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**UNITED STATES ENVIRONMENTAL PROTECTION AGENCY**

**WASHINGTON, D.C. 20460**

**OFFICE OF**

**PREVENTION, PESTICIDES**

**AND TOXIC SUBSTANCES**

**Date:** January 30, 2003

**Subject:** Occupational and Residential Risk Assessment to Support
Request for a Section 3 Registration of Cyromazine on Brassica (Cole)
Leafy Vegetables Group 5, and Turnip Greens.

  ------------ --------- --------- --------- ----------- -------- ------------- -------------- -------
  **DP         **PC      **Trade   **EPA     **MRID#**   **PRAT   **Class**     **Caswell#**   **40
  Barcode:**   Code:**   Name:**   Reg#**                Case**                                CFR**

  D285851      121301    Trigard   100-654   N/A         295479   Insecticide   N/A            N/A
                         ^®^                                                                   
  ------------ --------- --------- --------- ----------- -------- ------------- -------------- -------

**From:** Jack Arthur, Environmental Scientist

Registration Action Branch 3

Health Effects Division (7509C)

**To:** William Wassell, Risk Assessor

Registration Action Branch 3

Health Effects Division (7509C)

**Thru:** Stephen Dapson, Ph.D., Branch Senior Scientist

> Registration Action Branch 3

Health Effects Division (7509C)

**Introduction**

The Interregional Research Project Number 4 (IR-4) requests the
establishment of tolerances for residues of the insecticide cyromazine
on brassica (cole) leafy vegetables group 5 (including: abyssinian
cabbage; bok choy; broccoli; broccoli, Chinese; broccoli raab; Brussels
sprouts; cabbage; cabbage, Chinese; cabbage, Chinese mustard; cabbage,
seakale; cauliflower; cavalo broccolo; collards; Hanover salad; kale,
common; kohlrabi; mustard, wild; mustard, Chinese; mustard greens;
mustard spinach; and rape greens) and turnip greens . This memorandum
addresses risk from occupational and residential exposure only. An
aggregate human risk assessment for cyromazine will be included as a
separate HED memorandum.

***1.0 Executive Summary***

Cyromazine **is currently registered for a number of uses including,
on** mango, onion (green and dry bulb), potato, head lettuce, celery,
leafy vegetables (except Brassica) crop group, cucurbit vegetables crop
group, tomato, mushroom and pepper. The formulated end use product
evaluated in this assessment is labeled under the trade name Trigard^®^.
In this memorandum, the name cyromazine will be used for the active
ingredient (ai) in this product.

Cyromazine is an insecticide for the control of leafminers. The
formulation of cyromazine evaluated in this assessment is a wettable
powder, packaged in water-soluble packets (i.e., Trigard^®^ 75% ai). The
petitioner proposes multiple foliar sprays at a rate of 0.125 lb ai/A,
using ground or aerial equipment. Applications are proposed to begin
when leafminers first appear and continue throughout the season at 7-day
intervals to maintain control.

There are **no residential use sites** associated with current or
proposed uses of cyromazine. Therefore, a **residential risk assessment
was not conducted**.

There is a potential for occupational exposure to cyromazine during
mixing, loading, application, and postapplication activities. The Health
Effects Division\'s Hazard Identification Assessment Review Committee
(HIARC) did not select any dermal endpoints for cyromazine, because no
hazard was identified via the dermal route (i.e., no toxicity was
observed at the limit dose of 1,000 mg/kg/day; there are no concerns for
pre/postnatal toxicity; and dermal absorption is relatively low
\[13%\]). Therefore, the occupational risk assessment was based on
inhalation exposure only. For handlers, daily inhalation doses were
compared to the oral NOAELs of 10 mg/kg/day (based on decreases in
maternal body weight gain and food consumption in the developmental oral
study in the rabbit) and 7.5 mg/kg/day (based on alterations in
hematological parameters, body weight and body weight gain decreases and
increase in several organ weights in the 6-month feeding study in the
dog) to estimate the risk from short- and intermediate-term inhalation
exposures, respectively. Chronic exposures are not expected for handlers
of cyromazine for the proposed use patterns.

No chemical-specific handler exposure data were submitted in support of
this Section 3 registration. It is the policy of the HED to use data
from the Pesticide Handlers Exposure Database (PHED) Version 1.1 as
presented in PHED Surrogate Exposure Guide (8/98) to assess handler
exposures for regulatory actions when chemical-specific monitoring data
are not available (HED Science Advisory Council for Exposure Draft
Policy \# 7, dated 1/28/99).

Occupational **handlers' inhalation MOEs range from** **34,000** for
intermediate-term flagging sprays for aerial operations to **290,000**
for short-term mixing/loading wettable powder packaged in water-soluble
packets for groundboom application. These MOEs are greater than HED's
target MOE of 100, and therefore, are not of concern.

Occupational **postapplication dermal exposure** is possible following
treatment of crops with cyromazine. However, because no appropriate
dermal endpoints were identified for this exposure potential, and
inhalation exposure is expected to be negligible for reentry activities,
a postapplication risk assessment based foliar treatment was **not
conducted**.

The current label for Trigard^®^ has a 12‑hour restricted entry interval
(REI). The cyromazine technical material has been classified in Toxicity
Category III for acute dermal, and Toxicity Category IV for primary eye
irritation and primary skin irritation. Per the Worker Protection
Standard(WPS), a 12‑hour restricted entry interval (REI) is required for
chemicals classified under Toxicity Category III or IV. Therefore, the
REI of 12 hours is in compliance with the WPS.

***2.0 Hazard Profile***

On April 4, 2002, the Health Effects Division (HED) Hazard
Identification Assessment Review Committee (HIARC) reviewed the
recommendations of the toxicology reviewer for cyromazine with regard to
the acute and chronic Reference Doses (RfDs) and the toxicological
endpoint selection for use as appropriate in occupational/residential
exposure risk assessments. The potential for increased susceptibility of
infants and children from exposure to cyromazine was also evaluated as
required by the Food Quality Protection Act (FQPA) of 1996 according to
the 2002 OPP 10x guidance document. HED's FQPA Safety Factor Committee
met on August 12, 2002 and confirmed that the 10-fold safety factor for
increased susceptibility of infants and children should be removed
(i.e., reduced to 1x) for cyromazine for the U.S. population and all
population subgroups and for all exposure scenarios. The acute toxicity
and endpoint selection for cyromazine are in Tables 1 and 2,
respectively.

+--------+-------------+--------+-----------------------+-------------+
| **Ta   |             |        |                       |             |
| ble 1. |             |        |                       |             |
| Acute  |             |        |                       |             |
| To     |             |        |                       |             |
| xicity |             |        |                       |             |
| Data   |             |        |                       |             |
| on     |             |        |                       |             |
| Cyro   |             |        |                       |             |
| mazine |             |        |                       |             |
| Techn  |             |        |                       |             |
| ical** |             |        |                       |             |
+--------+-------------+--------+-----------------------+-------------+
| *      | **Study     | **MRID | **Results**           | **Toxicity  |
| *Guide | Type**      | \#**   |                       | Category**  |
| line** |             |        |                       |             |
|        |             |        |                       |             |
| *      |             |        |                       |             |
| *No.** |             |        |                       |             |
+--------+-------------+--------+-----------------------+-------------+
| 81-1   | Acute Oral  | 00     | LD~50~ = \> 3387      | III         |
|        |             | 082836 | mg/kg                 |             |
+--------+-------------+--------+-----------------------+-------------+
| 81-2   | Acute       | 00     | LD~50~ = \> 3100 g/kg | III         |
|        | Dermal-Rat  | 082839 |                       |             |
+--------+-------------+--------+-----------------------+-------------+
| 81-3   | Acute       | 43     | LC~50~ \> 0.744 mg/L  | III         |
|        | Inhalation  | 799901 |                       |             |
+--------+-------------+--------+-----------------------+-------------+
| 81-4   | Primary Eye | 00     | no irritation         | IV          |
|        | Irritation  | 082841 |                       |             |
+--------+-------------+--------+-----------------------+-------------+
| 81-5   | Primary     | 00     | mild irritant         | IV          |
|        | Skin        | 082842 |                       |             |
|        | Irritation  |        |                       |             |
+--------+-------------+--------+-----------------------+-------------+
| 81-6   | Dermal      | 00     | non-sensitizing       |             |
|        | Se          | 082843 |                       |             |
|        | nsitization |        |                       |             |
+--------+-------------+--------+-----------------------+-------------+

+-----------+-------------+-----------+-------------------------------+
| **Table   |             |           |                               |
| 2.        |             |           |                               |
| Summary   |             |           |                               |
| of        |             |           |                               |
| Toxi      |             |           |                               |
| cological |             |           |                               |
| Doses and |             |           |                               |
| Endpoints |             |           |                               |
| for       |             |           |                               |
| C         |             |           |                               |
| yromazine |             |           |                               |
| for Use   |             |           |                               |
| in Human  |             |           |                               |
| Risk      |             |           |                               |
| Ass       |             |           |                               |
| essment** |             |           |                               |
+===========+=============+===========+===============================+
| **E       | **Dose      | **Hazard  | **Endpoint for Risk           |
| xposure** | (m          | Based     | Assessment**                  |
|           | g/kg/day)** | Special   |                               |
| **S       |             | FQPA      |                               |
| cenario** | **UF /MOE** | Safety    |                               |
|           |             | Factor**  |                               |
+-----------+-------------+-----------+-------------------------------+
| **Dietary |             |           |                               |
| Risk      |             |           |                               |
| Asse      |             |           |                               |
| ssments** |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| **Acute   | NA          | NA        | An appropriate end point      |
| Dietary** |             |           | attributable to a single dose |
|           |             |           | (exposure) was not observed   |
|           |             |           | in oral toxicity studies.     |
+-----------+-------------+-----------+-------------------------------+
| **Chronic | NOAEL = 7.5 | 1x        | 6-Month Feeding-Dog           |
| Dietary** |             |           |                               |
|           | UF =100     |           | LOAEL = 75 mg/kg/day based on |
| [all      |             |           | alterations in hematological  |
| popula    | **Chronic   |           | parameters \[hematocrit, and  |
| tions]{.u | RfD** =     |           | hemoglobin (males)\], body    |
| nderline} | 0.075       |           | weight and body weight gain   |
|           |             |           | decreases and increase in     |
|           |             |           | several organ weights         |
+-----------+-------------+-----------+-------------------------------+
| **I       | NOAEL= 10   | 1x        | Developmental Toxicity-Rabbit |
| ncidental |             |           |                               |
| Oral**    | **MOE=**    |           | LOAEL=30 mg/kg/day based on   |
|           | 100         |           | decreases in body weight gain |
| S         |             |           | and food consumption          |
| hort-Term |             |           |                               |
|           |             |           |                               |
| (1 - 30   |             |           |                               |
| Days)     |             |           |                               |
|           |             |           |                               |
| Re        |             |           |                               |
| sidential |             |           |                               |
| Only      |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| **I       | NOAEL= 7.5  | 1x        | 6-Month Feeding-Dog           |
| ncidental |             |           |                               |
| Oral**    | **MOE** =   |           | LOAEL = 75 mg/kg/day based on |
|           | 100         |           | alterations in hematological  |
| Intermed  |             |           | parameters \[hematocrit, and  |
| iate-Term |             |           | hemoglobin (males)\], body    |
|           |             |           | weight and body weight gain   |
| (1 - 6    |             |           | decreases and increase in     |
| Months)   |             |           | several organ weights         |
|           |             |           |                               |
| Re        |             |           |                               |
| sidential |             |           |                               |
| Only      |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| **No      |             |           |                               |
| n-Dietary |             |           |                               |
| Risk      |             |           |                               |
| Asse      |             |           |                               |
| ssments** |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| *         | NA          |           | No hazard was identified via  |
| *Dermal** |             |           | the dermal route.             |
|           |             |           | Quantification of risk is not |
| S         |             |           | required. There are no        |
| hort-Term |             |           | concerns for pre/post natal   |
|           |             |           | toxicity.                     |
| (1 - 30   |             |           |                               |
| days)     |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Re        | **MOE** =   | NA        |                               |
| sidential | NA          |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Occ       | **MOE** =   | NA        |                               |
| upational | NA          |           |                               |
+-----------+-------------+-----------+-------------------------------+
| *         | NA          |           | No hazard was identified via  |
| *Dermal** |             |           | the dermal route.             |
|           |             |           | Quantification of risk is not |
| Intermed  |             |           | required. There are no        |
| iate-Term |             |           | concerns for pre/post natal   |
|           |             |           | toxicity.                     |
| (1 - 6    |             |           |                               |
| Months)   |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Re        | **MOE** =   | NA        |                               |
| sidential | NA          |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Occ       | **MOE** =   | NA        |                               |
| upational | NA          |           |                               |
+-----------+-------------+-----------+-------------------------------+
| *         | NA          |           | No hazard was identified via  |
| *Dermal** |             |           | the dermal route.             |
|           |             |           | Quantification of risk is not |
| Long-Term |             |           | required. There are no        |
|           |             |           | concerns for pre/post natal   |
| (\> 6     |             |           | toxicity.                     |
| Months)   |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Re        | **MOE** =   | NA        |                               |
| sidential | NA          |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Occ       | **MOE** =   | NA        |                               |
| upational | NA          |           |                               |
+-----------+-------------+-----------+-------------------------------+
| **Inh     | Oral NOAEL  |           | Developmental Toxicity-Rabbit |
| alation** | = 10        |           |                               |
|           |             |           | LOAEL=30 mg/kg/day based on   |
| S         |             |           | decreases in body weight gain |
| hort-Term |             |           | and food consumption          |
|           |             |           |                               |
| (1 - 30   |             |           |                               |
| days)     |             |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Re        | **MOE** =   | 1x        |                               |
| sidential | 100         |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Occ       | **MOE** =   | NA        |                               |
| upational | 100         |           |                               |
+-----------+-------------+-----------+-------------------------------+
| **Inh     | Oral NOAEL  |           | 6-Month Feeding-Dog           |
| alation** | = 7.5       |           |                               |
|           |             |           | LOAEL = 75 mg/kg/day based on |
| Intermed  |             |           | alterations in hematological  |
| iate-Term |             |           | parameters \[hematocrit, and  |
|           |             |           | hemoglobin (males)\], body    |
| (1 - 6    |             |           | weight and body weight gain   |
| Months)   |             |           | decreases and increase in     |
|           |             |           | several organ weights         |
+-----------+-------------+-----------+-------------------------------+
| Re        | **MOE** =   | 1x        |                               |
| sidential | 100         |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Occ       | **MOE** =   | NA        |                               |
| upational | 100         |           |                               |
+-----------+-------------+-----------+-------------------------------+
| **Inh     | Oral NOAEL  |           | 6-Month Feeding-Dog           |
| alation** | = 7.5       |           |                               |
|           |             |           | LOAEL = 75 mg/kg/day based on |
| Long-Term |             |           | alterations in hematological  |
|           |             |           | parameters \[hematocrit, and  |
| (\>6      |             |           | hemoglobin (males)\], body    |
| Months)   |             |           | weight and body weight gain   |
|           |             |           | decreases and increase in     |
|           |             |           | several organ weights         |
+-----------+-------------+-----------+-------------------------------+
| Re        | **MOE** =   | 1x        |                               |
| sidential | 100         |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Occ       | **MOE** =   | NA        |                               |
| upational | 100         |           |                               |
+-----------+-------------+-----------+-------------------------------+
| Cancer    | **Clas      |           |                               |
|           | sification: |           |                               |
|           | E**         |           |                               |
+-----------+-------------+-----------+-------------------------------+

NA = Not Applicable; MOE = Margin of Exposure.

***3.0 Use Profile***

The proposed uses for this Section 3 petition are summarized in Table 3.

+---------+-------+----------------------------------+-------+---------+
| **Table |       |                                  |       |         |
| 3.      |       |                                  |       |         |
| Summary |       |                                  |       |         |
| of Use  |       |                                  |       |         |
| Patter  |       |                                  |       |         |
| ns/Form |       |                                  |       |         |
| ulation |       |                                  |       |         |
| Inform  |       |                                  |       |         |
| ation** |       |                                  |       |         |
+=========+=======+==================================+=======+=========+
| **Form  | **A   | **Use Site**                     | **A   | **Fr    |
| ulation | pplic |                                  | pplic | equency |
| Type (% | ation |                                  | ation | of      |
| ai)**   | Met   |                                  | R     | Appl    |
|         | hod** |                                  | ate** | ication |
|         |       |                                  |       | (inte   |
|         |       |                                  | **(lb | rval)** |
|         |       |                                  | ai    |         |
|         |       |                                  | /A)** |         |
+---------+-------+----------------------------------+-------+---------+
| W       | Groun | brassica (cole) leafy vegetables | 0.125 | 6 apps  |
| ettable | dboom | group 5 (including: abyssinian   |       |         |
| Powder  | and   | cabbage; bok choy; broccoli;     |       | (7      |
| in      | A     | broccoli, Chinese; broccoli      |       | days)   |
| Water-  | erial | raab; Brussels sprouts; cabbage; |       |         |
| Soluble | Sp    | cabbage, Chinese; cabbage        |       | PHI = 7 |
| Packet  | rayer | Chinese mustard; cabbage,        |       | days    |
|         |       | seakale; cauliflower; cavalo     |       |         |
| (75%    |       | broccolo; collards; Hanover      |       |         |
| ai)     |       | salad; kale, common; kohlrabi;   |       |         |
|         |       | mustard, wild; mustard, Chinese; |       |         |
|         |       | mustard greens; mustard spinach; |       |         |
|         |       | and rape greens) and turnip      |       |         |
|         |       | greens                           |       |         |
+---------+-------+----------------------------------+-------+---------+

***4.0 Occupational Exposure***

4.1 [Handler Exposure and Risk]{.underline}

There is a potential for exposure to cyromazine during mixing, loading,
and application activities. An exposure/risk assessment using applicable
endpoints selected by the HIARC was performed. No chemical-specific
handler exposure data were submitted in support of this Section 3
registration. In accordance with HED's Exposure Science Advisory Council
(SAC) policy, exposure data from the Pesticide Handlers Exposure
Database (PHED) Version 1.1 as presented in PHED Surrogate Exposure
Guide (8/98) were used with other HED default values for acres treated
per day, body weight, and the level of personal protective equipment to
assess handler exposures.

Handler's exposure and risk were estimated for the following scenarios:
(1) mixing/loading wettable powder packaged in water-soluble packets for
aerial application, (2) mixing/loading wettable powder packaged in
water-soluble packets for groundboom application, (3) applying sprays
with fixed-wing aircraft, (4) applying sprays with a groundboom sprayer,
and (5) flagging sprays for aerial operations.

The minimum level of PPE for handlers is based on acute toxicity for the
end-use products. The Registration Division (RD) is responsible for
ensuring that PPE listed on the label is in compliance with the Worker
Protection Standard (WPS).

As mentioned previously, no dermal endpoint was selected for cyromazine
by the HIARC, because no hazard was identified via the dermal route
(i.e., no toxicity was observed at the limit dose of 1,000 mg/kg/day;
there are no concerns for pre/postnatal toxicity; and dermal absorption
is relatively low \[13%\]). Therefore, the occupational risk assessment
was based on inhalation exposure only. The daily inhalation doses were
compared to the oral NOAELs of 10 mg/kg/day (based on decreases in
maternal body weight gain and food consumption in the developmental oral
study in the rabbit) and 7.5 mg/kg/day (based on alterations in
hematological parameters, body weight and body weight gain decreases and
increase in several organ weights in the 6-month feeding study in the
dog) to estimate the risk from short- and intermediate-term inhalation
exposures, respectively. Chronic exposures are not expected for handlers
of cyromazine for the proposed use patterns.

The MOEs range from 34,000 for intermediate-term flagging sprays for
aerial operations to 290,000 for short-term mixing/loading wettable
powder packaged in water-soluble packets for groundboom application.
**These MOEs are above HED's target of 100, and therefore, are not of
concern.** Exposure assumptions and estimates for occupational handlers
are summarized in Table 4.

+---------------------+-------+-------+-----+--------+-------+--------+
| **Table 4.          |       |       |     |        |       |        |
| Inhalation Exposure |       |       |     |        |       |        |
| and Risk Assessment |       |       |     |        |       |        |
| for Occupational    |       |       |     |        |       |        |
| Handlers**          |       |       |     |        |       |        |
+=====================+=======+=======+=====+========+=======+========+
| PHED Scenario       | PHED  | A     | A   | Daily  | S     | Int    |
|                     | Unit  | pplic | rea |        | hort- | ermed- |
| Selected from PSEG  | Exp   | ation | T   | Dose   | Term  | Term   |
| (8/98)              | osure | Rate  | rea | ^4^    | Inhal | Inha   |
|                     | ^1^   | ^2^   | ted |        | ation | lation |
|                     |       |       | ^3^ | (mg/k  |       |        |
|                     | (     | (lb   |     | g/day) | MOE   | MOE    |
|                     | mg/lb | ai/A) | (   |        | ^5^   | ^5^    |
|                     | ai)   |       | A/d |        |       |        |
|                     |       |       | ay) |        |       |        |
+---------------------+-------+-------+-----+--------+-------+--------+
| 1\. Mixing/Loading  | 0.    | 0.125 | 350 | 0      | 6     | 50,000 |
| Wettable Powder     | 00024 |       |     | .00015 | 7,000 |        |
| packaged in         |       |       |     |        |       |        |
| Water-Soluble       |       |       |     |        |       |        |
| Packets for Aerial  |       |       |     |        |       |        |
| Application         |       |       |     |        |       |        |
+---------------------+-------+-------+-----+--------+-------+--------+
| 2\. Mixing/Loading  |       | 0.125 | 80  | 0.     | 29    | 2      |
| Wettable Powder     |       |       |     | 000034 | 0,000 | 20,000 |
| packaged in         |       |       |     |        |       |        |
| Water-Soluble       |       |       |     |        |       |        |
| Packets for         |       |       |     |        |       |        |
| Groundboom          |       |       |     |        |       |        |
| Application         |       |       |     |        |       |        |
+---------------------+-------+-------+-----+--------+-------+--------+
| 3\. Applying Sprays | 0.0   | 0.125 | 350 | 0.     | 24    | 1      |
| with Fixed-wing     | 00068 |       |     | 000043 | 0,000 | 80,000 |
| Aircraft (enclosed  |       |       |     |        |       |        |
| cockpit)            |       |       |     |        |       |        |
+---------------------+-------+-------+-----+--------+-------+--------+
| 4\. Applying Sprays | 0.    | 0.125 | 80  | 0      | 9     | 71,000 |
| with a Groundboom   | 00074 |       |     | .00011 | 5,000 |        |
| Sprayer (open cab)  |       |       |     |        |       |        |
+---------------------+-------+-------+-----+--------+-------+--------+
| 5\. Flagging        | 0.    | 0.125 | 350 | 0      | 4     | 34,000 |
| (Sprays) for Aerial | 00035 |       |     | .00022 | 6,000 |        |
| Operations          |       |       |     |        |       |        |
+---------------------+-------+-------+-----+--------+-------+--------+

^1^Unit Exposure values are based on exposure without a respirator.
There is low confidence in values used for M/L wettable powder in
water-soluble packets, high confidence in the values for groundboom
application and flagging for aerial operations, and medium confidence in
values used for aerial application with an enclosed-cockpit aircraft.

^2^ Maximum application rate of 0.125 lb ai/acre was used as a screening
value.

^3^Standard values for acres treated in a day were used.

^4^ Daily Dose = \[Unit Exposure (mg/lb ai handled) x Application Rate
(lb ai/A) x Acres Treated (A/day)\] / Body Weight (70 kg used because
endpoint effects were not considered gender-specific)

^5^ MOE = NOAEL/ Daily Inhalation Dose. Short-term Inhalation NOAEL = 10
mg/kg/day. Intermediate-term Inhalation NOAEL = 7.5 mg/kg/day.

4.2 [Postapplication Exposure and Risk]{.underline}

This action on cyromazine involves foliar applications. Therefore, there
is a potential for postapplication exposure to scouts, harvesters and
other field workers. However, because no appropriate dermal endpoints
were identified for this exposure potential, and postapplication
inhalation exposure is expected to be negligible, an occupational
postapplication risk assessment was not conducted. Non-occupational
postapplication risk in residential settings is covered in Section 5.0.

The current label for Trigard^®^ has a 12‑hour restricted entry interval
(REI). The cyromazine technical material has been classified in Toxicity
Category III for acute dermal, and Toxicity Category IV for primary eye
irritation and primary skin irritation. Per the Worker Protection
Standard(WPS), a 12‑hour restricted entry interval (REI) is required for
chemicals classified under Toxicity Category III or IV. Therefore, the
REI of 12 hours is in compliance with the WPS.

***5.0 Non-Occupational/Residential Exposure***

There are no residential use sites associated with current or proposed
uses of cyromazine. Therefore, a residential risk assessment was not
conducted.

[Off Target Non-Occupational Exposure]{.underline}

Spray drift is always a potential source of exposure to residents nearby
to spraying operations. This is particularly the case with aerial
application, but, to a lesser extent, could also be a potential source
of exposure from the ground application method employed for cyromazine.
The Agency has been working with the Spray Drift Task Force, EPA
Regional Offices and State Lead Agencies for pesticide regulation and
other parties to develop the best spray drift management practices. The
Agency is now requiring interim mitigation measures for aerial
applications that must be placed on product labels/labeling. The Agency
has completed its evaluation of the new data base submitted by the Spray
Drift Task Force, a membership of U.S. pesticide registrants, and is
developing a policy on how to appropriately apply the data and the
AgDRIFT computer model to its risk assessments for pesticides applied by
air, orchard airblast and ground hydraulic methods. After the policy is
in place, the Agency may impose further refinements in spray drift
management practices to reduce off‑target drift and risks associated
with aerial as well as other application types where appropriate.

CC: RAB3 RF

SignOff Date: January 2003

DP Barcode: D285851