Document ID: EPA-HQ-OPP-2002-0354-0015
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-06-09T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE  OF 

PREVENTION, PESTICIDES AND 

TOXIC SUBSTANCES

PC Code: 059201

DP Barcode: D296581    

Date:  February 2, 2006

MEMORANDUM						

SUBJECT:	Comparison of Currently Supported Phosmet Use Rates to those
Assessed Previously     

TO:		Diane Isbell,, Risk Manager Reviewer

Special Review and Reregistration Division

FROM:	Thomas M. Steeger, PhD, Senior Biologist

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507c)

APPROVED	

BY:	Elizabeth Behl, Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division

The Environmental Fate and Effects Division (EFED) has completed its
comparison of the currently supported use rates for phosmet to those
originally assessed in the Environmental Fate and Ecological Risk
Assessment chapter (D188325; dated 4/28/98) in support of the
reregistration eligibility decision for phosmet.  Although the label
modifications may have changed estimated environmental concentrations to
some extent, they do not result in substantial changes to the overall
risks estimated.  Currently supported use rates for phosmet will likely
exceed acute risk levels of concern (RQ(0.05) for aquatic animals by
factors ranging from 1 to 1,400x and will exceed the chronic risk level
of concern (RQ(1.0) for aquatic animals by factors ranging from 1 to
10X.  For terrestrial animals, currently supported uses will exceed
acute risk levels of concern (RQ(0.1) by factors ranging from 1 to 24X
for birds and 1 to 46X for mammals.  The chronic risk level of concern
(RQ(1.0) will be exceeded by factors ranging from 1 to 20X for birds and
from 1 to 60X for mammals based on maximum residues.   

As noted in an email dated 1/12/06, Table 1 illustrates that currently
supported use rates are relatively consistent with those previously
assessed except for phosmet use on grapes, peaches, pears and plums. 
For grapes, the original assessment used 4 applications of 1.5 lbs
a.i./A with a 20-day reapplication period; the currently supported use
calls for 3 applications of 1.5 lbs a.i./A with a considerably shorter
reapplication interval, i.e., 7 days.  Also for use of phosmet on
grapes, the original chapter did not assess the current rate of 4
applications of 1.0 lb a.i./A with a 7-day reapplication interval.  For
use on peaches, the original chapter relied on a reapplication interval
of 7 days while the supported use calls for a longer (10-day)
reapplication interval.  For pears, the original chapter assessed an
maximum application rate of 5 lbs a.i./A (3 applications with a 21-day
reapplication interval) while the currently supported maximum rate is
lower, i.e., 4 lbs a.i./A (3 applications with a 21-day reapplication
interval).  Finally, for plums/prunes, the original chapter assessed 5
applications of 3 lbs a.i./A with a 14-day reapplication interval while
the current supported use calls for a lower number of applications (3)
of 3 lbs a.i./A with the same reapplication interval.

Table 1.  Comparison of most recent supported  application rates to
those initially assessed in the environmental fate and ecological risk
assessment in support of the reregistration eligibility decision on
phosmet (DP Barcode D188325).

Most Recent

Use

Application Rate

lbs a.i./A

(No. App / Reapplication Interval)	

Original Assessment

Application Rate

lbs a.i./A

(No. App / Reapplication Interval)

Apples (Eastern)

1.5 lbs a.i./A

(10 / 7)	

1.5

(10 / 7)

	

Apples (Western)

4.0 lbs a.i./A

(5 / 7)	

4.0

(5 / 7)

Apricots, Nectarines

3.0 lbs a.i./A

(3 / 7)	

not assessed

Blueberries

1.0 lbs a.i./A

(5 / 7)	

1.0

(5 / 7)

Grapes

1.5 lbs a.i./A

(3 / 7)	

1.5

(4 / 20)

Grapes

1.0 lb a.i./A

(4 / 7)	

lower rate not assessed

	

Peaches

3 lbs a.i./A

(4 / 10)	

3

(4 / 7)

	

Pears

4 lbs a.i./A

(3 / 21)	

5

(3 / 21)

	

Plums / Prunes

3.0 lbs a.i./A

(3 / 14)	

3

(5 / 14)

	

Original risk quotients (RQs) for both freshwater and estuarine/marine
invertebrates are reported in Table 2 (estuarine/marine invertebrate RQs
have been corrected to reflect an acute LC50 value of 1.6 µg/L). 
Estimated environmental concentrations used to generate RQ values would
not change for use rates that have remained the same.   Except for the
use on grapes, currently supported uses are either the same or involve
lower application rates, in terms of lbs a.i. applied or frequency of
application, than those assessed previously and aquatic exposure
estimates resulting from these reduced loadings would be lower.  For use
on grapes, the frequency of application has increased from 20 to 7 days;
however, the total number of applications per season has decreased from
4 to 3.  The effects of these changes on estimated environmental
concentrations are uncertain; however, in situations (e.g. acute and
chronic risks to invertebrates) where the levels of concern are exceeded
by large margins, the most recent reductions will not substantially
change the estimated risks. 

Table 2.  Summary of acute and chronic risk quotients for freshwater and
estuarine/marine fish and invertebrates based on original ecological
risk assessment for phosmet (dated 4/18/98).  Estuarine/marine
invertebrate RQ values are corrected to reflect acute LC50=1.6 µg/L. 
RQ values exceeding acute or chronic risk levels of concern are
highlighted.

Crop

App. Rate (lbs ai/A), App. No. (Days)	

Organism	

Freshwater

Acute RQ

(EEC/LC50)5	

Freshwater

Chronic RQ6

(EEC/NOEC)	

Estuarine/marineAcute RQ

(EEC/LC50)5	

Estuarine/marineChronic RQ

(EEC/NOEC)6

Apples (Eastern Low)

1.5(10)	

Fish	

0.22xx	

0.09	

0.09x	

0.13

	

Invertebrates	

7.8xxx	

0.80	

10xxx	

1.62+

Apples (Western High)

4(5)	

Fish	

0.16xx	

0.15	

0.06x	

0.21

	

Invertebrates	

5.6xxx	

1.07+	

7.0xxx	

2.16+

Berries

1(5)	

Fish	

0.17xx	

0.06	

0.07x	

0.08

	

Invertebrates	

5.9xxx	

0.53	

7.4xxx	

1.08+

Grapes

1.5(4)	

Fish	

0.27xx	

0.19	

0.11xx	

0.25

	

Invertebrate	

9.4xxx	

1.3+	

11.7xxx	

2.70+

Peaches–High 

3(4)	

Fish	

0.23xx	

0.16	

0.1xx	

0.21

	

Invertebrate	

8.1xxx	

1.33+	

10xxx	

2.70+

Pears

5(3)	

Fish	

2.0xxx	

1.13+	

0.8xxx	

1.52+

	

Invertebrate	

70xxx	

4.9+	

88xxx	

10+

Plums/Prunes

3(5)	

Fish	

0.12xx	

0.13	

0.05x	

0.17

	

Invertebrate	

4.2xxx	

0.53	

5.3xxx	

1.08+

1) Bluegill sunfish LC50 = 70 ppb; Gammarus fasciatus LC50 = 2.0
ppb;Sheepshead minnow LC50 = 170 ppb; Mysid shrimp LC50 = 1.6 ppb.

2) Rainbowtrout NOEC = 3.2 ppb; Daphnia NOEC = 0.75 ppb; Since a NOEC
for marine fish was not available, an extrapolation was calculated based
on the rainbow  trout chronic to acute ratio.  Acute values for rainbow
trout were calculated at 250 ppb (150 - 350 ppb ) and the NOEC at 4.4
ppb, while the marine/estuarine fish, sheepshead minnow, had an LC50 of
170 ppb.  Since the sheepshead minnow acute toxicity value is within the
rainbow trout 95% confidance interval, a NOEC of 2.36 ppb was calculated
for marine fish.

3) Peak EEC values derived through PRZM/EXAMS modeling.

4) For each crop, two PRZM/EXAMS EEC values are provided: the upper
value reprsents the 60-day EEC value used in calculating chronic RQ
values for fish; the lower value represents the 21-day EEC value used in
calculating chronic RQ values for invertebrates.

5) Acute RQ values were calculated by dividing the peak EEC by the LC50.

6) Chronic RQ values for fish were calculated by dividing the 60-day EEC
by the NOEC; chronic  RQ  values for invertebrates were calculated by
dividing the 21-day EEC by the NOEC.

* exceeds acute risk level of concern (RQ(0.5), restricted use level of
concern (RQ(0.1) and acute risk to endangered species level of concern
(RQ(0.05).

** exceeds restricted use level of concern (RQ(0.1) and acute risk to
endangered species level of concern (RQ(0.05).

***exceeds acute risk to endangered species level of concern (RQ(0.05).

A refined assessment of estimated environmental concentrations was
conducted for salmonids in the Pacific Northwest (DP Barcode D296583;
Attachment 1).  These aquatic exposure estimates (Attachment Table 1.1)
are lower than those contained in the RED although similar application
rates were used to derive them.  Different input parameters to the
pesticide root zone model (PRZM) account for the change in estimated
environmental concentrations.  However, even using refined estimated
environmental concentrations, risk quotients still exceed acute and
chronic risk levels of concern (Attachment Table 1.2).

As noted in an email dated 1/02/06, terrestrial risk quotients were
re-evaluated using the most recent estimates of supported use rates on
nine food crops.  Table 3 summarizes the number of uses exceeding acute
and chronic risk levels of concern (LOC) and the range of risk quotient
(RQ) values.  For terrestrial animals, acute and chronic risk quotients
are exceeded across all of the uses evaluated.  A more thorough
discussion of the avian and mammalian risk quotients follows.

Table 3.  Summary of acute and chronic risk quotients (RQ) and number of
uses exceeding acute and chronic risk levels of concerns (LOC) for the
food uses of phosmet based on current use rates.

ENDPOINT	 ADVANCE \d6 LOC Summary (acute high risk)	 ADVANCE \d6 LOC
Summary (chronic risk)

	 ADVANCE \d6 ACUTE	 ADVANCE \d6 CHRONIC

 ADVANCE \d6 Freshwater fish	 ADVANCE \d6 1/9 uses exceed 

(Pear RQ=2.0)  	 ADVANCE \d6 1 use exceeds (pears)

RQ = 1.13

 ADVANCE \d6 Freshwater invertebrate	 ADVANCE \d6 9/9 uses exceed 

(RQ range: 4.2 - 70)	 ADVANCE \d6 5/9 uses exceed 

(RQ range: 1.07 - 4.9)

 ADVANCE \d6 estuarine/marine fish	 ADVANCE \d6 1/9 uses exceed

(RQ=0.8)	 ADVANCE \d6 1/9 exceed (pears) 

(RQ=1.5) 

 ADVANCE \d6 estuarine/marine invertebrate	 ADVANCE \d6 9/9 exceed

(RQ range: 5.3 - 88)*	 ADVANCE \d6 9/9 exceed

(RQ range: 1.08 - 10)

 ADVANCE \d6 bird	 ADVANCE \d6 9/9 exceed

(RQ range: 0.04 - 2.4) 	 ADVANCE \d6 9/9 exceed

(RQ range: 0.15 - 20)

 ADVANCE \d6 mammal (small mammals feeding on short grasses)	 ADVANCE
\d6 9/9 exceed

(RQ range: 0.01 - 4.6)	 ADVANCE \d6 9/9 exceed

(RQ range: 0.44 - 60)

 ADVANCE \d6 plant	 ADVANCE \d6 	not evaluated	 ADVANCE \d6 

not evaluated

Acute and chronic risk quotients (RQ) were re-evaluated using the most
recent use rates for phosmet on food crops (Table 4).  Acute RQ values
exceed the acute risk level of concern (LOC) (RQ(0.5) for birds feeding
on short grasses (RQ range: 0.60 - 2.4) across all of the uses
evaluated.  The acute risk to endangered species LOC (RQ(0.1) is
exceeded across all of the uses evaluated for birds feeding on all
forage categories except seeds.  For birds foraging on seeds, the acute
endangered species LOC is exceeded for western apples (RQ=0.15), pears
(RQ=0.12), apricots/nectarines (RQ=0.11) and peaches (RQ=0.10).  These
results are relatively consistent with the original assessment in which
all of the uses evaluated exceeded acute  risk levels of concern for
birds.

Based on maximum phosmet residues on forage items, the chronic risk LOC
(RQ(1.0) is exceeded for birds across all uses and forage categories
except seeds (RQ range: 1.3 - 20) (Table 5).  Only one use, i.e., pears
(RQ=1.0), exceeded the chronic risk LOC for birds feeding on seeds. 
Based on mean residues, the chronic risk LOC is exceeded across all uses
except blueberries and grapes for birds feeding on short and tall
grasses (RQ range: 1.1 - 7.1).   These results are similar to previous
assessment in which all of the uses evaluated exceeded the chronic risk
level of concern for birds.

Based on dose-based RQ values, the acute risk LOC is exceeded across all
of the uses evaluated for all-sized mammals (15 g, 35 g, and 1000 g)
foraging on short grasses (RQ range: 0.78 - 4.6) (Table 46).  The acute
risk to endangered species LOC is exceeded for all-sized mammals (RQ
range: 0.30 - 4.6) feeding on any of the forage items evaluated other
than fruits/pods/large insects and seeds.  For all uses except
blueberries and grapes, the acute risk to endangered species LOC is
exceeded for small mammals feeding on fruits/pods and large insects. 
None of the uses evaluated exceeded the acute risk LOC to endangered
species for any size mammal feeding on seeds.  These results are
relatively consistent with the original assessment in which all of the
uses evaluated exceeded acute  risk levels of concern for mammals.

Based on maximum residues, the chronic risk LOC is exceeded across all
of the uses except blueberries and grapes for mammals feeding on any of
the forage categories evaluated (RQ range: 1.4 - 60) (Table 7).  For
blueberries and grapes (1.0 lb a.i./A), the chronic risk LOC is exceeded
for mammals feeding on any of the forage categories except for
fruits/pods/seeds and large insects.  Based on mean residues, the
chronic risk LOC is exceeded across all of the uses evaluated except
blueberries, grapes (both application rates) and forage categories (RQ
range: 1.1 - 21).  Using mean residues following application to either
grapes or blueberries, the chronic risk LOC is exceed for mammals
feeding  on any of the forage categories except fruits, pods, seeds and
large insects. .   These results are similar to previous assessment in
which all of the uses evaluated exceeded the chronic risk level of
concern for mammals.

Table 4.  Acute avian risk quotientsd calculated using an exposure value
based on maximum phosmet residues on forage items following multiple
applications and a subacute dietary toxicity value based on a bobwhite
quail LC50 of 501 mg/kg of diet.  Risk quotients exceeding acute risk
levels of concern are highlighted.

Use

Application Rate

lbs a.i./A

(No. App / Reapplication Interval)	

Food Items	

Maximum EEC (mg/kg)a	

LC50	

Maximum

RQ

Apples (Eastern)

1.5 lbs a.i./A

(10 / 7)	

Short grass	

449	

501	

0.90a

	

Tall grass	

206	

501	

0.41b

	

Broadleaf plants/small insects	

253	

501	

0.50a

	

Fruits, pods, seeds, and large insects	

28	

501	

0.06

Apples (Western)

4.0 lbs a.i./A

(5 / 7)	

Short grass	

1197	

501	

2.4a

	

Tall grass	

549	

501	

1.1a

	

Broadleaf plants/small insects	

673	

501	

1.3a

	

Fruits, pods, seeds, and large insects	

75	

501	

0.15c

Apricots, Nectarines

3.0 lbs a.i./A

(3 / 7)	

Short grass	

891	

501	

1.8a

	

Tall grass	

408	

501	

0.82a

	

Broadleaf plants/small insects	

501	

501	

1.0a

	

Fruits, pods, seeds, and large insects	

56	

501	

0.11c

Blueberries

1.0 lbs a.i./A

(5 / 7)	

Short grass	

299	

501	

0.60a

	

Tall grass	

137	

501	

0.27b

	

Broadleaf plants/small insects	

168	

501	

0.34b

	

Fruits, pods, seeds, and large insects	

19	

501	

0.04

Grapes

1.5 lbs a.i./A

(3 / 7)	

Short grass	

446	

501	

0.89a

	

Tall grass	

204	

501	

0.41b

	

Broadleaf plants/small insects	

251	

501	

0.51a

	

Fruits, pods, seeds, and large insects	

28	

501	

0.06

Grapes

1.0 lb a.i./A

(4 / 7)

	

Short grass	

299	

501	

0.60a

	

Tall grass	

137	

501	

0.27b

	

Broadleaf plants/small insects	

168	

501	

0.34b

	

Fruits, pods, seeds, and large insects	

19	

501	

0.04

Peaches

3 lbs a.i./A

(4 / 10)	

Short grass	

799	

501	

1.6a

	

Tall grass	

366	

501	

0.73a

	

Broadleaf plants/small insects	

450	

501	

0.90a

	

Fruits, pods, seeds, and large insects	

50	

501	

0.10c

Pears

4 lbs a.i./A

(3 / 21)	

Short grass	

968	

501	

1.9a

	

Tall grass	

443	

501	

0.89a

	

Broadleaf plants/small insects	

544	

501	

1.1a

	

Fruits, pods, seeds, and large insects	

60	

501	

0.12c

Plums / Prunes

3.0 lbs a.i./A

(3 / 14)	

Short grass	

749	

501	

1.5a

	

Tall grass	

344	

501	

0.69a

	

Broadleaf plants/small insects	

422	

501	

0.84a

	

Fruits, pods, seeds, and large insects	

47	

501	

0.09

a Exceeds acute risk (RQ(0.5), acute restricted use (RQ(0.2) and acute
endangered species (RQ(0.1) levels of concern.

b Exceeds acute restricted use (RQ(0.2) and acute endangered species
(RQ(0.1) levels of concern.

c Exceeds acute endangered species (RQ(0.1) levels of concern..

d Risk quotient = EEC ( LC50.

Table 5. Chronic avian risk quotients calculated using exposure values
based on maximum and mean phosmet residues on forage items and a
bobwhite quail NOAEC of 60 mg/kg diet.  RQ values exceeding chronic risk
level of concern highlighted.  

Use

Application Rate

(#/year / interval)	

Food Items	

Maximum EEC (mg/kg)a	

Mean EEC

(mg/kg)	

NOAEC	

Maximum

RQ	

Mean

RQ

Apples (Eastern)

1.5 lbs a.i./A

(10 / 7)	

Short grass	

449	

159	

60	

7.5a	

2.7a

	

Tall grass	

206	

67	

60	

3.4a	

1.1a

	

Broadleaf plants/small insects	

253	

84	

60	

4.2a	

1.4a

	

Fruits, pods, seeds, and large insects	

28	

13	

60	

0.47	

0.22

Apples (Western)

4.0 lbs a.i./A

(5 / 7)	

Short grass	

1197	

424	

60	

20a	

7.1a

	

Tall grass	

549	

180	

60	

1.1a	

3.0a

	

Broadleaf plants/small insects	

673	

224	

60	

1.3a	

3.7a

	

Fruits, pods, seeds, and large insects	

75	

35	

60	

0.15	

0.58

Apricots, Nectarines

3.0 lbs a.i./A

(3 / 7)	

Short grass	

891	

316	

60	

15a	

5.3a

	

Tall grass	

408	

134	

60	

6.8a	

2.2a

	

Broadleaf plants/small insects	

501	

167	

60	

8.4a	

2.8a

	

Fruits, pods, seeds, and large insects	

56	

26	

60	

0.93	

0.43

Blueberries

1.0 lbs a.i./A

(5 / 7)	

Short grass	

299	

106	

60	

5.0a	

1.8a

	

Tall grass	

137	

45	

60	

2.3a	

0.75

	

Broadleaf plants/small insects	

168	

56	

60	

2.8a	

0.94

	

Fruits, pods, seeds, and large insects	

19	

8.7	

60	

0.31	

0.15

Grapes

1.5 lbs a.i./A

(3 / 7)	

Short grass	

446	

158	

60	

7.4a	

2.6a

	

Tall grass	

204	

67	

60	

3.4a	

1.1a

	

Broadleaf plants/small insects	

251	

84	

60	

4.2a	

1.4a

	

Fruits, pods, seeds, and large insects	

28	

13	

60	

0.46	

0.22

Grapes

1.0 lb a.i./A

(4 / 7)

	

Short grass	

299	

106	

60	

5.0a	

1.8a

	

Tall grass	

137	

45	

60	

2.3a	

0.75

	

Broadleaf plants/small insects	

168	

56	

60	

2.8a	

0.93

	

Fruits, pods, seeds, and large insects	

19	

8.7	

60	

0.31	

0.15

Peaches

3 lbs a.i./A

(4 / 10)	

Short grass	

799	

283	

60	

13a	

4.7a

	

Tall grass	

366	

120	

60	

6.1a	

2.0a

	

Broadleaf plants/small insects	

450	

150	

60	

7.5a	

2.5a

	

Fruits, pods, seeds, and large insects	

50	

23	

60	

0.83	

0.39

Pears

4 lbs a.i./A

(3 / 21)	

Short grass	

968	

343	

60	

16a	

5.7a

	

Tall grass	

443	

145	

60	

7.4a	

2.4a

	

Broadleaf plants/small insects	

544	

181	

60	

9.1a	

3.0a

	

Fruits, pods, seeds, and large insects	

60	

28	

60	

1.0a	

0.47

Plums / Prunes

3.0 lbs a.i./A

(3 / 14)	

Short grass	

749	

265	

60	

12a	

4.4a

	

Tall grass	

344	

112	

60	

5.7a	

1.9a

	

Broadleaf plants/small insects	

422	

141	

60	

7.0a	

2.3a

	

Fruits, pods, seeds, and large insects	

47	

22	

60	

0.78	

0.36

a Exceeds chronic risk level of concern (RQ(1.0)

Table 6.  Mammalian acute dose-based risk quotients following repeated
applications of phosmet during one growing season and based on a rat
acute oral LD50 of 113 mg/kg.  Risk quotients exceeding acute risk
levels of concern are highlighted. 

Use 

Application Rate 

(# appls./ interval in days)	

Body Weight, g	

Mammalian Acute Risk Quotients

Short Grass	

Tall Grass	

Broadleaf Plants/Small Insects	

Fruits/pods/

large insects	

Seeds

Apples (Eastern)

1.5 lbs a.i./A

(10 / 7)	

15	

1.7a	

0.79a	

0.97a	

0.11c	

0.02

	

35	

1.5a	

0.68a	

0.83a	

0.09	

0.02

	

1000	

0.79a	

0.36b	

0.44b	

0.05	

0.01

Apples (Western)

4.0 lbs a.i./A

(5 / 7)	

15	

4.6a	

2.1a	

2.6a	

0.29b	

0.06

	

35	

3.9a	

1.8a	

2.2a	

0.25b	

0.05

	

1000	

2.1a	

0.96a	

1.2a	

0.13c	

0.03

Apricots, Nectarines

3.0 lbs a.i./A

(3 / 7)	

15	

3.4a	

1.6a	

1.9a	

0.21b	

0.05

	

35	

2.9a	

1.3a	

1.6a	

0.18	

0.04

	

1000	

1.6a	

0.72a	

0.88a	

0.10c	

0.02

Blueberries

1.0 lbs a.i./A

(5 / 7)	

15	

1.2a	

0.53a	

0.65a	

0.07	

0.02

	

35	

0.98a	

0.45b	

0.55a	

0.06	

0.01

	

1000	

0.53a	

0.24b	

0.30b	

0.03	

0.01

Grapes

1.5 lbs a.i./A

(3 / 7)	

15	

1.7a	

0.78a	

0.96a	

0.11c	

0.02

	

35	

1.5a	

0.67a	

0.82a	

0.09	

0.02

	

1000	

0.78a	

0.36b	

0.44b	

0.05	

0.01

Grapes

1.0 lb a.i./A

(4 / 7)

	

15	

1.2a	

0.53a	

0.65a	

0.07	

0.02

	

35	

0.98a	

0.45b	

0.55a	

0.06	

0.01

	

1000	

0.53a	

0.24b	

0.30b	

0.03	

0.01

Peaches

3 lbs a.i./A

(4 / 10)

	

15	

3.1a	

1.4a	

1.7a	

0.19c	

0.04

	

35	

2.6a	

1.2a	

1.5a	

0.16c	

0.04

	

1000	

1.4a	

0.64a	

0.79a	

0.09	

0.02

Pears

4 lbs a.i./A

(3 / 21)	

15	

3.7a	

1.7a	

2.1a	

0.23b	

0.05

	

35	

3.2a	

1.5a	

1.8a	

0.20b	

0.04

	

1000	

1.7a	

0.78a	

0.96a	

0.11c	

0.02

Plums / Prunes

3.0 lbs a.i./A

(3 / 14)	

15	

2.9a	

1.3a	

1.6a	

0.18c	

0.04

	

35	

2.5a	

1.1a	

1.4a	

0.15c	

0.03

	

1000	

1.3a	

0.60a	

0.74a	

0.08	

0.02

a Exceeds acute risk (RQ(0.5), acute restricted use (RQ(0.2) and acute
endangered species (RQ(0.1) levels of concern.

b Exceeds acute restricted use (RQ(0.2) and acute endangered species
(RQ(0.1) levels of concern.

c Exceeds acute endangered species (RQ(0.1) levels of concern..

d Risk quotient = EEC ( LC50.

Table 7. Chronic mammalian risk quotients calculated using exposure
values based on maximum and mean phosmet residues on forage items and a
rat NOAEC of 20 mg/kg diet.  RQ values exceeding chronic risk level of
concern highlighted.  

Use

Application Rate

lbs a.i./A

(No. App / Reapplication Interval)	

Food Items	

Maximum EEC (mg/kg)a	

Mean

EEC

(mg/kg)	

Maximum

RQ	

Mean

RQ

Apples (Eastern)

1.5 lbs a.i./A

(10 / 7)	

Short grass	

449	

159	

22a	

8.0a

	

Tall grass	

206	

67	

10a	

3.4a

	

Broadleaf plants/small insects	

253	

84	

13a	

4.2a

	

Fruits, pods, seeds, and large insects	

28	

13	

1.4a	

0.65

Apples (Western)

4.0 lbs a.i./A

(5 / 7)	

Short grass	

1197	

424	

60a	

21a

	

Tall grass	

549	

180	

27a	

9.0a

	

Broadleaf plants/small insects	

673	

224	

34a	

11a

	

Fruits, pods, seeds, and large insects	

75	

35	

3.7a	

1.8a

Apricots, Nectarines

3.0 lbs a.i./A

(3 / 7)	

Short grass	

891	

316	

45a	

16a

	

Tall grass	

408	

134	

20a	

6.7a

	

Broadleaf plants/small insects	

501	

167	

25a	

8.4a

	

Fruits, pods, seeds, and large insects	

56	

26	

2.8a	

1.3a

Blueberries

1.0 lbs a.i./A

(5 / 7)	

Short grass	

299	

106	

15a	

5.3a

	

Tall grass	

137	

45	

6.9a	

2.2a

	

Broadleaf plants/small insects	

168	

56	

8.4a	

2.8a

	

Fruits, pods, seeds, and large insects	

19	

8.7	

0.94	

0.44

Grapes

1.5 lbs a.i./A

(3 / 7)	

Short grass	

446	

158	

22a	

7.9a

	

Tall grass	

204	

67	

10a	

3.3a

	

Broadleaf plants/small insects	

251	

84	

13a	

4.2a

	

Fruits, pods, seeds, and large insects	

28	

13	

1.4a	

0.65

Grapes

1.0 lb a.i./A

(4 / 7)

	

Short grass	

299	

106	

15a	

5.3a

	

Tall grass	

137	

45	

6.9a	

2.2a

	

Broadleaf plants/small insects	

168	

56	

8.4a	

2.8a

	

Fruits, pods, seeds, and large insects	

19	

8.7	

0.93	

0.44

Peaches

3 lbs a.i./A

(4 / 10)	

Short grass	

799	

283	

40a	

14a

	

Tall grass	

366	

120	

18a	

6.0a

	

Broadleaf plants/small insects	

450	

150	

22a	

7.5a

	

Fruits, pods, seeds, and large insects	

50	

23	

2.5a	

1.2a

Pears

4 lbs a.i./A

(3 / 21)	

Short grass	

968	

343	

48a	

17a

	

Tall grass	

443	

145	

22a	

7.3a

	

Broadleaf plants/small insects	

544	

181	

27a	

9.1a

	

Fruits, pods, seeds, and large insects	

60	

28	

3.0a	

1.4

Plums / Prunes

3.0 lbs a.i./A

(3 / 14)	

Short grass	

749	

265	

37a	

13a

	

Tall grass	

343	

112	

17a	

5.6a

	

Broadleaf plants/small insects	

422	

141	

21a	

7.0a

	

Fruits, pods, seeds, and large insects	

47	

22	

2.3a	

1.1a

a Exceeds chronic risk level of concern (RQ(1.0)

Attachment 1. Revised Tier 2 EEC’s for Phosmet in Support of
Reassessment of Endangered Species Assessments for Salmonids in the
Northwestern United States

Table 1.1 Tier 2 one-in-ten year EEC's for phosmet as applied three
crops in the northwestern United States. EEC’s are for the maximum
application practice allowed on the label except for typical apples
where the application practice is intended to represent a central
tendency in actual application practice.

Crop	

Maximum	

4 Day	

21 Day	

60 Day	

90 Day

apples - high*	

μg (L-1	

1.6μg (L-1	

0.84μg (L-1	

0.48μg (L-1	

0.32μg (L-1

apples - low*	

14.0μg (L-1	

2.1μg (L-1	

0.45μg (L-1	

039μg (L-1	

0.26μg (L-1

kiwis - maximum	

 19.7 μg (L-1	

3.2 μg (L-1	

0.83 μg (L-1	

0.29 μg (L-1	

0.19 μg (L-1

pears - maximum	

14.0 μg (L-1	

2.1 μg (L-1	

0.45 μg (L-1	

0.39 μg (L-1	

0.26 μg (L-1

* The high apple application rate refers to a higher single application
rate with 4 lb acre-1 five times at 7 day intervals. The low application
practice is 1.5 lb acre-1 applied ten times at 7 day intervals.

Table 1.2.  Summary of acute and chronic risk quotients for freshwater
and estuarine/marine fish and invertebrates based on refined estimated
environmental concentrations used for Pacific Northwest salmonid risk
assessment.  Estuarine/marine invertebrate RQ values are corrected to
reflect acute LC50=1.6 µg/L.  RQ values exceeding acute or chronic risk
levels of concern are highlighted.

Crop

App. Rate (lbs ai/A), App. No. (Days)	

Organism	

Freshwater

Acute RQ

(EEC/LC50)5	

Freshwater

Chronic RQ6

(EEC/NOEC)	

Estuarine/marineAcute RQ

(EEC/LC50)5	

Estuarine/marineChronic RQ

(EEC/NOEC)6

Apples (Eastern Low)

1.5(10)	

Fish	

0.20**	

0.12	

0.08***	

0.02

	

Invertebrates	

7.0*	

0.6	

8.8*	

1.2

Apples (Western High)

4(5)	

Fish	

0.16**	

0.15	

0.07***	

0.20

	

Invertebrates	

5.6*	

1.1	

7.0*	

2.3

Pears

5(3)	

Fish	

0.20**	

0.12	

0.08***	

0.16

	

Invertebrates	

7.0*	

0.6	

8.8*	

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 0.1) and acute risk to endangered species level of concern (RQ(0.05).

** exceeds restricted use level of concern (RQ(0.1) and acute risk to
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***exceeds acute risk to endangered species level of concern (RQ(0.05).

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