  SEQ CHAPTER \h \r 1 U. S. ENVIRONMENTAL PROTECTION AGENCY

Washington, D.C. 20460	

									            OFFICE OF

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

								

Date: December 13, 2007 

MEMORANDUM 					

Subject:	Novaluron and Novaluron Degradates (Chlorophenyl urea and
Chloroaniline) Drinking Water Assessment in Support of New Use
Registration Action for Tomato, Sugarcane, and Increase in Application
Rate to Brassica.

	PC Code: 124002

	DP Barcode: D345672, D340579, D340581, and D340583

To:		Dana Vogel, Branch Chief, RAB 1

		Health Effects Division (7509P)

		Susan Stanton, RIMUERB

Registration Division (7505P)

From:	Iwona L. Maher, Chemist, ERBI

		Thuy Nguyen, RAPL, ERB1

		Nancy Andrews, PhD, Branch Chief, ERBI

Environmental Fate and Effects Division (7507P)

The registrant is proposing to add two new uses:  tomato and sugarcane
to the RimOn 0.83EC and RimOn 10SC (tomato only) product labels, and
increase an application rate to brassica (RimOn 0.83EC).  Based on a
review and analysis of the application information provided on the
product labels for these two end-use products, drinking water estimated
concentrations from these new proposed uses are expected to be lower
than those from novaluron current use on apples.  According to HED MARC,
beside novaluron, there are two novaluron degradates of concern for
drinking water:
1-[3-Chloro-4-(1,1,2-trifluoro-2-trifluoromethoxyethoxy)phenyl]urea
(275-352I; chlorophenyl) and
3-chloro-4-(1,1,2-trifluoro-2-trifluoromethoxyethoxy)aniline (275-309I;
chloroaniline).  

According to the current label no more than 0.96 lbs a.i. (RimOn 7.5WDG)
may be applied to apples per acre per year, with the maximum rate per
application of 0.32 lbs a.i., a minimum intervals of 10 to 14 days
between applications, and up to 3 applications per year.  The proposed
maximum application rates are no more than 0.39 lbs a.i. (RimOn 0.83EC)
applied per acre per year (sugarcane).  Table 1 lists in detail the
proposed application rates for tomato, sugarcane, and brassica, and the
currently registered maximum application rate to apples.

Table 1.  Novaluron application rates for the proposed and registered1
uses.



Crop	Maximum application rate (lbs ai/A)	Maximum number of applications
per year	Minimum interval between applications

	Single	Annual





Apples 1	

0.32	

0.96	

3	

10

Brassica 	0.078	0.233	3	7

Tomato	0.078	0.233	3	7

Sugarcane	0.078	0.39	5	n/a2

1 – It shows only the maximum registered application rate for
novaluron registered uses.

2 – According to the proposed label the consequent applications to
sugarcane should be made in intervals depending on a pest pressure.

Because the proposed application rate for tomato, sugarcane, and
increased application rate for brassica uses are lower than the
application rate for apples (annually 0.96 lb a.i./acre), the drinking
water concentrations estimated for apples at the maximum application
rate are applicable to the new proposed uses on tomato, sugarcane, and
increased application to brassica.  At the maximum application rate on
apples, Tier II novaluron acute (peak) estimated drinking water
concentration is 11.4 μg/L, and exceeds the solubility of the compound
(3 μg/L), which is expected to be an upper bound environmental
concentration.  Novaluron estimated 1 in 10-year annual mean
concentration in drinking water is 1.8 μg/L (apples).  The 30-year
annual mean concentration is 1.2 μg/L (apples; Maher et. al., February
11, 2004, D285477).  Tier I chlorophenyl urea estimated peak drinking
water concentration from surface water sources is 4.6 μg/L, and
chloroaniline is 11.4 μg/L, based on novaluron’s maximum application
rate of 0.32 lb ai/acre applied 3 times a season (0.96 lbs ai/year;
apples).  Chlorophenyl urea scenario was based on assuming 26.6% (MRID
44961009) conversion from parent to chlorophenyl urea and using
molecular weight conversion to adjust from parent application rate to
chlorophenyl urea application rate.  Because non of the laboratory
studies submitted for novaluron were conducted long enough to establish
the pattern of formation and decline of chloroaniline the maximum
formation rate is unknown.  Therefore, chloroaniline scenario was based
on assuming 100% conversion from parent to chloroaniline and using
molecular weight conversion to adjust from parent application rate to
chloroaniline application rate.  An estimated annual average
concentration of chlorophenyl urea is 0.86 μg/L and chloroaniline is
2.6 μg/L from the same maximum novaluron application rate to apples (I.
Maher, February 11, 2004).  

Based on laboratory and field studies, novaluron appears to be immobile
and ranges from moderately persistent to persistent in the field.  It
biodegrades in soil under aerobic conditions with half-lives of 7 to14.5
days, strongly adsorbs to soil and sediment (simple Kd values ranged
from 95 to 247), and is stable to hydrolysis and photodegradation.  Due
to its high sorptive properties (Koc = 6,680-11,813) on soil, the
chemical has low potential for leaching into ground water.  In the
field, novaluron appears to degrade with half-lives ranging from 20 to
178 days.  The laboratory and field data suggest that novaluron may be
more persistent in colder climates. At 50 oC and pH 9 novaluron
hydrolyzes very rapidly with a half-life of 1.2 days. In aerobic soils
it degrades slower at 10 oC (i.e., half-life 31.9 days) than at 20 oC
(i.e., half-lives from 7 to 14.5 days).  Novaluron has the potential to
reach surface water through runoff weeks to months following its
application and through spray drift during application.

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 in the environment the major degradate chlorophenyl urea is expected to
further degrade to form chloroaniline.

The fate and transport data submitted for novaluron were complete.  
Fate data submitted for the novaluron degradate chlorophenyl urea
(275-352I) was limited to the adsorption/desorption study.  No data was
submitted for chloroaniline degradate.  For more detailed information on
the drinking water assessment from novaluron use on apples refer to
“Novaluron Estimated Drinking Water Concentration for Use in the Human
Health Drinking Water Risk Assessment.” memo (Maher et. al., February
11, 2004, D285477).

 

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