Date :

S u b j ect : UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON

, D.C. 20460

March 28, 20 16 OF F IC E OF CHEM I CAL SAF E TY

AN D P O LLUTI O N PRE V ENTI O N

A l d i car b

. Occup a tional and Resid e ntial Expo s ure Assess m en t in Support of Regi s t ration Re v i ew.

P C Code: 09830 I DP Ba r co de: 0430949

D ec i sio n N o.: 498310 R eg i s t r at i o n No.: 48210 -1

P et iti o n No.: NA R eg ul a t ory Ac ti o n : R eg i s tr a tion

Review

Ri s k Assessmen t T y p e: Occupa ti o n al/Reside nti a l Ex po s ur e Assessmen t C ase No.: 70 1 6

TX R No.: NA CAS No.: 116-06-3

MR ID No.: 4385250 1 40 CF R : 180. 269

F rom:

Thr o u g h:

To :

In t r o du ct i o n Matth ew Ll oy d

, CIH, Indu s trial H yg i eniJt 

# j 

# D 

# f**~** 

# -fi7

Risk Assess ment Branch V ll

## ~ H ea lth Effect s Di v i s i on (7509 P )

1 

# J} J. 

# J /

Micha e l M e tzger

, C hi ef J } 

# J} ·

# ~V Risk Assess ment Bran c h VIJ 

# lf 

# l fl vl \. · H

ea lth Effec t s D iv i s i o n (7509 P )

and

Wade Britt on
, Indu s tri a l H yg i e ni s t
Josh Go d s h a ll

, Bi o l ogist;iEx p osu re Sc ienc e Advisory Co mmit e (ExpoSAC) I H E D

S ue B a rlo w, C h e mical Re v i ew Manager

Tom Myers, Te am Leader

Ri s k Mana ge ment a nd Imp leme nt a tion Br a nch II

P es ticid e R e- Evaluation Di v i s ion ( 7508P)

T h e P es ti c ide R e-eva l uation Di v i s ion ( PRO ) requ es ted that th e H ea lth Effects Di v i s i o n ( HED )

co nduct a n exposure a nd ri sk assess m e nt fo r the r eg i s t e r

e d u ses of a ldi ca rb as part of r eg i s tration

r ev i ew

. Thi s m e morandum co nt a ins H E D 's occ upati o n a l / r esidential expos ur e a nd ri s k

Page I of26

### assessment required during re gistration review to reflect the updated scie nce policies and procedures.

It 

### is HED polic y to use the best available data t o assess exposure. Seve r al sources of generic

d a ta were u se d in thi s assessment as s urro ga te da ta in the absence of chemical-specific data

, including Pesticide Handl e r s Exposure Databa se Version 1.1 ( PI-!ED 1.1 ) ; th e Agricultural

Handl e r Exposure Ta s k Force (AHETF) database; o ther r eg istrant- s ubmitted ex po s ure monitoring studies (M RID 4385250 I)

. Some or these data are proprietary

, and s ubj ec t to th e data protection provisions of the Federal Insecticide

, Fun g icid e, and Rodenticide Act (FIFRA).

Note: 

### This memorandum was reviewed by the Exposu r e Sc i ence Advisory Committee (Ex po SAC) on 06 1 04 11 5.

Pa ge 2 of26Page 3 of 26 

### Table of Contents

1.0 Executive Summary

................................ ................................ ................................ ............. 4

2.0 Risk Assessment Conclusions and Recommendations

................................ ........................ 6

2.1 Summary of Risk Estimates

................................ ................................ ............................. 6

3.0 Hazard Characterization

................................ ................................ ................................ ....... 6

4.0 Use Profile

................................ ................................ ................................ ........................... 9

5.0 Residential Exposure and Risk Estimates

................................ ................................ .......... 12

6.0 Non

- Occupational Spray Drift Exposure and Risk Estimates

................................ ................ 12

7.0 Non

- Occupational Bystander Post

- Application In halation Exposure and Risk Estimates

..... 12

8.0 Occupational Exposure and Risk Estimates

................................ ................................ ...... 13

8.1 Occupational Handler Exposure/Risk Estimates

................................ ............................ 13

9.2 Occupational Post

- application Exposure/Risk Estimates

................................ .............. 19

9.2.1 Occupational Post

- application Inhalation Exposure/Risk Estimates

...................... 19

9.2.2 Occupational Post

- application Dermal Exposure/Risk Estimates

.......................... 20 Appendix A. Summary of Occupational and Residential Non

- cancer Algorithms

..................... 21 Appendix B. Summary of Available Occupational Handler Exposure Data

............................... 24Page 4 of 26



### 1.0 Executive Summary

The H ealth Effects Division (HED) has conducted an exposure and risk assessment for the registered uses of aldicarb as part of registration review. This memorandum contains HED’s occupational/residential exposure and risk assessment required during registration review to reflect the updated science policies and procedures.

Aldicarb [ 2

- methyl

- 2

- (methylthio)propanal O

- [(methylamino)carbonyl]oxime ] is a carbamate insecticide that is marketed only as a granular product (with either low

- dust corn cob grit or vinyl

- c oated gypsum

- based substrates ) with a concentration of 15 percent active ingredient. Aldicarb is used to control soil borne pests including mites, various insects, and nematodes on dry beans, sugar beets, cotton, peanut, sweet potato, and soybean.

The labe l

- required Personal Protective Equipment (PPE) varies depending on the handling scenario & packaging of the formulation (i

. e., substrate of the granular formulation) . For open pour handling, the PPE is coveralls over a long

- sleeved shirt and long pants, ch emical

- resistant gloves made of any waterproof material, and chemical

- resistant footwear plus socks. In addition, during loading, equipment cleaning or repair, or spill clean

- up, the labeling requires handlers to wear protective eyewear (goggles or face sh ield), a chemical

- resistant apron, and a NIOSH

approved respirator with a dust/mist filter. The exception to the above PPE requirements are when engineering controls (i.e., a closed loading /application system) are used. The restricted entry interval (REI) on the current labeling is 48 hours.

In acute lethality studies, aldicarb is highly toxic via the oral, dermal, and inhalation routes of exposure (Toxicity Category 1). It is not a dermal sensitizer, but due to severe effects (death) following corneal and dermal dosing, dermal and eye irritation studies were waived. Aldicarb toxicity studies have demonstrated cholinesterase inhibition (ChEI) activity in whole blood, plasma, red blood cells (RBC) and brain of rats, mice, and dogs following acute, subchronic , and chronic exposures and in plasma and RBC in humans following acute exposure. The toxicological endpoints selected for the dermal and inhalation routes of exposure w ere based on a common toxic effect ( RBC ChEI ) from an inten tional dosing human oral study 1 

### ; therefore, these routes were combined for the occupational exposure and risk assessment. For the occupational risk assessment, the level of concern (LOC) is for Margins of Exposure (MOEs) less than 10.

There are no currently registered residentia l uses . The potential for spray drift exposure is considered negligible because of the aldicarb product formulation (granular) and immediate soil incorporation of the product

.

There is potential for occupational handler exposure. The occupational asses sments were completed based on an available chemical

- specific occupational exposure monitoring study 2


### (used to assess the use of PPE during open pour/open cab applications) and based on surrogate data [ i.e., the Pesticide Handlers Exposure Database (PHED); used to assess the use of

1 Ethics Review Available: at http://www.epa.gov/osa/hsrb/files/april2006mtgfinalreport62606.pdf

2 Worker Loader and Applicator Exposure to Temik 15G (10/12/95) Sponsor: Rhone Poulenc Ag Company, 2 TW Alexander Drive, Research Triangle Park NC 27709 (EPA MRID 438525

- 01)Page 5 of 26



### engineeri ng controls during applications]

. Occupational handlers are assessed assuming short

and intermediate

- term dermal and inhalation exposure. There is no quantitative post

- application

assessment based on the limited exposur e potential since aldicarb is soil incorporated

.

For the open pour/open cab application scenarios, using chemical

- specific unit exposure data and assuming use of label required PPE (i.e., a double layer of clothing and a standard filtering facepiece respi rator) , there are combined dermal and inhalation risk estimates of concern (i.e., MOEs are < 10) for two scenarios. Mixer/loader risk estimates are of concern for the use on sugar beets at 4.95 lb ai/A (MOE = 4.5) and 3 lb ai/A (MOE = 7.4). For the closed loading/closed cab application scenarios (i.e., engineering controls) , using available surrogate unit exposure data for engineering controls, all combined dermal and inhalation risk estimates are of concern (i.e., MOEs ≤ 10)

.

The registered aldicarb granular product, which has either a low

- dust corn cob grit or viny l

coated gypsum

- based substrate, is considered a low

- dust formulation relative to the available surrogate unit exposure data from PHED ( which is based on clay

- based substrate granular

formulation s ). Exposure and risk estimates for handlers using the closed loading scenarios may be considered overestimates as the PHED surrogate unit exposures are based on granular

formulation s which are “ dustier” than the low

- dust form ulations such as the aldicarb products (low

- dust corn cob grit and vinyl

- coated gypsum based substrates).

Based on the Agency's current practices, a quantitative non

- cancer occupational post

- application inhalation exposure assessment was not performed for aldicarb at this time. If new policies or procedures are put into place, the Agency may revisit the need for a quantitative occupational

post

- application inhalation exposure assessment for aldicarb

.

Human Studies Review

An inten tional dosing human oral study was used for selection of points of departure in prior risk

assessment s . This study has been review ed by EPA’s HSRB, as required by EPA’s Human Subjects Protections Rule (40 CFR part 26 (effective April 7, 2006)). The HSRB discussed the study extensively during a meeting held on April 2

- 4, 2006 and concluded that the cholinesterase

data from the aldic arb human study were reliable for use in the aldicarb single chemical

aggregate r isk assessment. Additionally, it was concluded that there was no clear and convincing evidence of significant deficiencies in the ethical procedures that could have resulted in serious harm (based on the knowledge available at the time the study was conducted), nor that information provided to participants seriously impaired their informed consent. The final report

of the HSRB is available at http://www.epa.gov/osa/hsrb/files/april2006mtgfinalreport62606.pdf

.

The PHED has been reviewed from an ethics perspective and no issues were found which would preclude its us e in the risk assessment process. The chemical

- specific study (MRID 43852501) was also reviewed for ethical requirements pertaining to the usability of data andPage 6 of 26



### found to be acceptable for risk assessment. 3 

### Descriptions of data sources, as well as guidanc e on their use, can be found at the Agency website 4



### .

2.0 Risk Assessment Conclusions and Recommendations

There are occupational handler risk estimates of concern for several scenarios, depending on the application equipment/formulation combination , inc luding both the open pour /open cab and closed loading /closed cab systems.

There is no aldicarb chemical

- specific data for closed loading systems (i.e., engineering controls) ; therefore

, HED used surrogate unit exposure values from PHED to quantitatively calculate risk estimates for closed loading systems. Risk estimates for closed loading systems are of concern (MOEs< the LOC of 10) for both loading and applicator handler scenarios. However,

e xposure and risk estimates for handlers using the closed loading scenarios may be considered overestimates as the PHED surrogate unit exposures are based on a clay

- based substrate granular

formulation which is “ dustier” than low

- dust formulations such as t he aldicarb products (low

dust corn cob grit and vinyl

- coated gypsum based substrates).

There is no quantitative risk assessment for residential exposure because there are no registered

residential uses . In addition, there is no quantitative spray drift a ssessment based on the granular formulation type and the soil incorporation

. There are no exposure data requirements for

aldicarb

.

2.1 Summary of Risk Estimates

The following summarizes the occupational handler risk estimates based on the available toxicity and exposure data.

Open Mixing/Loading and Open

- cab Application Using Label

- specified PPE:

 Mixer/loader scenarios (using chemical

- specific data) :

o Sugar beets at 3 & 4.95 lbs ai/A (MOEs = 7.4 and 4.5, respectively)

Closed Mixing/Loading and Closed

- cab Application (i.e., engineering controls):

 Mixer/loader scenarios (using surrogate exposure data) :

o All scenarios (total MOE ranges from 0.12 to 0.99 based on a LO C of 10)

 Applicator scenarios (using surrogate exposure data):

o All scenarios (total MOEs ranges from <1 to 3.9 based on a LOC of 10)

3 .0 Hazard Characterization

Aldicarb has a n adequate toxicity database to conduct human health risk assessment.

Acute Toxicity

3 HSRB Report: http://www.epa.gov/osainter/hsrb/files/meeting

- materials/apr

- 4

- 6

- 2 006

- public

meeting/april2006mtgfinalreport62606.pdf

4 http://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/occup ational

- pesticide

- handler

- exposure

- dataPage 7 of 26



### In acute lethality studies, aldicarb is highly toxic via the oral, dermal, and inhalation routes of exposure (Toxicity Category 1). It is not a dermal sensitizer, but due to severe effects (death) following corneal and dermal dosing, dermal and eye irritation studies were waived.

Table 3.0.1 Acute Toxicity Profile

– Aldicarb

.

Guideline No. Study Type MRID(s) Results Toxicity Category

870.1100 Acute oral

- Rat 00057333 LD 50 = 0.8 mg/kg/day I

870.1200 Acute dermal

-

Rat 00091241

00069916 LD 50 = 20 mg/kg/day, water

LD 50 = 5 mg/kg, propylene glycol I

870.1300 Acute inhalation

-

Rat 00069916

00057333 LC 50 < 0.007 mg/L I

870.2400 Acute eye

irritation

- Rabbit 00069916 No corneal irritation at lethal dose N/A

870.2500 Acute dermal

irritation

- Rabbit 00069916 None at fatal levels N/A

870.2600 Skin sensitization

- Guinea Pig N/A N/A N/A



### Toxicological Points of Departure ( PODs ) Used for Risk Assessment

Aldicarb toxicity studies have demonstrated inhibition of cholinesterase activity in whole blood, plasma, red blood cells (RBC) and brain of rats, mice, and dogs following acute, subchronic , and chronic exposures and in plasma and RBC in humans following acute exposure. It should be

noted that aldicarb

- induced ChEI has been shown to be reversible in less than 24 hours. Both the acute and subchronic rat neurotoxicity studies show a variety of typical clinical signs of ChEI after oral exposures to aldicarb, including decreased motor activity, lacrimation, tremors, salivation, pinpoint pupils, and decreased grip strength. Aldicarb did not result in developmental toxicity in either rats or rab bits or in reproductive effects in the rat multi

- generation reproduction study. Additionally, there was no developmental toxicity in the developmental neurotoxicity study in rats.

In an acute oral study conducted in human volunteers, aldicarb treatment of both males and females resulted in statistically significant inhibition of both RBC and plasma cholinesterase. The results of the acute oral human study suggest a two

- fold difference between animals and

humans with respect to toxic responses following acute exposure to aldicarb, with human being the more sensitive species. HED selected a Benchmark Dose Level ( BMDL 10 

### ) as a point of departure for the dermal and inhalation routes of exposure [0.013 mg/kg/day] based on RBC

ChEI

.

Th e human study was reviewed by the Human Studies Review Board (HSRB), who concluded that use of the human study endpoint was appropriate for human health risk assessment. Because

these human data are considered reliable , and the study is considered scie ntifically valid, at thisPage 8 of 26



### time the Agency considers the human study to be the most suitable for the single

- chemical risk

assessment.

The specific toxic effect ( cholinesterase inhibition ) is common to the dermal, and inhalation routes; therefore, these ro utes can be combined for risk assessment.

For the occupational risk assessments, the level of concern (LOC) is for MOEs less than 10. The

LOC is based on a 10X for intra

- species, and a 1X for interspecies (reduced from 10X) because the endpoint is derive d from a human study.

Aldicarb is classified as not likely to be carcinogenic to humans, based on the lack of evidence of carcinogenicity in studies in rats and mice and the absence of a mutagenicity concern. Therefore, an exposure assessment for cancer risk assessment is not required.

Table 3.0.2 . Summary of Toxicological Doses and Endpoints for Aldicarb for Use in Risk Assessments

.

Exposure

Scenario Point of

Departure Uncertainty/

FQPA Safety

Factors 1 Level of

Concern for

Risk

Assessment Study and Toxicological Effects

Dermal Exposures (Short

- and

Intermediate

- Term) BMDL 10 = 0.013

mg/kg /day

DAF = 100% UF H = 10

UF A = 1x LOC for

MOE = 10X Human oral study

MRIDs 43829602, 45068601, 43442302, 43442305, 42373001

BMD 10 = 0.02 mg/kg, based on

RBC cholinesterase inhibition

Inhalation Exposures (Short

and Intermediate

Term) BMDL 10 = 0.013

mg/kg /day UF H = 10

UF A = 1x LOC for

MOE = 10X Human oral study

MRIDs 43829602, 45068601, 43442302, 43442305, 42373001

BMD 10 = 0.02 mg/kg, based on

RBC cholinesterase inhibition

Cancer Classification: Aldicarb is classified as Category E, Evidence of Non

- Carcinogenicity

for Humans

, based on the lack of evidence of carcinogenicity in studies in rats and mice and the absence of a mutagenicity concern.
Point of Departure (POD) = A data point or an estimated point that is derived from observed dose

- response data and used to

mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UF H = potential

variation in sensitivity among members of the human population (intraspecies). UF A = extrapolation from animal to human (interspecies); to human is not warranted due to the PoD based on human RBC cholinesterase data

. BMDL 10 = Benchmark Dose estimate based on the lower 95% confidence interval where 10% ChEI would be observed. MOE = margin of exposure. LOC =

level of concern.



### Absorption Since no inhalation absorption data are available, toxicity by the inhalation route is considered to be equivalent to the estimated toxicity by the oral route of exposure. No acceptable dermal absorption study was submitted, therefore a default value of 100 percent dermal absorption factor

was used to estimate dose. Given that aldicarb is h andled only as a granular, it is unlikely that 100 percent absorption would occur; however, the exact absorption factor could not be determined from the available toxicological studies.

Body WeightPage 9 of 26



### The standard body weight for the general population (80 k g) was used for all exposure scenarios

for adults covered in this risk assessment since the endpoints selected were not developmental

and/or fetal effects.

4 .0 Use Profile

Aldicarb is a broad spectrum insecticide and is currently registered as a granu lar formulation that is only applied via soil incorporation (EPA Reg. #87895

- 1)

. It is registered for use on a number of agricultural crops via ground

- based application equipment. Table 4.1 provides additional detail on the registered use sites.

The regi stered product is classified as a Restricted Use Pesticide (RUP) and may be purchased and used only by certified applicators or persons under their direct supervision. As a n RUP the

aldicarb product labels contain substantial protective meas ures to prevent worker exposure.

Aldicarb handlers must use either :

 Engineering Controls (i.e., a closed loading system), or

 a minimum of coveralls over a long

- sleeved shirt and long pants, chemical

- resistant gloves made of any waterproof material, and chemical

- resistant footwear plus socks. In addition, during loading, equipment cleaning or repair, or spill clean

- up, handlers must wear protective eyewear (goggles or face shield), a chemical

- resistant apron, and a

NIOSH

- approved respirator with a dust/mi st filter with the MSHA/NIOSH approval number prefix TC

- 21C or any N, R, P or HE filter.

The available product label indicate s that the product can be used generally once or twice per growing season ( pre

- plant or pre

- plant plus early post

- emergence ), depe nding on the pest to be treated. The intended pests for the maximum application rates are generally nematodes , and the

lesser rates for mites, thrips, mexican bean beetles, and other pests.

Table 4.1 provides a summary of the pests and directions per use for each target crop.Page 10 of 26

Table 4 .1. Summary of Directions for Use of Aldicarb

.

Applic. Equip. Formulation

[EPA Reg. No.] Applic. Rate (lb ai/A) Max. No. Applic. per Season Max. Seasonal

Applic. Rate (lb ai/A) PHI

(days) Use Directions and Limitations

Dry Bean

Motorized

Ground Equipment 15% ai granular

87895

- 1 2.1

[nematodes] 1

2.1 90  Apply granules in seed furrow & immediately cover with soil by mechanical means.

 FOR USE ONLY IN: Colorado, Oregon, Washington, Idaho, & Michigan 1.05

[aphids] 1

0.75

[seedcorn maggot] 1

Sugar Beet

Motorized

Ground Equipment 15% ai granular

87895

- 1 4.95

[nematodes] 1 at planting

application & 2 post

emergence applications 4.2 in California

4.95 in other

states 90  Apply granules in a 4 to 6 inch band and immediately cover w/ soil by mechanical means.

 Plant seed into or above treated zone

 FOR USE ONLY IN: California, Colorado, Idaho, Montana

, Nebraska, Oregon, Washington and Wyoming.

3

[leafminers leafhoppers]  Drill granules 1 to 3 in. below seedline. Granules can be placed in seed furrow if rate does not exceed 1.05 lb ai/acre. 2.1

[aphids]

Cotton

Motorized

Ground Equipment 15% ai granular

87895

- 1 1.05

[nematodes]

1 (at

- plant)

1 (post

emergence) 3.15 90  Max single application rate

 Apply granules in the seed furrow and immediately cover with soil by mechanical means.

0.75

[aphids/thrips] 90  Apply granules in the seed furrow and immediately cover with soil by mechanical means.

2.1

[side dress applications] 90  Max single rate for side dress applications

 Apply granules in the seed furrow and immediately cover with soil by mechanical means.

Peanut

Motorized

Ground Equipment 15% ai granular

87895

- 1 1.5 (post

- emergent rate; split application) 2.55 90  Do not make more than one application per crop per year in states other than Alabama, Florida, Georgia, North Carolina, Oklahoma, Texas & Virgin ia.Page 11 of 26

Table 4 .1. Summary of Directions for Use of Aldicarb

.

Applic. Equip. Formulation

[EPA Reg. No.] Applic. Rate (lb ai/A) Max. No. Applic. per Season Max. Seasonal

Applic. Rate (lb ai/A) PHI

(days) Use Directions and Limitations

[nematodes /post

pegging]  Apply granules in seed furrow & immediately cover w/ soil by

mechanical means.

 Post

- emergence applications are permitted only in fields where overhead irrigation is available.

1.05

[nematodes /thrips] At

- planting  Do not make more than one application per crop per year in states other than Alabama, Florida, Georgia, North Carolina, Oklahoma, Texas & Virginia.

 Apply granules in seed furrow & immediately cover w/ soil by

mechanical means.

Sweet Potato

Motorized

Ground Equipment 15% ai granular

87895

- 1 3

[nematodes/high rate] Pre

- plant or at

plant 3 120  For use only in Louisiana and Mississippi.

 Apply granules in a 12

- in. band over open furrow or soil surface and cover immediately during bed forming by mechanically hilling up 8 to 10 inches. 1.5

[nematodes/lower
rate]

Soybean

Motorized

Ground Equipment 15% ai granular

87895

- 1 1.05

[mexican bean beetle /thrips] 1 application

/per crop /per

year 1.05

90  FOR USE ONLY IN:

Georgia, North Carolina, South Carolina, & Virginia

 Apply granules in seed furrow and immediately cover with soil by mechanical means. 0.75

[nematodes /thrips] 0.75Page 12 of 26



### 5 .0 Residential Exposure and Risk Estimates

A quantitative residential assessment was not conducted b ecause a ldicarb is a n RUP and there

are no currently registered non

- occupational (residential) uses.

6.0 Non

- Occupational Spray Drift Exposure and Risk Estimates

Off

- target movement of pesticides can occur via many types of pathways and it is governed by a variety of factors. However, the a ldicarb end use product is formulated as a granular and will not result in spray drift because of how it is applied ( pre

- plant /post

- emergent soil incorporation)

.

7.0 Non

- Occupational Bystander Post

- Application Inhalation Exposure and Risk Estimates

There is an available air monitoring stud y 5 

### conducted in California by the California Air Resources Board (CARB)

. The report presents the results of application air monitoring ( in

Fresno County ) and ambient air monitoring ( in Fresno and Kern Counties )

.

Application site air monitoring (i.e., also known as field volatility) refers to the collection of air samples around the edges of a treated field during and after a pesticide application. Samples are generally collected for short intervals (e.g., < 8 hours), for at least the first day or two after application with subsequent samples increasing in duration. In th is type of study, it is typically known when an application occurred, the equipment used for the application, and the application rate. Application site monitoring data represents an exposure to vapors at or near the field edge resulting from an applicati on.

Ambient air monitoring typically is focused on characterizing the airborne pesticide levels within a localized airshed or community structure of some definition (e.g., city, township, or municipality). This type of monitoring effort also can be focus ed on capturing chronic background levels or other temporal characteristics of interest such as focusing on seasonal pesticide use patterns. Typically, samples are generally taken for 24 consecutive hours and collected at the same site over an extended pe riod of time (e.g., several weeks or months). In contrast to application site air monitoring, information on the precise timing and location of pesticide applications are rarely collected in ambient air monitoring studies. However, this does

not mean tha t an application did not occur near an ambient sampler during the monitoring period.

Two application studies were conducted in Fresno County ; however, d ue to problems with the first study, which was associated with cotton planting, a second study was cond ucted which was

associated with cotton “at first squaring.” First squaring refers to a process of manual weed control (tilling) during which the insecticide is applied to the cotton row berms

. Of the twenty application samples collected during the first s tudy, two were found to be detected ( meaning

r esults were below the limit of quantitation but equal to or above the limit of detection ) and the remaining 18 were less than the limit of detection ( LOD ) of 0.050 ug/ sample. For the second

5 Report for the Application and Ambient Air Monitoring of Aldicarb. California Environmental Protection Agency Air Resources Board. November 16, 1998. http://www.cdpr.ca.gov/docs/emon/pubs/tac/tacpdfs/aldicarb.pd fPage 13 of 26



### application study, all four background samples had results less than the LOD. Of the twenty

- four application samples collected

, all were found to be less than the LOD of 0.050 ug/s ample.

Ambient monitoring was initially conducted during a three week period from March 24 to April 11, 1997 in Fresno County. The monitoring was scheduled to coincide with cotton planting and the aldicarb samplers were collocated with samplers being used for an ambient phorate air monitoring study. No detectable levels of aldicarb were observed du ring the first three weeks of monitoring in Fresno County and so the remaining 3 weeks of monitoring was conducted in June in Kern County. Of the 60 ambient samples collected in Fresno County and the 55 collected in Kern County, all were found to be less than the LOD of 0.050 ug/ sample.

8 .0 Occupational Exposure and Risk Estimates

8 .1 Occupational Handler Exposure/Risk Estimates

HED uses the term handlers to describe those individuals who are involved in the pesticide application process. HED believes that there are distinct job functions or tasks related to applications and exposures can vary depending on the specifics of each task. Job requirements (amount of chemical used in each application), the kinds of equipment used, the target being treated, a nd the level of protection used by a handler can cause exposure levels to differ in a manner specific to each application event.

Based on the anticipated use patterns and current labeling, types of equipment and techniques that can potentially be used, occupational handler exposure is expected from the proposed uses. The quantitative exposure/risk assessment developed for occupational handlers is based on the occupational handler crop scenarios (and application rates) identified in Section 4.0

.

Occupational Handler Exposure Data and Assumptions

A series of assumptions and exposure factors served as the basis for completing the occupational handler risk assessments. Each assumption and factor is detailed below on an individual basis.

Unit Exposures: It is the policy of HED to use the best available data to assess handler exposure. For this assessment, two main sources of data were used:

 The first source of data was a c hemical

- specific study (MRID 43852501 6 

### ) that collected occupational han dler dermal and inhalation exposure data representative of the registered

“low dust” formulation

. A summary of the study data as collected is included in Appendix B. A dditional details on the study description and specifics of the data can be found in a p revious assessment (Memo, J. Dawson, D311821, 1/11/15). F or scenarios representing open loading and open cab application of low dust corn cob granules, unit exposure data from the chemical

- specific study were used. It should be noted that the study was c onducted without handlers wearing a respirator; however, the currently registered label requires handler s wear a respirator. Therefore, the inhalation unit exposures were adjusted to account for current label PPE (i

. e
., filtering facepiece

6 EPA MRID 43852501 : Rosenheck, L., Schuster, L. (1995) Worker Loader and Applicator Exposure to Temik 15G. Study

number 94388 , Unpublished study prepared by ABC Laboratories, Pan

- Ag Division; Rhone

- Poulenc Ag Company.Page 14 of 26



### respirator) [i. e., an 80% assumed reduction from the inhalation unit exposure).

 

### T he second source of data includes gene ric handler data

. The standard values recommended for use in predicting handler exposure that are used in this assessment, known as “unit exposures”, ar e outlined in the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table”, which, along with additional information on HED policy on use of surrogate data, including descriptions of the various sources, can be found at the Agency website 7



### . These data were used to assess scenarios representative of

c losed loading systems (engineering controls).

Area Treated or Amount Handled : Based on HED ExpoSAC Policy 9.1, Table 8 .1 .1 identifies the amount treated or handled per day per registered use site :

Table 8.1.1

– Area Treated or Amount Handled

. Equipment Type Area Treated/Amount Handled Crop / Use Site

Groundboom Equipment 80 acres for typical

- acreage field

crops  Sweet potatoes

200 acres for high acreage field

crops  Dry beans

 Sugar beets

 Cotton

 Peanuts (pre

- plant/at

- plant)

 Soybean



### Exposure Duration: HED classifies exposures from 1 to 30 days as short

- term and exposures 30 days to six months

as intermediate

- term. Exposure duration is determined by many things, including the exposed population, the use site, the pest pressure triggering the use of the pesticide, and the cultural practices surrounding that use site. For most agricultural uses, it is reasonable to believe that occupational handlers will not apply the same chemical ever y day for more than a one

- month time frame; however, there may be a large agribusiness and/or commercial applicators who may apply a product over a period of weeks (e.g., completing multiple applications for multiple clients within a region). Therefore, t his document includes an occupational exposure assessment

consistent with the short

- and intermediate

- term exposure durations discussed above.

Personal Protective Equipment: Estimates of dermal and inhalation exposure were calculated

for various levels of personal protective equipment (PPE). Results are presented for loaders and applicators based on the personal protective equipment identified on the label:

 Baseline, plus chemical

- resistant gloves and coveralls with a PF5 respiratory protection

device o r

 Engineering controls (closed loading system or closed cab )

.

Occupational Handler Non

- Cancer Exposure and Risk Estimate Equations The algorithms used to estimate non

- cancer exposure and dose for occupational handlers can be found in Appendix A

.

7 http://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/occupational

- pesticide

- handler

- exposure

- dataPage 15 of 26



### Combinin g Exposures/ Risk Estimates : Dermal and inhalation risk estimates were combined in this assessment, since the toxicological effects for these exposure routes were similar. Dermal and inhalation risk estimates were combined using the following formula:

Total MOE = Point of Departure (mg/kg/day) ÷ Combined dermal + inhalation dose (mg/kg/day)



### Summary of Occupational Handler Non

- Cancer Exposure and Risk Estimates

Occupational handler risk estimates are presented using both HED’s standard occupational exposure methodology and the available chemical

- /scenario

- specific handler data , where

available

.

Table 8.1.2 shows loader and applicator risk estimates assuming label

- specified PPE [open loading scenarios] using the available chemi cal

- specific handler data (occupational handlers with PPE)

. Table 8

. 1 .3 shows loader and applicator risk estimates assuming engineering controls (i.e. closed loading systems) are used (based on the PHED surrogate unit exposure data).

Where risk concerns exist, the combined risk estimates are driven by dermal exposure

. It should be noted that an assumption of 100% dermal absorption was used in the dermal exposure/risk calculations since an acceptable dermal absorption study was not submitted. Given that the registered product is a granular formulation, it is unlikely that 100% absorption would occur.

The following r isk estimates of concern were identified (and are noted in bold in the tables) :

Open Mixing/Loading and Open

- cab Application Using Label

- specified PPE:

 Mixer/loader scenarios (using chemical

- specific data) :

o Sugar beets at 3 & 4.95 lbs ai/A (MOEs = 7.4 and 5, respectively)

Closed Mixing/Loading and Closed

- cab Application (i.e., engineering controls):

 Mixer/loader scenarios (using surr ogate exposure data) :

o All scenarios (total MOE ranges from 0.12 to 0.99 based on a LOC of 10)

 Applicator scenarios (using surrogate exposure data):

o All scenarios (total MOEs ranges from <1 to 3.9 based on a LOC of 10)Page 16 of 26

Table 8 .1. 2

. Occupational Handler Non

- Cancer Exposure and Risk Estimates for Aldicarb

. Open Pour/Open Cab Application Using Label

- Required PPE (Double layer of clothing and PF5 Respirator) Using Chemical

- Specific Data.

Crop or Target Dermal Unit Exposure (μg/lb ai) 1

[Level of PP E] Inhalation Unit

Exposure (μg/lb ai) 1

[Level of PPE] Maximum

Application Rate (lb ai/A) 2 Area

Treated Daily (Acres) 3 Dermal Inhalation Total

Dose (mg/kg/day) 4 MOE

(LOC = 10) 5 Dose

(mg/kg/day) 6 MOE

(LOC = 10) 7 MOE

(LOC = 10) 8

Mixer/Loader (Load Granules

– tractor drawn spreader)

Sweet potato [e.g., nematodes]

0.22

[DL/G] 0.0 14

[PF5] 3 80 0.00066 20 0.000042 310 19

1.5 0.00033 39 0.000021 620 37

Sugar beet [e.g. nematodes] 4.95

200 0.00273 4.8 0.000174 75 4.5

Sugar beet [ leafminers/leafhoppers] 3 0.00165 7.9 0.000105 120 7.4

Dry bean [nematodes] ; Sugar beet [aphids] ; Cotton [side

- dress applications] 2.1 0.00116 11 0.0000735 180 10

Peanut [nematodes /post

- pegging] 1.5 0.000825 16 0.0000525 250 15

Dry bean [aphids]; Cotton [nematodes]; Peanuts [nematodes/thrips]; Soybean [mexican bean beetle/thrips] 1.05 0.000578 22 0.0000368 350 21

Dry bean [seedcorn maggot]; Cotton [aphids/thrips]; Soybean [nematodes/thrips] 0.75 0.000413 31 0.0000263 490 29

Applicator (granules

– tractor

- drawn spreader)

Sweet potato [e.g., nematodes]

0.089

[DL/G] 0.0 026

[PF5] 3 80 0.000268 49 0.0000078 1700 48

1.5 0.000134 97 0.0000039 3300 94

Sugar beet [e.g. nematodes] 4.95

200 0.0011 12 0.0000321 400 12

Sugar beet [leafminers/leafhoppers] 3 0.000668 19 0.0000195 670 18

Dry bean [nematodes] ; Sugar beet [aphids] ; Cotton [side

- dress applications] 2.1 0.000468 28 0.0000136 960 27

Peanut [nematodes /post

- pegging] 1.5 0.000334 39 0.00000975 1300 38

Dry bean [aphids]; Cotton [nematodes]; Peanuts [nematodes/thrips]; Soybean 1.05 0.000234 56 0.00000683 1900 54Page 17 of 26

Table 8 .1. 2

. Occupational Handler Non

- Cancer Exposure and Risk Estimates for Aldicarb

. Open Pour/Open Cab Application Using Label

- Required PPE (Double layer of clothing and PF5 Respirator) Using Chemical

- Specific Data.

Crop or Target Dermal Unit Exposure (μg/lb ai) 1

[Level of PP E] Inhalation Unit

Exposure (μg/lb ai) 1

[Level of PPE] Maximum

Application Rate (lb ai/A) 2 Area

Treated Daily (Acres) 3 Dermal Inhalation Total

Dose (mg/kg/day) 4 MOE

(LOC = 10) 5 Dose

(mg/kg/day) 6 MOE

(LOC = 10) 7 MOE

(LOC = 10) 8

[mexican bean beetle/thrips]

Dry bean [seedcorn maggot]; Cotton [aphids/thrips]; Soybean [nematodes/thrips] 0.75 0.000168 77 0.00000488 2700 75

1 Based on MRID 43852501 ; The study inhalation unit exposure (0.07 ug/lb ai) representative of baseline protection (i.e. no respirator) was adjusted to represent use of a PF5 respirator (i.e., 80% reduction in exposure). PF5 = a NIOSH

- approved respirator with a dust

- mist filter with MSHA/NIOSH approval number prefix TC

- 21 or any N, R, P or HE filter.

2 Based on registered label (Reg. No. 87895

- 00001 ).

3 Exposure Science Advisory Council Policy #9.1.

4 Dermal Dose = Derma l Unit Exposure ( μ g/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre ) × Area Treated (A /day) × DAF ( 100 %) ÷ BW ( 80 kg).

5 Dermal MOE = Dermal BMDL10 ( 0.013 mg/kg/day) ÷ Dermal Dose (mg/kg/day).

6 Inhalation Dose = Inhalation Unit Exposure ( μ g/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre) × Area Treated (A/day) ÷ BW ( 80 kg).

7 Inhalation MOE = Inhalation BMDL10 ( 0.013 mg/kg/day) ÷ Inhalation Dose (mg/kg/day).

8 Total MOE = BMDL10 ( 0.013 mg/kg/day) ÷ [ Derma l Dose + Inhalation Dose ]

Table 8 .1. 3 . Occupational Handler Non

- Cancer Exposure and Risk Estimates for Aldicarb

. Engineering Controls.

Crop or Target Dermal Unit Exposure (μg/lb ai) 1

[Level of PPE] Inhalation Unit

Exposure (μg/lb ai) 1

[Level of PPE] Maximum

Application Rate (lb ai/A) 2 Area Treated

Daily (Acres) 3 Dermal Inhalation Total

Dose (mg/kg/day) 4 MOE

(LOC = 10) 5 Dose

(mg/kg/day) 6 MOE

(LOC = 10) 7 MOE

(LOC = 10) 8

Loader (Load Granules

– tractor drawn spreader)

Sweet potato [e.g., nematodes]

8.6

[EC] 0.083

[EC] 3 80 0.0258 0.5 0.000249 52 0.5

1.5 0.0129 1 0.000125 100 0.99

Sugar beet [e.g. nematodes] 4.95

200 0.106 0.12 0.00103 13 0.12

Sugar beet [leafminers/leafhoppers] 3 0.0645 0.2 0.000623 21 0.2

Dry bean [nematodes] ; Sugar beet [aphids] ; Cotton [side

- dress applications] 2.1 0.0451 0.29 0.000436 30 0.29

Peanut [nematodes /post

- pegging] 1.5 0.0323 0.4 0.000311 42 0.4

Dry bean [aphids]; Cotton [nematodes]; Peanuts [nematodes/thrips]; Soybean 1.05 0.0226 0.58 0.000218 60 0.57Page 18 of 26

Table 8 .1. 3 . Occupational Handler Non

- Cancer Exposure and Risk Estimates for Aldicarb

. Engineering Controls.

Crop or Target Dermal Unit Exposure (μg/lb ai) 1

[Level of PPE] Inhalation Unit

Exposure (μg/lb ai) 1

[Level of PPE] Maximum

Application Rate (lb ai/A) 2 Area Treated

Daily (Acres) 3 Dermal Inhalation Total

Dose (mg/kg/day) 4 MOE

(LOC = 10) 5 Dose

(mg/kg/day) 6 MOE

(LOC = 10) 7 MOE

(LOC = 10) 8

[mexican bean beetle/thrips]

Dry bean [seedcorn maggot]; Cotton [aphids/thrips]; Soybean [nematodes/thrips] 0.75 0.0161 0.81 0.000156 83 0.8

Applicator

Sweet potato [e.g., nematodes]

2.0

[EC] 0.22

[EC] 3 80 0.006 2.2 0.00066 20 2

1.5 0.003 4.3 0.00033 39 3.9

Sugar beet [e.g. nematodes] 4.95

200 0.0248 0.52 0.00273 4.8 0.47

Sugar beet [leafminers/leafhoppers] 3 0.015 0.87 0.00165 7.9 0.78

Dry bean [nematodes] ; Sugar beet [aphids] ; Cotton [side

- dress applications] 2.1 0.0105 1.2 0.00116 11 1.1

Peanut [nematodes /post

- pegging] 1.5 0.0075 1.7 0.000825 16 1.5

Dry bean [aphids]; Cotton [nematodes]; Peanuts [nematodes/thrips]; Soybean [mexican bean beetle/thrips] 1.05 0.00525 2.5 0.000578 22 2.2

Dry bean [seedcorn maggot]; Cotton [aphids/thrips]; Soybean [nematodes/thrips] 0.75 0.00375 3.5 0.000413 31 3.1

1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” ( September, 2015 ) as noted; Level of mitigation: Eng. Controls.

2 Based on registered label (Reg. No. 87895

- 00001 ).

3 Exposure Science Advisory Council Policy #9.1.

4 Dermal Dose = Dermal Unit Exposure ( μ g/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre ) × Area Treated (A /day) × DAF ( 100 %) ÷ BW ( 80 kg).

5 Dermal MOE = Dermal BMDL10 ( 0.013 mg/kg/day) ÷ Dermal Dose (mg/kg/day).

6 Inhalation Dose = Inhalation Unit Exposure ( μ g/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre) × Area Treated (A/day) ÷ BW ( 80 kg).

7 Inhalation MOE = Inhalation BMDL10 ( 0.013 mg/kg/day) ÷ Inhalation Dose (mg/kg/day).

8 Total MOE = BMDL10 ( 0.013 mg/kg/day) ÷ [ Dermal Dose + Inhalation Dose ]Page 19 of 26



### Handler Risk Characterization:

The occupational handler scenarios assessed represent low dust formulations, while t he surrogate
data used to assess engineering controls are from studies using clay granules which are known to be more friable (i.e., more dusty) than engineered low dust formulations such as used for

aldicarb. The low

- dust vinyl

- coated scenarios associated with the closed loading scenario have lower exposure potential than the clay

- based substrate surrogate in the surrogate engineering control unit exposures.

HED notes that qualitatively the occupational exposure using engineering controls for any given handling or loading scenario is lower than the available chemical

- specific handler data (occupational handlers with PPE ). While the available chemical

- specific study is representative

of the low

- dust formulation, it cannot be used to estimate exposure from the use of engineering controls (i.e., closed loading and closed cab applications). HED acknowledges that the unit exposures for the use of engineering controls with the low

- dust formulation should be less than

th ose identified in the study for use of open pour/open cab application. It is noted that based on the surrogate unit exposure guide, closed loading/closed cab systems often provide up to 90% reduction in exposure.

9

. 2 Occupational Post

- application Exposure/ Risk Estimates

HED uses the term post

- application to describe exposures that occur whe n individuals are present in an environment that has been previously treated with a pesticide (also referred to as re

entry exposure). Such exposures may occur when workers enter previously treated areas to perform job functions, including activities rela ted to crop production, such as scouting for pests or harvesting. Post

- application exposure levels vary over time and depend on such things as the type of activity, the nature of the crop or target that was treated, the type of pesticide application,

and the chemical’s degradation properties. In addition, the timing of pesticide applications, relative to harvest activities, can greatly reduce the potential for post

- application exposure.

9 .2.1 Occupational Post

- application Inhalation Exposure/Risk Estimates

There are multiple potential sources of post

- application inhalation exposure to individuals performing post

- application activities in previously treated fields. These potential sources include volatilization of pesticides and resuspension of du sts and/or particulates that contain pesticides. The agency sought expert advice and input on issues related to volatilization of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, and received the SAP’s final report on March 2, 2010 ( http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPP

- 2009

- 0687

- 0037 ). The agency has evaluated the SAP report and has developed a Volatilization Screening Tool and a subsequent Volatilization Screenin g Analysis ( http://www.regulations.gov/#!docketDetail;D=EPA

- HQ

- OPP

- 2014

- 0219 ). During Registration Review, the A gency will utilize this analysis to determine if data (i. e., flux studies, route

- specific inhalation toxicological studies) or further analysis is required for a ldicarb.Page 20 of 26



### In addition, the Agency is continuing to evaluate the available post

- application inhalation exposure data generated by the Agricultural Reent ry Task Force. Given these two efforts, the Agency will continue to identify the need for and, subsequently, the way to incorporate occupational post

- application inhalation exposure into the agency's risk assessments.

9

. 2 .2 Occupational Post

- application Dermal Exposure/Risk Estimates

A quantitative post

- application assessment has not been conducted for a ldicarb because

a ldicarb is soil incorporated and there is limited potential for worker dermal exposure to soil incorporated pesticides.

In accordance with 40 CFR 158, dislodgeable foliar residue ( DFR ) data are required for all occupational (e.g., crop, nursery, greenhouse use sites) or residential (e.g., ornamental and vegetable gardens, pick your own farms, retail tree farms) uses that could result in post

application exposure to foliage. In the case of aldicarb, there are no currently labeled uses that would result in foliar residue; therefore, n o DFR data are required at this time. In the case that the registered use pattern changes, HED would reev aluate the need for a DFR study, depending on the pro posed label change.

The REI specified on the existing labels [48 hours] is based on the acute toxicity of aldicarb.

Aldicarb is classified as Toxicity Category I via the dermal, oral, and inhalation routes of

exposure. Due to severe effects (death) follow ing corneal and dermal dosing, dermal and eye irritation studies were waived in the acute toxicity database. Because of the limited wor ker exposure profile (soil

- incorporation), the REI on the labels is adequate to protect for worker exposure. Therefore, the [156 subpart K] Worker Protection Statement interim REI of 48 hours is adequate to protect agricultural workers from post

- application exposures to aldicarb.Page 21 of 26



### Appendix A. Summary of Occupational and Residential Non

- cancer Algorithms

Occupational Non

- cancer Handler Algorithms

Potential daily exposures for occupational handlers are calculated using the following formulas:

E=UE * AR * A * 0.001 mg/ug

where:

E = e xposure (mg ai/day),

UE = u nit e xposure (μ g ai/ lb ai),

AR = m aximum application rate according to proposed label (lb ai A or lb ai/gal ), and

A = a rea treated or amount handled (e.g., A/day, gal/day)

.

The daily doses are calculated using the following formula:

ADD= E * AF

BW

where:

ADD = average daily dose a bsorbed in a given scenario (mg ai/ kg / day),

E = e xposure (mg ai/day),

AF = absorption fa ctor (dermal and/or inhalation), and

BW = body weight (kg)

.

Margin of Exposure: Non

- cancer risk estimates for each application handler scenario are

calculated usin g a Margin of Exposure (MOE), which is a ratio of the toxicological endpoint to the daily dose of concern. The daily dermal and inhalation dose received by occupational

handlers a re compared to the appropriate POD ( i.e.

, NOAEL) to assess the risk to occup ational handlers for each exposure route. All MOE values a re calculated using the following formula:

MOE= POD

ADD

where:

MOE = m argin of e xposure: value used by HED to represent risk estimates (unitless),

POD = p oint of d eparture (mg/kg/day)

, and

ADD = average daily dose absorbed in a given scenario (mg ai/kg/day)

.

Occupational Non

- cancer Post

- application AlgorithmsPage 22 of 26



### Potential daily exposures for occupational post

- application workers are calculated using the following formulas:

DFR t 

### =AR * F* (1

- D) t 

### * ( 4 .54E8 ug

lb ) * ( 2.47E

- 8 A

cm 2 

### )

where:

DFR t 

### = dislodgeable foliage residue on day "t" (μg/cm 2 

### ),

AR = a pplication r ate (lb ai/acre),

F = fraction of ai retained on foliage or 25% (unitless),

D = fraction of residue that dissipates daily or 10% (unitless), and

t = number of days after application day (days)

.

E=TC * DFR t 

### * ET * 0.001 mg

ug

where:

E = e xposure (mg ai/day),

TC = t ransfer coefficient (cm 2 

### /hr),

DFR t 

### = d islodgeable f oliar r esidue on day “t” (μg/cm 2 

### ), and

ET = e xposure t ime (hours/day).

The daily doses are calculated using the following formula:

ADD= E * AF

BW

where:

ADD = average daily dose absorbed in a given scenario (mg ai/kg/day),

E = e xposure (mg ai/day),

AF = absorption fa ctor (dermal and/or inhalation), and

BW = body weight (kg).

Margin of Exposure: Non

- cancer risk estimates for each scenario are calculated using a Margin of Exposure (MOE), which is a ratio of the toxicological endpoint to the daily dose of concern. The daily dermal dose received by occupational post

- application workers is compared to the appropriate POD ( i.e.

, NOAEL) to assess the risk to occupational post

- application workers

. All

MOE values a re calculated using the following formula:

MOE= POD

ADD

where:Page 23 of 26



### MOE = margin of exposure: value used by HED to represent risk estimates (unitless),

POD = point of departure (mg/kg/day), and

ADD = average daily dose absorbed in a given scenario (mg ai/kg/day).Page 24 of 26



### Appendix B. Summary of Available Occupational Handler Exposure Data

One chemical

- specific study was submitted in support of the reregistration of aldicarb, and was judged to be appropriate for use in occupational exposure/risk assessments. These data have not been integrated with PHED for this assessment because the granules used are vinyl coated formulation (i.e ., a “low dust formulation”) which is likely to lead to differences in exposure. The study can be identified by the following information:

EPA MRID 43852501 : Rosenheck, L., Schuster, L. (1995) Worker Loader and Applicator Exposure to Temik 15G. Study number 94388 , Unpublished study prepared by ABC Laboratories,

Pan

- Ag Div ision; Rhone

- Poulenc Ag Company.

This study quantified exposure to aldicarb for workers loading and applying Temik 15G (EPA Reg. No. 264

- 330) at the maximum rate of 6 lb ai/acre in pe can groves using shank injection. Dermal and inhalation exposure levels to aldicarb and its two principal by

- products, aldicarb sulfoxide and aldicarb sulfone, were measured. Five replicates of the loading and application of

Temik 15G were monitored at e ach of the three locations for a total of 15 loading and 15 application replicates (mixer/loaders were monitored separately from the applicators). The study was conducted in three locations; Raymond, Mississippi; Brownwood, Texas; and Albany, Georgia.

Th e use of a modified Tye seeder in the three different locations was consistent with commercial agricultural practice (i.e., recommended equipment for aldicarb applications). The test subjects also wore protective clothing that met U.S. EPA Worker Protecti on Standards, consisting of nitrile rubber gloves, rubber boots, goggles, hard hat, a dust filtering respirator and a chemical resistant apron (loader only) over short

- sleeved shirt, short pants and coveralls. The duration of each loading replicate was ap proximately 4 hours, and during this time the modified seeder was loaded and emptied twice (once at the start and again after about 2 hours). The application replicates were monitored using open cab tractors over a period of approximately 4 hours. The lo aders handled a range of 900 lb to 1485 lb of Temik 15G (135 lb to 223 lb ai) per replicate. The average application rate was approximately 40 lb product per acre (6 lb ai/A, the maximum rate). Aldicarb was packaged in 45 pound bags and open cab tractors were used.

Dermal exposures were monitored using whole

- body dosimetry (long underwear, later sectioned into arms, chest, back, and lower body), handwashes and facial and neck swipes. The long underwear (100% cotton) was worn under short pants and a shor t sleeved shirt. Hand exposure was monitored by having each test subject remove gloves and wash both hands twice in detergent solution (0.01% v/v Aerosol OT 75). Face and neck exposures were monitored by wiping the face and neck with 10 percent cotton ga uze pads wet with the detergent solution. Inhalation exposures were monitored using a XAD2 resin tube, polyurethane foam, and glass fiber filter to collect both vapor and particulate matter. The tubes were attached to a personal air pump with a flow rate of approximately 1.5 liters/minute. The limits of quantification (LOQs) for each matrix are presented

in Table 1

.Page 25 of 26

Table 3: Limits of Quantification and Detection in Study

Area LOQ

(μg/ml) <LOQ:Replicates LOD (μg/ml) Non

- detects:Replicates

Loader Applicator Loader Applicator

Dermal: Arm, chest, back Lower Body

Handwash Facial Wipe 1.00

2.00

1.00

0.10 21:45

0:15

1:15

4:15 25:45

3:15

2:15

2:15 0.40

0.67

0.30

0.01 6:45

0:15

0:15

0:15 6:45

2:15

2:15

0:15

Inhalation:

OVS Tube 0.05 1:15 6:15 0.020 0:15 1:15

a LOD = Minimum Standard Concentration Tested (0.01μg/ml) * Dilution Factor. Arm, chest, back Dilution Factor = 40 Lower Body Dilution Factor = 67

Handwash Dilution Factor = 30 Facial Wipe Dilution Factor = 1

OVS Tube Dilution Factor = 1

Note: For Loaders : Aldicarb 38 of 90 samples were <LOQ, 11 of 90 samples were <LOD, Aldicarb sulfone 79 of 90 samples were < LOQ, 47 of 90 samples were <LOD and aldicarb sulfoxide 56 of 90 samples were < LOQ, 20 of 90 samples were

<LOD.

For Applicators: Aldicarb 56 of 90 samples were <LOQ, 15 of 90 samples were <LOD, Aldicarb sulfone 83 of 90 samples were < LOQ, 55 of 90 samples were <LOD and aldicarb sulfoxide 79 of 90 samples were < LOQ, 27 of 90 samples were

<LOD.



### For detected peaks whose values fell below the LOQ but above the limit of detection (LOD), results were reported as 50 percent of the LOQ. This is within current Agency guidelines. However, when the results fell below the LOD (i.e. "no peak detected"), t he study reported the result as only 10 percent of the LOQ. The study did not mention the LOD value used for this interpretation.

In place of the 10 percent LOQ value given non

- detects, 50 percent LOD was used in the exposure

calculations. The LOD for e ach matrix was calculated based on the lowest quantifiable level in the calibration curve as presented in the analytic al methods section of the study

.

The study was conducted in accordance with most of 875 Guidelines Group A, Applicator Monitoring Exposu re Test Guidelines. Field recovery for aldicarb, aldicarb sulfoxide, and aldicarb sulfone are presented in Table 2

.

Table 2 : Field Fortification Recoveries.

Matrix Field Percent Recovery (CV %)*

n Aldicarb Aldicarb Sulfoxide Aldicarb Sulfone

Inhalation Tube 77 (4) NA NA 8

Handwash 78 (13) 75 (5) 90 (11) 8

Facial Swab 84 (7) 92 (5) 92 (4) 8

Body Dosimeter 83 (7) 81 (5) 91 (3) 8

* CV = standard deviation  mean



### Laboratory recovery for aldicarb, aldicarb sulfoxide and aldicarb sulfone is presented in Table 3

. Storage stability data were acceptable. Control samples had residues less than the LOQ and the recoveries were within the EPA acceptable range of 70

- 120%.Page 26 of 26

Table 3 : Laboratory Recoveries.

Matrix Laboratory Percent Reco very (CV %, n)

Aldicarb Aldicarb Sulfoxide Aldicarb Sulfone

Inhalation Tube 81 (16, n=24) 84 (12, n=24) 83 (10, n=24)

Handwash 93 (7.6, n=17) 83 (9.7, n=17) 98 (7.7, n=17)

Facial Swab 90 (13, n=13) 90 (9.7, n=13) 92 (11, n=13)

Body Dosimeter 83 (16, n= 21) 89 (12, n=21) 96 (10, n=21)



### The values used in risk assessment were adjusted for field recovery (results below 90 percent increased to 100 p ercent) and normalized to mg ( μg for inhalation) of aldicarb exposure per lb of aldicarb handled (incorporating the 50 percent LOD value for non

- detects and 50 percent LOQ for values below the LOQ). The values calculated are presented in Table 4

.

Table 4 : Results from Aldicarb Pecan Loader and Applicator Study.

Task Dermal (mg ai exposure/ lb ai handled) Inhalation (μg ai exposure/ lb ai handled)

Arithmetic

Mean* Geometric

Mean Median Arithmetic

Mean* Geometric

Mean Median

Loader 0.00022 0.00019 0.00017 0.070 0.025 0.022

Applicator 0.000089 0.000081 0.000078 0.013 0.0044 0.0044

* Used as the unit exposure for occupational risk estimation