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EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE PETITIONS

PUBLISHED IN THE FEDERAL REGISTER   

EPA Registration Division contact: William Cutchin (703) 305‐7990

TEMPLATE:

Syngenta Crop Protection, LLC  

IN‐10553

EPA has received a pesticide petition (IN‐10553) from Syngenta Crop Protection,

LLC, P.O. Box 18300, Greensboro, NC 27419‐8300 requesting, pursuant to section 408(d)

of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40

CFR part 180.960 to establish an exemption from the requirement of a tolerance for

polyurethane‐type polymers (CAS. No.'s 1161844‐26‐3, 1161844‐30‐9, 1161844‐43‐4,

1161844‐51‐4, 1161844‐53‐6, 693252‐31‐2, 162993‐60‐4, and 630102‐86‐2) as a carrier

in or on raw agricultural commodities and food products. Tolerance exemption

descriptors for polymers produced by the reaction of either 1,6‐hexanediisocyanate;

2,4,4‐trimethyl‐1,6‐hexanediisocyanate; 5‐isocyanato‐1‐(isocyanatomethyl)‐1,3,3‐

trimethyIcyclohexane (isophoronediisocyanate); 4,4'‐methylene‐bis‐1,1'‐

cyclohexanediisocyanate; 4,4'‐methylene‐bis‐1,1' benzyldiisocyanate; or 1,3‐bis‐(2‐

isocyanatopropan‐2‐yl)benzene with polyethylenglycol and end‐capped with one or a

mixture of more than one of octanol, decanol, dodecanol, tetradecanol, hexadecanol,

octadecanol, and octadec‐9‐enol or polyethyleneglycol ethers of octanol, decanol,

dodecanol, tetradecanol, hexadecanol, octadecanol, and octadec‐9‐enol.
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EPA has determined that the petition contains data or information regarding the

elements set forth in section 408 (d)(2) of  FDDCA; however, EPA has not fully evaluated

the sufficiency of the submitted data at this time or whether the data supports granting

of the petition. Additional data may be needed before EPA rules on the petition.

A. Residue Chemistry

1. Plant metabolism. Waived under the polymer exemption definition.

2. Analytical method. An analytical method to determine the MW of the polymer

is dynamic light scattering.

3. Magnitude of residues. Waived under the polymer exemption definition.

B. Toxicological Profile

The available toxicity data and considered its validity, completeness, and

reliability as well as the relationship of the results of the studies to human risk. EPA has

also considered available information concerning the variability of the sensitivities of

major identifiable subgroups of consumers, including infants and children for the low

risk polymer classification.

These polyurethane‐type polymers are not acutely toxic by the oral and dermal

routes of exposure, or via inhalation under normal use conditions. Concentrated

materials are generally not corrosive, eye and skin irritants and not dermal sensitizers.

There is no evidence that these polyurethane‐type polymers are neurotoxic, mutagenic,

or clastogenic.  

Specific information on the studies evaluated and the nature of the adverse

effects findings by polyurethane‐type polymers as well as the no‐observed‐adverse‐

effect‐level (NOAEL) and the lowest‐observed‐adverse‐effect‐level (LOAEL) from the

toxicity studies can be found at http://www.regulations.gov in documents allowing the

approval of defined low risk polymeric compounds.
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1. Acute toxicity.  Waived under the polymer exemption definition.

2. Genotoxicty. NA

3. Reproductive and developmental toxicity. NA

4. Subchronic toxicity. NA

5. Chronic toxicity. Syngenta used a qualitative structure activity relationship

(SAR) database, DEREK11, to determine if there were structural alerts for potential

carcinogenicity of several representative large molecular weight polymers such as the

polyurethane‐type polymers and no structural alerts for carcinogenicity were identified

in any case. Polyurethane‐type polymers are not expected to be carcinogenic. Therefore

a cancer dietary exposure assessment is not necessary to assess cancer risk.

6. Animal metabolism. NA

7. Metabolite toxicology. NA

8. Endocrine disruption. This class of chemistry does not belong to a class of

chemicals known or suspected of having adverse effects on the estrogen receptor or

endocrine system.

C. Aggregate Exposure

1. Dietary exposure. In evaluating dietary exposure to polyurethane‐type

polymers, Syngenta considered exposure under the polymer exemption classification

and established a definition for molecules that meet the criteria of that definition

qualify for exemption from the requirement of a tolerance. EPA assessed dietary

exposures from large molecular weight polymers in food as follows: First acute and
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chronic exposure; In conducting the acute and chronic dietary exposure assessments,

Syngenta used food consumption information from the United States Department of

Agriculture (USDA) 1994‐1996 and 1998 Nationwide Continuing Surveys of Food Intake

by Individuals (CSFII). As to residue levels in food, no residue data were submitted for

the polyurethane‐type polymers. In the absence of specific residue data, EPA has

developed an approach which uses surrogate information to derive upper bound

exposure estimates for the subject inert ingredients. Upper bound exposure estimates

are based on the highest tolerance for a given commodity from a list of high‐use

insecticides, herbicides, and fungicides. A complete description of the dietary exposure

and risk assessment for low risk polymers can be found at http://www.regulations.gov.

Syngenta believes the assumptions used to estimate dietary exposures lead to an

extremely conservative assessment of dietary risk based on the EPA assessment and

definition requirements for these polymers. Assuming that the level of residue for an

inert ingredient is equal to the level of residue for the active ingredient will overstate

exposure. The concentration of active ingredient in agricultural products is generally at

least 15 percent of the product and often can be much higher. Further, pesticide

products rarely have a single inert ingredient; rather, there is generally a combination of

different inert ingredients used which additionally reduces the concentration of any

single inert ingredient in the pesticide product relative to that of the active ingredient.

In the case of polyurethane‐type polymers, EPA made a specific definition of what

constitutes an acceptable polymeric compound and the proposed exemption for

polyurethane‐type polymers meets that criteria.  

Accordingly, although sufficient information to quantify actual residue levels in

food is not available, the conservative assumptions will lead to a significant

exaggeration of actual exposures. Syngenta does not believe that this approach

underestimates exposure in the absence of residue data.

i. Food. NA

ii. Drinking water. Syngenta used screening level water exposure models in the

dietary exposure analysis and risk assessment for polyurethane‐type polymers in

drinking water. These simulation models take into account data on the physical,

chemical, and fate/transport characteristics of large molecular weight polymers. Further

information regarding EPA drinking water models used in pesticide exposure

assessment can be found at:

http://www.epa.gov/oppefedl/models/water/index.htmInsert text.
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2. Non‐dietary exposure. The term "residential exposure" is used in this

document to refer to non‐occupational, non‐dietary exposure (e.g., for lawn and garden

pest control, indoor pest control, termiticides, and flea and tick control on pets).

Polyurethane‐type polymers may be used as inert ingredients in pesticide products that

are registered for specific uses that could result in indoor residential exposures.  

A screening level residential exposure and risk assessment was completed for

polymeric products used as inert ingredients in pesticide formulations. In this

assessment, representative scenarios, based on end‐use product application methods

and labeled application rates, were selected. For each of the use scenarios, the Agency

assessed residential handler (applicator) inhalation and dermal exposure for outdoor

scenarios with high exposure potential (i.e., exposure scenarios with high end unit

exposure values) to serve as a screening assessment for all potential residential

pesticides containing polyurethane‐type polymers. Similarly, residential post application

dermal and oral exposure assessments were also performed utilizing high end outdoor

exposure scenarios. Analysis can be found at http://www.regulations.gov in documents

on the polymer exemption risk assessment.

D. Cumulative Effects

Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to

establish, modify, or revoke a tolerance, the Agency consider "available information"

concerning the cumulative effects of a particular pesticide's residues and "other

substances that have a common mechanism of toxicity.

Syngenta has not found that polyurethane‐type polymers share a common

mechanism of toxicity with any other substances, and polyurethane‐type polymers do

not appear to produce a toxic metabolite produced by other substances. For the

purposes of this tolerance action, therefore, Syngenta has assumed that polyurethane‐

type polymers do not have a common mechanism of toxicity with other substances. For

information regarding EPA's efforts to determine which chemicals have a common

mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see

EPA's website at http://www.epa.gov/pesticides/cumulative.
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E. Safety Determination

EPA determines whether acute and chronic pesticide exposures are safe by

comparing aggregate exposure estimates to the aPAD and cPAD. The aPAD and cPAD

represent the highest safe exposures, taking into account all appropriate SFs. EPA

calculates the aPAD and cPAD by dividing the POD by all applicable UFs. For linear

cancer risks, EPA calculates the probability of additional cancer cases given the

estimated aggregate exposure. Short‐, intermediate‐, and chronic‐term risks are

evaluated by comparing the estimated aggregate food, water, and residential exposure

to the POD to ensure that the MOE called for by the product of all applicable UFs is not

exceeded.

1. U.S. population. Determination of safety: based on the risk assessments

conducted by the agency, Syngenta concludes that there is a reasonable certainty that

no harm will result to the general population.

2. Infants and children. Syngenta has determined that EPA has reviewed reliable

data that show the safety of infants and children would be adequately protected.

F. International Tolerances

Syngenta is not aware of any country requiring a tolerance for these

polyurethane‐type polymers nor have any CODEX Maximum Residue Levels been

established for any food crops at this time.