  SEQ CHAPTER \h \r 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES

WASHINGTON, D.C. 20460

 										   

June 27, 2007			

			

MEMORANDUM			

Subject:	Allethrins: Revised Occupational and Residential Exposure
Assessment and Recommendations for The Reregistration Eligibility
Decision (RED). 

		[PC Codes 004003, 004004, 004005 and 004007, DP Barcode D340744]

From:		Timothy Dole, CIH, Industrial Hygienist 

		Reregistration Branch 1

		Health Effects Division 

Through:	Whang Phang, Ph. D., Senior Scientist

		And

		Michael Metzger, Branch Chief

Reregistration Branch 1

		Health Effects Division 

		

To:		Molly Clayton, Chemical Review Manager

		Special Review and Registration Division

Attached is the Revised Occupational and Residential Exposure and Risk
Assessment document for the allethrins HED RED Chapter.  This assessment
has been revised to incorporate risk assessment and risk mitigation
changes that have occurred since the end of the public comment period.

This page intentionally left blank.Table of Contents

  TOC \o "1-3" \h \z \u    HYPERLINK \l "_Toc146337253"  Executive
Summary	  PAGEREF _Toc146337253 \h  4  

  HYPERLINK \l "_Toc146337254"  1.0	Hazard Identification	  PAGEREF
_Toc146337254 \h  7  

  HYPERLINK \l "_Toc146337255"  1.1	Acute Toxicology Categories	 
PAGEREF _Toc146337255 \h  7  

  HYPERLINK \l "_Toc146337256"  1.2	Toxicological Endpoints	  PAGEREF
_Toc146337256 \h  7  

  HYPERLINK \l "_Toc146337257"  1.3	Incident Report	  PAGEREF
_Toc146337257 \h  8  

  HYPERLINK \l "_Toc146337258"  2.0	Summary of Use Patterns and
Formulations	  PAGEREF _Toc146337258 \h  8  

  HYPERLINK \l "_Toc146337259"  2.1	Target Pests and Use Sites	  PAGEREF
_Toc146337259 \h  8  

  HYPERLINK \l "_Toc146337260"  2.2	Formulations	  PAGEREF _Toc146337260
\h  9  

  HYPERLINK \l "_Toc146337261"  2.3	Smart Meeting Information	  PAGEREF
_Toc146337261 \h  9  

  HYPERLINK \l "_Toc146337262"  2.4	Application Rates	  PAGEREF
_Toc146337262 \h  10  

  HYPERLINK \l "_Toc146337263"  2.5	Use Data	  PAGEREF _Toc146337263 \h 
11  

  HYPERLINK \l "_Toc146337264"  3.0	Occupational Handler Exposure and
Risk	  PAGEREF _Toc146337264 \h  12  

  HYPERLINK \l "_Toc146337265"  3.1	Occupational Handler Exposure Data	 
PAGEREF _Toc146337265 \h  13  

  HYPERLINK \l "_Toc146337266"  3.2	Occupational Handler Exposure
Assumptions	  PAGEREF _Toc146337266 \h  14  

  HYPERLINK \l "_Toc146337267"  3.3	Occupational Handler Exposure and
Risk Estimates	  PAGEREF _Toc146337267 \h  15  

  HYPERLINK \l "_Toc146337268"  3.4	Occupational Handler Risk
Characterization	  PAGEREF _Toc146337268 \h  16  

  HYPERLINK \l "_Toc146337269"  4.0	Occupational Post Application
Exposure and Risk	  PAGEREF _Toc146337269 \h  17  

  HYPERLINK \l "_Toc146337270"  4.1	Occupational Post Application
Exposure Data Sources	  PAGEREF _Toc146337270 \h  17  

  HYPERLINK \l "_Toc146337270"  4.2	Occupational Post Application
Assumptions and Calculation Methods	  PAGEREF _Toc146337270 \h  17  

  HYPERLINK \l "_Toc146337271"  4.3	Occupational Post Application
Exposure and Risk Estimates	  PAGEREF _Toc146337271 \h  18  

  HYPERLINK \l "_Toc146337272"  4.4	Occupational Post Application Risk
Characterization	  PAGEREF _Toc146337272 \h  18  

  HYPERLINK \l "_Toc146337273"  5.0	Residential Handler Exposure and
Risk	  PAGEREF _Toc146337273 \h  19  

  HYPERLINK \l "_Toc146337274"  5.1	Residential Handler Exposure Data	 
PAGEREF _Toc146337274 \h  19  

  HYPERLINK \l "_Toc146337275"  5.2	Residential Handler Exposure
Assumptions	  PAGEREF _Toc146337275 \h  19  

  HYPERLINK \l "_Toc146337276"  5.3	Residential Handler Risk Estimates	 
PAGEREF _Toc146337276 \h  19  

  HYPERLINK \l "_Toc146337277"  5.4	Residential Handler Risk
Characterization	  PAGEREF _Toc146337277 \h  20  

  HYPERLINK \l "_Toc146337278"  6.0	Residential Post Application
Exposures and Risks	  PAGEREF _Toc146337278 \h  20  

  HYPERLINK \l "_Toc146337279"  6.1	Residential Post Application
Exposure Data	  PAGEREF _Toc146337279 \h  21  

  HYPERLINK \l "_Toc146337280"  6.2	Residential Post Application
Exposure Assumptions	  PAGEREF _Toc146337280 \h  22  

  HYPERLINK \l "_Toc146337281"  6.3	Residential Post Application
Exposure and Risk Estimates	  PAGEREF _Toc146337281 \h  24  

  HYPERLINK \l "_Toc146337282"  6.4	Residential Post Application Risk
Characterization	  PAGEREF _Toc146337282 \h  25  

  HYPERLINK \l "_Toc146337283"  7.0	References:	  PAGEREF _Toc146337283
\h  27  

 

Appendices

A	Occupational and Residential Exposure and Risk Calculations for
Allethrins	28

B	Allethrin Post Application Risk from Time Metered Device Applications
41	

  SEQ CHAPTER \h \r 1 Executive Summary

Background and Purpose

  SEQ CHAPTER \h \r 1 This occupational and residential exposure and
risk assessment is being conducted as part of EPA’s human health risk
assessment for the Allethrins Reregistration Eligibility Decision (RED).
 This document addresses the exposures and risks associated with
occupational and residential exposure to allethrins based on label
prescribed uses.  This document has been revised to include the
following risk assessment and risk mitigation changes.

Risk Assessment Changes

1.	The POD for intermediate term incidental oral exposures has been
changed from 6.0 mg/kg/day to 8.0 mg/kg/day based upon a benchmark dose
analysis.

2.	The air concentration data for the indoor space spray scenario have
been adjusted to account for field recovery.

3.	The occupation fogger handler unit exposure data have been deleted
due to human study ethics concerns.

Risk Mitigation Changes (To be included in the Allethrin RED)

1.   The residential PCO product labels will be limited to a 0.1 percent
spray dilution rate, and language to labeling will be added reducing the
volume from 1 gallon per 1000 ft2 to 0.5 gallon per 1000 ft2. 

2.	The maximum spray dilution for indoor fogging applications will be
reduced from 3.0 percent (as listed on the Esbiol 300 Insect label
#432-870) to 1.5 percent.

3.	The consumer surface and space sprays, which currently range from
0.05 percent to 0.5 percent ai in products, will be limited to 0.25
percent ai.

4.	The consumer product labels will be changed to require spot treatment
only.  The broadcast surface applications to rugs and carpets will be
eliminated.   

5.	The use of the 6 ounce outdoor total release fogger will be deleted
from the Raid Yard Guard label (4822-394).

6.	The pet uses (aerosols sprays and shampoos) will be cancelled.  The
pet bedding uses will remain as spot treatments.

Hazard Identification

Allethrins are of low to moderate acute toxicity (i.e. Tox III or II)
for oral exposures and they are of low toxicity (i.e. Tox III and IV)
for dermal and inhalation exposures.  Allethrins cause minor skin or eye
irritation (Tox III and IV) and they are not dermal sensitizers.

  SEQ CHAPTER \h \r 1 Endpoints were selected only for inhalation and
incidental oral exposures. No endpoints were selected for dermal
exposure because no effects were observed at the limit dose in the
dermal toxicity studies and because of negligible absorption (0.22 %) of
a structurally related chemical (pyrethrin) measured in human studies.
The endpoints are listed below:   

A NOAEL of 1.3 mg/kg/day was selected from a 28 day inhalation study in
rats during which clinical signs (limb tremors, hunched posture,
vocalization during handling) were observed at a LOAEL of 6.5 mg/kg/day.
 This endpoint is applicable to short, intermediate and long term
inhalation exposures.

A NOAEL of 20 mg/kg/day was selected from a 30 day oral study in dogs
during which liver toxicity was observed at a LOAEL of 63 mg/kg/day. 
This endpoint is applicable to short term incidental oral exposures.

A Benchmark Dose of 8 mg/kg/day was selected from a 6 month oral study
in dogs during which liver toxicity was observed at a LOAEL of 36
mg/kg/day and a NOAEL of 6 mg/kg/day.  This endpoint is applicable to
intermediate term incidental oral exposures.

The target MOE (i.e. level of concern) for residential incidental oral
and inhalation exposures is 1000 which includes the standard uncertainty
factors of 10 for inter-species extrapolation and 10 for intra-species
variation as well as a database uncertainty factor of 10X to account for
the possible difference in toxicity between adults and children.   The
target MOE for occupational inhalation exposures is 100 because the
database uncertainty factor does not apply to occupational exposures.  

 

Occupational Exposure and Risk

  SEQ CHAPTER \h \r 1 

Based on toxicological criteria and potential for exposure, inhalation
exposures were assessed for a variety of occupational handler and post
application scenarios.  Dermal exposures were not assessed because no
systemic effects were observed at the limit dose in dermal toxicity
studies in animals.  

	The occupational handler exposure scenarios that were assessed included
surface spray  applications using low pressure hand wand, high pressure
handwand or aerosol can and indoor space spray applications using
handheld foggers.   Most of the MOEs for surface sprays are above the
target MOE of 100 and the risks are not of concern.  The high pressure
handwand scenario is of concern with an MOE of 81 and requires a PF5
filtering facepiece respirator (i.e. a dust mask) to achieve the target
MOE.  The handheld fogger scenario is also of concern with an MOE of 2.8
to 4.2 and requires PF50 Full Face respirators to achieve the target
MOE.

	Occupational post application inhalation exposures have been assessed
for a metered release scenario.  Based upon the label requirement that
applications be made only during non-business hours, worker exposures
were assumed to begin in the morning immediately after the night time
applications ceased and were averaged over an eight hour period.  The
resulting MOE is 850, which exceeds the target MOE of 100 and is not of
concern.  This MOE is conservative because it is assumed that the
aerosols would remain airborne until they were removed by ventilation
and the effects of aerosol settling are not considered.  Aerosol
settling could be a major factor depending upon the aerosol size and
rate of evaporation.  

Residential Exposure and Risk

 

	Residential handler exposures were assessed for aerosol can application
to a variety of use sites.  All of the handler MOEs exceed the target
MOE of 1000, therefore, the handler risks are not of concern.   

Residential post application inhalation exposures were assessed for
space sprays, yard and patio foggers, mosquito coils and fly mats.  Most
of the scenarios are not of concern because the MOEs exceed 1000.  The
yard and patio fogger scenario is of concern because the MOE of 650 does
not exceed the target MOE of 1000; however, this scenario is only of
concern when the product is in the form of a total release fogger.   The
yard and patio scenario is not of concern when the product is in the
form of a hand held fogger and the spray duration is 9 seconds or less. 


  The space spray application rates and resultant exposures are variable
depending upon the label considered. Although the Raidtm label is fairly
specific (apply 10 second spray per 1000 ft3) other labels contain
statements such as “fill room with mist” which are less specific. 
Many of the labels also require that the room be kept closed for 15
minutes and ventilated thoroughly prior to entry.

	

Residential post application incidental oral exposures were assessed for
consumer applied indoor foggers, PCO applied broadcast surface sprays
and consumer applied spot treatment surface sprays.  The MOEs for these
scenarios exceed 1000 and are not of concern.  

1.0	Hazard Identification

1.1	Acute Toxicology Categories

The acute toxicity data for allethrins are summarized in   SEQ CHAPTER
\h \r 1 Table 1.  Allethrins are of low to moderate acute toxicity (i.e.
Tox category III or II) for oral exposures and they are of low toxicity
(i.e. toxicity category III and IV) for dermal and inhalation exposures.
 Allethrins cause minor skin or eye irritation (Tox III and IV) and they
are not dermal sensitizers.	

Table   SEQ Table \* ARABIC  1  – Acute Toxicity of Allethrins

Guideline

 No.	Study Type	Bioallethrin	Esbiol	Esbiothrin	Pynamin Forte

870.1100	Acute Oral	III	II	II	III

870.1200	Acute Dermal 	III	III	III	III

870.1300	Acute Inhalation 	IV	III	III	IV

870.2400	Primary Eye Irritation	III	III	IV	III

870.2500	Primary Skin Irritation 	IV	IV	III	IV

870.2600	Dermal Sensitization	negative	negative	negative	negative



1.2	Toxicological Endpoints

  SEQ CHAPTER \h \r 1  The points of departure (PODs) that were used to
complete this assessment are summarized in Table 2.  PODs were selected
only for incidental oral and inhalation exposures.  No PODs were
selected for dermal exposure because no effects were observed at the
limit dose in the dermal toxicity studies and because of negligible
absorption (0.22 %) of pyrethrin, which is a structurally related
chemical, measured in human studies.  

	The POD for intermediate term incidental oral exposure was selected
based upon a benchmark dose analysis because of the 6x difference
between the NOAEL (6 mg/kg/day) and the LOAEL (36 mg/kg/day).  A 10%
response for the bench mark dose (i.e. BMD10) was selected because of
the mild nature of the lesions, characterized as "acute swelling of
hepatocytes", which did not progress in severity at the high dose.  The
lesions were accompanied by increased relative liver weight and moderate
increases in alkaline phosphatase in males.  The selected BMDL10 value
was 267 ppm, which is lower 95% confidence limit on the BMD10.   This
dietary concentration was converted to a mg/kg/day dose by using the
dose in males, which was lower than that in females:  267 ppm/200 ppm x
6.1 mg/kg/day = 8 mg/kg/day.  

The target MOE (i.e. level of concern) for residential incidental oral
and inhalation exposures is 1000.  This includes the standard
uncertainty factors of 10 for interspecies extrapolation and 10 for
intraspecies variation as well as a database uncertainty factor of 10X
to account for the possible difference in toxicity between adults and
children.  The target MOE for occupational inhalation exposures is 100
because the database uncertainty factor does not apply to occupational
exposures.   



Table   SEQ Table \* ARABIC  2  –PODs for Assessing Occupational and
Residential Risks for Allethrins

Exposure Scenario	Point of Departure (POD)	Target MOE	Study and
Toxicological Effects

Incidental Oral 

Short Term 

(1 - 30 days)	NOAEL = 20 mg/kg/day

	Residential  = 1000*

Occupational = N/A	30-day dog  (Esbiothrin)

LOAEL = 63 mg/kg/day based on elevated liver enzymes and increased liver
weight.

Incidental Oral 

Intermediate Term 

(1 - 6 months)	BMDL10 = 8 mg/kg/day

	Residential  = 1000*

Occupational = N/A	6 month dog  (Bioallethrin)

LOAEL = 36 mg/kg/day based on microscopic liver changes (hepatocellular
degeneration). NOAEL = 6 mg/kg/day.

Dermal

(All populations)	N/A - No systemic toxicity at 1000 mg/kg/day with
Esbiothrin or Esbiol and negligible dermal absorption with pyrethrins
(0.22%). 

Inhalation 

(All populations)

All durations	NOAEL = 1.3 mg/kg/day

	Residential  = 1000*

Occupational = 100	28-day inhalation study in rats (Esbiol) LOAEL = 6.5
mg/kg/day based on clinical signs in females (limb tremors, hunched
posture, vocalization during handling)

Cancer	Classification:  Suggestive Evidence of Carcinogenicity, but Not
Sufficient to Assess Human Carcinogenic Potential

* Includes a Database UF of 10x to account for the possible difference
in toxicity between adults and children  

1.3	Incident Report 

An incident report is currently being prepared by the Chemistry and
Exposure Branch of HED.

2.0	Summary of Use Patterns and Formulations

Allethrins are a mixture of synthetic pyrethroid insecticides that are
structurally related to natural pyrethrum.  They cause immediate, but
temporary paralysis of the target insects.  They are usually used with a
synergist such as piperonyl butoxide that prevents insect recovery. 
Allethrins are used for commercial, horticultural and residential
applications.  Commercial applications include space, broadcast and
crack and crevice treatment in a variety of commercial, industrial and
institutional (CII) sites.  Horticultural applications include foliar
and fogger treatment on non-food plants.  Residential uses include pest
control in homes and outdoor domestic structures, and on gardens. 
Allethrins are formulated as liquid concentrates, ready to use (RTU)
liquids, aerosol sprays, mosquito coils and mosquito mats.

2.1	Target Pests and Use Sites

  SEQ CHAPTER \h \r 1 Insecticides containing allethrins are used to
control flying and crawling insects at a variety of occupational and
residential use sites as listed below:

Domestic (household):

Crawling and flying insect killers (CFIK) for use indoors as space,
general surface, spot and crack & crevice applications in food and
non-food areas.  Use on house plants and residential greenhouses.  Use
on pet premises (bedding, dog houses, etc.).  CFIK for use outdoors as
localized space and contact spray, perimeter treatments (sidewalks,
decks, patios, outside surfaces of buildings, etc.), and application to
ornamental plants.

Commercial/Industrial/Institutional (CII):

CFIK for use indoors as space, general surface, spot and crack & crevice
applications in food and non-food areas.  Also for use on indoor plants.
 CFIK for use outdoors as localized space and contact sprays and
perimeter treatments (sidewalks. entranceways, outside surfaces of
buildings, etc.). Also for use on ornamental plants in landscaped areas.

Greenhouses:

Use in commercial greenhouses to control various plant pests on
ornamentals as a space and/or contact spray.

2.2	Formulations

	  SEQ CHAPTER \h \r 1 Based on the EPA’s pesticide registration
database (OPPIN) and information provided in the Use Closure Memo of
March 22, 2006, allethrins are formulated as emulsifiable concentrates,
liquid concentrates, pressurized liquids, ready to use liquid sprays,
mosquito coils and mosquito mats.  The registered products are
formulated and used as listed in Table 3 below.

Table 3 – Allethrin Formulations and Use Categories

Formulation	Number of LabelsA	Domestic Household	Commercial

Industrial

Institutional	Greenhouse	Animal TreatmentB

Pressurized Liquid	136	YES	YES	YES	YES

RTU Liquids 	31	YES	YES	YES	YES

Emulsifiable Concentrates	3	NO	YES	YES	YES

Liquid Concentrates	6	NO	YES	YES	YES

Mosquito Coils and MatsC	15	YES	NO	NO	NO

A. As listed in the Use Closure Memo.

B. Primarily includes cats, dogs and horses.   Excludes animals used for
food.

C. Listed as impregnated materials in OPPIN.



2.3	Smart Meeting Information

	Smart meetings were held with the allethrin registrants on 10/07/2003
and 11/03/2005.  A summary of information obtained from these meetings
is included in Table 4.

Table 4 – Allethrin Smart Meeting Information 

Use 	Indoor/

Outdoor	Percent ai	Comments

Crawling Insect Killer Aerosols

(Surface Spray)	Both	0.05 to 0.25	Spray until wet (20 to 50 ml/m2). 
Droplet size is 50 to 80 micron.

Wasp and Hornet Aerosols	Outdoor	0.05 to 0.1 (water or solvent based)
Spray nest for to 2 – 3 seconds.  Discharge rate is 20 grams per
second in a jet stream with a range of 15 to 20 feet.

Yard and Patio Foggers 

(i.e. hand held foggers)	Outdoor	0.1 to 0.15 

(water based)	Spray for 2 to 3 sec. at bushes, grass etc.  Typical
discharge rate is 5-6 gram product per sec.  Application rate is 1 to 3
seconds per square meter. Droplet size is 50 to 100 micron.  

Flying Insect Killer Aerosols 

(Space Spray)	Both	0.1 to 0.25 (usually water based)	Spray room for 3-5
sec. Keep room closed for 15 minutes and ventilate (i.e. open windows)
prior to re-entry.  Discharge rate 1 gram per second.  Droplet size is
10 to 25 micron.  Not very effective outdoors.  Very common overseas. 
Not common in the U.S.

Total Release Aerosols 

(i.e. stationary foggers)	Indoor	1.2 to 3.0 (usually water based)	6
ounce can treats 5000 to 6000 ft3 room. Droplet size is 40 to 50 micron.
Vacate room for several hours.  Ventilate for 30 minutes.

Mosquito and Fly Repellent Mats	Outdoor	Mosquito 7%

Fly         24%	Mats weigh 0.93 grams and last 10 hours.  Protect an
average patio (15 x 15 ft).  Aerosol size is very small (<2 microns).

Mosquito Repellent Coils	Outdoor	0.25 to 0.3 %	Coils weigh 12 grams and
burn for 6 to 7 hours.



2.4	Application Rates

  SEQ CHAPTER \h \r 1 

The application rates are provided in Tables 5 and 6. The occupational
rates in Table 5 are based upon ready to use (RTU) products that are
used by pest control operators (PCOs) and are expressed in terms of
spray dilution.  The rates in Table 6 are based upon PCO applications of
RTU products in residential areas or residential handler application of
aerosol can consumer products.  Some of the residential rates are based
upon information provided by the registrants in the Allethrin Smart
Meetings or agreed upon during RED negotiations.  Additional information
was extracted from the labels listed in the Use Closure Memo.  

Table 5 – Occupational Application Rates

Product Type	Representative Label	Application Type	Use Sites

	Spray Dilution

(Percent ai)

Handler Exposures

RTU	1021-1478	General Surface Spray Undiluted	CII*, domestic, greenhouse
and animal premise indoor space, general surface, spot and crack &
crevice applications 	1.5

RTU	35138-80	General Surface Spray Diluted in Water	Greenhouse
applications to non-food ornamental plants	0.11

RTU	1021-1478	ULV Space Spray	Same as above	1.5

Aerosol Can 	5602-192	Surface Spray	Same as above	0.54

Post Application Exposures

Aerosol Can	10807-69	Time Metered Aerosol	Non-residential food handling
area	0.90

RTU = Ready to Use (product can be poured directly into a sprayer
without mixing with water)

CII    = Commercial Industrial Institutional





Table 6 – Allethrin Residential Application Rates

Product Type	Label	Application Type	Spray Dilution

(Percent ai)	Application Rate

Handler Exposures

Aerosol Can	Various	Indoor surface or space spray	0.20	N/A

	Various 	Hand Held Yard and Patio Fogger	0.15	N/A

	Various	Wasp and Hornet Spray	0.10	N/A

Post Application Exposures

Aerosol Can	11715-96	Indoor Total Release AerosolA	1.2	3.6 mg/m3

RTU	Various	PCO applied surface spray 	0.05B

0.10C	0.0042 lb ai/1000 ft2

Aerosol Can	Various	Space SprayE	0.20D	0.32 mg/m3



Space SprayF

2.2 mg/m3

Aerosol Can	4822-513	Space SprayE	0.10	0.16 mg/m3



Space SprayG

0.35 mg/m3



Space SprayF

1.1 mg/m3

Mosquito Coil	Various	12 grams per coil	0.3	2 coils per patioH

Fly Mat	Various	0.93 grams per mat	24	2 mats per patioH

Aerosol Can	4822-394	Hand Held Yard and Patio Fogger	0.15	3 second spray
per patioI

	4822-394	Total Release Yard and Patio Fogger	0.15	Two cans per patioG

Notes (See Appendix A for more detailed information)

A. Based upon one 1.5 ounce fogger applied to a room with an interior
volume of 5000 ft3.

B. Based upon the RED, the maximum spray dilution is 0.05 percent when
the spray volume is 1 gallon per 1000 ft2.  

C. Based upon the RED, the maximum spray dilution is 0.10 percent when
the spray volume is 0.5 gallon per 1000 ft2.  

D. Based upon the RED, the amount of allethrin in consumer products used
for space sprays will be limited to 0.2 percent.

E. Based upon the application of 9.31 grams of product to a 2048 ft3
room as was done in the NDETF study.

F. Based upon SOP assumptions - an entire 15 ounce can is used in a
14,400 ft3 typical residence.

G. Based upon a spray duration of 10 seconds/1000 ft3 as stated on the
label.

H. Based upon SOP assumptions.

I. Based upon the Allethrin Smart Meeting.



2.4	Application Methods and Equipment

  SEQ CHAPTER \h \r 1 	Allethrins can be applied with the following
types of equipment; aerosol cans, trigger pump sprayers, hand held
sprayers (high or low pressure handwands), cold foggers and thermal
foggers.

Use Data

As discussed in the smart meeting, most allethrin is sold into the
consumer market and a smaller amount is sold into the
institutional/industrial market.  Allethrin is not registered for use on
food crops.  Allethrin is registered for non-food horticultural uses,
however the USDA NASS Reports on Nursery and Floriculture indicate less
than 50 pounds were used in 2001 and 2003.  Usage data from the
California Department of Pesticide Regulation (CDPR) indicate the
reportable use (consumer use is not reported) of allethrin occurs
primarily in structural pest control and landscape maintenance.    Most
of this usage is d-trans allethrin while the usage for the other
allethrins (listed as allethrin, other related or listed as d-allethrin)
is much lower.  The CDPR data for d-trans allethrin are summarized in
Table 7.

Table 7 – CDPR Use Data for D-Trans Allethrin (Pounds)

Commodity	2005	2004	2003	2002	2001	2000

Landscape Maintenance	2.0	3.2	1.5	1.6	5.5	2.0

Public Health	0.6	0.3	61.1	46.6	1.0	5.7

Structural Pest Control	97.2	92.3	158.2	115.1	90.1	92.9

All Other Uses*	1.0	0.6	0.8	0.6	0.4	0.3

Total (Pounds per Year)	100.8	96.4	221.6	163.9	97.0	100.9

*Generally includes animal premise, regulatory pest control and rights
of way.



	

According to the CDPR data, there were 8,600 allethrin applications made
in 2004, most of which used pressurized liquid products (i.e. aerosol
cans).  There were only a few applications made with ready to use or
liquid concentrate products.  The CDPR data for the amounts of
pyrethroid insecticides used in structural pest control are summarized
in Table 8.  These data indicate that other pyrethroid insecticides such
as permethrin, cypermethrin and bifenthrin are used more than allethrin.
 

Table 8 – CA DPR Use Data for Pyrethroids Used in Structural Pest
Control

Chemical	Pounds Applied per Year*

	2005	2004	2003	2002	2001

Permethrin	390,000	302,000	285,000	240,000	197,000

Cypermethrin	200,600	190,000	177,000	156,000	151,000

Bifenthrin	38,500	  40,950	42,600	29,600	20,400

Cyfluthrin (and beta-cyfluthrin)	36,100	  32,600	32,300	41,400	25,600

Lamba Cyhalothrin	13,700	  16,300	10,000	5,380	8,500

Deltamethrin	13,350	  12,100	17,700	12,500	17,100

Pyrethrin	2,750	    3,700	3,000	2,720	1,900

Esfenvalerate	250	         98	133	357	913

Resmethrin	160	         76	270	319	67

Allethrin	97	         92	158	115	90

Phenothrin	48	       117	27	29	26

Tetramethrin	4	           3	5	4	6

*Sorted by the amount used in 2005



3.0	Occupational Handler Exposure and Risk

  SEQ CHAPTER \h \r 1 	

	 The term “handler” applies to individuals who mix, load, and apply
the pesticide product.  Because most allethrin products are packaged in
aerosol cans, most of the allethrin uses involve application only. 
There are a few products packaged as ready to use liquids or liquid
concentrates, which are applied with mechanical sprayers, compressed air
sprayers or foggers.  These products are used in food and non-food
commercial/ industrial/institutional areas, non-food greenhouses and
non-food animal premises.   Based upon these labels, HED assessed the
following occupational handler scenarios.  

  SEQ CHAPTER \h \r 1 1)	Mix/Load/Apply liquids with backpack sprayer or
LP handwand 

2) 	Mix/Load/Apply liquids with HP handwand 

3)	Mix/Load/Apply liquids with a fogger

4) 	Aerosol can application. 

3.1	Occupational Handler Exposure Data 

PHED Exposure Data  SEQ CHAPTER \h \r 1 

	It is the policy of the HED to use data from the Pesticide Handlers
Exposure Database (PHED) when chemical-specific monitoring data or other
handler-specific data are not available.  PHED was designed by a task
force of representatives from the US. EPA, Health Canada, the California
Department of Pesticide Regulation, and members of the American Crop
Protection Association.  The PHED exposure data were used for the low
pressure handwand/back sprayer, aerosol can and HP handwand scenarios.  
The low pressure handwand and back sprayer scenarios were combined
because they have the same inhalation unit exposures.

Fogger Exposure Data 

	In the previous assessment, data from two studies were used to estimate
worker exposures during fogging applications.  These studies include a
University of Florida study on greenhouse applicators (Nigg et. al.,
1987) and an MGK study that monitored applicator exposure to prallethrin
during ULV cold fogging (Bergman, 2002).  Both the Nigg study and MGK
study have data quality concerns because only one worker was monitored. 
The MGK study also has ethics concerns because proper informed consent
procedures were not followed.   Based upon these concerns, the OPP
Ethics Reviewer and HED Management decided that neither study should be
used for risk assessment. (EPA, 2007).  These studies have thus been
deleted from this assessment.

National Pest Management Association Survey 

	Information on how pest control operators use pesticide products was
obtained from a survey conducted by the National Pest Management
Association (NPMA).  NPMA sponsored a “Pest Control Operators (PCO)
Product Use and Usage Information Survey”.  Using a retrospective
telephone survey method, the enumerator (Dr. Richard Patterson of the
University of Florida) contacted 148 PCO firms and was able to complete
67 surveys.  The survey was national in scope and included 12-23
responses from each of four regions.  The survey collected information
on where PCOs apply their products, product brands that are used for
wood destroying insects and general pest control, and the amount of time
PCOs spend on application, travel, equipment set up, mixing/loading
products, administrative and other activities.  

	OPP’s Biological and Economic Analysis Division (BEAD) reviewed the
NPMA survey and drew the following conclusions regarding the robustness
and validity of the survey data.  Given that there are approximately
19,000 PCO firms in the U.S., it is highly unlikely that a sample size
of 67 represents a statistically valid sample.  The use of a
retrospective survey methodology may have introduced errors in the data.
 Pesticide survey firms like Doane use a prospective survey instrument
sent to growers in advance thus allowing them to keep detailed accounts
of their pesticide usage in real time throughout the year.  Despite its
small size and retrospective methodology, however, the information
collected is far more robust than BEAD typically gets when asking
questions of this nature.  BEAD typically contacts 1-5 PCO’s and asks
chemical specific questions which may bias the responses if PCO’s
value the chemical under review. (D. Brassard, 05/17/04)

3.2	Occupational Handler Exposure Assumptions and Calculation Methods

Surface Spray Application Assumption	

  SEQ CHAPTER \h \r 1 The following assumptions were used in estimating
risks to occupational handlers from exposure to allethrins during
surface spray application:

The body weight of an adult handler is 70 kg.

The exposure duration ranges from short to long term. (Note – The
endpoint for inhalation exposures is the same for all durations of
exposure)

Respiratory protection either not worn (No Resp.) or consists of a
filtering facepiece dustmask (PF5 Resp.) or a full face piece respirator
(PF50).

The application rates for low pressure handwand/backpack sprayer, high
pressure handwand and fogger application are from the PCO product labels
and are listed in Table 5 above.  The application rates are expressed in
terms of product dilution rather than area treated.  

The application rate for PCO aerosol can application is from label
5602-192. 

Undiluted products could be used for contact sprays, surface sprays and
crack and crevice treatments at a wide variety of industrial and
institutional sites as listed on the labels.

Dilute sprays could be used for foliar applications in greenhouses.

For standard surface spray applications, a PCO could apply 40 gallons of
undiluted pesticide solution per day using a low pressure hand-wand or
backpack sprayer.  This assumption is from ExpoSAC Policy #9.  

A greenhouse applicator could apply 1000 gallons of a dilute spray
solution per day using a high-pressure hand-wand based upon ExpoSAC
Policy #9.   

Surface Spray Application Calculation Methods

The above assumptions were used with the PHED unit exposure data to
calculate inhalation exposures and risks in the standard manner as
outlined in the 1998 PHED Surrogate Exposure Guide.  The calculation
methods are detailed in Appendix A. Only inhalation exposures have been
assessed because no systemic effects were observed at the limit dose in
the dermal toxicity studies in test animals and no toxicity endpoint was
selected for dermal exposure.   The target MOE is 100 for short,
intermediate and long term inhalation exposures.

Space Spray (i.e. fogging) Applications Assumptions	

  SEQ CHAPTER \h \r 1 The following assumptions were used in estimating
risks to occupational handlers from exposure to allethrins during space
spray application:

The fogger applicator would be exposed to the average of the initial
concentration and the application rate concentration during hand held
fogging.

The spray dilutions range from 1.0 to 1.5 percent based upon product
labels.

The initial concentration is 0 mg/m3 based on the assumption that
allethrin residues from previous applications have dispersed or settled
out on surfaces.

The application rate concentration is 11 or 16 mg/m3 based upon the
application of 1.0 ounce of 1.0 or 1.6 percent spray per 1000 cubic feet
based upon product labels.

The applicator will be exposed to average concentration for 240 minutes
per 480 minute work day with the unexposed time being spent in
transportation and setup.  If an Actisol Commercial Unit is used as is
specified on the labels, the applicator could treat 134,000 cubic feet
in 240 minutes.   This is based upon the spray output of the Actisol
unit (0.56 ounces per minute @ 15 PSI).

Space Spray  Applications Calculation Methods:

The above assumptions were used to calculate a daily inhalation exposure
and risks as detailed in Appendix A.   The same POD of 1.3 mg/kg/day was
used as for surface spray applications and the same target MOE is 100 is
also applicable.

3.3	Occupational Handler Exposure and Risk Estimates

  SEQ CHAPTER \h \r 1 	  Risk estimates (i.e. MOEs) for the surface
spray handler scenarios are summarized in Table 11.  Most of the
inhalation MOEs are above the target MOE of 100 without respirators
(i.e. No Resp.) and therefore the inhalation risks are not of concern.  
The high pressure handwand scenario is of concern without respirators
and requires a PF5 filtering facepiece respirator (i.e. a dust mask) to
achieve the target MOE.  

Table 11 – Occupational Handler Risks from Surface Spray
Applications

Exposure Scenario	Dilution	Spray Dilution

(Percent ai)	Amount Sprayed per Day	lb ai  handled per day	Inhalation
MOE

M/L/A liquids with LP hand-wand or backpack sprayer	Undiluted	1.5	40
gallons	5	600 – No Resp.

M/L/A liquids with LP hand-wand or backpack sprayer	Diluted in water
0.11	40 gallons	0.37	8100 – No Resp.

M/L/A liquids with HP hand-wand (Greenhouse Use)	 Diluted in water	0.11
1000 gallons	9.2	81 – No Resp.

400 – PF5 Resp. 

Aerosol Can application	Undiluted	0.54	6 cans

 (16 oz ea)	0.032	2300 – No Resp.

 MOEs highlighted in bold font indicate risks of concern because they do
not exceed the target MOE of 100.



	The risks for the space spray applications are summarized in Table 12. 
The MOEs are of concern when respirators are not worn.  The MOEs are not
of concern if PF50 Full Face Respirators with appropriate cartridges are
worn.

Table 12 – Occupational Handler Risks from Space Spray Applications 

Label #	Spray Dilution	Application Rate 

(lb ai/1000 ft3)	Average Concentration

(mg/m3)	Respirator Worn	Inhalation MOE

1021-1478	1.5	0.0010	8.0	None	2.8

1021-1453	1.0	0.00067	5.4

4.2

1021-1478	1.5	0.0010	8.0	PF50 Full Face	140

1021-1453	1.0	0.00067	5.4

210

MOEs highlighted in bold font indicate risks of concern because they do
not exceed the target MOE of 100.



		

3.4	Occupational Handler Risk Characterization 

	It is likely that fogging of larger spaces is done using automatic
equipment which reduces operator exposure.   Additional exposure data
and information regarding fogging application methods could be used to
refine the risks.

4.0	Occupational Post Application Exposure and Risk

	According to the product labels, Allethrins are used as space sprays in
a wide variety of indoor areas such as barns, greenhouses, food storage
areas, food processing areas, restaurants and residences.   For many of
the applications there are restrictions such as “Do not apply when
people are present” or “Do not allow unprotected persons to enter
until treated area has been thoroughly ventilated” which minimize post
application exposures.   There is one product (Misty Mizer Insectide
III, 10807-69) which is applied from a time metered device; however, the
label requires that the device be set to operate only 12 hours per day
during off hours.  

	Given the above use characteristics, occupational post application
inhalation exposures are anticipated primarily from time metered device
applications.  To assess these exposures, a scenario that involves the
metered release into an industrial work area was evaluated based upon
the Misty Mizer label #10807-69.

4.1	Occupational Post Application Exposure Data Sources 

No exposure data was available to assess post application exposures.

4.2	Occupational Post Application Assumptions and Calculation Methods

Assumptions

The following assumptions were used in estimating risks to workers from
post application exposure to allethrins:

The Misty Mizer product is applied at 15 minute intervals for 12 hours
at night during non-business hours in accordance with the label.

The initial concentration of 0.0055 mg/m3 is based upon one spray of 100
mg (as stated on the label) of product containing 0.9% allethrin applied
to a 6000 cubic foot space.

The night time air exchange rate is 0.2 for an unventilated space based
upon MCCEM.  It is assumed that the mechanical ventilation system will
be turned off at night.

The final concentration at the end of the night time applications is
0.11 mg/m3 based upon one spray applied every 15 minutes for 12 hours in
a room ventilated at a rate of 0.2 air changes per hour. 

The day time air exchange rate is 1.0 air changes per hour.   

The average air concentration is for the eight hour period that begins
when the applications end and the ventilation system is turned on at the
beginning of the workday.

The breathing rate is 1.0 m3 per hour and the exposure time is eight
hours per day.

Calculation Methods

The post application allethrin air concentrations were calculated using
a rate of purging formula taken from the ACGIH Manual of Industrial
Ventilation, 22nd Edition (This formula is also in the EPA MCCEM).  
This formula accounts for the decrease in airborne concentrations that
result from the mechanical ventilation of an interior space.   For the
night time scenario, the decline in air concentrations that occurred
during the 15 minute time periods between applications was calculated.  
The application concentration (0.0055 mg/m3) was added to the calculated
concentration at 15 minute intervals which caused the calculated
concentration to rise throughout the night because the night time
ventilation rate (0.2 air change per hour) did not completely remove the
allethrin between applications.   For the day time scenario, the
applications ceased and the ventilation rate increased to 1.0 air change
per hour which caused the allethrin concentrations to rapidly decline. 
Worker exposures were assumed to begin in the morning immediately after
the night time applications ceased and were averaged over an eight hour
period.    

4.3	Occupational Post Application Exposure and Risk Estimates

The exposure and risk estimates for post application exposures are
detailed in Table A2 of Appendix A and the air concentration profile is
included in Appendix B.  The inhalation MOE is 850, which exceeds the
target MOE of 100 and is not of concern.   This MOE is representative of
a space that is ventilated at the rate of 0.20 air changes per hour at
night and 1.0 air change per hour during the day.

4.4	Occupational Post Application Risk Characterization

The risk for the metered release scenario is conservative because it was
assumed that the aerosols would remain airborne until they were removed
by ventilation and the effects of aerosol settling were not considered. 
Aerosol settling could be a major factor depending upon the aerosol size
and rate of evaporation.  Information regarding the aerosol size and
evaporation rate could be used to refine the risks.

5.0	Residential Handler Exposure and Risk

  SEQ CHAPTER \h \r 1   SEQ CHAPTER \h \r 1 	All of the allethrin
products that are intended for application by residents are packaged in
aerosol spray cans, therefore, the residential handler exposures involve
application only.  The following residential handler exposure scenario
was assessed:  

1)	Aerosol can application

5.1	Residential Handler Exposure Data

  SEQ CHAPTER \h \r 1 PHED unit exposure data were used to assess
exposures from aerosol can applications.    

5.2	Residential Handler Exposure Assumptions

	The following assumptions were used in estimating risks from
residential handler exposure to allethrins:

The body weight of an adult handler is 70 kg.

One aerosol can is used per day.  This assumption is based upon the HED
Science Advisory Committee on Exposure SOP #12: “Recommended Revisions
to the Standard Operating Procedures for Residential Exposure
Assessment” (2/22/2001).	

Each aerosol can contains 15 to 16 ounces by weight of product based
upon the labels included in the Use Closure Memo. 

The percent ai in the products ranges from 0.10 to 0.25 percent by
weight based upon the labels and limits established in the RED.

5.3	Residential Handler Risk Estimates

	The inhalation risk estimates (i.e. MOEs) for residential handlers are
summarized in Table 12 below and detailed calculations are provided in
Appendix A.  All of the MOEs exceed the target MOE of 1000 and therefore
the risks are not of concern.

Table 12 – Residential Handler Risks for Allethrin

Use Scenario	Percent ai in Product	Amount of Product Used per Day	Amount
of ai used per day 	Inhalation MOE*

Handler Exposures – Aerosol Can Application

Indoor Surface or Space Spray 

Hand Held Yard and Patio Fogger	

Wasp and Hornet Nests	0.25

0.15

0.10	One 15 ounce can

One 16 ounce can

One 16 ounce can	0.0024 lb

0.0015 lb

0.0010 lb	29,000

46,000

70,000

*All of the MOEs exceed the target MOE of 1000 and therefore the risks
are not of concern.



5.4	Residential Handler Risk Characterization

	Some allethrin products are packaged as ready to use trigger sprayer
bottles.  The handler risks calculated from aerosol can application are
protective of risks from trigger sprayer applications because the unit
exposure values are lower for trigger sprayer application.

6.0	Residential Post Application Exposures and Risks

	The term “post-application” describes individuals who are exposed
to pesticides after entering areas previously treated with pesticides. 
Allethrin post application incidental oral exposures may occur after
surface applications of allethrin are made to residential areas such as
carpets and vinyl flooring.  Inhalation exposures may occur after space
spray application.  Incidental oral exposures were assessed for toddlers
and inhalation exposures were assessed for adults and toddlers.  Dermal
exposures were not assessed because no systemic effects were observed at
the limit dose in the dermal toxicity studies in test animals and no
toxicity endpoint was selected for dermal exposure.  The following
scenarios were assessed:

Toddler incidental oral ingestion of residues on indoor surfaces after
fogger treatment.

Toddler incidental oral ingestion of residues on indoor surfaces after
PCO broadcast surface treatment.

Toddler incidental oral ingestion of residues on indoor surfaces after
Consumer spot surface treatment.

4)	Inhalation exposures from space spray application

5)	Inhalation exposures from mosquito coils and fly mats

6)	Inhalation exposures from yard and patio foggers

	In the previous version of this assessment (D334788), incidental oral
exposures from PCO broadcast surface sprays were assessed at spray
dilutions that ranged from 0.25 to 3.0 percent with a spray volume of 1
gallon per 1000 ft2 and risks of concern were identified.  In response
to these concerns, the registrants have agreed to limit the spray
dilution to 0.05 percent when the spray volume is 1 gallon per 1000 ft2
or 0.10 percent when the spray volume is 0.50 gallons per 1000 ft2. 

Because many of the consumer applied products contain greater than 0.05
percent allethrins, the residential applications of consumer products
will be limited to spot treatments in accordance with the allethrin RED
and broadcast surface applications to areas such as rugs and carpets
will be eliminated.   Some of the existing labels already require spot
treatments, for example, the Real Kill label#9688-86 states: “FOR SPOT
TREATMENT ONLY - Direct spray into cracks and crevices in walls, dark
corners of rooms, cabinets, closets, along and behind baseboards,
beneath and behind sinks, stoves, refrigerators and cabinets, around
plumbing and other utility installations and wherever else these pests
may find entrance”.  Given that the typical consumer  product is an
aerosol can which contains approximately 16 ounces by weight, which is
roughly equivalent to 16 ounces by volume, and given that spray volume
is 1 gallon per 1000 ft2 as stated in the Allethrin Smart Meeting, the
area that could be treated with one can is 125 ft2 or approximately 10
percent of a typical 1250 ft2 house.

6.1	Residential Post Application Exposure Data

	Exposure data for assessing post-application exposures from the use of
foggers and aerosols in indoor residential settings were based upon
pyrethrin studies conducted by the Non-Dietary Exposure Task Force
(NDETF).  The pyrethrin study data are considered applicable for
allethrin because of the structural similarity between pyrethrin and
allethrin.   

The NDETF conducted studies to examine the deposition of residues from
total release foggers.  The studies conducted with formulations of
pyrethrin/piperonyl butoxide and permethrin/pyrethrins were submitted to
EPA in January 2004.  The studies simulated the use of a fogger and
aerosol products indoors to provide data on air dispersion and
deposition on surfaces (walls, floor).  Carpet and vinyl were selected
as the flooring surfaces of interest because of their different physical
and chemical properties and because they represent a significant amount
of the floor coverings used in homes in North America.  While the focus
of the NDETF efforts was on total release foggers, a study was also
conducted to determine both dispersion (air levels) and deposition (on
flooring) of pyrethrin/piperonyl butoxide resulting from the use of a
hand held aerosol spray can.  Potential direct exposure of the user was
also measured. Air sampling from the breathing zone of the applicator
and analysis of residues on cotton gloves was performed.  A more
detailed evaluation of the NDETF Study data provided in separate review
(D302120, B. Daiss, 5/11/04).

	Post-fogger release floor concentration was based on data from NDETF
Study Volume 2, “Post-Application Deposition Measurements for
Pyrethrins & Piperonyl Butoxide Following Use of a Total Release Indoor
Fogger”.  The measured mean floor concentration was 2.25 µg/cm2
following fogger application at the rate of 0.00076 lb ai per 1000 ft3. 
HED used the mean measured deposition which excluded the concentration
on the floor center coupon because the coupon under the total release
canister appeared to be an outlying data point.  The maximum pyrethrin
concentration measured on the coupon under the total release canister
was 121 µg/cm2.  The next highest concentration was 6.68 µg/cm2 on a
coupon at a distance of two feet from the canister.  This deposition
pattern was not repeated in findings from NDETF Study Volume 23,
“Post-Application Deposition Measurements for Pyrethrins & Piperonyl
Butoxide Following Use of a Total Release Indoor Fogger”.  The mean
floor concentration including the floor center coupon was 5.79 µg/cm2. 

	

	Transfer of pyrethrins from fogger treated carpet was assumed to be 8%
of deposition based on data from Volume 29 of the NDETF Study,
“Measurement of Transfer of Pyrethrin and Piperonyl Butoxide Residues
from Vinyl and Carpet Flooring Treated with a Fogger Formulation to DSS
Wetted Hands Following a Single Hand Press”.  Transfer of pyrethrins
from fogger treated vinyl flooring was assumed to be 11% of deposition
based on data from Volume 13 of the NDETF Study, “Measurement of
Transfer of Pyrethrin and Piperonyl Butoxide Residues from Vinyl and
Carpet Flooring Treated with a Fogger Formulation to DSS Wetted Hands
Following a Single Hand Press”.

	Indoor air concentration for the period during and after aerosol space
spray application was based on data from Volume 18 of the NDETF Study,
“Measurement of Air Concentration, Dermal Exposure, and Deposition of
Pyrethrin and Piperonyl Butoxide Following the Use of an Aerosol
Spray”.  The measured two hour time weighted average air concentration
at the 5 foot level (air samples were also collected at the one foot
level) was 0.022 µg/L (0.022 mg/m3) following aerosol application of
9.3 grams of a 0.5% pyrethrin formulation.  This application was made to
a simulated residential room that had an interior volume of 2048 ft3.  
The theoretical concentration is 0.80 mg ai/m3 based upon the above
parameters and assuming no deposition (the room was not ventilated
during the two hour time period). 

	

6.2	Residential Post Application Exposure Assumptions

	The following assumptions were used in estimating risks from
residential post application exposure to allethrins:

General Assumptions

The body weight of an adult is 70 kg

The body weight of a toddler is 15 kg

The breathing rates are 1.0 m3/hr for adults and 0.7 m3/hr for children.
 These values are from SOP #12 and are recommended for scenarios of a
few hours in duration.  

Exposure is assessed on day of application (i.e., day zero) 

The application rates were generally taken from the product labels, the
Allethrin Smart Meeting or the limits to be established in the RED. 

Indoor Fogger Surface Treatment Post Application Exposure Assumptions

The application rate is 3.6 mg/m3 based upon the Speer 4X Indoor Fogger
(formerly 11715-96, transferred to 2724-552) which is a 1.5 ounce fogger
containing 1.2 percent allethrin.  It is assumed that one fogger will
treat a 5000 ft3 (141.5 m3) room as stated on the label.

 The indoor surface residue is 0.65 µg/cm2 based on NDETF study data
for pyrethrin and the above application rate.  

The hand transfer efficiency is 8% for carpet and 11% for vinyl based on
NDETF data

The saliva extraction factor is 50 percent.

The surface portion of hand put in mouth is 20 cm2

The hand-to-mouth (HMT) exposure frequency is 20 times per hour for
short term exposures as listed in SOP #12.  This is a 90th percentile
value from a video observation study of 30 preschool children.

The HTM exposure frequency is 9.5 times per hour for intermediate term
exposures as listed in SOP 12. This is the mean value from the video
observation study.

The exposure duration is 4 hours for hard surface floors and 8 hours for
carpeted floors.

PCO Broadcast Indoor Surface Treatment Post Application Exposure
Assumptions 

The spray dilution is 0.05 percent when the spray volume is 1 gallon per
1000 square feet.

The spray dilution is 0.10 percent when the spray volume is 0.5 gallon
per 1000 square feet.

The hand transfer efficiency is 8% for carpet and 11% for vinyl based on
NDETF data

The saliva extraction factor is 50 percent.

The surface portion of hand put in mouth is 20 cm2

The HTM exposure frequency is 20 times per hour for short term
exposures.  

The HTM exposure frequency is 9.5 times per hour for intermediate term
exposures.

The exposure duration is 4 hours for hard surface floors and 8 hours for
carpeted floors.

Consumer Spot Indoor Surface Treatment Post Application Exposure
Assumptions

The spray dilution ranges from 0.05 to 0.5 percent based upon the
consumer product labels.

One 16 ounce aerosol can is applied based upon the residential SOPs.

The application will made as a spot treatment as required by the
Allethrin RED.

The spray volume is 1 gallon/1000 ft2 based on the Allethrin Smart
Meeting.

One can treats 125 ft2 which is 10 percent of the area of a typical 1250
ft2 house.

The exposure duration is 0.4 hours for hard surface floors and 0.8 hours
for carpeted floors based upon the Residential SOP values of 4 hours for
hard surface floor and 8 hours for carpeted floors for broadcast
application times a correction factor of 0.1 to account for the smaller
area treated during spot treatments.  

The hand transfer efficiency is 8% for carpet and 11% for vinyl based on
NDETF data

The saliva extraction factor is 50 percent.

The surface portion of hand put in mouth is 20 cm2

The HTM exposure frequency is 20 times per hour for short term
exposures.  

The HTM exposure frequency is 9.5 times per hour for intermediate term
exposures.

Space Spray Application Exposure Assumptions

The products contain 0.1 or 0.2 percent based upon existing labels and
the Allethrin RED. 

Three application rates were considered with the lowest rate based upon
the amount of spray applied during the NDETF study, the medium rate
based upon the Raid label and the highest rate based upon SOP
assumptions.

The air concentration of 0.022 mg/m3 from the NDETF study was adjusted
to reflect the above rates.

The exposure duration is 2 hours because air monitoring, which was
conducted for two hours after application, indicated that the air
concentrations dropped from an initial value of 0.12 mg/m3 to 0.014
mg/m3.

Mosquito Coil and Fly Mat Exposure Assumptions 

The percent a.i. is 0.3 percent for mosquito coils and 24 percent for
fly mats based upon the product labels.

The weight of the mosquito coils and mats is 12 grams and 0.93 grams,
respectively, based upon the allethrin smart meetings.

The duration of emission is 6 hours for a coil and 10 hours for a mat
based upon the allethrin smart meetings.

The number of mats or coils used is two per treatment based upon the
residential SOPs.

The space treated is 90.62 m3 based upon the a 20 foot by 20 foot patio
with a “ceiling height” of 8 feet as specified in the residential
SOPs.  (3200 ft3 = 90.62 m3) 

The initial concentration is calculated as an instant release where all
of the material is thrown up into the space as stated in the residential
SOPs.

The time weighted average (TWA) concentration is 100 times less than the
initial concentration based upon the residential SOPs.

The exposure duration is 5 hours for adults and 3 hours for children
based upon the Residential SOPs. 

Hand Held Yard and Patio Fogger Assumptions

The percent a.i. is 0.15 based upon the product labels.

The spray discharge rate is 6 grams of product per second based upon the
Allethrin Smart Meeting.

The spray duration is 3 seconds based upon the Allethrin Smart Meeting.

The space treated is 90.62 m3.

The initial concentration is calculated as an instant release.

The TWA concentration is 100 times less than the initial concentration.

The exposure duration is 5 hours for adults and 3 hours for children. 

Total Release Yard and Patio Fogger Assumptions

The percent a.i. is 0.15 based upon the product labels.

The container size is 1.5 ounces based upon the Raid Yard Guard label
4822-394. The 6.0 ounce size will be eliminated from this label in
accordance with the RED.

The space treated is 90.62 m3.

Two containers are used as specified in the Residential SOPs.

The initial concentration is calculated as an instant release.

The TWA concentration is 100 times less than the initial concentration.

The exposure duration is 5 hours for adults and 3 hours for children.

6.3	Residential Post Application Exposure and Risk Estimates

	   The exposure and risk estimates for the residential post application
scenarios are summarized in Table 13 and the calculations are included
in Appendix A.  Most of the scenarios are not of concern because the
MOEs approach or exceed the target MOE of 1000.   The outdoor fogger
scenario is of concern for inhalation exposures because the inhalation
MOE of 650 does not exceed the target MOE of 1000.   

Table 13 – Allethrin Residential Post Application Risk Summary

Source of Exposure	Application Rate	Exposed Population	MOE*

Incidental Oral Exposures (Short Term)

Fogger Treatment - Carpet Floors  

Fogger Treatment - Vinyl Floors 	3.6 mg/m3

	Children	3600

5200

PCO Surface Treatment - Carpet Floors  

PCO Surface Treatment - Vinyl Floors 	0.0042 lb ai/1000 ft2	Children
1200

1700

Consumer Spot Treatment - Carpet Floors  

Consumer Spot Treatment - Vinyl Floors 	0.25% Spray	Children	2200

3400

Consumer Spot Treatment - Carpet Floors  

Consumer Spot Treatment - Vinyl Floors 	0.05% Spray	Children	11000

17000

Incidental Oral Exposures (Intermediate Term)

Fogger Treatment - Carpet Floors  

Fogger Treatment - Vinyl Floors 	3.6 mg/m3	Children	3000

4400

PCO Surface Treatment - Carpet Floors  

PCO Surface Treatment - Vinyl Floors 	0.0042 lb ai/1000 ft2	Children	960

1400

Consumer Spot Treatment - Carpet Floors  

Consumer Spot Treatment - Vinyl Floors 	0.25% Spray	Children	1900

2800

Consumer Spot Treatment - Carpet Floors  

Consumer Spot Treatment - Vinyl Floors 	0.05% Spray	Children	9600

14000

Inhalation Exposures (Short/Intermediate Term)

Space Spray – 0.25 Percent Product 	0.40 mg/m3

(based upon the NDETF study)	Children

Adults	         1300

4200

Space Spray – 0.10 Percent Product 	0.16 mg/m3

(based upon the NDETF study)	Children

Adults	3050

10000

	0.35 mg/m3

(Based upon Raid label 4822-513)	Children

Adults	1400

4800

Mosquito Coils	2 coils per  patio	Children

Adults	7000

14000

Fly Mats	2 mats per patio	Children

Adults	1800

3600

Hand Held Yard and Patio Fogger 	3 second spray per patio

(based on the Smart Meeting)	Children

Adults	3100

6200

Hand Held Yard and Patio Fogger 	9  second spray per patio

(Back calculated)	Children

Adults	1000

2200

Total Release Yard and Patio Fogger	Two 1.5 ounce foggers per patio
Children

Adults	650

1300

*MOEs in bold font do not approach or exceed the target MOE of 1000 and
indicate risks of concern.

6.4	Residential Post Application Risk Characterization 

A summary of the Residential Exposure Joint Venture (REJV) household
inventory data for consumer products that contain allethrin is listed in
Table 14.  There were no indoor total release aerosol (i.e. fogger)
products listed for allethrin in the REJV.

Table 14 – REJV Data for Consumer Products 

Product Type	Number of Households with Product On Hand	Percent Allethrin
in Product



5th Percentile	50th Percentile	99th Percentile

Wasp and Hornet Killer	1417	0.05	0.05	0.14

Crawling Insect Killer	1113	0.05	0.05	0.10

General	957	0.05	0.20	0.44

Flying Insect Killer	921	0.13	0.14	0.25

Yard and Patio Fogger	320	0.10	0.14	0.14

Mosquito Coil	171	0.10	0.14	0.35

Fly Mat	48	21.97	21.97	21.97



The space spray application rates and resultant exposures are variable
depending upon the label considered and user adherence to label
instructions.  Although the Raid label is fairly specific (apply 10
second spray per 1000 ft3) other labels contain statements such as
“fill room with mist” which are less specific.  Many of the labels
also require that the room be kept closed for 15 minutes and ventilated
thoroughly prior to entry.. 

The yard and patio fogger scenario is only of concern when the product
is in the form of a total release fogger.   The yard and patio scenario
is not of concern when the product is in the form of a hand held fogger
and the spray duration is 9 seconds or less.   Both product forms are on
the same label (4822-394) and it is not which form is used the most
often.  

Inhalation exposures following the release of a total release aerosol
fogger used indoors was not assessed because the fogger labels typically
require actions that reduce exposure.   The Speer  4X Indoor Fogger
label, for example, has the following statement “DO-NOT RE-ENTER
BUILDING FOR FOUR HOURS; then open exterior doors and windows and allow
to air for 60 minutes before reoccupying area”.   This label has the
highest concentration of allethrin (1.2% a.i.) and the most recent
approval date (5/20/2003).   The other fogger labels have lower
concentrations of allethrin and are much older with approval dates that
range from 1981 to 1992. Only inhalation exposures were assessed for
outdoor fogger applications.    

Incidental oral exposures following the release of a total release
aerosol fogger used outdoors were not assessed because it was assumed
that the aerosols would disperse before they would settle out.

7.0	References:

Nigg et al., 1987.  Pesticide Exposure to Florida Greenhouse
Applicators, Nigg, H.N., Stamper, J.H. and Mahon, W.D., University of
Florida, 1987 (MRID 403505-01)

Bergman, 2003.  Applicator Exposure and Air Sampling Following
Application of ETOC Fogging Concentrate 2764 by ULV Fogging, Bergman,
John T., McLaughlin Gormley King Company, 2003 (MRID 458693-01)

EPA, 2007.  “Re: Use of the Prallethrin and/or Nigg Studies”, Email
from John Carley to Molly Clayton, March 1, 2007

Appendix A - Occupational and Residential

Exposure and Risk Calculations for Allethrins

Table A1 – Allethrin Inhalation MOE’s for Occupational Handlers
Applying Surface Sprays

Exposure Scenario	Inhalation Unit ExposureA   (µg/lb ai)	Use	Spray
DilutionB (Percent ai)

	Amount Sprayed per Day	lb ai per handled per dayE	Inhalation DoseF

(mg/kg/day)	Inhalation MOEG

PCO Applications to Commercial, Industrial and Institutional Sites

M/L/A liquids with LP hand-wand or backpack sprayer	30	Surface Spray
Undiluted	1.5	40 gallonsC	5	0.0022	600 – NRH

M/L/A liquids with LP hand-wand or backpack sprayer	30	Surface Spray
Diluted in Water	0.11	40 gallonsC	0.37	0.00016	8100 – NR

M/L/A liquids with HP hand-wand	120	Surface Spray Diluted in water	0.11
1000 gallonsC	9.2	0.016	81 – NR

400 – PF5I

Aerosol Can application	1300	Surface Spray	0.50	6 cansD	0.030	0.00056
2300 – NR



Footnotes:

A.  SEQ CHAPTER \h \r 1 	Unit Exposure values are from PHED (See Table
A12)

B.	Spray dilutions are from labels 432-870 (3 percent), 35138-80 (0.11
percent) and 5602-192 (0.50 percent)

 C.	Based upon ExpoSAC Policy 9.

D.	Screening level estimate based upon professional judgment.

E.	LB ai handled per day = (Spray dilution/100) * (8.35 lbs/gallon of
spray solution or 1 lb per aerosol can) * Amount sprayed per day 

F.	Inhalation dose (mg/kg/day) = [unit exposure (ug/lb ai) * 0.001 mg/ g
* lb ai handled per day)] / Body weight (70 kg).

G.	MOE = NOAEL/Dose where the NOAEL is 1.3 mg/kg/day. 

H.	No respirator is worn.

I.	PF5 filtering facepiece dust/mist respirator is worn.

* The target MOE is 100.  MOEs that are less than 100 indicate risks of
concern and are highlighted in bold font.

 

Table A2 – Allethrin Inhalation MOE’s for Occupational Handlers
Applying Space Sprays 

Label #	Spray Dilution	Application RateB 

(lb ai/1000 ft3)	Initial Concentration 

(mg/m3)	Final Concentration

(mg/m3)	Average Concentration

(mg/m3)	Inhalation ExposureC (mg/day)	Inhalation DoseD

(mg/kg/day)	Inhalation MOEE

No Respirators Worn (i.e. PF =1)

432-870	3.0A	0.0020	0	32	16	64	0.90	1.4

1021-1478	1.5	0.0010	0	16	8.0	32	0.46	2.8

1021-1453	1.0	0.00067	0	11	5.4	21	0.30	4.2

Full Face Respirators Worn (i.e. PF = 50)

432-870	3.0	0.0020	0	32	16	1.3	0.018	70

1021-1478	1.5	0.0010	0	16	8.0	0.63	0.0090	140

1021-1453	1.0	0.00067	0	11	5.4	0.42	0.0060	210



Footnotes:

A.    This rate is will be cancelled per the Allethrin RED and is
included only for reference.

B.	Based upon the application of 1 fluid ounce per 1000 cubic feet.

C.	Inhalation Exposure (mg/day) = [Average Concentration (mg/m3) *
Breathing Rate (1 m3/hr) * Exposure Time (4 hours/day)] / [Respirator
Protection Factor (1 or 50)] 

D.	Inhalation Dose (mg/kg/day = Inhalation Exposure (mg/day) / Body
Weight (70 kg)

E.	MOE = NOAEL/Dose where the NOAEL is 1.3 mg/kg/day. 

* The target MOE is 100.  MOEs that are less than 100 indicate risks of
concern and are highlighted in bold font.

Table A3 – Allethrin Occupational Post-Application Inhalation Risks
Following Metered Release

Exposure Scenario	Initial Air Concentration

(mg/m3)	Air Exchange Rate	Final Air Concentration

(mg/m3)	Average Air ConcentrationE

(mg/m3)	DoseF (mg/kg/day)	MOEG

Nighttime Application During Non-Business Hours (As Required by the
label)	0.0055A

(at minute 0)	0.2B	0.11C

(at minute 720)	N/A	N/A	N/A

Daytime Exposure During Business Hours	0.11 

(at minute 720)	1.0D	0.000036

(at minute 1200)	0.013	0.0015	870



A.  The initial concentration is based upon one spray of 100 mg of
product containing 0.9% allethrin applied to a 6000 cubic foot space.

B.  The air exchange rate is 0.2 for an unventilated space based upon
MCCEM.  It is assumed that the mechanical ventilation system will be
turned off at night.

C.  The final concentration is based upon one spray applied every 15
minutes for 12 hours in a room ventilated at a rate of 0.2 air changes
per hour. 

D.  The air change rate is 1.0 for a typical industrial space.

E.  The average air concentration is for the eight hour period that
begins when the applications end and the ventilation system is turned on
at the beginning of the workday.

	

F.   Dose				=  	(Average air concentration * Breathing rate * exposure
duration)

     									Body Weight

 where:   	Air Concentration	=	Average air concentration (mg/m3) 

               	Breathing rate		=	1.0 m3 per hour  

                 	Exposure Duration	=	8 hours 

Body Weight		=	70 kg

G. MOE = NOAEL/Dose where the NOAEL is 1.3 mg/kg/day. 

Note - Air Concentrations were calculated using the following formula
taken from the ACGIH Manual of Industrial Ventilation (Graph is included
in Appendix B).

Air Concentration at time t	=	Initial Air Concentration * 0.5 (t/0.693 *
Q/V)

where:		time (t)	 		=	1 minute intervals 

		Volume (V)		= 	6000 ft3

		Ventilation Rate (Q)	= 	20 CFM (Night) and 100 CFM (Day)

		Initial Air Concentration	=	0.0055 mg/m3 (Night) and 0.26 mg/m3 (Day)

* The target MOE is 100.  The MOE exceeds the target MOE and indicate
that the risks are not of concern.

 Table A4 - Allethrin Inhalation MOEs for Residential Handlers

Exposure Scenario	Inhalation Unit Exposure 

(µg/lb ai)	Use	Percent a.i. in product	Amount of Product Used per Day	

Amount a.i. Used per Day (lb)	Inhalation Dose (mg/kg/day)	Inhalation MOE

Aerosol Can Application	1300	Indoor Space or Surface Spray	0.25	1 15
ounce can	0.0024	0.000045	29,000



Hand Held Yard and Patio Fogger	0.15	1 16 ounce can	0.0015	0.000028
46,000



Wasp and Hornet Nests 	0.10	1 16 ounce can	0.0010	0.000019	70,000



  SEQ CHAPTER \h \r 1 * Baseline inhalation unit exposures represent no
respirator.  Unit Exposure values are from PHED or submitted studies
(see Table A12)

* Inhalation dose = [unit exposure value * 0.001 mg/ g * Amount Used per
Day (lb)] / Body weight (70 kg).

* MOE = NOAEL/Dose where the NOAEL is 1.3 mg/kg/day 

* The target MOE is 1000.  All of the MOEs exceed the target MOE and
indicate that the risks are not of concern.

 Table A5 - Allethrin Incidental Oral Ingestion Risks to Toddlers
Playing on Indoor Surfaces after Indoor Fogger Treatment

Indoor Surface	Product 

Application RateA

(mg/m3)	Study 

Application RateB 

(mg/m3)	Measured Indoor Surface ResidueC

(ug/cm2)	Adjusted Indoor Surface ResidueD (µg/cm2)	Hand Transfer
Efficiency 	Daily Oral Dose (mg/kg/day)	Incidental Oral MOE*

Short Term Exposures

Carpet	3.6	12	 2.25	0.66	8.0%	0.0056	3600

Vinyl



	11.0%	0.0039	5200

Intermediate Term Exposures

Carpet	3.6	12	 2.25	0.66	8.0%	0.0027	3000

Vinyl



	11.0%	0.0018	4400



A   Based upon one 1.5 ounce (42.5 gm) fogger containing 1.2% allethrin
applied to a room with an interior volume of 5000 ft3  (141.5 m3) and an
eight foot ceiling.

B.  Based upon 141 gm of a fogger product containing 0.5% pyrethrin
applied to a room with an interior volume of 2048 ft3 (58 m3) and an
eight foot ceiling.

C.  The mean of n=32 floor residues (excluding the center coupon)
measured 3 hours after fogger application.   The SD was 1.35 ug/cm2.

D.  The measured residue was adjusted to account for the product
application rate.

Daily Oral Dose  (mg/day)	 =	(ISR * HTE * SEF * SA * Freq * ED *  0.001
mg/ug) / BW

where:	ISR	=	Indoor Surface Residue (ug/cm2)

			HTE	=	Hand Transfer Efficiency - measured in NDEF Study	

		SEF	=	Saliva Extraction Factor (50%)

			SA	=	Surface Area of Two Fingers (20 cm2)

			Freq	=	Frequency of Hand to Mouth Events (20 events per hour for
short term exposures and 9.5 events per hour for intermediate term
exposures)

		ED	=	Exposure Duration = 4 hours/day for vinyl floors and 8 hours for
carpeted floors 

			BW 	=	15 kg for toddler

 MOE		= 	NOAEL (20 mg/kg/day for short term exposures and 8 mg/kg/day
for intermediate term exposures)/Daily Oral Dose (mg/kg/day) 

* The target MOE is 1000 for incidental oral exposures. MOEs that are
less than 1000 indicate risks of concern and are highlighted in bold
font.

Note – The data cited above is from NDETF Study “Post Application
Deposition Measurements for Pyrethrins and Piperonyl Butoxide Following
Use of a Total Release Indoor Fogger”, Project ID 98-0022-PY01, MRID
461886-02.  This data is property of the NDETF.Table A6 - Allethrin
Incidental Oral Ingestion Risks to Toddlers Playing on Indoor Surfaces
after Surface Treatment (PCO Broadcast)

Spray Dilution (Percent Allethrin)	Spray Volume

per 1000 ft2	Application RateC

(lb ai/1000 ft2)	Indoor Surface ResidueD (µg/cm2)	Indoor Surface	Hand
Transfer EfficiencyE 	Daily Oral DoseF (mg/kg/day)	Incidental Oral MOEG

Short Term Exposures

0.05A	1 gallon	0.0042	2.05	Carpet	8.0%	0.017	1200

0.10B	0.5 gallon

	Vinyl	11.0%	0.012	1700

Intermediate Term Exposures

0.05A	1 gallon	0.0042	2.05	Carpet	8.0%	0.0083	960

0.10B	0.5 gallon

	Vinyl	11.0%	0.0057	1400



A.  Based upon the RED, the maximum allowable spray dilution is 0.05
percent when the spray volume is 1 gallon per 1000 square feet.

B.  Based upon the RED, the maximum allowable spray dilution is 0.10
percent when the spray volume is 0.5 gallon per 1000 square feet.

C.  Application Rate = (Spray Dilution/100) * Spray Volume (Gallons) *
Spray Density (8.35 lb/gallon)

D.  Indoor Surface Residue (ug/cm2) = (lb ai/1000 ft2 * 454 gm/lb *
1,000,000 ug/gm) / (1000 ft2 * 929 cm2/ft2) 

E.  Based upon the NDEF study.

F.  Daily Oral Dose (mg/day)	=	(ISR * HTE * SEF * SA * Freq * ED * 0.001
mg/ug) / BW

where:	ISR	=	Indoor Surface Residue (ug/cm2)

				HTE	=	Hand Transfer Efficiency 

			SEF	=	Saliva Extraction Factor (50%)

				SA	=	Surface Area of Two Fingers (20 cm2)

				Freq	=	Frequency of Hand to Mouth Events (20 events/hour for short
term and 9.5 events/hour for intermediate term)

			ED	=	Exposure Duration = 4 hours/day for vinyl floors and 8 hours/day
for carpeted floors

				BW 	=	15 kg for toddler

G. MOE				= 	NOAEL (20 mg/kg/day for short term exposures and 8
mg/kg/day for intermediate term exposures)/Daily Oral Dose (mg/kg/day) 

* The target MOE is 1000 for incidental oral exposures.  All of the MOEs
approach or exceed the target MOE and indicate that the risks are not of
concern.

Table A7 - Allethrin Incidental Oral Ingestion Risks from Surface
Treatment (Consumer Spot Treatment)

Percent ai in Product	Application RateA

(lb ai/1000 ft2)	Indoor SurfaceB Residue (µg/cm2)	Indoor Surface	Hand
Transfer EfficiencyC 	Daily Oral DoseD (mg/kg/day)	Incidental Oral MOEE

Short Term Exposures

0.25

(based on the RED)	0.021	10.3	Carpet	8.0%	0.0090	2200



	Vinyl	11.0%	0.0060	3400

0.05

(minimum labels)	0.0042	2.06	Carpet	8.0%	0.0018	11000



	Vinyl	11.0%	0.0012	17000

Intermediate Term Exposures

0.25

(based on the RED)	0.021	10.3	Carpet	8.0%	0.0042	1900



	Vinyl	11.0%	0.0029	2800

0.05

(minimum labels)	0.0042	2.06	Carpet	8.0%	0.00083	9600



	Vinyl	11.0%	0.00057	14000



A.  Based upon a spray volume of 1 gallon of product applied to 1000
square feet.

B.  Indoor Surface Residue (ug/cm2) = (lb ai/1000 ft2 * 454 gm/lb *
1,000,000 ug/gm) / (1000 ft2 * 929 cm2/ft2) 

C.  Based upon the NDEF study.

D.  Daily Oral Dose  (mg/day)	=	(ISR * HTE * SEF * SA * Freq * ED * 
0.001 mg/ug) / BW

where:	ISR	=	Indoor Surface Residue (ug/cm2)

				HTE	=	Hand Transfer Efficiency 

			SEF	=	Saliva Extraction Factor (50%)

				SA	=	Surface Area of Two Fingers (20 cm2)

				Freq	=	Frequency of Hand to Mouth Events (20 events/hour for short
term and 9.5 events/hour for intermediate term)

			ED	=	Exposure Duration = 0.4 hour/day for vinyl floors and 0.8
hours/day for carpeted floors 

				BW 	=	15 kg for toddler

E. MOE				= 	NOAEL (20 mg/kg/day for short term exposures and 8
mg/kg/day for intermediate term exposures)/Daily Oral Dose (mg/kg/day) 

* The target MOE is 1000 for incidental oral exposures. MOEs that are
less than 1000 indicate risks of concern and are highlighted in bold
font.

Table A8- Allethrin Inhalation Risks from Indoor Space Spray
Application

Allethrin Application Rate

(mg/m3)	Application Rate Basis	NDETF Study Application Rate 

(mg/m3)	Measured Breathing Zone ConcentrationE

(mg/m3) 	Adjusted Breathing Zone ConcentrationF

(mg/m3)	Exposed Individual	DoseG

(mg/kg/day)	MOEH

Assuming 0.25 Percent Allethrin in Product

0.40	NDETF StudyA, B	0.80	

0.022 

	0.011	Adult	0.00031	4200





	Child	0.0010	1300

Assuming 0.10 Percent Allethrin in Product

0.16	NDETF StudyA, C	0.80	0.022	0.0044	Adult	0.00013	10000





	Child	0.00042	3050

0.35	2006 Raid LabelD

	0.0096	Adult	0.00027	4800





	Child	0.00090	1400



A. Based upon the application of 9.31 grams of product to a room with an
internal volume of 58 cubic meters as was done in the NDETF study.

B. NDETF study rate of 0.80 mg/m3 at 0.50 percent ai adjusted for 0.25
percent ai.

C. NDETF study rate of 0.80 mg/m3 at 0.50 percent ai adjusted for 0.10
percent ai.

D. Raid label 4822-513 of 2006 which contains 0.1% allethrin.  Based
upon a spray duration of 10 seconds/1000 ft3 times a nozzle discharge
rate of 1 gram/second.

E. The 2 hour TWA at the 5 foot sampler height for time t = 0 to time t
= 120 minutes after application (adjusted for field recovery of 85
percent).  

F. (Allethrin Application Rate/NDETF Study Application Rate) * Measured
Breathing Zone Concentration

G.   SEQ CHAPTER \h \r 1 Inhalation Dose	= 	(BZC * BR * ED) / BW

where:	

  BZC		=	Breathing Zone Concentration (mg/m3) - measured air
concentration from NDETF study adjusted to reflect the application rate

		BR		=	Breathing rate for adult or child (m3/hr) (1.0 m3/hr adult, 0.7
m3/hr child)

		BW	 	=	70 kg for adult; 15 kg for toddler

		ED		= 	Exposure Duration (2 hr/day)

H. Inhalation MOE	= 	NOAEL/ Inhalation Dose, where the NOAEL = 1.3
mg/kg/day 

*The target MOE is 1000 for inhalation exposures.  MOEs that are less
than 1000 indicate risks of concern and are highlighted in bold font.

Table A9 - Allethrin Inhalation Risks to Residents from Mosquito Coils
and Fly Mats

Application Method	Exposed Individual	Percent ai	Product WeightA 
Emission DurationA 	Amount  a.i. EmittedB 	Space TreatedC 	Initial
ConcentrationD 	Time Weighted Average ConcentrationE 	Inhalation  DoseF
(mg/kg/day)	MOE

Mosquito Coil	Adult	0.3	12 grams	6 hours	12 mg	90.62 m3	0.13 mg/m3
0.0013 mg/m3	0.000094	14000

	Child







0.00018	7000

Fly Mat	Adult	24	0.93 grams	10 hours	44.6 mg	90.62 m3	0.50 mg/m3	0.0050
mg/m3	0.00036	3600

	Child







0.00070	1800



A. Based upon the allethrin smart meetings.

B. Amount ai emitted = percent a.i. * product weight * 2 units used per
treatment (as specified in the residential SOPs)

C. Based upon a 20 foot by 20 foot patio with a “ceiling height” of
8 feet as specified in the Residential SOPs.  (3200 ft3 = 90.62 m3)

D. Assuming that all of the emitted a.i. remains in the treated space.

E.  Divided the initial concentration by a dilution factor of 100 to
account for dispersion and dilution as specified in the Residential
SOPs.

F.    SEQ CHAPTER \h \r 1 Inhalation Dose	= 	(TWA * BR * ED) / BW

where:	

TWA		=	Time Weighted Average Concentration (mg/m3) 

	BR			=	Breathing rate for adult or child (1.0 m3/hr adult, 0.7 m3/hr
child)

	BW 		=	Body Weight (70 kg for adult, 15 kg for child)

	ED			= 	Exposure Duration (5 hrs/day for adult, 3 hrs/day for child)

G. Inhalation MOE	= 	NOAEL/ Inhalation Dose, where the NOAEL = 1.3
mg/kg/day 

* The target MOE is 1000 for inhalation exposures. All of the MOEs
exceed the target MOE and indicate that the risks are not of concern.

Table A10 - Allethrin Inhalation Risks to Residents from Hand Held Yard
and Patio Foggers 

Exposed Individual	Spray DurationA	Amount of Product AppliedB 	Amount 
a.i. EmittedC

	Space TreatedD 	Initial ConcentrationE 	Time Weighted Average
ConcentrationF 	Inhalation  DoseG

(mg/kg/day)	MOEH

Adult	3 seconds	18 grams	27 mg	90.62 m3	0.30 mg/m3	0.0030 mg/m3	0.00021
6200

Child





	0.00042	3100

Adult	9.3 seconds	56 grams	84 mg	90.62 m3	0.93 mg/m3	0.0093 mg/m3
0.00066	2000

Child





	0.0013	1000



A. The 3 second spray duration is from the Allethrin Smart Meeting.  The
9.3 second spray duration is back calculated from the target MOE of 1000
for children.

B. Amount of product applied (grams) = Spray duration (seconds) * nozzle
discharge rate (6 grams per second per the Allethrin Smart Meeting).

C. Amount a.i. emitted (mg) = (0.15 percent a.i./100) * Amount of
product applied (grams) * 1000 mg per gram

D. Based upon a 20 foot by 20 foot patio with a “ceiling height” of
8 feet as specified in the Residential SOPs.  (400 ft2 = 37m2 and 3200
ft3 = 90.62 m3)

E. Assuming that all of the emitted a.i. remains in the treated space.

F. Divided the initial concentration by a dilution factor of 100 to
account for dispersion as specified in the Residential SOPs.

G.    SEQ CHAPTER \h \r 1 Inhalation Dose	= 	(BZC * BR * ED) / BW

where:	

BZC	=	Breathing Zone Concentration (mg/m3) 

			BR	=	Breathing rate for adult or child (1.0 m3/hr adult, 0.7 m3/hr
child)

			BW 	=	Body Weight (70 kg for adult, 15 kg for child)

			ED	= 	Exposure Duration (5 hrs/day for adult, 3 hrs/day for child)

H. Inhalation MOE	= 	NOAEL/ Inhalation Dose, where the NOAEL = 1.3
mg/kg/day 

* The target MOE is 1000 for inhalation exposures. All of the MOEs
exceed the target MOE and indicate that the risks are not of concern.

Table A11 - Allethrin Inhalation Risks to Residents from Total Release
Yard and Patio Foggers 

Exposed Individual	Fogger SizeA	Amount of Product AppliedB 	Amount  a.i.
EmittedC

	Space TreatedD 	Initial ConcentrationE 	Time Weighted Average
ConcentrationF 	Inhalation  DoseG

(mg/kg/day)	MOEH

Adult	1.5 ounce	85 grams	128 mg	90.62 m3	1.42 mg/m3	0.0014 mg/m3	0.0010
1300

Child





	0.0020	650



A. Taken from the Raid Yard Guard Outdoor Fogger Formula VII label
(4822-394).

B. Based upon the total release of two foggers (two foggers assumed per
the residential SOPs).

C. Amount a.i. emitted (mg) = (0.15 percent a.i./100) * Amount of
product applied (grams) * 1000 mg per gram

D. Based upon a 20 foot by 20 foot patio with a “ceiling height” of
8 feet as specified in the Residential SOPs.  (400 ft2 = 37m2 and 3200
ft3 = 90.62 m3)

E. Assuming that all of the emitted a.i. remains in the treated space.

F. Divided the initial concentration by a dilution factor of 100 to
account for dispersion as specified in the Residential SOPs.

G.    SEQ CHAPTER \h \r 1 Inhalation Dose	= 	(BZC * BR * ED) / BW

where:	

BZC	=	Breathing Zone Concentration (mg/m3) 

			BR	=	Breathing rate for adult or child (1.0 m3/hr adult, 0.7 m3/hr
child)

			BW 	=	Body Weight (70 kg for adult, 15 kg for child)

			ED	= 	Exposure Duration (5 hrs/day for adult, 3 hrs/day for child)

H. Inhalation MOE	= 	NOAEL/ Inhalation Dose, where the NOAEL = 1.3
mg/kg/day 

* The target MOE is 1000 for inhalation exposures.  MOEs that are less
than 1000 indicate risks of concern and are highlighted in bold font.

Table A12 – Unit Exposure Values Used in Allethrin Occupational and
Residential Exposure Assessment 

Scenario	Data Source	Inhalation Unit Exposure 

(µg/lb ai handled)	Replicates	Grade/Confidence

Occupational

Mix/load/apply liquids HP handwand	PHED	120	13	A/Low Confidence

Mix/load/apply liquids LP handwand	PHED	30	80	ABC/Medium Confidence

Mix/load/apply liquids backpack sprayer	PHED	30	11	A/Low Confidence

Aerosol can application	PHED	1,300	15	AB/High Confidence

Residential

Aerosol can application	PHED	1,300	15	AB/High Confidence



LP=low pressure. HP=high pressure.

Appendix B - Allethrin Post Application Risk from Time Metered Device
Applications

Application Parameters 	Ventilation Parameters	Inhalation Exposure and
Risk

% AI	0.9	Time of Day	Night	Day	8 Hour Average Air Concentration (mg/m3)
0.013

Weight of product (gm)	340	Room Volume (CF)	6000	Breathing Rate (m3/hr)
1

Days of Use per can	68	Ventilation Rate (CFM)	20	100	Exposure Time
(hours/day)	8

Duration of Operation per day (hours)	12	Air Changes Per Hour 	0.2	1.0
Body Weight (kg)	70

Spray Frequency per hour	4

Dose (mg/kg/day)	0.0015

Number of sprays per can	3264

NOAEL	1.3

Amount product per spray (gm)	0.10

MOE	846

Amount ai per spray (mg)	0.94



Area Treated (cf)	6000



Area Treated (m3)	170



Initial Concentration (mg/m3)	0.0055





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