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OFFICE OF
PREVENTION, PESTICIDES AND
TOXIC SUBSTANCES

MEMORANDUM

SUBJECT:

TO:

FROM:

THRU:

This memorandum addresses the mitigation techniques proposed by the registrant in an effort
to reduce potential worker exposure to fenamiphos. The proposed techniques were initiated by the
registrant based on the results of the worker exposure assessment presented in the Reregistration
Eligibility Decision document for Fenamiphos: Case #0333. SRRD has requested that OREB conduct
an exposure assessment for the major use sites and provide Margins of Exposure based on this
assessment.

Table 1. Summary Exposure Values Including the Proposed Mitigation Techniques presents
exposure scenarios presented by the registrant in the mitigation proposal. Each scenario was defined
by the types of potential mixing/loading and application equipment that could be employed based on
the major use sites. An assessment was conducted for those sites which were determined to be the
major use sites and representative of the use patterns.

Explanation of Some Table Descriptions:

"Proposed Application Rates" - Proposed application rates were provided by BEAD. According to the
information presented these are the maximum application rates proposed by the registrant. It should
be noted that these rates are not reflected on the current labels.

"Daily Maximum Acres Treated" - The estimated acres treated per day were based on the table provided
from the registrant and the information on farm size provided by BEAD, with the exception of acres/day
for chemigation which was estimated based on OREB's use information in conjunction with the
registrant's information. [According to BEAD (conversation with R. Michell, 7/14/95), the figures
presented by the registrant and the farm size information prepared by E. Mauer/BEAD (4/7/95) should
be used to assess worker exposure. OREB recommends that BEAD verifies the use informatioTTused
to conduct this exposure assessment to confirm that it is in accordance with usage and rate
modifications.]

&



UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

JUL 2 I 1995

EVALUATION OF THE MITIGATION MEASURES PROPOSED BY MILESJNC. IN
SUPPORT OF FENAMIPHOS (NEMACUR) REREGISTRATION DATA REQUIREMENTS

Barry O'Keefe, Chemical Manager

Special Review and Reregistration Division (7508W)

Laura E. Morris, Environmental Scientist

Larry C. Dorsey, Chiefs
Occupational and Resrajential Exposure'Brand
Health Effects Divisior/(7509C)

/-v:i	ui..

4/*>no/ nrv~


-------
/

2

"Unit Dermal Exposure" and "Unit Inhalation Exposure" based on surrogate exposure data from PHED
Version 1.1. There was high confidence in the data for all expoture scenarios except groundboom
application for enclosed cabs for which there is medium confidence in the data.

I Note: It was discussed at the Fenamiphos Team meeting, that ornamentals were not a
primary site of concern based on percent crop treated usage information,' and that the decision to
conduct an assessment on ornamentals would be based on poisoning incident data. According to
discussion with J. Blondell/OREB (5/1/95) [summary of incidents forwarded electronically 5/1/95 to B.
O'Keefe/SRRD and J. Smith/HED], from 1985 - 1991 there were a total of 7 cases reported from
California: In 1990, 29 of the 2,396 fenamiphos applications were on ornamentals, and the number of
reported incidents were low. In addition, from the 19 incidents reported from the poisoning center, it
could not be determined if any of the incidents were based on ornamental use. Based on this
information, an assessment was not conducted on ornamentals.]

Table 2. Summary of Exposure Values and Risk Calculations presents the daily dermal and
inhalation exposure calculations. In addition, the margins of exposure are indicated based on both the
estimated combined dermal and inhalation exposure and the NOEL of 0.5 mg/kg/day from Tox ll/HED.


-------
3

TABLE 1. SUMMARY EXPOSURE VALUES INCLUDING PROPOSED MITIGATION TECHNIQUES FOR FENAMIPHOS

Exposure
Scenario

Formulation

Application Type

Crops

Proposed
Application
Rate (lb
ai/acre)'

Daily
Maximum
Acres
Treated

Unit
Dermal
Exposure
(mg/lb ai)

Unit

Inhalation
Exposure
(ug/lb ai)

Open Mixing

Emulsifiable

Concentrates

Nemacur 3 EC

Open mixing
operations

citrus

7.5

200

0.041
0.022

"1.2

cotton

3.0

50

fruit trees
(peaches)

7.5

28

grapes

6.0

40

tobacco

6.0

50

turf

10

10

Closed Mixing

Emuisifiabie

Concentrates

Nemacur 3 EC

Closed mixing
operations

citrus

7.5

200

0.0091

0.08

cotton

3.0

50

fruit trees
(peach)

7.5

28

grapes

6.0

40

tobacco

6.0

50

turf

10

10


-------
Table 1. Summary Exposure Values Including Proposed Mitigation Techniques for Fenamiphos (continued)

Exposure
Scenario

Formulation

Application Type

Crops

Proposed
Application
Rate (lb ai/acre)

Daily
Maximum
Acres
Treated

Unit
Dermal
Exposure
(mg/lb ai)

Unit

Inhalation
Exposure
(ug/lb ai)

Open Mixing
for

Chemigation

Nemacur 3EC

Low Pressure

citrus

3.0

800**

0.041
0.022

1.2

fruit trees

28

grapes

40

turf

10.0

10

Closed Mixing
for

Chemigation

Nemacur 3EC

Low Pressure

citrus

3.0

800**

0.0091

0.08

fruit trees

28

grapes

40

turf

10.0

10

Open Mixing
Granuiars

15G
10G

All open mixing

cotton

3.0

50

0.0061
0.003?

1.7

turf

10.0

10

Closed Mixing
Granuiars

15G
10G



cotton

3.0

50

0.00011

0.034

turf

10.0

10


-------
Table 1. Summary Exposure Values Including Proposed Mitigation Techniques for Fenamiphos (continued)

Exposure
Scenario

Formulation

Application Type

Crops

Proposed
Application
Rate (lb ai/acre)

Daily

Maximum
Acres T-eatad

Unit
Dermal
Exposure
(mg/lb ai)

Unit

Inhalation
Exposure
(ug/lb ai)







Applicator Expos

sure







Groundboom
Application
open cab

Nemacur 3EC
15Q

Banding

citrus

7.5

200

0.011A

0.7

cotton

3.0

50

fruit trees

7.5

28

grapes

6.0

40

tobacco

6.0

50

turf

10

10

cotton

3.0

50

turf

10

10

Groundboom
Application
enclosed cab

Nemacur 3EC
15G

Banding

citrus

7.5

200

0.0071*

0.04

cotton

3.0

50

fruit trees

7.5

28

grapes

6.0

40

tobacco

6.0

50

turf

10

10

cotton

3.0

50

turf

10

10

1	PHED Clothing Scenario - workers wearing long sleeved shirts, long pants, and chemical resistant gloves.

1A Workers wearing long sleeved shirts, long pants, and no gloves.

2	PHED Clothing Scenario - workers wearing coveralls over long sleeved shirts, long pants, and chemical resistant gloves.


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TABLE 2. SUMMARY OF EXPOSURE VALUES AND RISK CALCULATIONS

Exposure
Scenario

Formulation

Application Type

Crops

Daily Dermal

Exposure

(mg/kg/day)

Daily
Inhalation
Exposure
(mg/kg/day)

MOE

(dermal
and

inhalation)

Open Mixing

Emulsifiable

Concentrates3

Nemacur 3 EC

Open mixing
operations

citrus

0.5

0.03

9.4*10 1

cotton

0.05

3.0* 10"3

9.43

fruit trees
(peaches)

0.07

4.2*10"3

6.74

grapes

0.08

4.8*103

5.9

tobacco

0.1

6.0* 10"3

4.72

turf

0.03

2.0* 10'3

94

Closed Mixing
Emulsifiable
Concentrates4

Nemacur 3 EC

Closed mixing
operations

citrus

0.225

0.002

2.20

cotton

0.022

2.0* 10"4

22

fruit trees
(peach)

0.032

2.8* 10"4

,15.7

grapes

0.036

3.2M0"4

13.8

tobacco

0.045

4.0* 10"4

11.1

turf

0.015

1.3*10-4

33.3


-------
Table 2. Summary of Exposure Values and Risk Calculations (continued)

Exposure
Scenario

Formulation

Application Type

Crops

Daily Dermal

Exposure

(mg/kg/day)

Daily

Inhalation
Exposure
(mg/kg/day)

MOE

(dermal

and

inhalation)

Open Mixing
for

Chemigation3

Nemacur 3EC

Low Pressure

citrus

0.8

0.048

5.89*10'

fruit trees

0.028

0.0017

16.7

grapes

0.04

0.0024

11.8

turf

0.033

0.002

14.2

Closed Mixing
for

Chemigation4

Nemacur 3EC

Low Pressure

citrus

0.36

0.0032

1.38

fruit trees

0.0126

1.1M0"4

39.4

grapes

0.018

1.6*10"*

27.5

turf

0.015

1.3M0"4

33

Open Mixing
Granuiars3

15G

All open mixing

cotton

0.0075

4.25*103

42.5

turf

0.005

2.83* 10"3

63.9

Closed Mixing
Granuiars4





cotton

0.00025

0.00085

1,515

turf

1.67M0-4

5.67*10"®

2,232


-------
Table 2. Summary of Exposure Values and Risk Calculations (continued) j

Exposure
Scenario

Formulation

Application Type

Crops

Daily
Dermal
Exposure
(mg/kg/day)

Daily
Inhalation
Exposure
(mg/kg/day)

MOE

(dermal

and

inhalation)





Appli

cator Exposure







Groundboom
Application
open cab6

Nemacur 3EC

Banding

citrus

0.25

0.0175

1.87

cotton

0.025

1.75*10"3

18.7

fruit trees

0.035

2.45 *10"3

13.4

grapes

0.04

0.0028

11.7

tobacco

0.05

0.0035

9.34

turf

0.0167

1 17,10-3

27.9

15G

cotton

0.025

1 75*10"3

18.7

turf

0.0167

1,17*10'3

27.9

Groundboom
Application
enclosed cab5

Nemacur 3EC

•

Banding

citrus

0.175

0.001

2.84

cotton

0.0175

0.0001

28.4

fruit trees

0.0245

0.00014

20

grapes

0.028

0.00016

17.7

tobacco

0.035

0.0002

14.2

turf

0.0117

6.67*105

29.2

15G

cotton

0.175

0.001

2.84

turf

0.012

6.67*10®

29.2


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9

Footnotes for Table 2. Summary of Exposure Values and Risk Calculations

3	Daily dermal expsosure values based on workers wearing coveralls over long sleeved shirts and long
pants, and chemical resistant gloves.

4	Daily dermal exposure values based on workers wearing long sleeved shirts, long pants, and chemical
resistant gloves.

6 Daily dermal exposure values based on workers wearing long sleeved shirts, long pants and no gloves.

Daily exposure {mg/kg/day) = [(Exposure (mg/lb ai) * Max. Application Rate (lb ai/aere) * Max.
Treated)/60 kg (body weight)!

MOE = NOEL/Exposure, NOEL = 0.50 mg/kg/day based on 21 day maternal toxicity study on rabbits.

CONCLUSIONS/RECOMMENDATIONS

Margins of Exposure were less than 100 for all exposure scenarios which the exception of
closed mixing/loading for granular formulations. The registrant has reduced the application rates, the
number of acres treated per day, and in some cases cancelled the use of the granular formulation on
some crops. Therefore, it is not probable that additional mitigation techniques would result in
acceptable MOEs. The registrant may want to consider providing dermal absorption data if the data
would demonstrate that absorption was significantly less than 100%.

Attachments (4)

cc: Laura Morris/OREB (w/Attachments)

Paula Deschamp/HED/7509C
Jane Smith/HED/7509C
Rich Michell/BEAD/7503W (w/Attachments)
Chemical File
Correspondence File

0)


-------
Attachment 1

Table 1. PROPOSED FENAMIPHOS RISK REDUCTION USE PROFILE17 (6/5/95 Draft)

CROP

FORMULATION

PESTS

PROPOSED
APPLICATION
RATE (LBS.
AI/A)2'

METHOD OF

APPLICATION

(TIMING)

COMMMENTS3'

CITRUS

3 EC

[Granular
proposed to
be cancel-
led]

Nematodes,
suppression
of Citrus
root weevil
complex
(including
Fuller rose
beetle)

2.5-5.0
(FL); 5.0-
7.5 (other
states)

Band & Inc.,
band width =
50% of row
spacing
(postplant)

PHI =30 days;
In CA, do not
apply to

Kumquat, Tangelo
or Citrus
hybrids; see
also Florida
limitations47;

Band: maximum
seasonal rate =
the maximum







1.5-3.0
(all
states)

Chemigation
[low pressure
irrigation]
(postplant)

application
rate; maximum of
2 applications
per season

Chemiaation:
seasonal limit =
3-6 lbs ai/acre
(FL= 3-4.5 lbs);
maximum of 4
applications/
season; RAI =30
days;

1


-------
CROP

FORMULATION

PESTS

PROPOSED
APPLICATION
RATE (LBS.
AI/A)2'

METHOD OF

APPLICATION

(TIMING)

COMMMENTS37

COTTON

3 EC

Nematodes,
Thrips

1.5-3.0
(4 0" rows)

18" Band Soil

Inject.

(preplant)

CA only; maximum
rate of 3 lbs
ai/A (any row
spacing)







0.75-2.2
(4 0" rows)

IF or covered
Band, or 6-12"
Band & Inc.
(at planting)

EC label also
recommends an at
planting tank
mix with Treflan



15G



1.0-1.5
(4 0" rows)

IF (at
planting)

applied as a 12-
18" band

FRUIT TREES
(PEACH)

3 EC

Nematodes

5.0-7.5

Band & Inc.,
band width
equal to 50%
of row spacing
(postplant);
incorporate
mechanically
or with
irrigation

PHI =45 days;
Band: 7.5 lbs
ai/A/year;
Chemicration: 1-4
applications per
season; 3-6 lbs
ai/A/season; RAI
= 3 0 days







1.5-3.0

Chemigation
[low pressure
irrigation]
(postplant)



I
m
D

7)



O

(D
3

(D

CO
(D

55"
(/>
co
a>

CO
o
55"

3
O
(D

7)



(D

co
oo
rvj
¦&.

"0

S)
CD
(D

O
<0

2


-------
CROP

FORMULATION

PESTS

PROPOSED
APPLICATION
RATE (LIS.
AI/A)2'

METHOD OP

APPLICATION

(TIMING)

COMMMENTS3'

GRAPES

3 EC

Nematodes

1.5-3.0

Chemigation
[low pressure
irrigation]
(postplant)

PHI = 2 days;
maximum of 6 lbs
ai/A/season;
Chemiaation: 1-4
applications/
season; 3-6 lbs
ai/A/season; RAI
=30 days

3.0-6.0

Band & Inc.,
band width =
50% of row
spacing
(postplant)

TOBACCO
(excludes
shade
tobacco)

3 EC

Nematodes,
suppression
of Aphids

4.0-6.0

Broadcast &
Inc.

(preplant)

label also
recommends two
tank mixes with
insecticides
(chlorpyrifos,
ethoprop)

TURF (Sod
farms, Golf
courses,
Cemeteries,
Industrial
grounds)

10G

Nematodes

10

Broadcast &
Inc. w/irri-
gation (post-
plant)

1-2 applications
per year; EC
formulation is
not recommended
for use on tees
and greens; Many
restrictions on
both formulat-
ions5'

TURF (Golf
courses, Sod
farms)

3 EC

Nematodes

10

Broadcast
(coarse spray)
k Inc. w/irri-
gation (post-
plant)


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Abbreviations: Inc. = Incorporate; IF = In-furrow; RAI = repeat application interval; PHI
= preharvest interval

1/ Reflects risk reduction proposals submitted by Miles, Inc. on 10/26/94 and amended by
their 1/6/95 letter.

2/ Where specific row spacings are listed for specific rates, these rates will vary
inversely with changes in the row spacing utilized. The row spacings listed were obtained
from the labels and documents published by one or more major production states and are
presumed to reflect commonly used row spacings. Preliminary estimates of overall seasonal
rates, calculated from national usage data (i.e., total pounds applied ¦*- total acres
treated, for each crop), are: Citrus = 6.2 lbs/A; Cotton = 0.75 lbs/A; Peaches = 11.5
lbs/A; Grapes = 1.3 lbs/A; Tobacco = 3.4 lbs/A; no information available on turf usage.

3/ The following general use restrictions apply to all labeled crops, except turf and
ornamentals: "When used on erodible soils, best management practices for minimizing
runoff should be employed. Consult your local Soil Conservation Service for
recommendations in your use area."; "Do not apply within 100 feet of the following aquatic
areas: lakes, resevoirs. rivers, permanent streams, marshes, natural ponds and
estuaries."; "Do not cultivate within 10 feet of an aquatic area to allow growth of a
vegetative filter strip,

II

4/ Florida Use Restrictions: a] "Apply between October 15 and April 30"; b] "Do not
apply within 300 ft. of a drinking water well. If soils have a permeability rate greater
than 20 inches per hour, do not apply within 1,000 ft of a drinking water well unless it
is known or reasonably believed based on authorative sources that such wells are either
cased to 100 ft below ground level or a minimum of 30 ft below the water table."

5/ Only for use on golf courses and sod farms in CA; Do not apply more than 20 lbs
ai/A/year; Do not treat more than 10 acres at a time on any golf course, with a 3-day
minimum interval before an additional 10 acres (or less) can be treated; Do not apply w/in
10' of any surface body of water or fairway surface drains; Do not apply between noon and
sunset during the heavy thunderstorm season (June thru September); On sod farms, treated
turf should not be cut for sod or sod handled for 30 days after treatment; Do not apply
product after soil has become saturated with water (reached field capacity); apply
irrigation only so that puddling or runoff does not occur; Irrigation must be completed
within 6 hours after treatment;

4


-------
•~'Att^dhment 2

[R. Michell 4/18/95]

SUMMARY OF PROPOSED USE-RELATED RISK MITIGATION LABELING CHANGES
FOR FENAMIPHOS (10/20/94 LABELING DRAFTS S 1/6/95 Latter)

ALL CROPS (Excluding Turf & Ornamentals) -

EC & 10G Formulations;

•	imposed, the restriction "When used on erodible soils,
best management practices for minimizing runoff should
be employed. Consult vour local Soil Conservation
Service for recommendations in vour use area,";

•	imposed the restriction "Do not apply within 100 feet
of the following aquatic areas: lakes, resevoirs.
rivers, permanent streams, marshes, natural ponds and
estuaries.";

•	imposed the restriction "Do not cultivate within 10
feet of an aguatic area to allow growth of a vegetative
filter strip."

band treatment	-*

•	lowered maximum application rate, in states other
than FL, from 10 to 7.5 lbs ai/A;

•	lowered the dosage range in FL from 5 to 10 to 2.5 to
5 lbs ai/A

•	lowered maximum seasonal rate, in states other than
FL, from 10 to 7.5 lbs ai/A/season;

•	imposed a restriction in FL prohibiting applications
within 300 to 1,000 ft of a drinking water well (see
label for precise language) ;

•	lowered the maximum seasonal rate, in FL, from 10 to
5 lbs ai/A/season.

chemiaation

•	lowered the maximum application rate, in all states,
from 4.5 to 3 lbs ai/A;	"

•	lowered the maximum number of applications, in all
states, from 6 to 4 per season;

•	increased the repeat application interval, in all
states, from 14 to 30 days;

•	lowered the seasonal dosage range, in states other
than FL, from 4.5 to 9 to 3 to 6 lbs ai/A/season;

•	lowered the seasonal dosage range, in FL, from 4.5 to
10 to 3 to 4.5 lbs ai/A/season;

•	imposed a restriction in FL prohibiting applications
within 300 to 1,000 ft of a drinking water well (see
label for precise language); .

•	imposed a limitation in FL that applications must be
made between October 15 and April 30.

15G Formulation;

CITRUS -

EC Formulation


-------
HED Records Center Series 361 Science Reviews - File R113824 - Page 15 of 19

• proposed to cancel (band treatment).

COTTON -

EC Formulation:

•	no changes proposed (in-furrow, covered or
incorporated band, and soil injection [band]
treatments).

15G Formulation:

•	no changes proposed (in-furrow treatment).

TOBACCO (excluding shade tobacco) -

EC Formulation:

•	no changes proposed (preplant broadcast treatment).

Granular Formulations:

•	not registered.

PEACHES -

EC Formulation:
band treatment -

•	changed dosage range from 5 to- 10 to 5 to 7.51bs
ai/A;

•	reduced maximum amount applied/year from 10 to 7.5
lbs ai/A/year;

chemigation treatment -

•	changed dosage range from 1.5 to 4.5 to 1.5 to 3 lbs
ai/A;

reduced the maximum no. of applications per season from
6 to 4;

•	increased the repeat application interval from 14 to
3 0 days;

•	lowered the minimum and maximum amounts applied per
season from 4.5 to 9 to 3 to 6 lbs ai/A/season.

Granular Formulations

•	not registered.

GRAPES -

EC Formulation:
band treatment -

2


-------


•	lowered the dosage rate from 3 gal/A to 1 to 2 gal/A;

•	lowered the maximum amount/season from 3 to 2 gal/A.

chemiaation treatment -

•	changed the dosage range from 1 qt to 1 gal to 2 qt
to 1 gal/A;

•	changed the total no. applications from one or more
to 1 to 4 applications;

•	added a 30 day minimum interval between repeat
applications.

Granular Formulations

•	not registered.

TURF -

EC & iog Formulations:
broadcast treatment -

•	imposed a 10 acre maximum treatment area on any golf
course with a 3-day minimum interval before an
additional 10 acres (or less) can be treated;

•	imposed a prohibition against applications within 10
ft, of any surface body of water or fairway surface
drain;

•	imposed a prohibition against applications being made
between noon and sunset during the heavy thunderstorm
season (June thru September);

•	delete claim for control of mole crickets.**

** Note: stated in their letter, but not reflected on labeling.

3


-------
Attachment 3

The following list reflects the average farm size by state and
'site. The'numbers in parentheses are estimates of the. relative
percentage of total US fenamiphos usage for each site. (E.
Maurer 4/7/95)

CITRUS:

CA - 35 acres (27)

FL - 108 acres (73)

, COTTON;

CA - 453 acres	(5)

NC - 176 acres	(4)

SC - 223 acres	(20)

TX - 322 acres	(71)

GRAPEVINES:

CA - 73 (99)

MI - 15 (1)

PEACHES: ¦

CA - 28 acres (34)

MI - 9 acres (33)

NC - 7 acres (33)

TOBACCOS

FL -	30 acres (1)

GA -	24 acres (19)

NC -	16 acres (58)

SC -	26 aicres (19)

VA -	7 acres (3)

GOLF COURSES:

CA - 125 acres	(5.9)

. FL - 128 acres	(8.0)

MI -134 acres	(6.1)

NY - 138 acres	(6.5)

OH - 136 acres	(6.0)


-------
Attachment 4

X

NEMACUR

MIXER/LOADER/APPLICATOR INFORMATION



UNIT

HR/DAY

HR/YR

NO. OF

A PPL TYPE (%)

ACRES/DAY

CROP



ML

A

ML

A

MLA

LPI

BAND

BCST

LPI

BAND

BCST

TOBACCO/NC

<25 A



6



12

2

0

0

100

0

0

12

NC

>100 A



8



24

1

0

0

100

0

0

35

NC

Custom



10



400

I

0

0

100

0

0

55

GA

100 A

1.3

10

2.6

20

2

0

35

65

0

50

50

rfTDtic/cf cr»
*L»»* i Ix U 0/*





1



2

1

80

0

0

200

0

0

FL-G





8



8

1

0

20

0

0

200

0

CA-EC





2-4



210-420

1(80%)

50

5b

0

6

6



COTTON



0.7

6

2.2

18

1-2

0

100

0

0

40-50

0

I PEANUT



0.7

6

2*2

18

1-2

0

100

0

0

40-50

0

1 GRAPE 1





8



24

1

85

15

0

80

40

0

1 2





1-3



13-39

1(80%)

95

5

0

20

1

0

I 3



/I

1/4

/112

332/414

1(90%)

85

15

0

34

18

0

CABBAGE





1-4



24-96

1(95%)

0

100

0

0 .

7

0

BftOCCOU





1-6



10-60

1(95%)

0

100

0

0

10

0

PINEAPPLE/HI





2-4



78-156

1(75%)

75

0

25

10

0

3

TURF





6

•

12-36

1(20%)

0

0

100

.0

0

3-8 EC



\









2(60%)











25-40 G


-------