			

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

DATE:	12/20/06 

	SUBJECT:	Foramsulfuron: Human Health Risk Assessment for the Proposed
uses in/on 

	Sweet Corn and Popcorn.  PC code: 122020, Petition No. 5E7004, DP
Barcode: 324201

				

FROM:	Karlyn J. Bailey, Toxicologist and Risk Assessor 

	Registration Action Branch 2

Health Effects Division (7509P)

		

THRU:	Richard Loranger, Branch Senior Scientist

	Christina Swartz, Branch Chief

	Registration Action Branch 2

Health Effects Division (7509P)

TO:	James Tompkins/Ching-Tsen, Team 25

		Herbicide Branch 

		Registration Division (7505P)

The Health Effects Division (HED) of the Office of Pesticide Programs
(OPP) is charged with estimating the risk to human health from exposure
to pesticides.  The Registration Division (RD) of OPP has requested that
HED evaluate hazard and exposure data and conduct dietary, occupational,
residential and aggregate exposure assessments, as needed, to estimate
the risk to human health that will result from proposed uses of
foramsulfuron in/on sweet corn and popcorn.

In a previous risk assessment (D273636, Y. Donovan), HED evaluated
foramsulfuron hazard and exposure data for use on corn.  HED concluded
that the toxicology and residue chemistry data submitted for
foramsulfuron supported a tolerance exemption, due to its lack of
toxicity [40 CFR § 180.1219].  It was concluded that a human health
risk assessment was not needed.  

For the proposed uses on sweet corn and popcorn, HED also recommends a
tolerance exemption due to the absence of toxicity in the database;
therefore, a human health risk assessment is not needed for the proposed
uses.       

Recommendation for Tolerances and Registration for Use In/On Sweet Corn
and Popcorn

 

HED concludes that the toxicology and residue chemistry data support a
tolerance exemption for foramsulfuron in/on sweet corn and popcorn.  Due
to its lack of toxicity, a human health risk assessment is not needed
for this chemical.  The 40 CFR § 180.1219 should be modified to include
sweet corn (K+ CWHR) and popcorn, grain. 

Hazard AND DIETARY/non-dietary exposure

 

HED previously determined that the toxicological profile of
foramsulfuron supports a tolerance exemption for this chemical, as no
adverse effects were observed in the submitted toxicological studies
regardless of the route of exposure (HED Doc. No. 014671, 09/19/01). 
The tolerance exemption recommendation of the HIARC removed all residue
chemistry data requirements (D267582, Y. Donovan).  Thus, no dietary,
occupational, residential or aggregate exposure assessments are needed
for HED to conclude with reasonable certainty that dietary and
non-dietary exposures to foramsulfuron do not pose a significant human
health risk.

Drinking Water assessment

The Environmental Fate and Effects Division (EFED) completed an
evaluation of the section 3 New Use request for the addition of sweet
corn and popcorn to the Option label for foramsulfuron.  EFED reviewed
the proposed label (3264-685) and found the proposed conditions
(application rate, number of applications, etc.) consistent with those
evaluated in a previous EFED risk assessment (D267565).  In addition,
EFED evaluated the relative geographic extent of sweet corn and popcorn
acreage and found them consistent with field corn previously assessed.

The previous assessment evaluated both ecological risk and drinking
water exposure for both aerial and ground applications and EFED believes
that the potential ecological risks and drinking water exposure values
communicated in the earlier assessment do not need to be repeated and
should be used by RD in determining whether to grant this petition
(memo, D324203).

In summary, EFED’s previous assessment predicted the following
drinking water exposure concentrations:

PRZM/EXAMS-Index Reservoir

(Two aerial applications per year, each at 0.0365 lb a.i./acre and 14
days apart).

Acute (yearly peak upper 10%): 			1 µg/L (parts per billion, or ppb)

Chronic, non-cancer (yearly avg. upper 10%): 	0.3 µg/L (parts per
billion, or ppb)

Chronic, cancer (yearly average): 		0.2 µg/L (parts per billion, or
ppb)

SCI-GROW 2-Ground Water

Acute and Chronic:				0.05 µg/L (parts per billion, or ppb)

Cumulative Exposure

Section 408(b)(2)(D)(v) of the FFDCA requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency consider
"available information concerning the cumulative effects” of a
particular pesticide's residues and "other substances that have a common
mechanism of toxicity.”

Unlike other pesticides for which EPA has followed a cumulative risk
approach based on a common mechanism of toxicity, EPA has not made a
common mechanism of toxicity finding as to foramsulfuron and any other
substances, and foramsulfuron does not appear to produce a toxic
metabolite produced by other substances. For the purposes of this
tolerance action, therefore, EPA has not assumed that foramsulfuron has
a common mechanism of toxicity with other substances.  For information
regarding EPA’s efforts to determine which chemicals have a common
mechanism of toxicity and to evaluate the cumulative effects of such
chemicals, see the policy statements released by EPA’s Office of
Pesticide Programs concerning common mechanism determinations and
procedures for cumulating effects from substances found to have a common
mechanism on EPA’s website at   HYPERLINK
"http://www.epa.gov/pesticides/cumulative/" 
http://www.epa.gov/pesticides/cumulative/ .

Conclusion

HED concludes that the toxicology and residue chemistry data support a
tolerance exemption for foramsulfuron.  Due to its lack of toxicity, a
human health risk assessment is not needed.

REFERENCES

FQPA Human Health Risk Assessment for the Use of Foramsulfuron on Corn. 
Y. Donovan, D273636. 02/26/02.

Ecological Risk Assessment and Drinking Water Assessment for the
Proposed Addition of Sweet Corn and Popcorn to the Option Label Use of
Foramsulfuron on Corn. M. Corbin, D324203 and D324283.  09/21/06.

Foramsulfuron: Report of the Hazard Identification Assessment Review
Committee. A. Levy, HED DOC.NO. 014671. 09/19/01.

Evaluation of Residue Chemistry Data to Support Tolerances for Use of
Foramsulfuron on Field Corn. Y. Donovan, D267582.  03/05/02

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