 4.45       | 0.4    | 0.475  | 210    |
+--------------+-------------+------------+--------+--------+--------+
|              | 24          | 1.43       | 0.4    | 0.914  | 110    |
+--------------+-------------+------------+--------+--------+--------+
| 4            | 2           | 2.56       | 0.4    | 0.136  | 730    |
+--------------+-------------+------------+--------+--------+--------+
|              | 4           | 2.17       | 0.4    | 0.231  | 430    |
+--------------+-------------+------------+--------+--------+--------+
|              | 24          | 0.695      | 0.4    | 0.445  | 230    |
+--------------+-------------+------------+--------+--------+--------+

^a^ Air concentrations calculated by MCCEM using inputs described in
Table 4.11 of the Occupational and Residential Exposure chapter of this
RED. Model provided air concentrations at 15-minute intervals. Starting
after the REI, the TWA was calculated for each exposure time duration
(See Appendix B).

^b^ Inhalation rate is based on sedentary activity of adults and young
children (USEPA, 1997a)

^c^ Inhalation Dose = Exposure Duration x TWA x Inhalation Rate / Body
Weight (70 kg for adults, 15 kg for children)

^d^ Short-Term Inhalation MOE = Short-Term Inhalation NOAEL (100
mg/kg/day) / Inhal. Dose

**4.2 Dietary Exposure/Risk for Antimicrobial Uses**

Dietary risk assessment incorporates both exposure and toxicity of a
pesticide. A maximum acceptable dose at which there is no unreasonable
adverse health effects is used for risk assessment. This dose is
expressed as percent of the population adjusted dose (PAD). The PAD is
equivalent to Reference Dose (RfD) divided by the special FQPA Safety
Factor. Agency is concerned when the estimated dietary risks exceed 100%
of PAD (aPAD or cPAD). For OPP, an acute toxicological endpoint was not
selected.

The Agency has addressed out the dietary exposure and risk assessment
for OPP and its salts (sodium and potassium). OPP and its sodium and
potassium salts are used as disinfectants and sanitizers in the
following scenarios:

-   Counter tops

-   Tables

-   Refrigerators

-   Preservative in papermaking

-   Preservative in adhesive

-   Mushroom premises

-   Plastics, polymers

The uses of these chemicals as antimicrobials in the scenarios shown
above may result in pesticide residues in human food. **These uses are
considered indirect food uses.**

The maximum rate of application for OPP in sanitizer end-use solutions
is 400 ppm as indicated in 40CFR 180.940. Label searches indicate at the
end-use level application rates are much higher than the limit Agency
has set in the 40 CFR. Hence we have carried out the dietary assessment
for all the scenarios listed above, except plastics and polymers. Table
4-11 summarizes the quantitative risks evaluated by AD for: disinfectant
uses for counter tops, disinfectant use for dish washing, slimidice use
for pulp and paper, paper coatings, and paper adhesives. For the
remaining uses, either a quantitative assessment was not required or
there is data gap as indicated in each subsection. (For detailed
calculations see Bob Quick's Memo on Indirect Food Contact Dietary Risk
Assessment, 2006)

**4.2.1** **Mushroom Houses**

> There are no EPA pesticide tolerances for residues of OPP and/or
> NA-OPP/K-OPP in mushrooms (40CFR 180.129). Mushrooms have not been
> classified into any crop groupings under 40 CFR 180.41. Search of USDA
> Pesticide Data Program (PDP) for the monitoring data of years 2001,
> 2002 and 2003 showed residues of OPP on mushrooms up to 0.75 ppm
> level. 2001 data showed the presence of OPP residues in 63/184 samples
> (33%); 2003 data showed the presence of residues in 35/552 samples
> (6%). There is a definite decline in the presence of OPP. However, the
> highest residues were still at 0.75 ppm.
>
> The presence of OPP/NA-OPP/K-OPP in mushrooms may be due to
> disinfection of non-food contact surfaces in mushroom houses, or
> potentially from absorption of OPP by wood in the mushroom houses.
> **The Agency recommends that a tolerance for indirect residues of OPP
> and its Salts in mushrooms under 40 CFR 180.129 subsection should be
> established.**

2.  **Poultry Hatcheries, Poultry Laying Facilities, Greenhouse and
    Hydroponic Uses.**

> Label searches indicate that use of OPP products in poultry hatcheries
> appear to be non-food use. No residues are expected. EPA Reg# 11725-7
> indicates a registered use for poultry laying operation but it does
> not appear a sanitizer use. Measurable residues would not be expected
> to occur in the egg from this type of use.

3.  **Greenhouse and Hydroponic Uses**

> For greenhouse and hydropnic uses there are label restrictions against
> applying to crop, soil or growing media in which a crop is grown. A
> potable rinse is recommended before treated surface contact crop or a
> substrate which is likely to contact crop. **The Agency recommends a
> confirmatory data to show whether OPP residues are absorbed into
> treated surfaces and whether the potable water rinses eliminate the
> residues.**

4.  **Polymers and Plastics Uses**

> OPP is registered for use into polymers and plastics which are likely
> to contact food (EPA Reg #: 464-126), applied at a rate of 0.1 to
> 0.5%. The Agency in its database does not have any information about a
> migration study on OPP migration into plastics and polymers. **The**
> **Agency recommends a migration study should be conducted on migration
> of OPP to food from plastics and polymers**.

**4.2.5 Wood and Wood Product Use.**

From the language of the label (EPA Reg#: 464-126, at an application
rate 1-3%) it is not clear if OPP migrates from pallets (used to
transfer fruits and vegetables) made of OPP-treated wood migrates into
fruits and vegetables. **The** **Agency recommends that industry provide
residue data to show how much OPP migrates from wood products into
food.**

**4.2.6 Paper Adhesive Use**

> FDA has provided a pre-estimated residue value of 7 ppb for OPP when
> it is used as a paper adhesive in food packaging materials.
>
> There is no acute dietary NOAEL, and hence the Agency has estimated
> the chronic dietary risks for use scenarios discussed above Estimated
> EDIs, DDD and % cPAD are provided in the Table 4-11.
>
> **Table 4-11 Cumulative Estimated Dietary Intake (EDI)/ Daily Dietary
> Dose (DDD) and % cPADs for OPP from INDIRECT Food uses**

+-------------+--------------+----------------+----------------+------+
| **Use**     | **Dietary    | **Estimated    | **Daily        | **%  |
|             | C            | Daily Intake   | Dietary        | cP   |
|             | oncentration | (µ             | Dos            | AD** |
|             | (ppb)**      | g/person/day** | e(mg/kg/day)** |      |
+-------------+--------------+----------------+----------------+------+
| Counter     | 280          | 840 (adult)    | 0.012 (adult)  | 3.0  |
| top/        |              |                |                |      |
| d           |              | 420 (child)    | 0.056 (child)  | 14   |
| isinfectant |              |                |                |      |
+-------------+--------------+----------------+----------------+------+
| D           | 91.5         | 274 (adult)    | 0.004 (adult)  | 1.0  |
| ishwashing/ |              |                |                |      |
| d           |              | 137.5 (child)  | 0.0092 (child) | 2.0  |
| isinfectant |              |                |                |      |
+-------------+--------------+----------------+----------------+------+
| Paper       | 1120         | 3360 (adult)   | 0.048 (adult)  | 12.0 |
| slimicide   |              |                |                |      |
| use         |              | 1680 (child)   | 0.017 (child)  | 4.0  |
+-------------+--------------+----------------+----------------+------+
| Paper       | 3200         | 9600 (adult)   | 0.014 (adult)  | 3.6  |
| Coating/    |              |                |                |      |
| p           |              | 480 (child)    | 0.032 (child)  | 8.0  |
| reservative |              |                |                |      |
+-------------+--------------+----------------+----------------+------+
| Paper       | 7            | 21 (adult)     | 0.0003 (adult) | 0.08 |
| Adhesive    |              |                |                |      |
| p           |              | 10.5 (child)   | 0.0007(child)  | 0.17 |
| reservative |              |                |                |      |
+-------------+--------------+----------------+----------------+------+
| Cumulative  | 4978         | 14935 9adult)  | 0.090 (adult)  | 20   |
|             |              |                |                |      |
|             |              | 3148 (child)   | 0.17 (child)   | 29   |
+-------------+--------------+----------------+----------------+------+

2.  **DIETARY EXPOSURE ASSESSMENT FOR CONVENTIONAL (AGRICULTURAL)
    PESTICIDES.**

Tolerances (40 CFR Part 180.129) were established for the residues of
orthophenylphenol and its sodium salt (FR Notice 27938, 1981 and its
amendment FR Notice 32015, 1983). The tolerances were established for
the fungicidal post-harvest application of these chemicals: Raw
agricultural commodities (RAC) including: apple, cantaloupe, carrot,
cherry, citrus, citron, cucumber, grapefruit, kiwifruit, kumquat, lemon,
lime, nectarine, orange, bell pepper, peach, pear, pineapple, plum,
prune, sweet potato, tangerine, tomato. The established tolerances vary
from 125 ppm (high end) on cantaloupe to 5 ppm (cherry, nectarine)
levels.

This part of the non-cancer dietary risk assessment was carried out by
OPP's Health Effects Division (DP Barcode: D319639). It was conducted
using the Dietary Exposure Evaluation Model (DEEM- FDIC™), Version 2.03
as well as Lifeline Model Version 3.0 which uses food consumption data
from the USDA's Continuing Surveys of Food Intake by Individuals (CSFII)
from 1994-1996 and 1998. This assessment is tier 1, conservative
(assumes 100% crop treatment) and uses the deterministic approach. As
input parameters for modeling analyses, residue level tolerances
(indicated above) were used as point estimates. The chronic analyses
were below Agency's level of concern for the general US Population (7.1%
of cPAD) and all other populations subgroups (the most highly exposed
being children 1-2 years old with a 24.6% of the cPAD)

Table 4-12 summarizes the Dietary Exposure and Risk for OPP/NA-OPP/K-OPP
based on DEEM-FCID™ and Lifeline Model results.

Assumptions: 1) To the established pears and citrus tolerances (40 CFR
180.29), 1 ppm contribution by residues of OPP on mushrooms was added
and DEEM-FCID was run.

2\) Reference dose RfD, Chronic = 0.39 mg/kg/day. There are no dietary
concerns due to this additional exposure scenario.

**Table 4-12**

===============================================================================

**Total Exposure by Population Subgroup**

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Total Exposure

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Population mg/kg Percent of

Subgroup body wt/day Rfd

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--
\-\-\-\-\-\-\-\-\-\-\-\-- \-\-\-\-\-\-\-\-\-\-\-\-\-\--

U.S. Population (total) 0.027769 7.1%

U.S. Population (spring season) 0.027756 7.1%

U.S. Population (summer season) 0.025804 6.6%

U.S. Population (autumn season) 0.027836 7.1%

U.S. Population (winter season) 0.029815 7.6%

Northeast region 0.036468 9.4%

Midwest region 0.025900 6.6%

Southern region 0.023917 6.1%

Western region 0.028107 7.2%

Hispanics 0.036660 9.4%

Non-hispanic whites 0.025299 6.5%

Non-hispanic blacks 0.031023 8.0%

Non-hisp/non-white/non-black 0.037770 9.7%

All infants (\< 1 year) 0.037606 9.6%

Nursing infants 0.020614 5.3%

Non-nursing infants 0.044057 11.3%

Children 1-6 yrs 0.077565 19.9%

Children 7-12 yrs 0.041654 10.7%

Females 13-19 (not preg or nursing) 0.026256 6.7%

Females 20+ (not preg or nursing) 0.019846 5.1%

Females 13-50 yrs 0.022823 5.9%

Females 13+ (preg/not nursing) 0.025276 6.5%

Females 13+ (nursing) 0.025877 6.6%

Males 13-19 yrs 0.028211 7.2%

+--------------------+-----------+-------+---+------+-------+---+-------+
| **Table 4-13       |           |       |   |      |       |   |       |
| Estimated Chronic  |           |       |   |      |       |   |       |
| Dietary Exposure   |           |       |   |      |       |   |       |
| and Risk from use  |           |       |   |      |       |   |       |
| of Na-OPP as an    |           |       |   |      |       |   |       |
| inert              |           |       |   |      |       |   |       |
| ingredient.**      |           |       |   |      |       |   |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Population         | Generic   | OPP/  |   |      | %cPAD |   |       |
| Subgroup^2^        | Estimated | salts |   |      |       |   |       |
|                    | Ex        | Esti  |   |      |       |   |       |
|                    | posure^1^ | mated |   |      |       |   |       |
|                    | (m        | E     |   |      |       |   |       |
|                    | g/kg/day) | xposu |   |      |       |   |       |
|                    |           | re^3^ |   |      |       |   |       |
|                    |           |       |   |      |       |   |       |
|                    |           | (     |   |      |       |   |       |
|                    |           | mg/kg |   |      |       |   |       |
|                    |           | /day) |   |      |       |   |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| U.S. Population    | 0.120     | 0     | \ | 0    | 0.31% | \ | 1.5%  |
| (total)            |           | .0012 | - | .006 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| All infants (\< 1  | 0.245     | 0     | \ | 0    | 0.63% | \ | 3.1%  |
| year)              |           | .0025 | - | .012 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Children (1-2      | 0.422     | 0     | \ | 0    | 1.1%  | \ | 5.4%  |
| years)             |           | .0042 | - | .021 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Children (3-5      | 0.310     | 0     | \ | 0    | 0.79% | \ | 4.0%  |
| years)             |           | .0031 | - | .016 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Children (6-12     | 0.174     | 0     | \ | 0    | 0.45% | \ | 2.2%  |
| years)             |           | .0017 | - | .009 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Youth (13-19       | 0.100     | 0     | \ | 0    | 0.26% | \ | 1.3%  |
| years)             |           | .0010 | - | .005 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Adults (20-49      | 0.087     | 0.    | \ | 0    | 0.22% | \ | 1.1%  |
| years)             |           | 00087 | - | .004 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Adults (50+ years) | 0.086     | 0.    | \ | 0    | 0.22% | \ | 1.1%  |
|                    |           | 00086 | - | .004 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+
| Females (13-49     | 0.087     | 0.    | \ | 0    | 0.22% | \ | 1.1%  |
| years)             |           | 00087 | - | .004 |       | - |       |
+--------------------+-----------+-------+---+------+-------+---+-------+

^1^Exposure estimates are based on highest-tolerance-level residues of
high-use active ingredients for all food forms, including meat, milk,
poultry, and eggs

^2^ Only representative population subgroups are shown

^3^ Generic exposures based on application rates of 1 - 5 lb ai/acre
were adjusted for the tolerance exemption limitation of 0.1% maximum
formulation and maximum application rates (0.05 lb inert/acre); the
generic exposures were divided by a factor of 20 (1/0.05) and 100
(5/0.05)

cPAD = 0.39 mg/kg/day

4.  **AGGREGATE RISK ASSESSMENT**

In order for a pesticide registration to continue, it must be shown
"that there is reasonable certainty that no harm will result from
aggregate exposure to pesticide chemical residue, including all
anticipated dietary exposures and other exposures for which there are
reliable information." Aggregate exposure is the total exposure to a
single chemical (or its residues) that may occur from dietary (i.e.,
food and drinking water), residential, and other non-occupational
sources, and from all known or plausible exposure routes (oral, dermal,
and inhalation).

In performing aggregate exposure and risk assessments, the Office of
Pesticide Programs has published guidance outlining the necessary steps
to perform such assessments (General Principles for Performing Aggregate
Exposure and Risk Assessments, November 28, 2001; available at
http://www.epa.gov/pesticides/trac/science/aggregate.pdf). Steps for
deciding whether to perform aggregate exposure and risk assessments are
listed, which include: identification of toxicological endpoints for
each exposure route and duration; identification of potential exposures
for each pathway (food, water, and/or residential); reconciliation of
durations and pathways of exposure with durations and pathways of health
effects; determination of which possible residential exposure scenarios
are likely to occur together within a given time frame; determination of
magnitude and duration of exposure for all exposure combinations;
determination of the appropriate technique (deterministic or
probabilistic) for exposure assessment; and determination of the
appropriate risk metric to estimate aggregate risk

The short-term dermal toxicity endpoint for OPP was based on skin
irritation observed in a 21-day dermal toxicity study in rats. In
comparison, the oral and inhalation endpoints are based on systemic
effects from a developmental toxicity study in rats. Therefore, the
short-term dermal exposures were aggregated in a separate analysis from
the short-term inhalation and oral exposures. However, for
intermediate-term oral, dermal, and inhalation exposures, the same study
and endpoint was used. Therefore, all intermediate-term exposures were
aggregated together as appropriate.

The toxicological endpoints for OPP and OPP salts are assumed to be
identical. The target MOEs for all routes of exposures for all durations
is set at 100 for occupational and residential scenarios. Examination of
product labels, showed that exposure to handlers can occur in a number
of and residential environments. Post-application exposures also occur
in these settings.

**5.1 Acute and Chronic Dietary Aggregate Risk**

In general, acute and chronic dietary aggregate risks are represented by
dietary (direct, indirect, and inert exposures) and drinking water
exposures. As there is no acute dietary endpoint selected for OPP and
drinking water exposure is not of concern, an acute aggregate dietary
assessment is not performed for OPP. Exposure from direct food, indirect
food, and inert uses for OPP have been assessed. Exposure from [direct
food]{.underline} and [inert]{.underline} uses was conducted using the
Dietary Exposure Evaluation Model software with the Food Commodity
Intake Database (DEEM-FCIDJ), Version 2.00, which incorporates
consumption data from USDA=s Continuing Surveys of Food Intakes by
Individuals (CSFII), 1994-1996 and 1998. Exposures from [indirect
food]{.underline} uses of OPP from counter top disinfectants,
dishwashing disinfectants, paper slimicides, paper coatings, and paper
adhesives were derived from FDA's methodology.

Results of indirect food use exposure are presented in Table 4-11 while
results of direct food use exposure are presented in Table 4-12. Results
of dietary exposure from the inert use of OPP are presented in Table
4-13. Total aggregate dietary exposure and risk is shown below in Table
5-1 for direct, indirect, and inert uses of OPP. The results indicate
that for adults, 31.5% of the cPAD is occupied from all dietary exposure
sources, while for children, 68.7% of the cPAd is occupied from all
dietary sources. These percentages are below 100% of the cPAD and are
thus not of concern to the Agency.

+------------------+-----------------+----------+--------+------------+
| **Table 5-1      |                 |          |        |            |
| Aggregate        |                 |          |        |            |
| Dietary          |                 |          |        |            |
| Exposures and    |                 |          |        |            |
| Risks (direct,   |                 |          |        |            |
| indirect, and    |                 |          |        |            |
| inert uses)**    |                 |          |        |            |
+------------------+-----------------+----------+--------+------------+
| ### Population   | **Direct        | #        |        | **cu       |
|                  | Dietary         | ## Indir |        | mulative** |
|                  | Exposure        | ect Diet |        |            |
|                  | (mg/kg/day)**   | ary Expo |        | **% cPAD** |
|                  |                 | sure (mg |        |            |
|                  |                 | /kg/day) |        |            |
+------------------+-----------------+----------+--------+------------+
|                  |                 |          |        |            |
+------------------+-----------------+----------+--------+------------+
|                  | **Active**      | **       | **I    |            |
|                  |                 | Active** | nert** |            |
+------------------+-----------------+----------+--------+------------+
| Dose (mg/kg/day) |                 |          |        |            |
+------------------+-----------------+----------+--------+------------+
| U.S. Population  | 0.027           | 0.090    | 0.006  | 31.5       |
+------------------+-----------------+----------+--------+------------+
| Children         | 0.077           | 0.17     | 0.021  | 68.7       |
+------------------+-----------------+----------+--------+------------+

**5.2 Short-and Intermediate-Term Aggregate Risk**

Short- term aggregate exposures and risks were assessed for adults and
children that could be exposed to OPP and OPP salt residues from the use
of products in non-occupational environments. The short-term dermal
toxicity endpoint (NOAEL of 100 mg/kg/day from a 21-day dermal toxicity
study) was based on skin irritation. In comparison, the short-term oral
and inhalation endpoints were based on systemic effects from the same
study and toxic effect (NOAEL of 100 mg/kg/day from developmental
toxicity studies). Therefore, short-term dermal exposures were
aggregated in a separate analysis from the short-term inhalation and
oral exposures.

For OPP, the short-term aggregate assessment includes average (chronic)
dietary exposure and estimated exposures from incidental oral and
inhalation exposure that are believed to co-occur. For short-term
aggregate risk to adults, the average dietary exposure was aggregated
with short-term oral and inhalation exposures that occur from mopping,
wiping, and air deodorizer uses the short-term incidental oral and
inhalation residential exposures. Dermal aggregate risk is assessed
separately as the study and endpoint used for risk assessment was
different for this route of exposure.

Results of the short-term dermal aggregate assessment are presented in
Tables 5-2a and 5-2b. The results showed no aggregate risks of concern
to adults applying OPP through wiping, mopping, or air deodorizing
activities (total MOE = 333) or to children from post-application
exposures (MOE = 355).

+-----------------+-----------------+-----------------+-----------------+
| **Table 5-2a    |                 |                 |                 |
| Short-term      |                 |                 |                 |
| Aggregate       |                 |                 |                 |
| Exposure and    |                 |                 |                 |
| Risk Assessment |                 |                 |                 |
| for Adults**    |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Exposure      | **Exposure      | **Margin of     | **Total MOE**   |
| Routes**        | (mg/kg/day)**   | Exposure**      |                 |
+-----------------+-----------------+-----------------+-----------------+
| Dietary         | 0.123           | 317             | **333**         |
| aggregate       |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Inhalation      | 0.0157          | 6,300           |                 |
| exposure        |                 |                 |                 |
|                 | 0.0043          | 23,000          |                 |
| -wiping         |                 |                 |                 |
|                 | 0.0001          | 670,000         |                 |
| -mopping        |                 |                 |                 |
|                 |                 |                 |                 |
| -air deodorizer |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Inhalation      | 0.00026         | 370,000         |                 |
| post-app        |                 |                 |                 |
|                 |                 |                 |                 |
| Air deodorozer  |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

a: Aggregate MOE = 1/(1/MOEdiet) + (1/MOEwipe, app-inhal) +
(1/MOEmop,app-inhal) + (1/MOEair deodorizer, app-inhal) + (1/MOEair
deodorizer, post-inhal))

+-----------------+-----------------+-----------------+-----------------+
| **Table 5-2b    |                 |                 |                 |
| Short-term      |                 |                 |                 |
| Aggregate       |                 |                 |                 |
| Exposure and    |                 |                 |                 |
| Risk Assessment |                 |                 |                 |
| for Children**  |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| **Exposure      | **Exposure      | **Margin of     | **Total MOE**   |
| Routes**        | (mg/kg/day)**   | Exposure**      |                 |
+-----------------+-----------------+-----------------+-----------------+
| Dietary         | 0.115           | 339             | **355**         |
| aggregate       |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Oral exposure   | 0.0824          | 1200            |                 |
|                 |                 |                 |                 |
| -mopping        |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Inhalation      | 0.00095         | 105,000         |                 |
| post-app        |                 |                 |                 |
|                 |                 |                 |                 |
| Air deodorozer  |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

a: Aggregate MOE = 1/(1/MOEdiet) + (1/MOEmop,post- app:oral) + (1/MOEair
deodorizer, post app: inhal))

Table 5-3 presents the results of short-term dermal aggregate exposure
and risk. For dermal aggregate exposures, there were no risks of concern
to either adults or children.

  ------------ ------------- -------------- --------------- ---------------
  **Table 5-3                                               
  Short-term                                                
  Aggregate                                                 
  Dermal                                                    
  Exposures                                                 
  and Risks**                                               

  Exposure     **Adults**                   **Children**    
  Routes                                                    

               Exposure      Margin of      Exposure        Margin of
               (mg/kg/day)   Exposure       (mg/kg/day)     Exposure

  Wiping       0.672         150            0.674           150

  mopping      0.129         780            N/A             

  Air          0.0064        16,000         N/A             
  deodorizer                                                

  Pet product  0.00052       190,000        0.32            310
  (inert use)                                               

  **TOTAL      0.807         **141**        0.99            **111**
  MOE**                                                     
  ------------ ------------- -------------- --------------- ---------------

a: Aggregate MOE = 1/((1/MOEwipe) + (1/MOEmop) + (1/MOEair deodorizer))

Intermediate-term aggregate risks (children only) are presented in Table
5-4. The intermediate-term toxicity endpoints for all of the routes of
exposure (oral, dermal and inhalation) are based on the same study and
same toxic effect (NOAEL of 39 mg/kg/day from a chronic/carcinogenicity
study); therefore, all intermediate-term routes were aggregated together
as appropriate. There are no intermediate-term residential scenarios
identified for adults. For children, intermediate-term scenarios were
identified for post-application oral, inhalation, and dermal exposures
from household cleaning. Intermediate-term aggregate risk (children
only) was calculated to be 247. This value are above the target MOE of
100 and is thus not of concern.

  ----------------------- ----------------------- -----------------------
  **Table 5-4                                     
  Intermediate-term                               
  Aggregate Exposure and                          
  Risks for Children**                            

  Exposure Routes         Exposure                Margin of Exposure

  Dietary aggregate       0.115                   339

  Post-app incidental     0.0057                  6800
  oral from mopping                               

  Post-app dermal from    0.0421                  930
  mopping                                         

  Incidental Oral pet     0.0039                  10,000
  product inert use                               

  Inhalation air          0.00095                 41,000
  deodorizer post-app                             

  **Total**               0.167                   **247**
  ----------------------- ----------------------- -----------------------

a: Aggregate MOE = 1/(1/MOEdiet) + (1/MOEinc. oral post-app) +
(1/MOEdermal post-app) + (1/MOE inc.oral pet product) + (1/MOE
inhalation air deodorizer)

The exception to the above is for adult and child dermal
post-application exposures to textile OPP residues (which alone are of
concern to the Agency), and which were not included into the aggregate
assessment as this would make aggregate risk of concern. This exposure
scenario needs to be addressed in order to make exposure from this use
of OPP not of concern.

**6.0 CUMULATIVE RISK**

FQPA (1996) stipulates that when determining the safety of a pesticide
chemical, EPA shall base its assessment of the risk posed by the
chemical on, among other things, available information concerning the
cumulative effects to human health that may result from dietary,
residential, or other non-occupational exposure to other substances that
have a common mechanism of toxicity. The reason for consideration of
other substances is due to the possibility that low-level exposures to
multiple chemical substances that cause a common toxic effect by a
common mechanism could lead to the same adverse health effect as would a
higher level of exposure to any of the other substances individually. A
person exposed to a pesticide at a level that is considered safe may in
fact experience harm if that person is also exposed to other substances
that cause a common toxic effect by a mechanism common with that of the
subject pesticide, even if the individual exposure levels to the other
substances are also considered safe.

AD did not perform a cumulative risk assessment as part of this RED for
OPP because AD has not yet initiated a review to determine if there are
any other chemical substances that have a mechanism of toxicity common
with that of OPP. For purposes of this RED, EPA has assumed that OPP
does not have a common mechanism of toxicity with other substances.

On this basis, the Registrant must submit, upon EPA's request and
according to a schedule determined by the Agency, such information as
the Agency directs to be submitted in order to evaluate issues related
to whether orthophenylphenol shares a common mechanism of toxicity with
any other substance and, if so, whether any tolerances for OPP need to
be modified or revoked. If AD identifies other substances that share a
common mechanism of toxicity with OPP, AD will perform aggregate
exposure assessments on each chemical, and will begin to conduct a
cumulative risk assessment.

The Health Effects Division, Office of Pesticide Programs, has recently
developed a framework proposed for conducting cumulative risk
assessments on substances that have a common mechanism of toxicity. This
guidance was issued for public comment on January 16, 2002 (67 FR
2210-2214) and is available from the OPP Website at:
http://www.epa.gov/pesticides/trac/science/cumulative_guidance.pdf. In
the guidance, it is stated that a cumulative risk assessment of
substances that cause a common toxic effect by a common mechanism will
not be conducted until an aggregate exposure assessment of each
substance has been completed.

Before undertaking a cumulative risk assessment, AD will follow
procedures for identifying chemicals that have a common mechanism of
toxicity as set forth in the A*Guidance for Identifying Pesticide
Chemicals and Other Substances that Have a Common Mechanism of
Toxicity*@ (64 FR 5795-5796, February 5, 1999).

**7.0 OCCUPATIONAL EXPOSURE AND RISK**

A complete explanation of the occupational exposure and risk assessment
can be found in the supporting disciplinary chapter entitled
[Occupational and Residential Exposure Chapter for Orthophenylphenol &
Orthophenylphenol Salts]{.underline} (D320537). Summary information is
provided in this section.

The occupational handler scenarios were assessed to determine dermal and
inhalation exposures. The general assumptions and equations that were
used to calculate occupational handler risks are provided in the section
of the occupational and residential exposure chapter entitled [Criteria
for Conducting the Risk Assessment]{.underline}. The majority of the
scenarios were assessed using CMA data and Equations. However, for the
occupational scenarios in which CMA data were insufficient, other data
and methods were applied.

For the majority of the occupational handler scenarios assessed, MOEs in
the occupational setting were above the target MOE of 100 for dermal,
inhalation and total exposures, except for the following scenarios:

-   Agricultural premises, fogging: intermediate-term PPE Total MOE = 98

-   Commercial/Institutional premises, wiping: short-term baseline
    dermal MOE= 74, intermediate-term baseline dermal MOE = 68, and
    intermediate-term baseline Total MOE = 64.

-   Medical premises, mopping: short-term baseline dermal MOE= 93,
    intermediate-term baseline dermal MOE = 84, and intermediate-term
    baseline Total MOE = 78.

-   Materials Preservatives, liquid pour preservation of textiles:
    short-term PPE dermal MOE= 92, intermediate-term PPE dermal MOE =
    83, and intermediate-term Total MOE = 78.

-   Materials Preservatives, painter (applying paint post-preservation),
    airless sprayer: baseline dermal short-term MOE = 66.

-   Using EPA's Wall Paint Exposure Model (WPEM), an inhalation MOE of
    43 was calculated for professional painters breathing the vapor of
    OPP.

All of the occupational inhalation MOEs were above the target MOE of
100, except for the following scenario:

Agricultural equipment, fogger IT inhalation MOE = 880

[]{.mark}

1.  **Occupational Post-application Exposures**

Occupational post-application exposures were assessed for inhalation
from fogging use and dermal and inhalation from metalworking fluid use.
In addition, the potential for inhalation exposures to the vapor of OPP
may occur to bystanders as a result of material preservative
applications in industrial settings. Currently, no data are available to
assess these bystander exposures and therefore, monitoring data are
needed.

1.  **Fogging**

Inhalation exposures were assessed for entry into a building which has
gone through a fogging application; it is assumed that dermal
post-application exposure is negligible. The inhalation exposure
assessment was conducted using the Multi-Chamber Concentration and
Exposure Model (MCCEM v1.2). Based on the MCCEM .csv output, MOE values
were calculated. Both the short-term MOE (690) and the intermediate-term
MOE (270) were above the target MOE of 100 but below 1,000. Therefore,
the Agency may request that a confirmatory inhalation toxicity study be
submitted since the current inhalation endpoint is based on an oral
toxicity study.

**7.1.2** **Metalworking Fluids: Machinist**

There is a potential for dermal and inhalation exposure when a worker
handles treated metalworking fluids. This route of exposure occurs after
the chemical has been incorporated into the metalworking fluid and a
machinist is using/handling this treated end-product.

For dermal exposures, a short-, intermediate-, and long-term exposure
estimate were derived using the 2-hand immersion model from ChemSTEER.
The dermal MOE value calculated is above the target MOE of 100 for
intermediate- and long-term dermal exposures (MOE = 290). However, there
is concern with short term dermal exposure because the calculated MOE of
54 is below the target MOE of 100. It should be noted that the
short-term end point is based on the dermal irritation and therefore, a
higher film thickness value was used in comparison to the
intermediate-term and long-term exposures.

For inhalation exposures, a screening-level intermediate and long term
inhalation exposure estimate for treated metalworking fluids has been
developed using the OSHA PEL for oil mist. The inhalation MOE values for
IT/LT and ST exposures to OPP and OPP salts are all above the target MOE
of 100 (IT/LT MOE = 3,600 and ST MOE = 9,300).

2.  **Wood Preservation**

OPP and OPP salts are used in products that are intended to preserve
wood (non-pressure treated wood). As noted on label Reg \# 67869-24, OPP
Salt for wood preservation serves the purpose, *"for the temporary
protection of freshly sawn lumber against staining and molding. \[The
product\] are applied to the freshly sawn lumber by either dipping or
spraying."*

Handler and post application scenarios that have been identified for
wood preservation were extracted from MRID 455243-04, "*Measurement and
Assessment of Dermal and Inhalation Exposures to Didecyl Dimethyl
Ammonium Chloride (DDAC) Used in the Protection of Cut Lumber (Phase
III)"* (Bestari et al., 1999). This proprietary study includes the
potential ways that an individual can come into contact with preserved
wood.

CMA unit exposure data were used to assess exposure to the composite
wood blender/spray operators. The liquid pump preservative unit
exposures for gloved workers were used in this assessment. The dermal UE
was 0.00629 mg/lb ai and the inhalation UE was 0.000403 mg/lb ai. These
values are based on two replicates where the test subjects were wearing
a single layer of clothing and chemical resistant gloves. The quantity
of the wood being treated was derived from other wood preservative
estimates for the amount of wood slurry treated because no chemical
specific data were available for OPP.

Calculation of short-, and intermediate term and IT total MOEs for the
workers adding the preservative to the wood slurry showed that all of
the MOEs were above the target MOE of 100 and therefore do not pose a
concern. However, the IT inhalation MOE (840) for the blender/spray
operators adding the chemical via closed-liquid pumping is less than
1,000 and therefore a confirmatory inhalation toxicity study is
warranted based on these results.

For dip tank operators, the exposure assessment was conducted
differently than for the other job functions. This was because
concentrations of DDAC in the diptanks were known. Calculation of dermal
and inhalation MOEs as well as total intermediate term MOEs showed that
all were above the target MOE of 100.

CMA data were inadequate to represent the other job functions associated
with preservation on non-pressure treated wood (e.g., chemical
operators, trim saw operators, millwrights, cleanup crews, and
construction workers). As very little chemical specific data were
available regarding typical exposures to OPP as a wood preservative,
surrogate data were used to estimate exposure and risks. Inhalation and
dermal exposures associated with wood preservation were assessed using
surrogate data from a study review *Measurement and Assessment of Dermal
and Inhalation Exposures to Didecyl Dimethyl Ammonium Chloride (DDAC)
Used in the Protection of Cut Lumber (Phase III)* (Bestari et al.,
1999). This study is proprietary; therefore, data compensation needs to
be paid for use of the data in this exposure assessment. It was assumed
that the workers at facilities using OPP and OPP salt preservatives are
performing similar tasks as those monitored in the DDAC study.

Calculation of short- and intermediate-term dermal and inhalation MOEs
for these other job functions (chemical operators, trim saw operators,
millwrights, cleanup crews, and construction workers) showed all MOEs
above the target level of 100. In addition, the total intermediate term
MOEs were also above the target level of 100 for the entire list of job
functions.

3.  **Summary of Registered Conventional (Agricultural) Uses**

**7.3.1 Occupational Handler Exposure Scenarios**

OPP and NA-OPP are used as a conventional post-harvest fungicide for
citrus and pears. Application rates range from 0.0066 to 0.19 lb
ai/gallon solution (0.05 to 2%). Treatment rates range from 3,000-10,000
lbs fruit/gallon of solution depending on the concentration of ai. For
example, the RTU thermo-fogging product has an application rate of
0.0633 lb ai/2200 lbs fruit. It is to be noted that in the absence of
actual chemical specific data, the Agency utilizes data from the
Pesticide Handler Exposure Database (PHED), Version 1.1 to assess
handler exposures. The potential exists for dermal and/or inhalation
exposure during the following occupational handler scenarios:

-   M/L liquid concentrate solutions for post-harvest foaming, dipping,
    drenching, brushing, spraying treatments;

-   Loading RTU solutions for post-harvest foaming, dipping, drenching,
    brushing, spraying treatments;

-   Loading RTU solution for thermo-fogging post-harvest treatment using
    an XEDA® Electrofogger; significant dermal and inhalation exposures
    are not expected for thermo-fogging applications -- workers are not
    present within the storage rooms during the application process;

-   Application of solutions by foaming, dipping, drenching, brushing,
    spraying. *Note: this scenario is not a typical "applicator"
    scenario. The assessment for automated application estimates
    exposures and risks (inhalation exposure only -- automated
    application process results in negligible dermal exposure) for
    workers in the vicinity of the application process*.

    A study designed to evaluate potential postapplication exposures of
    workers to NA-OPP/OPP during post-harvest pear and citrus fruit
    handling activities was conducted by Dow Chemical to fulfill a
    portion of the data requirements requested by the Agency in a Data
    Call-In (DCI) in 1992. A protocol of the study was reviewed and
    comments and recommendations were made by HED (Morris, 1993 . The
    submitted study (MRID 43432901), completed in 1994, is titled
    "Evaluation of Postapplication Exposures to Sodium o-Phenlyphenate
    Tetrahydrate/o-Phenylphenol to Workers During Post-Harvest
    Activities at Pear and Citrus Fruit Packaging Facilities."

    The study, mainly designed to evaluate postapplication activities
    (i.e., sorters and packers), included area (i.e., background) air
    monitoring data. It is assumed that this data captured NA-OPP/OPP
    air concentrations during the automated application process and will
    be used to quantitatively assess inhalation risk for process-area
    workers during this process (dermal exposure during the automated
    application process is considered negligible). It should be noted
    that the stated intention of the area monitoring was *not* for
    quantitative assessment of inhalation exposures during application.
    It was determined, however, that this data, although mostly
    collected in the sorting/packing areas, provided a reasonable
    representation of inhalation exposure for workers in the vicinity of
    the operation during the application process.

With the use of chemical-resistant gloves (i.e., baseline/gloves PPE),
short-term dermal risks are not of concern for handlers. Short-term
inhalation risks are not of concern at baseline PPE (i.e., no
respiratory protection). Intermediate-/long-term dermal risks are not of
concern when chemical-resistant gloves are used and
intermediate-/long-term inhalation risks are not of concern at baseline
PPE. Tables 7-1 and 7-2 below summarize the handler risk estimates.

+---------------+---------+----------+------+-----------+------------+
| **Table 7-1   |         |          |      |           |            |
| Short-term    |         |          |      |           |            |
| Dermal and    |         |          |      |           |            |
| Inhalation    |         |          |      |           |            |
| Risks for     |         |          |      |           |            |
| OPP, and      |         |          |      |           |            |
| salts Handler |         |          |      |           |            |
| Activities**  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| **Exposure    | *       | **App    | **Sh |           |            |
| Scenario**    | *Crop** | lication | ort- |           |            |
|               |         | Rate**   | term |           |            |
|               |         |          | Ri   |           |            |
|               |         | **(lb    | sk** |           |            |
|               |         | ai/lb    |      |           |            |
|               |         | fruit)** |      |           |            |
+---------------+---------+----------+------+-----------+------------+
|               |         |          | **De |           | **         |
|               |         |          | rmal |           | Inhalation |
|               |         |          | M    |           | MOE**      |
|               |         |          | OE** |           |            |
|               |         |          |      |           | **(Target  |
|               |         |          | *    |           | MOE =      |
|               |         |          | *(Ta |           | 100\*)**   |
|               |         |          | rget |           |            |
|               |         |          | MOE  |           |            |
|               |         |          | =    |           |            |
|               |         |          | 10   |           |            |
|               |         |          | 0)** |           |            |
+---------------+---------+----------+------+-----------+------------+
|               |         |          | **Ba | *         | **         |
|               |         |          | seli | *Baseline | Baseline** |
|               |         |          | ne** | /Gloves** |            |
+---------------+---------+----------+------+-----------+------------+
| M             |         |          |      |           |            |
| ixing/Loading |         |          |      |           |            |
| & Loading     |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| M             | Citrus  | 0        | 26   | 3300      | 64000      |
| ixing/loading | & Pears | .0000633 |      |           |            |
| EC/SC for     |         |          |      |           |            |
| Automated     |         |          |      |           |            |
| Post-harvest  |         |          |      |           |            |
| Applications  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Loading RTU   | Citrus  | 0        | 130  | 16000     | 300000     |
| for Automated | only    | .0000133 |      |           |            |
| Post-harvest  |         |          |      |           |            |
| Applications  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Loading RTU   | Pears   | 0        | 58   | 7300      | 140000     |
| for           | only    | .0000288 |      |           |            |
| Thermofogging |         |          |      |           |            |
| applications  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Automated     |         |          |      |           |            |
| Application   |         |          |      |           |            |
| Process       |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Activities    | Citrus  | NA       | Ne   |           | 6100       |
| during        | & Pears |          | glig |           |            |
| automated     |         |          | ible |           |            |
| application   |         |          |      |           |            |
| (i.e.,        |         |          |      |           |            |
| operations    |         |          |      |           |            |
| monitoring)   |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
|               | Citrus  |          |      |           |            |
|               | only    |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+

+---------------+---------+----------+------+-----------+------------+
| **Table 7-2   |         |          |      |           |            |
| Intermedia    |         |          |      |           |            |
| te-/Long-term |         |          |      |           |            |
| Dermal and    |         |          |      |           |            |
| Inhalation    |         |          |      |           |            |
| Risks for     |         |          |      |           |            |
| OPP, and      |         |          |      |           |            |
| salts Handler |         |          |      |           |            |
| Activities**  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| **Exposure    | *       | **App    | *    |           |            |
| Scenario**    | *Crop** | lication | *Int |           |            |
|               |         | Rate**   | erme |           |            |
|               |         |          | diat |           |            |
|               |         | **(lb    | e-/L |           |            |
|               |         | ai/lb    | ong- |           |            |
|               |         | fruit)** | term |           |            |
|               |         |          | Ri   |           |            |
|               |         |          | sk** |           |            |
+---------------+---------+----------+------+-----------+------------+
|               |         |          | **De |           | **         |
|               |         |          | rmal |           | Inhalation |
|               |         |          | M    |           | MOE**      |
|               |         |          | OE** |           |            |
|               |         |          |      |           | **(Target  |
|               |         |          | *    |           | MOE =      |
|               |         |          | *(Ta |           | 100\*)**   |
|               |         |          | rget |           |            |
|               |         |          | MOE  |           |            |
|               |         |          | =    |           |            |
|               |         |          | 10   |           |            |
|               |         |          | 0)** |           |            |
+---------------+---------+----------+------+-----------+------------+
|               |         |          | **Ba | *         | **         |
|               |         |          | seli | *Baseline | Baseline** |
|               |         |          | ne** | /Gloves** |            |
+---------------+---------+----------+------+-----------+------------+
| M             |         |          |      |           |            |
| ixing/Loading |         |          |      |           |            |
| & Loading     |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| M             | Citrus  | 0        | 24   | 3000      | 25000      |
| ixing/loading | & Pears | .0000633 |      |           |            |
| EC/SC for     |         |          |      |           |            |
| Automated     |         |          |      |           |            |
| Post-harvest  |         |          |      |           |            |
| Applications  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Loading RTU   | Citrus  | 0        | 110  | 14000     | 120000     |
| for Automated | only    | .0000133 |      |           |            |
| Post-harvest  |         |          |      |           |            |
| Applications  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Loading RTU   | Pears   | 0        | 53   | 6700      | 55000      |
| for           | only    | .0000288 |      |           |            |
| Thermofogging |         |          |      |           |            |
| applications  |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Automated     |         |          |      |           |            |
| Application   |         |          |      |           |            |
| Process       |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
| Activities    | Citrus  | NA       | Ne   |           | 2400       |
| during        | & Pears |          | glig |           |            |
| automated     |         |          | ible |           |            |
| application   |         |          |      |           |            |
| (i.e.,        |         |          |      |           |            |
| operations    |         |          |      |           |            |
| monitoring)   |         |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+
|               | Citrus  |          |      |           |            |
|               | only    |          |      |           |            |
+---------------+---------+----------+------+-----------+------------+

**7.3.2 Occupational Postapplication Exposure and Risk Assessment**

In the case of NA-OPP/OPP post-harvest commodity applications, workers
performing sorting and packing activities are potentially exposed to
NA-OPP/OPP following application. Additionally, potential dermal and
inhalation exposures exist for storage room re-entry workers following
thermo-fogging applications performing post-treatment residue sampling
and for workers transporting treated pears from the storage room to be
processed and/or distributed.

Although the label specifying use with the XEDA® Electrofogger requires
users to follow the machine's operator instructions, which, in turn,
directs re-entry workers to wear SCBA when oxygen levels are low, it is
recommended that this provision be directly referenced on the label for
workers re-entering the storage room to collect residue samples or
perform other early re-entry activities.

It is recommended that sorters (including pre-sorters) and packers of
citrus fruits and pears wear chemical-resistant gloves with baseline PPE
(i.e., long-sleeve shirt and pants). It was noted in the study that
sorters/packers typically wear short-sleeve shirts, so
chemical-resistant gloves with arm extensions (instead of a long-sleeve
shirt) may be more appropriate. The incident reports, OPP/NA-OPP's
classifications as Category I and II acute dermal irritants,
respectively, and the absence of acute toxicity data warrant use of this
additional PPE. Currently, some labels require handlers to wear baseline
PPE with chemical-resistant gloves and goggles or a faceshield.

Table 7-3 below summarizes the postapplication risk estimates for citrus
and pear facilities. Short-term risk calculations are shown using both
the arithmetic mean and maximum reported exposures;
intermediate-/long-term risks are calculated using the arithmetic mean
only. Additionally, all dermal risk estimates are calculated with
exposures adjusted for the maximum labeled application rate (2%
solution).

+---------------+-------+-----+----+-----+-----+---------+----------+
| **Table 7-3   |       |     |    |     |     |         |          |
| Po            |       |     |    |     |     |         |          |
| stapplication |       |     |    |     |     |         |          |
| Risk          |       |     |    |     |     |         |          |
| Estimates for |       |     |    |     |     |         |          |
| Sorters and   |       |     |    |     |     |         |          |
| Packers in    |       |     |    |     |     |         |          |
| Citrus Fruit  |       |     |    |     |     |         |          |
| and Pear      |       |     |    |     |     |         |          |
| Facilities**  |       |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
| **Po          | *     | **S |    |     |     | **In    |          |
| stapplication | *Crop | hor |    |     |     | termedi |          |
| Activity**    | (Sta  | t-t |    |     |     | ate-/Lo |          |
|               | te)** | erm |    |     |     | ng-term |          |
|               |       | Ris |    |     |     | Risk**  |          |
|               |       | k** |    |     |     |         |          |
|               |       |     |    |     |     | **      |          |
|               |       | **( |    |     |     | (Target |          |
|               |       | Tar |    |     |     | MOE =   |          |
|               |       | get |    |     |     | 1       |          |
|               |       | MOE |    |     |     | 00\*)** |          |
|               |       | =   |    |     |     |         |          |
|               |       | 100 |    |     |     |         |          |
|               |       | )** |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               |       | **  |    | **I |     | *       | **In     |
|               |       | Der |    | nha |     | *Dermal | halation |
|               |       | mal |    | lat |     | MOE**   | MOE**    |
|               |       | MO  |    | ion |     |         |          |
|               |       | E** |    | MO  |     |         |          |
|               |       |     |    | E** |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               |       | **  | *  | **  | *   | *       | **Mean** |
|               |       | Mea | *M | Mea | *Ma | *Mean** |          |
|               |       | n** | ax | n** | x** |         |          |
|               |       |     | ** |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
| Pre-sorting   | C     | 240 | 1  | 20  | 11  | 220     | 7900     |
|               | itrus |     | 50 | 000 | 000 |         |          |
|               | (FL)  |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               | C     | 870 | 5  | 5   | 2   | 790     | 2300     |
|               | itrus |     | 80 | 900 | 800 |         |          |
|               | (CA)  |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
| Sorting       | Pears | 120 | 51 | 5   | 3   | 110     | 2200     |
|               | (WA)  |     |    | 800 | 600 |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               | C     | 770 | 5  | 28  | 18  | 700     | 11000    |
|               | itrus |     | 50 | 000 | 000 |         |          |
|               | (FL)  |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               | C     | 2   | 8  | 72  | 20  | 2000    | 28000    |
|               | itrus | 200 | 80 | 000 | 000 |         |          |
|               | (CA)  |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
| Packing       | Pears | 190 | 1  | 7   | 5   | 170     | 2800     |
|               | (WA)  |     | 30 | 300 | 700 |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               | C     | 1   | 6  | 120 | 100 | 1100    | 47000    |
|               | itrus | 300 | 20 | 000 | 000 |         |          |
|               | (FL)  |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               | C     | 5   | 24 | 81  | 33  | 5000    | 32000    |
|               | itrus | 500 | 00 | 000 | 000 |         |          |
|               | (CA)  |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+
|               |       |     |    |     |     |         |          |
+---------------+-------+-----+----+-----+-----+---------+----------+

**8.0 ENVIRONMENTAL RISK**

**8.1 Ecological Hazard**

2-phenylphenol and its salts demonstrate low toxicity to birds, and
moderate toxicity to mammals, freshwater fish, freshwater invertebrates,
and algae.

The low exposure potential from the indoor uses of 2-phenylphenol and
salts, coupled with the tendency for the compounds to degrade under
environmental conditions, result in low likelihood of adverse acute
effects to wildlife and aquatic organisms from the indoor uses. Risk
from the antisapstain used has been assessed on a screening level.

Laboratory studies indicate that 2-phenylphenol demonstrates some
potential to act as an endocrine disruptor. When the appropriate
screening and/or testing protocols being considered under the Agency's
Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC)'s
Endocrine Disruptor Screening Program (EDSP) have been developed,
2-phenylphenol may be subjected to additional screening and/or testing
to better characterize effects related to endocrine disruption.

2.  **Environmental fate and Transport**

Orthophenylphenol is stable and persistent in abiotic aqueous medium at
pHs 5, 7 and 9. When exposed to sunlight in neutral aqueous medium, it
degrades with a half life of 14 days. Photolytically, therefore, it is
not stable. Exposure to uv light (at 253.7 nm), results in the
degradation products: phenyl benzoquinone, phenylhydroquinone, and
2-hydroxy benzofuran. Its half life in air is 14 hours (measured against
the reaction with hydroxyl radical). OPP in its vapor form in the air is
unstable and not persistent. It is immobile in soils with a K~OC~ value
of 10,000. Ground water contamination does not seem likely. The major
degradation route appears to be through biodegradation in aerobic and
anaerobic environments. The observed half-life values vary from three
hours to three week, depending on the exposure sites (holding pond to
open river etc.) When wood is treated for antisapstain use, NA-OPP
leaches up to 58% the first day after application (highest application
rate for NA-OPP is 4%). After day 14, 86% of NA-OPP leaches out from the
treated wood.

3.  **Environmental Exposure and Risk**

Most uses of 2-phenylphenol are considered to be indoor uses. The
discharge of any effluents which might contain 2-phenylphenol residues
is regulated by the NPDES program; facilities discharging any such
effluents are required to have an NPDES permit prior to discharging
effluents into receiving waters. EPA/ORD/NRML's Treatability Database
shows that wastewater treatment technologies have 95% removal efficiency
for phenolic compounds. This, coupled with 2-phenylphenol's tendency to
degrade under aerobic and anaerobic conditions in the environment,
indicates that environmental exposure from the indoor uses of
2-phenylphenol is likely to be low.

Based on the results of the antisapstain modeling, runoff from
antisapstain treating facilities will exceed acute high risk, restricted
use, and endangered species LOCs for freshwater fish, freshwater
invertebrates, and aquatic plants. Chronic risks cannot be assessed at
this time due to a lack of chronic toxicity data.

The model used to estimate exposure from antisapstain uses is intended
as a Tier I screening model, and, as such, has inherent assumptions and
uncertainties that may result in over- or under-estimation of exposure
levels. Since the model is only intended as a screening-level model,
further refinement of the model is recommended to more accurately assess
risks from the antisapstain uses of 2-phenylphenol.

Methods to reduce the amount of 2-phenylphenol potentially released from
antisapstain-treated wood could potentially mitigate the risks. Possible
mitigation methods might include, but are not limited to, lowering the
application rate or requiring specific storage conditions to prevent
exposure of recently treated wood to weather (e.g., full covering)
and/or prevent the release of any associated runoff into aquatic
habitats (e.g., drip pads). 2-phenylphenol is not very mobile in soils,
so any 2-phenylphenol leached outdoors will likely bind to soils and not
reach aquatic habitats as free 2-phenylphenol.

4.  **Endangered Species Consideration**

Section 7 of the Endangered Species Act, 16 U.S.C. Section 1536(a)(2),
requires all federal agencies to consult with the National Marine
Fisheries Service (NMFS) for marine and anadromous listed species, or
the United States Fish and Wildlife Services (FWS) for listed wildlife
and freshwater organisms, if they are proposing an \"action\" that may
affect listed species or their designated habitat. Each federal agency
is required under the Act to insure that any action they authorize,
fund, or carry out is not likely to jeopardize the continued existence
of a listed species or result in the destruction or adverse modification
of designated critical habitat. To jeopardize the continued existence of
a listed species means \"to engage in an action that reasonably would be
expected, directly or indirectly, to reduce appreciably the likelihood
of both the survival and recovery of a listed species in the wild by
reducing the reproduction, numbers, or distribution of the species.\" 50
CFR. \' 402.02.

To facilitate compliance with the requirements of the Endangered Species
Act subsection (a)(2) the Environmental Protection Agency, Office of
Pesticide Programs has established procedures to evaluate whether a
proposed registration action may directly or indirectly reduce
appreciably the likelihood of both the survival and recovery of a listed
species in the wild by reducing the reproduction, numbers, or
distribution of any listed species (U.S. EPA 2004). After the Agency=s
screening-level risk assessment is performed, if any of the Agency=s
Listed Species LOC Criteria are exceeded for either direct or indirect
effects, a determination is made to identify if any listed or candidate
species may co-occur in the area of the proposed pesticide use. If
determined that listed or candidate species may be present in the
proposed use areas, further biological assessment is undertaken. The
extent to which listed species may be at risk then determines the need
for the development of a more comprehensive consultation package as
required by the Endangered Species Act.

For certain use categories, the Agency assumes there will be minimal
environmental exposure, and only a minimal toxicity data set is required
(Overview of the Ecological Risk Assessment Process in the Office of
Pesticide Programs U.S. Environmental Protection Agency - Endangered and
Threatened Species Effects Determinations, 1/23/04, Appendix A, Section
IIB, pg.81). Chemicals in these categories therefore do not undergo a
full screening-level risk assessment, and are considered to fall under a
Ano effect@ determination. The active ingredient uses of 2-phenylphenol,
with the exception of the antisapstain wood preservation use, fall into
this category. Using Tier I screening modeling to assess potential
exposure from antisapstain wood preservation uses of 2-phenylphenol,
risks to Listed Species are indicated. Since the model is only intended
as a screening-level model, and, as such, has inherent uncertainties and
limitations which may result in inaccurate exposure estimations, further
refinement of the model is recommended before any regulatory action is
taken regarding the antisapstain uses of 2-phenylphenol. Additionally,
impacts from the antisapstain use could potentially be mitigated with
precautions to prevent leaching and runoff when wood is stored outdoors
(see Label Hazard Statements/Use Recommendations, below). Due to these
circumstances, the Agency defers making a determination for the
antisapstain uses of 2-phenylphenol until additional data and modeling
refinements are available. At that time, the environmental exposure
assessment of the antisapstain use of 2-phenylphenol will be revised,
and the risks to Listed Species will be reconsidered.

9.  **INCIDENT REPORT ASSESSMENT**

OPP and its sodium and potassium salts are used fungicides and
disinfectants. OPP is known to be a skin and mucous membrane irritant.
NA-OPP and K-OPP are known for their corrosivity. We have used two
approaches to determine the potential health effects of incidences on
humans by OPP, NA-OPP and K-OPP. 1) Gather and analyze the incidence
reports obtained from different sources; 2) A Literature search of
chronic health effects associated with OPP/NA-OPP/K-OPP exposure,
including results from epidemiological studies, if any.

The Following databases were consulted for poisoning incidence data on
OPP:

1)  Office of Pesticides Programs (OPP) Incident Data System (IDS)

2)  Poison Control Centers

3)  California Department of Pesticide Regulations

4)  National Pesticide Telecommunications Network (NTPT)

5)  Published Scientific Literature on Incidences

**9.1 OPP's Incident Data System (IDS)**

A total of 72 individual human incident cases submitted to EPA's OPP are
associated with exposure to products containing OPP/NA-OPP and K-OPP.
These products are used as surface disinfectants and are registered by a
number of registrants. Most of the reported incidences were not of
serious nature. Reported incidents were for humans and animals. The
observed symptoms were: burning eyes, itchy skin, difficulty in
breathing, coughing, nausea, vomiting, hives, headache, swollen mouth,
dizziness, burning throat, erythema, ulceration of foot, nasal
irritation, corneal abrasion, vertigo, muscle, weakness, diarrhea,
ocular irritation, nose bleed, dyspnea, and tremor. These symptoms
occurred by individuals through dermal and respiratory exposure, usually
from a spray. The symptoms usually cleared after a few minutes or a few
hours. No severe symptoms or death occurred from exposure to this
chemical.

**9.2 Poison Control Center**

A total of 22, 318 incident cases have been reported associated with
exposure to phenolic disinfectants. These incident reports were recorded
between 1993 through 1998 by the American Association of Poison Control
Centers (PCC) and Toxic Exposure Surveillance System (TESS) between the
years of 1993-through 1998. None of these reported incident relate to
OPP or NA-OPP or K-OPP. Most of the incidences ( \> 93%) were associated
with no effects to only minor effects. It was concluded that the
remaining 3 % incidents were not related to the chemical exposures. Of
the total cases reported, only eleven were considered to have severe
clinical effects. Death occurred in one case. The primary symptoms in
the major incidences were: GI tract effect, neurotoxic signs,
cardiovascular effects and respiratory effects.

**9.3 California Data- 1982-through 2003.**

The California database does not record any OPP, NA-OPP or K-OPP related
incidence. A total of 360 cases recorded possibly related to phenolic
disinfectants use and these were submitted to the California Pesticide
Illness Surveillance Program. The database presents the types of
illnesses for each year, total number of workers that took time off as a
result of their illness and how many were hospitalized and for how long.

4.  **National Pesticide Telecommunications Network (NPTN)**

There are no incidences reported in the NPTN database related to OPP,
NA-OPP or K-OPP.

5.  **Hazardous Substances Data Bank (HSDB)**

HSDB indicates that a fatal dose of 10.0 g reported and toxic effects on
urothelium of the bladder were observed in two humans due to
orthophenylphenol poisoning.

A second incident report in the scientific literature is with Microban
(0.21 % OPP, 0.69 % diisobutylpehnoxy-ethoxyethyldimethyl ammonium
chloride, and 0.04% bromine). Symptoms observed were: primary skin and
mucous irritation, and these were elevated on Monday and Tuesday, but
the symptoms normalized by the end of the week. It was not obvious which
one component caused the symptoms or if it was a combined effect of the
three.

6.  **Conclusions**

OPP and salts appear to cause dermal effects, which is perhaps due to
irritation. Inhalation is another route which shows some symptoms as
indicated above. However, it is clear that all the databases and
published literature show that specific chemical toxic effects can not
be attributed specifically to OPP or NA-OPP or K-OPP only, as most of
the symptoms appear in a mixture of active ingredients, one of them OPP
or its salts.

**10.0 References**

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+-----------------------------------------------------------------------+
| MRID 43928801: Eigenberg, D.; Lake, S. (1995): A Two-Generation       |
| Dietary Reproduction                                                  |
|                                                                       |
| Study in Sprague-Dawley Rats Using Technical Grade                    |
| ortho-Phenylphenol:                                                   |
|                                                                       |
| Lab Project Number: 93-672-VX: 7788. Unpublished study prepared by    |
| Bayer Corp. 1213 p.                                                   |
+-----------------------------------------------------------------------+

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