Sethoxydim Risk Assessment

Worksheet Table of Contents 
Section/Title 
Page No.  
Worksheet F11b: Consumption of contaminated vegetation by a large mammal, chronic 
WS-59  
exposure scenario off-site.  
scenario.  
exposure scenario.  
exposure scenario off-site.  
scenario.  
Worksheet F12: Consumption of contaminated vegetation by a large bird, acute exposure 
WS-61  
Worksheet F13a: Consumption of contaminated vegetation by a large bird, chronic on-site 
WS-62  
Worksheet F13b: Consumption of contaminated vegetation by a large bird, chronic 
WS-64  
Worksheet F14: Consumption of contaminated insects by a small bird, acute exposure 
WS-67  
SUMMARY TABLES FOR ECOLOGICAL RISK ASSESSMENT  
Worksheet G01: Summary of Exposure Scenarios for terrestrial animals 
WS-66  
Terrestrial Plants from Runoff.  
Terrestrial Plants from Drift and Wind Erosion.  
Worksheet G02: Summary of quantitative risk characterization for terrestrial animals. 
WS-67  
Worksheet G03: Quantitative Risk Characterization for Aquatic Species. 
WS-68  
Worksheet G04: Summary of Exposure Assessment and Risk Characterization for 
WS-69  
Worksheet G05: Summary of Exposure Assessment and Risk Characterization for 
WS-70  
STANDARD REFERENCES FOR WORKSHEETS 
WS-71  

---

GENERAL ASSUMPTIONS, VALUES, and MODELS 
Worksheet A01 [CONST]: Constants and conversion factors used in 
calculations 
Conversion 
ID 
Value 
mg/lb 
mg_lb 
453,600 
mL/gallon 
ml_gal 
3,785 
lb/gallon to mg/mL 
lbg_mgml 
119.8 
lb/acre to 
:
g/cm
2 
lbac_ugcm 
11.21 
lb/acre to mg/cm
2 
lbac_mgcm 
0.01121 
gallons to liters 
gal_lit 
3.785 
Worksheet A02 [STD]: General Assumptions Used in Worker Exposure Assessments 
Parameter 
ID 
Value 
Units 
Reference 
Body Weight 
(General) 
Surface area of both 
hands 
Surface area of lower 
legs 
Weight of liquid 
adhering to surface 
of skin after a spill 
BW 
70
kg 
Hands 
840 
cm
2 
LLegs 
2070 
cm
2 
Liq 
0.008 
mL/cm
2 
ICRP (1975), p. 13 
U.S. EPA/ORD 1992, p. 8-11 
U.S. EPA/ORD 1992, p. 8-11 
Mason and Johnson 1987 
WS-5  

---

Worksheet A03 [PUBL]: General Assumptions Used in Exposure Assessments for the General Public 
Verbal Description: This table contains various values used in the exposure assessments for the general public. 
Three general groups of individuals are considered: adult male, adult female, and a 2 year old child.  Values are 
specified for body weight, surface areas for various parts of the body, water intake, fish consumption, and the 
consumption of fruits or vegetables.  Not all types of value are specified for each group.  The only values 
specified are those used in the risk assessment. 
Description 
ID 
Value 
Units  
Reference 
Body Weights 
Male, Adult 
BWM 
70 
kg  
ICRP (1975), p. 13. 
Female, Adult 
BWF 
64 
kg  
See Note 1 below. 
Child,  2-3 years old 
BWC 
13.3 
kg  
U.S. EPA/ORD 1996, p. 7-1, Table 
7-2 
1
This is  the average value (63.79 kg), rounded to the nearest kg for 3 different groups of women between 15-49 years old: control (62.07 kg), 
pregnant (65.90 kg), and lactating (63.48 kg).  See Burnmaster 1998, Table III, p.218. This is identical to the body weight for females, 45-55 years 
old, 50
th
 percentile from U.S. EPA, 1985, page 5, Table 2-2, rounded to nearest kilogram. 
Body Surface Areas 
Female, feet and lower legs 
SAF1 
2915 
cm
2  
U.S. EPA/ORD 1992, p. 8-11, 
Table 8-3, total for feet and lower 
legs 
Female, exposed skin when 
SAF2 
5300 
cm
2  
U.S. EPA/ORD 1992, p. 8-11, 
wearing shorts and a T-shirt  
Table 8-3, total for arms, hands, 
lower legs, and feet. 
Child, male, 2-3 years old, 
SAC 
6030 
cm
2 
U.S. EPA/ORD 1996, p. 6-15, 
total body surface area 
Table 6-6, 50
th
 percentile. 
Water Intake 
Adult 
typical 
WCAT 
2 
L/day  
U.S. EPA/ORD 1996, p. 3-28, 
Table 3-30, midpoint of mean (1.4 
L/day) and 90
th
 percentile (2.4 
L/day) rounded to one significant 
place. 
lower range for exposure 
WCAL 
1.4 
L/day 
U.S. EPA/ORD 1996, p. 3-28, 
assessment 
Table 3-30, mean 
upper range 
WCAH 
2.4 
L/day  
U.S. EPA/ORD 1996, p. 3-28, 
Table 3-30, 90
th
 percentile 
Child, <3 years old 
typical 
WCT 
1 
L/day  
U.S. EPA/ORD 1996, p. 3-28, 
Table 3-30, midpoint of mean 
(0.61L/day) and 90
th
 percentile (1.5 
L/day) rounded to one significant 
place. 
lower range for exposure 
WCL 
0.61 
L/day 
U.S. EPA/ORD 1996, p. 3-28, 
assessment 
Table 3-30, mean 
upper range 
WCH 
1.50 
L/day 
U.S. EPA/ORD 1996, p. 3-28, 
Table 3-30, 90
th
 percentile 
WS-6  

---

Worksheet A03 [PUBL](continued): General Assumptions Used in Exposure Assessments for the General 
Public 
Description  
ID 
Value 
Units 
Reference 
Fish Consumption 
Freshwater anglers, typical 
FAT 
0.010 
kg/day 
U.S. EPA/ORD 1996, p. 10-51, 
intake per day over a 
average of means from four studies 
prolonged period 
rounded to one significant place. 
Freshwater anglers, maximum 
FAU 
0.158 
kg/day 
Ruffle et al. 1994 
consumption for a single day 
Native American subsistence 
FNT 
0.081 
kg/day 
U.S. EPA/ORD 1996, p. 10-51, 
populations, typical intake per 
median value of 94 individuals 
day 
Native American subsistence 
FNU 
0.770 
kg/day 
U.S. EPA/ORD 1996, p. 10-51, 
populations, maximum for a 
highest value of 94 individuals 
single day 
Consumption of Fruits and Vegetables 
Consumption of fruit, total 
Central 
FrTC 
0.00168 
kg fruit/kg 
U.S. EPA/ORD 1996, Table 9-3, p. 
bw/day 
9-11, Central and upper estimates 
are mean and 95
th
 percentile,
Lower 
FrTL 
0.00168 
respectively.  The 5
th
 percentile is 
given as zero.  For these 
Upper 
FrTU 
0.01244 
worksheets, the central estimate is 
used for the lower bound. 
Consumption of vegetables, total 
Central 
VgTC 
0.0036  
kg veg/kg 
U.S. EPA/ORD 1996, Table 9-12, 
bw/day 
p. 9-12, mean, 5
th
 percentile and
Lower 
VgTL 
0.00075 
95
th
 percentile. 
Upper 
VgTU 
0.01 
Consumption of vegetables, homegrown 
Central 
VgHC 
0.000761  
kg veg/kg 
U.S. EPA/ORD 1996, Table 12-15, 
bw/day 
p. 9-14, mean, 5
th
 percentile and
Lower 
VgHL 
0.0000777 
95
th
 percentile for individuals 
Upper 
VgHU 
0.00492 
between 20 and 39 years old.. 
Worst-case scenario for 
VAcute 
0.454 
kg food 
1 lb.  The approximate mid range 
consumption in a single day, 
of the above typical and upper 
acute exposure scenario only. 
limits based on the 64 kg body 
weight. 
Miscellaneous 
Estimate of dislodgeable 
DisL 
0.1 
none 
Harris and Solomon 1992, data on 
residue as a proportion of 
2,4-D 
application rate shortly after 
application. 
WS-7  

---