UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, DC 20460

			OFFICE OF  PREVENTION, PESTICIDES,  AND TOXIC SUBSTANCES

 

July 27, 2007

MEMORANDUM:

Subject:		Occupational and Residential Exposure Chapter for the Busan 77
Reregistration Eligibility Decision (RED) Document (Case 3034)

To:			ShaRon Carlisle, Chemical Review Manager,

			Regulatory Management Branch II

Antimicrobials Division (7510P)

From: 			Cassi Walls, Ph.D., Chemist

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

Thru:			Norm Cook, Branch Chief

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

Chemical Name:	Poly(oxyethylene(dimethylminino)ethylene(dimethyliminio)
ethylenedichloride (Busan 77)

		

PC Code:		069183 

CAS Registry No. 	31512-74-0TABLE OF CONTENTS

  TOC \h \l "1-4"   HYPERLINK \l "_Toc173130095"  EXECUTIVE SUMMARY	 
PAGEREF _Toc173130095 \h  3  

  HYPERLINK \l "_Toc173130096"  1.0	INTRODUCTION	  PAGEREF _Toc173130096
\h  6  

  HYPERLINK \l "_Toc173130097"  1.1	Purpose	  PAGEREF _Toc173130097 \h 
6  

  HYPERLINK \l "_Toc173130098"  1.2	Criteria for Conducting Exposure
Assessments	  PAGEREF _Toc173130098 \h  6  

  HYPERLINK \l "_Toc173130099"  1.3	Chemical Identification	  PAGEREF
_Toc173130099 \h  8  

  HYPERLINK \l "_Toc173130100"  1.4	Physical/Chemical Properties	 
PAGEREF _Toc173130100 \h  8  

  HYPERLINK \l "_Toc173130101"  2.0	USE INFORMATION	  PAGEREF
_Toc173130101 \h  8  

  HYPERLINK \l "_Toc173130102"  2.1	 Formulation Types and Percent
Active Ingredient	  PAGEREF _Toc173130102 \h  8  

  HYPERLINK \l "_Toc173130103"  2.2	Summary of Use Pattern and
Formulations	  PAGEREF _Toc173130103 \h  8  

  HYPERLINK \l "_Toc173130104"  3.0	SUMMARY OF TOXICITY DATA	  PAGEREF
_Toc173130104 \h  9  

  HYPERLINK \l "_Toc173130105"  3.1	Acute Toxicity	  PAGEREF
_Toc173130105 \h  9  

  HYPERLINK \l "_Toc173130106"  3.2	Summary of Toxicity Endpoints	 
PAGEREF _Toc173130106 \h  10  

  HYPERLINK \l "_Toc173130107"  4.0	RESIDENTIAL EXPOSURE ASSESSMENT	 
PAGEREF _Toc173130107 \h  11  

  HYPERLINK \l "_Toc173130108"  4.1	Summary of Registered Uses	  PAGEREF
_Toc173130108 \h  11  

  HYPERLINK \l "_Toc173130109"  4.2	Dietary Exposure	11 

  HYPERLINK \l "_Toc173130110"  4.3	Drinking Water Exposure	11 

  HYPERLINK \l "_Toc173130111"  4.4	Residential Exposure	11 

4.4.1	Residential Handler Exposures	12

  HYPERLINK \l "_Toc173130112"  4.4.2	Residential Post-application
Exposures	  PAGEREF _Toc173130112 \h  15  

  HYPERLINK \l "_Toc173130114"  5.0	RESIDENTIAL AGGREGATE RISK
ASSESSMENTS AND RISK CHARACTERIZATION	  PAGEREF _Toc173130114 \h  17  

5.1	Acute and Chronic Dietary Aggregate Risk	17

  HYPERLINK \l "_Toc173130115"  5.2	Short-, Intermediate-Term Aggregate
Risk	  PAGEREF _Toc173130115 \h  Error! Bookmark not defined.  

  HYPERLINK \l "_Toc173130116"  6.0	OCCUPATIONAL EXPOSURE ASSESSMENT	18 

  HYPERLINK \l "_Toc173130117"  6.1	Summary of Registered Uses	18 

  HYPERLINK \l "_Toc173130118"  6.2	Occupational Handler Exposures	 
PAGEREF _Toc173130118 \h  21  

  HYPERLINK \l "_Toc173130119"  6.3	Occupational Post-application
Exposures	  PAGEREF _Toc173130119 \h  29  

  HYPERLINK \l "_Toc173130120"  6.4	Metalworking Fluids:  Machinist	 
PAGEREF _Toc173130120 \h  29  

  HYPERLINK \l "_Toc173130122"  6.7	Data Limitations/Uncertainties	 
PAGEREF _Toc173130122 \h  31  

  HYPERLINK \l "_Toc173130123"  7.0	REFERENCES	  PAGEREF _Toc173130123
\h  32  

 

EXECUTIVE SUMMARY tc \l1 "EXECUTIVE SUMMARY 

		The Antimicrobials Division (AD) prepared this occupational and
residential exposure chapter for the inclusion in the poly[oxyethylene
(dimethylimino)

ethylene (dimethylimino) ethylene dichloride] (referred to as Busan 77
in this document) Reregistration Eligibility Decision Document (RED). 
It addresses the potential risks to humans that result from the use of
this chemical in occupational and residential settings. 

At this time Busan 77 is an active ingredient used for in residential
premises (Use Site Category IV), materials preservation (Use Site
Category VII), and industrial processes and water systems (Use Site
Category VIII).  The percentage of Busan 77 in various end-use products
can range from 1.7% to 60%.  Products containing Busan 77 are formulated
as liquid concentrates and granules.

The routes and duration of exposure evaluated in this assessment
include: short- (ST) (1-30 days) and intermediate-term (IT) (1 - 6
months) dermal, inhalation, and incidental oral exposures.  The
following is a summary of the NOAELs:

ST incidental oral and inhalation NOAELs = 500 mg/kg/day

IT incidental oral and inhalation NOAELs = 221 mg/kg/day

ST dermal irritation NOAEL = 125 µg/cm2

ST and IT dermal systemic NOAEL =  no endpoint identified

The target margin of exposure (MOE) varies by route and duration of
exposure.  For Busan 77, the target MOE is 100 for all routes and
duration of exposure.  It should be noted that since the inhalation
NOAEL is based on an oral study that an additional 10X (i.e., MOE =
1,000) may be warranted to request that an inhalation-specific study be
conducted.   

	Based on examination of product labels describing uses for this
antimicrobial chemical, it has been determined that exposure to handlers
can occur in a variety of occupational and residential environments. 
Additionally, post-application exposures are likely to occur in these
settings.  The representative scenarios selected by AD were evaluated
using maximum application rates as stated on the product labels. To
assess the handler and post-application exposures and risks, AD used
standard assumptions, surrogate unit exposure data from the Chemical
Manufacturers Association (CMA) antimicrobial exposure study, EPA’s
Health Effects Division’s (HED) Standard Operating Procedures (SOPs)
for Residential Exposure Assessments, and EPA’s SWIMODEL.

Handler Risk Summary

		For the residential handler dermal and inhalation assessment, all
exposures result in MOEs above 100 and are therefore not of concern. 
Furthermore, all of the inhalation MOEs were above 1,000 and therefore a
confirmatory inhalation-specific toxicity study is not warranted based
on the exposure scenarios.

		For the occupational handler inhalation risk assessment, all exposures
result in MOEs above 100 and are therefore not of concern.  Furthermore,
all of the inhalation MOEs were above 1,000 and therefore a confirmatory
inhalation-specific toxicity study is not warranted based on the
exposure scenarios.

	It should be noted that short-term dermal exposures were not assessed
for the occupational handler because the endpoint is based on dermal
irritation.  Instead, dermal irritation exposures and risks will be
mitigated using default personal protective equipment (PPE) requirements
based on the toxicity of the end-use product.  To minimize dermal
exposures, the minimum PPE required for mixers, loaders, and others
exposed to end-use products that result in classification of category I,
II, or III for skin irritation potential will be a long-sleeve shirt,
long pants, shoes, socks, chemical-resistant gloves, and a
chemical-resistant apron. Note that chemical-resistant eyewear will be
required if the end-use product is classified as category I or II for
eye irritation potential. 

	It should be further noted that most of the labels pertaining to
occupational applications do not require PPE such as gloves.  All of
these labels will need to be updated to include PPE considering that the
dermal toxicological effect is skin irritation. 

Post-application Risk Summary

Occupational post-application exposures are assumed to be minimal and
therefore not quantitatively assessed.  However, a machinist working
with preserved metal working fluid was addressed.  The machinist
inhalation MOE was above 1,000 however, the ST-dermal MOE was 20 and is
therefore a concern.

For the residential postapplication risk assessment, MOEs are all above
the target MOE of 100 for all scenarios and therefore not a concern.

Aggregate Risk Summary

		At this time, an aggregate assessment was not conducted because
post-application exposures to textiles manufactured in facilities using
Busan 77 were not assessed.  Textile residue data are needed in order to
appropriately evaluate post-application and aggregate exposures. 
Furthermore, the total oral assessment (i.e., dietary + incidental oral)
is addressed in the Busan 77 preliminary risk assessment document.

Data Limitations and Uncertainties:

There are a number of uncertainties associated with this assessment,
including the following: 

A textile residue study for the fresh water microbiocide use in textile
manufacturing facilities is needed to conduct the post-application
residential dermal and incidental oral exposure assessment. 

Surrogate dermal and inhalation unit exposure values were taken from the
proprietary CMA antimicrobial exposure study (US EPA 1999: DP Barcode
D247642). Most of the CMA data are of poor quality therefore, AD
requests that confirmatory monitoring data be generated to support the
values used in these assessments.  

The CMA unit exposure data used for the secondary recovery in oilfields
and water cooling tower operations are based on metering pump
applications made in a pulp and paper facilities.  Since the volume of
water being treated in secondary recovery and cooling water tower
operations is so large, the available CMA data can not be reliably
extrapolated because they are based on activities that handle much lower
volumes and possibly different techniques.  Therefore, it was assumed
that pulp and paper chemical metering applications, which are typically
large operations, can be representative of other large operations. 
Additional exposure data should be collected to confirm the estimates
for large scale applications 

The quantities handled/treated were estimated based on information from
various sources that can be further refined from input from registrants.


Currently Busan 77 can be used to preserve starch used in paper
manufacturing (EPA Reg. No. 55137-1).  However, the technical registrant
recently stated that this use will be cancelled.  Therefore, all labels
listing the starch preservation use must be updated to reflect this
cancellation.

Currently the label language for most of the products does not contain
specific PPE requirements.  All of these labels need to be updated to
require PPE for occupational handlers for the protection from dermal
irritation effects.

1.0	 INTRODUCTION tc \l1 "1.0	INTRODUCTION 

		1.1	Purpose  tc \l2 "1.1	Purpose  

		This document presents the results of a review of the potential human
health effects of occupational and residential exposure to
poly[oxyethylene (dimethylimino)

ethylene (dimethylimino) ethylene dichloride] (referred to as Busan 77
in this document).  This information is for use in EPA’s development
of the Busan 77 Reregistration Eligibility Decision (RED) Document. 

		1.2	Criteria for Conducting Exposure Assessments tc \l2 "1.2	Criteria
for Conducting Exposure Assessments 

		An occupational and/or residential exposure assessment is required for
an active ingredient if (1) certain toxicological criteria are triggered
and (2) there is potential exposure to handlers (mixers, loaders,
applicators, etc.) during use or to persons entering treated sites after
application is complete.  For Busan 77, both criteria are met.

In this document, scenarios were assessed by using unit exposure data to
estimate occupational and residential handlers’ exposures. Unit
exposures are estimates of the amount of exposure to an active
ingredient a handler receives while performing various handler tasks and
are expressed in terms of micrograms or milligrams (1mg = 1,000 µg) of
active ingredient per pounds of active ingredient handled.  A series of
unit exposures have been developed that are unique for each scenario
typically considered in assessments (i.e., there are different unit
exposures for different types of application equipment, job functions,
and levels of protection).  The unit exposure concept has been
established in the scientific literature and also through various
exposure monitoring guidelines published by the U.S. EPA and
international organizations such as Health Canada and OECD (Organization
for Economic Cooperation and Development).

Using surrogate unit exposure data, maximum application rates from
labels, and estimates of daily amount handled, exposures and risks to
handlers were assessed.  The exposure/risks were calculated using the
following equations:

Daily Exposure: Daily dermal or inhalation handler exposures are
estimated for each applicable handler task with the application rate,
quantity treated/handled in a day, and the applicable dermal or
inhalation unit exposure using the following formula:

Daily Exposure:	E = UE x AR x AT						(Eq. 1)

Where:  

E	=	Amount (mg a.i./day) deposited on the surface of the skin that is
available for dermal absorption or amount inhaled that is available for
inhalation absorption;

UE	=	Unit exposure value (mg ai/lb ai) derived from August 1998 PHED
data or from 1992 CMA data;

AR	=	Maximum application rate based on a logical unit treatment, square
feet (sq. ft.), gallons (gal), or cubic feet (cu. ft). Maximum values
are generally used (lb a.i./sq ft, lb ai/gal, lb ai/cu ft); and

AT 	=	Normalized application area based on a logical unit treatment such
as square feet  (sq ft/day), gallons (gal/day), or cubic feet (cu
ft/day).

Daily Dose: The daily dermal or inhalation dose is calculated by
normalizing the daily exposure by body weight and adjusting, if
necessary, with an appropriate absorption factor.  For Busan 77, a
dermal endpoint was used for evaluation of dermal exposures and an
inhalation endpoint was used for evaluation of inhalation exposures;
therefore, an absorption factor of 100% was used for all exposures. 
Daily dose was calculated using the following formula:

Daily Dose:	ADD = E x ABS							(Eq. 2)

			   BW						

Where:

ADD 	= 	Absorbed dose received from exposure to a chemical in a given
scenario (mg active ingredient/kg body weight/day);

E 	=	Amount (mg ai/day) deposited on the surface of the skin that is
available for dermal absorption or amount inhaled that is available for
inhalation absorption;

ABS 	= 	A measure of the amount of chemical that crosses a biological
boundary such as lungs (% of the total available absorbed); and

BW	= 	Body weight determined to represent the population of interest in
a risk assessment (kg).

Margins of Exposure:  Non-cancer inhalation and dermal risks for each
applicable handler scenario are calculated using a Margin of Exposure
(MOE), which is a ratio of the daily dose to the toxicological endpoint
of concern.

Margins of Exposure:	MOE = NOAEL or LOAEL					(Eq. 3)

					ADD

Where:

MOE 			= 	Margin of exposure, value used to represent risk or how close
a chemical exposure is to being a concern (unitless);

NOAEL or LOAEL	= 	Dose level in a toxicity study, where no observed
adverse effects (NOAEL) or where the lowest observed adverse effects
(LOAEL) occurred in the study; and

ADD 			= 	Average daily dose or the absorbed dose received from exposure
to a chemical in a given scenario (mg ai/kg body weight/day).

	A series of assumptions and exposure factors served as the basis for
completing the handler risk assessment.  Each general assumption and
factor for both residential and occupational assessments is detailed
below.  Assumptions specific to the use site category are listed in each
separate section of this document.  The general assumptions and factors
include:

Busan 77 products are registered for various use patterns and use
conditions too numerous to conduct a comprehensive assessment for this
document.  As such, this risk assessment has been patterned on a series
of scenarios that are believed to represent the vast majority of Busan
77 uses.

Average body weight of 70 kg for adults was to complete the handler risk
assessment (US EPA, 1997b). 

Exposure factors used to calculate daily exposures to handlers were
based on applicable data, if available.  When appropriate data were
lacking, values from a scenario deemed similar were used. 	

The maximum application rates allowed by labels were assumed

		1.3	Chemical Identification tc \l2 "1.3	Chemical Identification 

		The chemical under review is poly[oxyethylene (dimethylimino)

ethylene (dimethylimino) ethylene dichloride] (Busan 77).  The Product
Code for this chemical is 069183 and the CAS RN is 31512-74-0.  

		1.4	Physical/Chemical Properties tc \l2 "1.4	Physical/Chemical
Properties 

		Table 1.2 shows physical/chemical characteristics that have been
reported for Busan 77.

Table 1.2.  Physical/Chemical Properties of Busan 77



Molecular Weight	3,386 g/mol

Water solubility	Completely soluble



Vapor Pressure	10.8 mm Hg (20 o ), 

14.4 mm Hg (25 o C) 1

1 The vapor pressure studies were conducted on TGAI which is 60% active
in 40% water.  It is, therefore, likely that some of the measured values
may not be attributed the pure TGAI. Considering the fact the study was
conducted with 60/40: polymer/water ratio, the extremely high vapor
pressure value is likely due to water vapor.

It should be further noted that a preliminary EPISuite analysis
estimated a very low vapor pressure (i.e., <<1 x 10-10 mm Hg) of Busan
77.  Given the fact that the cited vapor pressure is likely of water not
the polymer, the high molecular weight, and extremely low vapor pressure
estimated from EPISuite, vapor inhalation exposures were not necessary
to assess.

2.0	 USE INFORMATION tc \l1 "2.0	USE INFORMATION 

		2.1	 Formulation Types and Percent Active Ingredient tc \l2 "2.1	
Formulation Types and Percent Active Ingredient 

		The products containing Busan 77 as the active ingredient (a.i.) are
formulated as soluble concentrates or granules in end-use products. 
Concentrations of Busan 77 in these products range from 1.7% to 60%.

		

		2.2	Summary of Use Pattern and Formulations tc \l2 "2.2	Summary of Use
Pattern and Formulations 

	Busan 77 is an industrial microbiocide/microbiostat, algaecide,
bacteriostat, and molluscicide that is an active ingredient in over 150
registered products.  AD determined potential occupational and
residential exposure scenarios by reviewing currently registered labels.
 These scenarios are presented in Table 2.1.  Based on this review of
the labels, it was determined that Busan 77 products are intended for
use in residential premises (Use Site Category IV), as materials
preservatives (Use Site Category VII), and in industrial processes and
water systems (Use Site Category VIII).

Table 2.1. Potential Use Scenarios Based on Product Labels for Busan 77



Use Site Category	

Example Use Sites	

Scenarios

Use Site Category IV

Residential and Public Assess Premises	Used in residential and
non-commercial environments	Swimming pools 

Spas, whirlpools and hot tubs

Waterbed mattress water

Ornamental ponds and fountains

Aquariums



Use Site Category VII

Material Preservatives	

Used in the production of industrial items	

Metal working fluids



Use Site Category VIII

Industrial processes and water systems	

Used on fresh water supplies for commercial and industrial systems	

Water cooling towers (recirculating and once-through)

Air washer water systems

Fire protection systems

Pulp and paper water systems

Textile water systems

Petroleum secondary recovery systems

	

From Table 2.1, representative exposure scenarios were selected for
assessment in this document.  These scenarios were selected to be
representative of the vast majority of uses and are believed to provide
high-end estimates of dermal, inhalation, or incidental ingestion
exposure.  The representative scenarios assessed in this document are
shown in Table 4.1 (residential) and Table 6.1 (occupational).

3.0	SUMMARY OF TOXICITY DATA tc \l1 "3.0	SUMMARY OF TOXICITY CONCERNS
RELATING TO EXPOSURE 

	3.1	Acute Toxicity

 tc \l2 "3.1	Acute Toxicity 

The acute toxicity data for Busan 77 is summarized below in Table 3.1.

Table 3.1 Acute Toxicity Profile Busan 77

Guideline Number	Study Type	MRID Number/ Classification	Toxicity
Category

870.1100	Acute Oral Toxicity 	41373401/

93062009	III

870.1200	Acute Dermal Toxicity 	41373401/

93062009	III

	Acute Inhalation Toxicity 	41877501	III

870.2400	Primary eye irritation 	41361701/

93062011	III

870.2500	Primary Skin irritation 	41298601/

93062012	IV

870.2600	Dermal Sensitization 	40750301/

93062013	Not a sensitizer



	3.2	Summary of Toxicity Endpoints tc \l2 "3.2	Summary of Toxicity
Endpoints 

The toxicological endpoints were selected for Busan 77.  Table 3.2
summarizes the toxicological endpoints used in the evaluation of
exposures and MOEs.  The reader is referred to the following memorandum
for more details: Busan 77 – Revised Report of the Antimicrobials
Division’s Toxicology Endpoint Selection Committee (ADTC) dated July
10, 2007.

Table 3.2. Summary of Toxicological Dose and Endpoints for Busan 77 for
Use in Risk Assessment



Exposure  Scenario	

Dose (mg/kg/day)

	

   Endpoint	

   Study



Acute Dietary	

This risk assessment not required



Chronic Dietary	NOAEL = 100 mg/kg/day

Chronic RfD = 1.0 mg/kg/day	Systemic: Clinical alterations and reduced
body weigh gain	Chronic Toxicity in rats

LOAEL = 300 mg/kg/day



Occupational /Residential Exposure



Incidental Oral 

Short Term

(1 – 30 Days)

	Systemic: 

NOAEL: 500 mg/kg/day

MOE = 100 

	Systemic: Increased mortality	Developmental Toxicity Study – Rat

LOAEL = 700 mg/kg/day 





Incidental Oral 

Intermediate Term

(1 – 6 months)

	Systemic: 

NOAEL: 221 mg/kg/day

MOE = 100 	Systemic: Renal tubular mineralization 	Subchronic toxicity
in rats

LOAEL = 752 mg/kg/day



Dermal

Short-term 

 [1 Day to 30 Days]

	

Dermal Irritation: 

+ NOAEL: 125 µg/cm2

(10 mg/kg/day)

MOE = 100	

Dermal: dermal irritation in both sexes 

Systemic: No systemic effects

	

90-day dermal toxicity study in rats

MRID 40170601

LOAEL = 100 mg/kg/day



Dermal

Intermediate-term 



	

No endpoint identified in the database



Inhalation

Short- and intermediate- and long-term

	

MOE = 100

DB UF = an additional 10x is necessary for route extrapolation.  If
results are below an MOE of 1,000, a confirmatory inhalation study is
warranted.	

	

See incidental oral endpoints

Cancer	Group “D” based on increased thyroid C-cell adenomas.  Refer
to HED CARC for definitive evaluation of carcinogenic potential

+ TGAI based on dermal endpoint = (10 mg/kg x 0.2kg rat x 1000 µg/mg) /
16 cm2 = 125 µg/cm2

4.0	RESIDENTIAL EXPOSURE ASSESSMENT tc \l1 "4.0	RESIDENTIAL EXPOSURE
ASSESSMENT  

	4.1	Summary of Registered Uses tc \l2 "4.1	Summary of Registered Uses 

	Busan 77 is currently registered for several residential aquatic uses. 
It is used to control algal growth in swimming pools, spas, hot tubs,
ornamental ponds, decorative fountains, and aquariums.  Furthermore, it
can also be used to control odor-causing and slime-forming bacteria in
waterbed mattress water.  Table 2.1 presents a summary of exposure
scenarios that may occur from the residential use site category based on
examination of product labels.  Table 4.1 identifies the representative
residential exposure scenarios assessed in this document.

Table 4.1. Representative Uses Associated with Residential Exposure 



Representative Use	

Exposure Scenario	

Application Method	

Reg. #	

Application Rate

Swimming Pool 	ST handler: dermal (irritation) and inhalation (aerosol) 
Open pour

(solid)1

Open pour (liquid)	3432-28

57787-11

	0.0012 fl oz ai/gal

(30 oz/5,000 gal x 20%ai)

0.0012 oz ai/gal

(117 fl oz/10,000 gal x 10%ai)

(product density = 8.5lb/gal)

	ST and IT post-app: incidental oral and dermal2	NA	57787-11

	9.3 mg ai/L

(117 fl oz/10,000 gal x 10%ai x gal/128oz x 8.5 lb/gal x 4.54E5 mg/lb x
0.264 gal/L)

Spa/whirlpool/hot tub/ornamental ponds	ST handler: dermal (irritation)
and inhalation (aerosol)	Open pour (liquid)	1448-346

	0.0012 fl oz ai/gal

(3 fl oz/1000 gal x 40%ai)

(product density =9.12lb/gal)

Aquarium	ST handler: dermal (irritation) and inhalation (aerosol)	Open
pour (liquid)	14802-8

	0.00023 fl oz ai/gal

(5ml/40 gal x 5.4%ai x fl oz/29.57ml)

(product density = 8.4lb/gal)

Waterbed mattress water	ST handler: dermal (irritation) and inhalation
(aerosol)	Open pour (liquid)	42373-6

	0.0044 fl oz ai/gal

(8 fl oz/180 gal x 10%ai)

(product density = 8.5lb/gal)

1 Note: since the application rates are the same, the dermal irritation
exposure from the open solid pour scenario was represented by the open
pour liquid scenario.  Furthermore, the open liquid pour scenario is
considered worst-case as compared to the solid pour for dermal
irritation due to physical nature of the product and its potential to
contact skin during the application.

2 Note: post-application exposure to swimming pool residues is
representative for post-application exposure to spa/whirlpool residues
since the application rates are the same for both uses

	

	4.2	Dietary Exposure tc \l2 "4.2	Dietary Exposure/Risk Pathway  

Any risks pertinent to dietary exposures are discussed in the
Preliminary Risk Assessment.

	4.3	Drinking Water Exposure tc \l2 "4.3	Drinking Water Exposure/Risk
Pathway  

Any risks pertinent to drinking water exposures are discussed in the
Preliminary Risk Assessment. 

	4.4	Residential Exposure tc \l2 "4.4	Residential Exposure/Risk Pathway 

	The exposure scenarios assessed in this document for the representative
uses selected by AD are shown in Table 4.1. The table also shows the
maximum application rate associated with the representative use and the
EPA Registration number for the corresponding product label.  For
handlers, the representative uses assessed through direct product
application to swimming pools (open pouring of solids and liquids),
spas/whirlpools (open pouring of liquids) and aquariums (open pouring of
liquids).   It should be noted, that the application to spas/whirlpools
also represents the application to ornamental ponds/fountains since the
rates are the same and the amount of water treated is higher for the
spas than the ponds/fountains.

	4.4.1	Residential Handler Exposures

	The residential handler scenarios described in Table 4.1 were assessed
to determine dermal and inhalation (aerosol) exposures.  All of the
dermal and inhalation scenarios were assessed using CMA data and
Equations 1-3 in Section 1.2, “Criteria for Conducting Risk
Assessment.”  The assumptions and factors used in the dermal and
inhalation exposure scenarios include:

Unit Exposure Values: Unit exposure values were taken from the
proprietary Chemical Manufacturers Association (CMA) antimicrobial
exposure study (USEPA, 1999: DP Barcode D247642). 

For liquid pour in swimming pool, whirlpool, ornamental pond, aquarium,
and waterbed mattress scenarios, the cooling tower CMA data for liquid
pour was used for dermal exposures.  This set of data was used because
no other CMA data sets represent ungloved replicates pouring liquid. 
The dermal hand unit exposure value is 0.196 mg/lb a.i. After
normalization for the surface area of the hand (820 cm2), the dermal
unit exposure value is 0.000239 mg/lb a.i/cm2. For inhalation exposures,
the CMA preservative data were used for these exposures.  The inhalation
unit exposure is 0.00346 mg/lb a.i. and is based on 2 replicates.
Although this unit exposure is based on minimal replicates, the exposure
value is similar to the one found in PHED for a similar scenarios.  

For solid pour in swimming pool scenarios, the CMA solid pour
preservative data were used for inhalation exposures.  The inhalation
unit exposure is 0.00119 mg/lb a.i. and is based on 10 replicates. Note
that since the application rates are the same, the dermal irritation
exposure from the open solid pour scenario was represented by the open
pour liquid scenario.  Furthermore, the open liquid pour scenario is
considered worst-case as compared to the solid pour for dermal
irritation due to physical nature of the product and its potential to
contact skin during the application.

Quantity handled/treated: The quantities handled/treated used in the
assessment were AD standard assumptions. 

For the swimming pool scenarios, it was assumed that a residential pool
contains 20,000 gallons of water.

For the whirlpool/spa scenario, it was assumed that a residential spa
contains 1,000 gallons of water.

For the aquarium scenario, it was assumed that a typical aquarium
contains 100 gallons of water.

For the waterbed mattress scenario, it was assumed that a waterbed
mattress contains 180 gallons of water.

Duration of Exposure:  The duration of exposure for most homeowner
applications of algaecide products is believed to be best represented by
the short-and intermediate-term durations because the applications occur
episodically (i.e., weekly) not daily.  

Results

	The resulting short- and intermediate-term exposures and MOEs for the
representative residential handler scenarios are presented in Table 4.2.
The calculated MOEs were above the target dermal and inhalation MOE of
100 for all scenarios.  Furthermore, all inhalation MOEs exceeded 1,000
therefore, a confirmatory inhalation toxicity study is not warranted
based on the results of these exposure scenarios. 

	

Table 4.2 Residential Handler Exposures and MOEs for Busan 77

Exposure Scenario	Application Method	Unit Exposure	Amount treated

(gal/day)	Use Ratea	Amount ai handled (lb ai/day)b	ST/IT Exposure	ST
MOEsf

Target MOE = 100	IT MOEsf

Target MOE = 100



Dermal  (mg/lb ai/cm2)	Inhal (mg/lb ai)



Dermal (mg/cm2)c	Inhalation (mg/kg/day)d	Dermal	Inhalation	Inhalation

Swimming pools	Open pour - liquid	0.00023	0.00346	20,000	0.0012	fl oz
ai/gal	1.6	3.6E-04	7.7E-05	350	6,500,000	2,900,000

	Open pour - solid	NA	0.0119	20,000	0.0012	oz ai/gal	1.5	NA	2.6E-04	NA
2,000,000	870,000

Spas/whirlpools/

ponds	Open pour - liquid	0.00023	0.00346	1,000	0.0012	fl oz ai/gal	0.086
2.0E-05	4.2E-06	6,400	120,000,000	52,000,000

Aquariums	Open pour - liquid	0.00023	0.00346	100	0.00023	fl oz ai/gal
0.0015	3.4E-07	7.4E-08	360,000	6,800,000,000	3,000,000,000

Waterbed mattress	Open pour - liquid	0.00023	0.00346	180	0.0044	fl oz
ai/gal	0.053	1.2E-05	2.6E-06	10,000	190,000,000	84,000,000

a: see Table 4.1

b: Liquid Amt ai handled (lb ai/day) = use rate (fl oz ai/gal) x
gal/128oz x product density (lb/gal) x amt treated (gal treated/day)

    Solid Amt ai handled (lb ai/day) = use rate (oz ai/gal) x lb/16oz x
amt treated (gal treated/day)

c: Dermal exposure (mg/cm2) = Dermal unit exposure (mg/lb ai/cm2) x Amt
ai handled (lb ai/day) 

e: Inhalation exposure (mg/kg/day) = Inhalation unit exposure (mg/lb ai)
x Amt ai handled (lb ai/day)/70 kg

f: MOE = NOAEL / Exposure; where ST dermal NOAEL = 125 µg/cm2 (or 0.125
mg/cm2);  ST inhalation NOAEL = 500 mg/kg/day; IT inhalation NOAEL = 221
mg/kg/day

	4.4.2	Residential Post-application Exposures tc \l3 "4.4.2	Residential
Post-application Exposures 

	The Busan 77 uses that can lead to potential residential exposures are
those associated with the industrial textile use and recreational
swimming pool and spas/whirlpool use.  Swimming pools and
spas/whirlpools can be treated with Busan 77 to control algae. 
Therefore post-application dermal and incidental oral exposures to
treated water may occur.  Note that inhalation exposures (vapor) were
not assessed due to the extremely low vapor pressure of Busan 77.   

Post-application Exposures from Busan 77 Textile Freshwater System Use

	Busan 77 can be used “to control the growth of bacteria and fungi in
holding and processing tanks of industrial fresh water systems supplying
water to pulp and paper mills, textile mills, and other manufacturing
plants” (EPA Reg. No. 1448-42).   As stated on the label “absorbents
rapidly absorb the product.”  Therefore, it is anticipated that
absorbents such as textiles will absorb Busan 77 and post-application
residential dermal and incidental oral exposures to treated textiles may
occur.  However, the level of residues remaining on the textile is
unknown and can not be accurately modeled at this time.  Busan 77 is
intended to control microorganism growth in the water used in the
facility not to preserve the textile. Since the application rate is in
terms of volume of water not textile, the rate can not be extrapolated
to estimate the amount of residue remaining on the textile that comes in
contact with the treated water.  Therefore, a textile residue study is
needed in order to conduct the post-application residential exposures.

Post-application Dermal Exposure from Busan 77 Swimming Pool and Spa
Uses

There are post-application dermal exposures to Busan 77 associated with
use of swimming pool and spa use.  The SWIMODEL 3.0 was developed by EPA
as a screening tool to conduct exposure assessments of pesticides found
in swimming pools and spas (Versar, 2003). The SWIMODEL uses
well-accepted screening exposure assessment equations to calculate the
total worst-case exposure for swimmers expressed as a mass-based intake
value (mg/event).   The model estimates absorbed dermal exposure based
on the chemical’s permeability constant (Kp).  For Busan 77, the
dermal toxicological effect is based on skin irritation not an absorbed
systemic effect.  Therefore, the SWIMODEL is not appropriate to use to
estimate dermal exposure for Busan 77.  

The film thickness methodology was used to estimate dermal exposure to
pool and spa treated water.   The following equation was used to develop
the short-term dermal doses:

Dose = Cw x FT

where:

Dose		=	Daily dose for pools (µg/cm2),

Cw		=	Chemical concentration in pool water (mg ai/L = µg ai/cm3),

FT		=	Film thickness of water on the skin (cm)

The short-term dermal doses and MOEs for adults and children are
presented in Table 4.3.  It should be noted that adults and children,
competitive and noncompetitive swimmers, and pool users and spa users
will all have the same exposures and MOEs using the film thickness
approach.  The resulting MOE is above the target MOE of 100 and
therefore not of concern.

Table 4.3.   Short-term Adult and Child Dermal Exposures and MOEs for
Busan 77 used in Swimming Pools and Spas



Scenario	CW

(µg ai/cm3)a	

FT

(cm) b

	

Dose

(µg/cm2) c	

MOE d



Pool and spa	9.31	0.0049	0.046	2,700

a mg/L = µg/cm3

b Film thickness of water on skin as cited in EFAST users’ manual
(USEPA, 2007 and 1987)

dMOE=  NOAEL (125 µg/cm2)/ Dermal Dose (µg/cm2)   

Post-application Incidental Ingestion from Busan 77 Swimming Pool Uses

The SWIMODEL 3.0 was used to estimate post-application incidental
ingestion of treated swimming pool water.  Detailed information and the
downloadable executable file are available at   HYPERLINK
"http://www.epa.gov/oppad001/swimodel.htm" 
http://www.epa.gov/oppad001/swimodel.htm .  Although, the actual model
was not used in this assessment, the same equations and default
parameters as provided in the SWIMODEL User's Manual (version 3.0)  were
used in a spreadsheet format to estimate post-application incidental
oral exposures.  Incidental ingestion of treated water is typically
associated with use of swimming pools not spas or whirlpools therefore,
the oral exposures were only estimated for swimming pool use.  Both
short- and intermediate-term exposures durations were assessed since
there is a potential for exposure every day for competitive swimmers. tc
\l4 "4.4.2.1	Treated Carpet 

The following equation was used to develop ingestion doses:

 				

where:

Dose	=	Daily dose for pools, (mg/kg/day),

Cw	=	Chemical concentration in pool water (mg/L),

IR	=	Ingestion rate of pool water (L/hr),

ET	=	Exposure time (hrs/day),

BW	=	Body weight (kg) (US EPA, 1997b),

The water concentration in pool water is based on information provided
in the labels.  The ingestion rate used in the SWIMODEL 3.0 is based on
the value used in EPAs Residential SOPs (U.S. EPA, 1997a) and an EPA
pilot study as discussed in ACC’s swimmer survey (ACC, 2002).  The
exposure time is based on ACC’s swimmer survey for competitive
swimmers (ACC, 2002) and the NHAPs data for non-competitive/recreational
swimmers (US EPA, 1996).   Table 4.4 presents the incidental ingestion
exposures and MOEs for swimmers in Busan 77 treated pools.  All of the
MOEs are above the target MOE of 100 and are therefore not of concern. 

Table 4.4.  Short-and Intermediate-term Adult and Child Incidental
Ingestion Exposures and MOEs for Busan 77 used in Swimming Pools





	

Adult	

Child 

7-10 yrs	

Child 

11-14 yrs



	

Comp.	

Non-Comp.	

Comp.	

Non-Comp.	

Comp.	

Non-Comp.



Cw (mg/L)	9.31	9.31	9.31	9.31	9.31	9.31



IR (L/hr)	

0.0125	

0.0125	

0.05	

0.05	

0.025	

0.05



ET(hr/day)	

3	

1	

1	

1	

2	

1



BW(kg)	

70	

70	

30	

30	

48	

48



Dose (mg/kg/day)	0.0050	0.0033	0.016	0.016	0.0097	0.0097

ST MOE	100,000	150,000	32,000	32,000	52,000	52,000

IT MOE	44,000	66,000	14,000	14,000	23,000	23,000

aMOE = NOAEL mg/kg/day/ Dose (mg/kg/day).  ST Oral NOAEL = 500
mg/kg/day, IT Oral NOAEL = 221 mg/kg/day; ST and IT Target MOE = 100

5.0	RESIDENTIAL AGGREGATE RISK ASSESSMENT AND CHARACTERIZATION tc \l1
"5.0	RESIDENTIAL AGGREGATE RISK ASSESSMENTS AND RISK CHARACTERIZATION 

	

5.1	Acute and Chronic Dietary Aggregate Risk

	This is included in the Preliminary Risk Assessment.

Short- and Intermediate-Term Aggregate Risk

	In order for a pesticide registration to continue, it must be shown
“that there is reasonable certainty that no harm will result from
aggregate exposure to pesticide chemical residue, including all
anticipated dietary exposures and other exposures for which there are
reliable information.”  Aggregate exposure is the total exposure to a
single chemical (or its residues) that may occur from dietary (i.e.,
food and drinking water), residential, and other non-occupational
sources, and from all known or plausible exposure routes (oral, dermal,
and inhalation).  However, this assessment only addresses non-dietary
residential aggregate exposures and risks.  The Preliminary Risk
Assessment (PRA) of the RED will address the complete aggregate
assessment including both dietary and non-dietary residential exposures
and risks. 

	In performing aggregate exposure and risk assessments, the Office of
Pesticide Programs has published guidance outlining the necessary steps
to perform such assessments (General Principles for Performing Aggregate
Exposure and Risk Assessments, November 28, 2001; available at
http://www.epa.gov/pesticides/trac/science/aggregate.pdf).  Steps for
deciding whether to perform aggregate exposure and risk assessments are
listed, which include: identification of toxicological endpoints for
each exposure route and duration; identification of potential exposures
for each pathway (food, water, and/or residential);  reconciliation of
durations and pathways of exposure with durations and pathways of health
effects; determination of which possible residential exposure scenarios
are likely to occur together within a given time frame; determination of
magnitude and duration of exposure for all exposure combinations;
determination of the appropriate technique (deterministic or
probabilistic) for exposure assessment; and determination of the
appropriate risk metric to estimate aggregate risk

	Short- and intermediate-term aggregate exposures and risks were
considered for adults and children that could be exposed to Busan 77
residues from the use of products in non-occupational environments.  The
following lists summarize all of the non-dietary, non-occupation
potential sources of Busan 77 exposures for adults and children:

Adult Busan 77 exposures sources:

Applying Busan 77 to swimming pools

Applying Busan 77 to spas/whirlpools 

Applying Busan 77 to ornamental ponds/fountains

Applying Busan 77 to aquariums

Post-application exposures to swimming pool water residues

Post-application exposures to textile residues

	

Child Busan 77 exposures sources:

Post-application exposures to swimming pool water residues

Post-application exposures to textile residues

The use patterns of Busan 77 products and probability of co-occurrence
were considered when selecting scenarios for incorporation in the
aggregate assessment.  It was determined that an aggregate assessment
could not be conducted at this time due to the lack of textile residue
data.  The aggregate assessment should include post-application
exposures to swimming pool water residues as well as post-application
exposure to textile residues.

It should be noted that there is a potential for an adult to apply a
Busan 77 product to a swimming pool and subsequently swim in the treated
pool in one day.  However, because the dermal toxicological effect is
skin irritation and not a systemic effect, any product remaining on the
residential handler following an application would be diluted or
“washed off”once the handler enters the swimming pool.  Therefore,
an aggregate assessment incorporating these scenarios would actually
overestimate dermal exposure and is thus not appropriate to assess in
this case. 

6.0	OCCUPATIONAL EXPOSURE ASSESSMENT tc \l1 "6.0	OCCUPATIONAL EXPOSURE
AND RISK 

	6.1	Summary of Registered Uses tc \l2 "6.1	Summary of Registered Uses 

	The exposure scenarios assessed in this document for the representative
uses selected by AD are shown in Table 6.1.  The table also shows the
maximum application rates associated with the representative use and the
appropriate EPA Registration number for the product label.  For
handlers, the representative uses assessed include: material
preservative (metalworking fluid), industrial water systems biocide and,
swimming pool and spa algaecide.  

	Potential occupational handler exposures can occur during the
application of Busan 77 through either liquid/solid pour or liquid pump
methods.  Liquid/solid pour refers to transferring the antimicrobial
product from a small container to an open vat.  Liquid pump refers to
transferring the preservative by connecting/disconnecting a chemical
metering pump from a tote or by gravity flow.  Due to their complexity
or special considerations, exposures for some scenarios are discussed in
separate sections, including exposures for a machinist working with
Busan 77 treated metalworking fluids (Section 6.4). 

 

Short-term dermal exposures were not assessed for most occupational
handler scenarios because the endpoint is based on dermal irritation. 
Instead, dermal irritation exposures and risks will be mitigated using
default personal protective equipment requirements based on the toxicity
of the end-use product.  To minimize dermal exposures, the minimum PPE
required for mixers, loaders, and others exposed to end-use products
that result in classification of category I, II, or III for skin
irritation potential will be a long-sleeve shirt, long pants, shoes,
socks, chemical-resistant gloves, and a chemical-resistant apron.  Note
that chemical-resistant eyewear will be required if the end-use product
is classified as category I or II for eye irritation potential. Most of
the labels currently do not require PPE; based on this assessment all of
these labels will need to be updated to reflect the PPE requirement.

	Since gloves are also not a viable mitigation option for a machinist
using biocide treated metalworking fluids, the short-term dermal
exposure was assessed for this scenario.

Table 6.1.  Representative Exposure Scenarios Associated with
Occupational Exposures to Busan 77

Representative Use	Method of Application	Exposure Scenario	Registration
#	Application Rate

Residential Premises

Swimming Pools	Liquid pour 

Solid pour	Handler: ST and IT inhalation	3432-28

57787-11

	0.0012 fl oz ai/gal

(30 oz/5,000 gal x 20%ai)

0.0012 oz ai/gal

(117 fl oz/10,000 gal x 10%ai)

Product density = 8.5lb/gal

Material Preservatives

Metalworking fluid	Liquid pour 

Liquid pump

Use of treated metalworking fluid	Handler (worker pouring preservative
into fluid being treated): ST and IT inhalation

Machinist:  ST dermal and 

ST and IT inhalation	1448-42

	0.006% to 0.06% ai

(or 60 to 600 ppm ai)

(0.01 to 0.1% product based on total weight of fluid x 60% ai)

Product density = 9.6 lb/gal

Industrial Processes and Water Systems

Pulp/paper and textile water systems	Liquid pump	Handler: ST and IT
inhalation	1448-42	0.0007 fl oz ai/gal

(11 fl oz/10,000 gal x 60% ai)

Product density = 9.6 lb/gal

Cooling tower waters (recirculating)	Liquid pour 

Liquid pump	Handler: ST and IT inhalation

	1448-398

	Initial dose: 

0.0042 fl oz ai/gal

(69.6 fl oz/1,000 gal x 6%ai)

Maintenance dose:

0.0021 fl oz ai/gal

(34.8 fl oz/1,000 gal x 6%ai)

Product density = 8.7 lb/gal

Cooling tower waters 

(once-through)	Liquid pour 

Liquid pump	Handler: ST and IT inhalation

	55137-1

	0.0012% ai

(60 ppm x 20%ai)

Product density = 8.69 lb/gal

Air washer water systems

	Liquid pour 

Liquid pump	Handler: ST and IT inhalation

	402-123

	0.0042 fl oz ai/gal

(83.25 fl oz/1,000 gal x5%ai)

Product density = 8.4 lb/gal

Fire protection systems

	Liquid pour 

Liquid pump	Handler: ST and IT inhalation	1448-398

	0.0056 fl oz ai/gal

(92.8 fl oz/1,000 gal x 6%ai)

Product density = 8.7 lb/gal

Petroleum secondary recovery systems	Liquid pour 

Liquid pump	Handler: ST and IT inhalation	1448-398

	0.0056 fl oz ai/gal

(92.8 fl oz/1,000 gal x 6%ai)

Product density = 8.7 lb/gal

Note: inhalation exposure refers to exposure to the aerosols not the
vapor

	6.2	Occupational Handler Exposures tc \l2 "6.2	Occupational Handler
Exposures 

	The occupational handler scenarios included in Table 6.1 were assessed
to determine inhalation exposures.  The general assumptions and
equations that were used to calculate occupational handler risks are
provided in Section 1.2, Criteria for Conducting the Risk Assessment.
The majority of the scenarios were assessed using CMA data and Equations
1 through 3.  

Swimming Pool Systems

Busan 77 can be used to control the growth of algae in swimming pools
(EPA Reg. No. 57787-11 and 3432-28).  Table 6.1 presents the scenarios
and associated application rates assessed for this algaecide use.  Based
on standard assumptions, AD assumed that a professional pool maintenance
worker can treat ten 20,000 gallon pools per day (e.g., 200,000 gallons
of pool water are treated per day).  It should be noted that the
spa/whirlpool algaecide use is represented by the pool use since the
application rates are the same.

The potential for occupational exposure was based on the loading of the
product by liquid open pouring and granular open pouring. 
Chemical-specific exposure data were not submitted to support the
algaecide use.  Therefore, AD developed a screening-level assessment
using surrogate data to determine the potential risks associated with
swimming pool treatments.  The most representative data available are
the monitoring data from the CMA study data.  The following lists the
unit exposures used in this assessment:

liquid open pour: CMA inhalation UE of 0.00346 mg/lb ai from the liquid
open pour preservative study, which was based on only 2 replicates, was
used.  Although this exposure scenario is based on minimal replicates,
the exposure values are similar to those found in PHED for similar
scenarios. 

solid open pour: CMA inhalation UE of 0.0119 mg/lb ai from the solid
open pour preservative study, which was based on 10 replicates, was
used.  

Table 6.2 presents the potential ST and IT inhalation exposures and
risks for swimming pool algaecide use of Busan 77.  All of the MOEs are
above the target MOE of 100 and therefore not a concern.  Furthermore,
the MOEs are also above 1,000 therefore a confirmatory inhalation
toxicity study is not warranted based on this use.

Metal Working Fluid

Busan 77 can be used “for the inhibition of bacterial degradation of
aqueous solutions or emulsions of the cutting fluids or oils employed as
lubricants in the machining and processing of metals” (EPA Reg. No.
1448-42).  Table 6.1 presents the scenarios and associated application
rates assessed for this materials preservative (e.g., metalworking
fluid) use.  Based on standard assumptions, AD assumed that 300 gallons
of fluid is preserved per day.  

The potential for occupational exposure was based on the loading of the
product by liquid open pouring and connecting/disconnecting a chemical
metering pump from a tote.  Chemical-specific exposure data were not
submitted to support the materials preservative use. Therefore, AD
developed a screening-level assessment using surrogate data to determine
the potential risks associated with metalworking fluid preservation. 
The most representative data available are the monitoring data from the
CMA study data.  The following lists the unit exposures used in this
assessment:

liquid open pour: CMA inhalation UE of 0.00854 mg/lb ai from the
metalworking fluid study, which was based on 8 replicates, was used.

liquid pump: CMA inhalation UE of  0.00348 mg/lb a.i. from the
metalworking fluid study, which was based on 2 replicates, was used.  

Table 6.2 presents the potential ST and IT inhalation exposures and
risks for metalworking fluid preservation use of Busan 77.  All of the
MOEs are above the target MOE of 100 and therefore not a concern. 
Furthermore, the MOEs are also above 1,000 therefore a confirmatory
inhalation toxicity study is not warranted based on this use.

Industrial Freshwater Systems: Pulp/Paper and Textile Mills

Busan 77 can be used “to control the growth of bacteria and fungi in
holding and processing tanks of industrial fresh water systems supplying
water to pulp and paper mills, textile mills, and other manufacturing
plants.  In pulp and paper mills, treatments of the fresh water with
Busan 77 can make an important contribution to slime control.  The use
of Busan 77 as described will reduce the development of slime in fresh
water pipes, fresh water spraying nozzles, and on the pulp and paper
mill machining parts contacted by fresh water.  However, Busan 77 is not
recommended for use as the primary microbiocide for pulp and paper mill
slime control since absorbents such as wood pulp rapidly absorb the
product and greatly reduce its concentration in the circulating water
” (EPA Reg. No. 1448-42).   Table 6.1 presents the scenarios and
associated application rates assessed for this freshwater microbiocide
use.  Based on standard assumptions, AD assumed that 20,000 gallons of
water is treated per day.  

	It should be noted that Busan 77 can also be used to preserve starch
used in paper manufacturing (EPA Reg. No. 1448-42 and 55137-1). 
However, the technical registrant recently stated that this use will be
cancelled.  Therefore, all labels listing the starch preservation use
must be updated to reflect this cancellation.

The potential for occupational exposure was based on the loading of the
product by and connecting/disconnecting a chemical metering pump from a
tote.  Chemical-specific exposure data were not submitted to support the
pulp and paper and textile manufacturing uses.  Therefore, AD developed
a screening-level assessment using surrogate data to determine the
potential risks associated with pulp and paper and textile
manufacturing.  The most representative data available are the
monitoring data from the CMA study data.  The following lists the unit
exposures used in this assessment:

liquid pump: CMA inhalation UE of 0.000265 mg/lb ai from the pulp and
paper preservative loading study, which was based on 7 replicates, was
used. 

Table 6.2 presents the potential ST and IT inhalation exposures and
risks for the pulp and paper and textile water system use of Busan 77. 
All of the MOEs are above the target MOE of 100 and therefore not a
concern.  Furthermore, the MOEs are also above 1,000 therefore a
confirmatory inhalation toxicity study is not warranted based on this
use.

Cooling Water Systems

Busan 77 can be used “to control the growth of microorganisms
including bacteria, algae, and fungi in recirculating cooling water
system” (EPA Reg. No. 1448-398).  Furthermore, Busan 77 can be used
“to control mollusks such as Corbicula species in once-through cooling
water systems” as well as “control algae and mollusks such as
Corbicula and Dreissena species in potable water treatment systems”
(EPA Reg. No. 55137-1).  Table 6.1 presents the scenarios and associated
application rates assessed for the various cooling water system uses. 
It should be noted that the once-through cooling water system scenario
also represents the potable water system scenario.

  

At this time, a screening-level assessment has been developed for the
recirculating use as well as the once through use.  The daily amount of
biocide handled that was used in this assessment was based on the
following information provided by provided by Dick Youmans of Buckman
Labs (personal communication on 6/30/04 and 10/27/04).   Workers in
small systems could manually pour 5 to 10 gallons of biocide into the
system but larger systems would utilize chemical pumps in order to save
time and labor expense.  Recirculating cooling water systems can vary
tremendously in volume and are believed to be generally less than 50
million gallons.  The range of volume assessed for the large scale once
through power generators (label does not restrict the product to power
generators but they represent the high end) includes 2 to 500 million
gallons.  The 2 million gallons were selected as the low range based on
it representing the “de minimus” flow for EPA’s Cooling Water
Intake Structure Rule (40CFR125.90).  Although a few power generators
may have water flows of approximately 1 to 3 billion gallons, these few
utilities are atypical.  EPA assumed that if the large utilities apply
Busan 77 it would be applied as a continuous feed over 6 days (i.e., 500
million gallons treated/6 days = 83.3 million gallons of water treated
per day).   

Based on the above information, AD assumed that workers handle 10
gallons of biocide per day when making open pour applications. 
Furthermore, AD assessed exposure to workers of recirculating cooling
water systems ranging from 20,000 to 50 million gallons treating via
chemical metering pumps as well as, exposure to workers of once-through
cooling water systems ranging from 2 to 83 million gallons treating via
chemical metering pumps.

The potential for occupational exposure is based on the loading of the
product by liquid open pouring and connecting/disconnecting the chemical
metering pump.  Chemical-specific exposure data were not submitted to
support the cooling tower use.   Therefore, the AD has developed a
screening-level assessment using surrogate data to determine the
potential risks associated with the cooling tower uses.  The most
representative data available for industrial scenarios are the
monitoring data from the CMA study.  The following lists the unit
exposures used in this assessment:

liquid open pour:  CMA inhalation UE of 0.45 mg/lb ai from the cooling
water systems liquid open pour study, which was based on only 5
replicates, was used. Although this exposure scenario was based on
minimal replicates, the exposure value is similar to those found in PHED
for similar scenarios. 

liquid pump in small systems: CMA inhalation UE of 0.00432 mg/lb ai from
the cooling water system liquid pump loading study, which was based on 4
replicates, was used. 

liquid pump in large systems: CMA inhalation UE of 0.000265 mg/lb ai
from the pulp and paper preservative loading study, which was based on 7
replicates, was used.  It should be noted that the UE from the pulp and
paper study was selected for this scenario rather than data from the
cooling water study because the pulp and paper scenario is more
representative of large scale systems such as those in large cooling
water systems.

Table 6.2 presents the potential ST and IT inhalation exposures and
risks for the recirculating and once-through cooling water tower uses of
Busan 77.  All of the MOEs are above the target MOE of 100 and therefore
not a concern.  Furthermore, the MOEs are also above 1,000 therefore a
confirmatory inhalation toxicity study is not warranted based on this
use.

Air Washer Systems

	Busan 77 can be used to control algae, bacteria and fungi in industrial
air washing systems (EPA Reg. No. 402-123).  Table 6.1 presents the
scenarios and associated application rates assessed for air washer
system uses.  Based on the use information provided by Carl Watson of
Buckman Labs via personal communication (7/11/07), it was assumed that
10,000 gallons of air washer water is treated per day.

The potential for occupational exposure was based on the loading of the
product by liquid open pouring and connecting/disconnecting a chemical
metering pump from a tote.  Chemical-specific exposure data were not
submitted to support the air washer system use.  Therefore, AD developed
a screening-level assessment using surrogate data to determine the
potential risks associated with the air washer system use.  The most
representative data available are the monitoring data from the CMA study
data.  The following lists the unit exposures used in this assessment:

liquid open pour:  CMA inhalation UE of 0.00346 mg/lb ai from the liquid
open pour preservative study, which was based on only 2 replicates, was
used.  Although this exposure scenario is based on minimal replicates,
the exposure values are similar to those found in PHED for similar
scenarios. 

liquid pump: CMA inhalation UE of 0.000403 mg/lb ai from liquid pump
preservative study, which was based on only 2 replicates, was used. 

Table 6.2 presents the potential ST and IT inhalation exposures and
risks for the air washer system use of Busan 77.  All of the MOEs are
above the target MOE of 100 and therefore not a concern.  Furthermore,
the MOEs are also above 1,000 therefore a confirmatory inhalation
toxicity study is not warranted based on this use.

Fire Water Protection Systems

	Busan 77 can be used to control “microorganisms which may foul or
cause corrosion in firewater protection systems” (EPA Reg. No.
1448-398).  Table 6.1 presents the scenarios and associated application
rates assessed for fire water system uses.  Based on the use information
provided by Carl Watson of Buckman Labs via personal communication
(7/11/07), it was assumed that 50,000 gallons of fire protection water
is treated per day.

The potential for occupational exposure was based on the loading of the
product by liquid open pouring and connecting/disconnecting a chemical
metering pump from a tote.  Chemical-specific exposure data were not
submitted to support the fire water protection system use.  Therefore,
AD developed a screening-level assessment using surrogate data to
determine the potential risks associated with the fire water system use.
 The most representative data available are the monitoring data from the
CMA study data.  The following lists the unit exposures used in this
assessment:

liquid open pour:  CMA inhalation UE of 0.00346 mg/lb ai from the liquid
open pour preservative study, which was based on only 2 replicates, was
used.  Although this exposure scenario is based on minimal replicates,
the exposure values are similar to those found in PHED for similar
scenarios. 

liquid pump: CMA inhalation UE of 0.000403 mg/lb ai from liquid pump
preservative study, which was based on only 2 replicates, was used. 

Table 6.2 presents the potential ST and IT inhalation exposures and
risks for the fire water protection system use of Busan 77.  All of the
MOEs are above the target MOE of 100 and therefore not a concern. 
Furthermore, the MOEs are also above 1,000 therefore a confirmatory
inhalation toxicity study is not warranted based on this use.

Oil-Well Uses

Busan 77 can be used to maintain bacterial control in oil field water
systems (EPA Reg. No. 1448-398).  Table 6.1 presents the scenarios and
associated application rates assessed for the various oilfield uses.

  

The following use information provided by Carl Watson of Buckman Labs
via personal communication (7/14/04 and 10/29/04) was used to estimate
the amount of product handled per day during oil-well activities. 
Biocide is typically added directly to drilling rig mud tanks via open
pouring. Over a 3 to 6 week period, while a 13,000 ft well is being
drilled, 1 to 2 drums (1 drum = 42 gallons) of biocide may be used if
microbiological problems are encountered.  Therefore, the short-term
exposure assessment used 5.6 gallons for the amount of biocide handled
per day by the drilling rig worker [i.e., (2 drums x 42 gal/drum) / (5
days/week x 3 weeks) = 5.6 gal/day].  The intermediate-term exposure
assessment used 2.8 gallons for the amount of biocide handled per day by
the drilling rig worker [i.e., (2 drums x 42 gal/drum) / (5 days/week x
6 weeks) = 2.8 gal/day].  For the secondary recovery application, the
biocide is meter pumped into the produced water before it is reinjected
into the formation or well.  In large operations produced water volume
can exceed 10,000 barrels/day (1 barrel = 42 gallons); therefore 420,000
gallons of water can be treated in secondary recovery operations. 
Furthermore, although crew changes may occur in drilling rig operations,
typically a designated customer representative is responsible for the
biocide feeding.  Therefore, one person would be involved with the
biocide application activities on a daily basis.

The potential for occupational exposure is based on the loading of the
product by liquid open pouring and connecting/disconnecting the chemical
metering pump.  Chemical-specific exposure data were not submitted to
support the oilfield use.   Therefore, the AD has developed a
screening-level assessment using surrogate data to determine the
potential risks associated with the oilfield uses.  The most
representative data available for industrial scenarios are the
monitoring data from the CMA study.  The following lists the unit
exposures used in this assessment:

liquid open pour:  CMA inhalation UE of 0.00346 mg/lb ai from the liquid
open pour preservative study, which was based on only 2 replicates, was
used.  Although this exposure scenario is based on minimal replicates,
the exposure values are similar to those found in PHED for similar
scenarios. 

liquid pump: CMA inhalation UE of 0.000265 mg/lb ai from the pulp and
paper preservative loading study, which was based on 7 replicates, was
used.  It should be noted that the UE from the pulp and paper study was
selected for this scenario rather than the materials preservative study
because the pulp and paper scenario is more representative of large
scale systems such as those in oilfields.

Table 6.2 presents the potential ST and IT inhalation exposures and
risks for the oilfield biocide use of Busan 77.  All of the MOEs are
above the target MOE of 100 and therefore not a concern.  Furthermore,
the MOEs are also above 1,000 therefore a confirmatory inhalation
toxicity study is not warranted based on this use.

Table 6.2 Occupational Handler Exposures and MOEs for Busan 77

Exposure Scenario	Application Method	Unit Exposure	Amount handled/

treated

(gal/day)	Use Ratea	Amount ai handled

 (lb ai/day)b	ST/IT Exposure	ST MOEsd

Target MOE = 100	IT MOEsd

Target MOE = 100



Inhalation 

(mg/lb ai)



Inhalation (mg/kg/day)c	Inhalation	Inhalation

Residential Premises

Swimming pools	Open pour - liquid	0.00346	200,000	0.0012	fl oz ai/gal
15.5	7.7E-04	650,000	290,000

	Open pour - solid	0.0119	200,000	0.0012	oz ai/gal	15.0	2.6E-03	200,000
87,000

Materials Preservative

Metal working fluid	Open pour - liquid	0.00854	300	0.06%	%ai	1.73
2.1E-04	2,400,000	1,000,000

	Metering pump	0.00348	300	0.06%	%ai	1.73	5.2E-08	9,700,000,000
4,300,000,000

Industrial Processes and Water Systems

Paper/Textile Mills	Metering pump	0.000265	20,000	0.0007	fl oz ai/gal
0.99	2.5E-09	200,000,000,000	90,000,000,000

Oil Field:

Water-based drilling fluids	Open pour - liquid	0.00346	5.6 (ST)

2.8 (IT)	0.0056	fl oz ai/gal	0.0021 (ST)

0.0011 (IT)	1.0E-07 (ST)

5.2E-08 (IT)	4,800,000,000	4,200,000,000

Oil Field:

Secondary recovery	Metering pump	0.000265	420,000	0.0056	fl oz ai/gal
158.9	6.02E-04	830,000	370,000

Recirculating Cooling Water	Open pour - liquid	0.45	10	0.0042	fl oz
ai/gal	0.0028	1.8E-05	27,000,000	12,000,000

	Metering pump	0.00432	20,000	0.0042 (ST)

0.0021 (IT)	fl oz ai/gal	5.68 (ST)

2.84 (IT)	3.5E-04 (ST)

1.8E-04 (IT)	1,400,000	1,300,000

	Metering pump	0.000265	50,000,000	0.0042 (ST)

0.0021 (IT)	fl oz ai/gal	14192 (ST)

7096 (IT)	5.4E-02 (ST)

2.7E-02 (IT)	9,300	8,200

Once-through Cooling Water	Open pour - liquid	0.45	10	0.0012%	%ai	0.0010
6.7E-06	75,000,000	33,000,000

	Metering pump	0.000265	2,000,000	0.0012%	%ai	208.56	7.9E-04	630,000
280,000

	Metering pump	0.000265	83,000,000	0.0012%	%ai	8655.24	3.3E-02	15,000
6,700

Air washer systems	Open pour - liquid	0.00346	10,000	0.0042	fl oz ai/gal
2.73	1.4E-04	3,700,000	1,600,000

	Metering pump	0.000403	10,000	0.0042	fl oz ai/gal	2.73	1.6E-05
32,000,000	14,000,000

Fire water protection systems	Open pour - liquid	0.00346	50,000	0.0056
fl oz ai/gal	18.92	9.4E-04	530,000	240,000

	Metering pump	0.000403	50,000	0.0056	fl oz ai/gal	18.92	1.1E-04
4,600,000	2,000,000

a: see Table 6.1

b: Liquid Amt ai handled (lb ai/day) = use rate (fl oz ai/gal) x
gal/128oz x product density (lb/gal) x amt treated (gal treated/day)

    Solid Amt ai handled (lb ai/day) = use rate (oz ai/gal) x lb/16oz x
amt treated (gal treated/day)

c: Inhalation exposure (mg/kg/day) = Inhalation unit exposure (mg/lb ai)
x Amt ai handled (lb ai/day)/70 kg

d: MOE = NOAEL / Exposure; where ST inhalation NOAEL = 500 mg/kg/day; IT
inhalation NOAEL = 221 mg/kg/day

Exposure Calculations and Results 			

	The calculated inhalation exposures and MOEs are shown in Table 6.2. 
All MOEs in the occupational setting were above the target MOE of 100
for ST and IT inhalation exposures.

	 

	6.3	Occupational Post-application Exposures tc \l2 "6.3	Occupational
Post-application Exposures 

	No occupational post-application exposures are assumed to occur for the
scenarios summarized in Table 6.1; any post-application exposures from
these uses are expected to occur in a residential setting.  These
exposure scenarios are assessed in the residential exposure assessment
in Section 4.

	6.4	Metalworking Fluids:  Machinist tc \l2 "6.4	Metalworking Fluids: 
Machinist 

	There is the potential for dermal and inhalation exposure when a worker
handles treated metalworking fluids.  This route of exposure occurs
after the chemical has been incorporated into the metalworking fluid and
a machinist is using/handling this treated end-product.

Dermal Exposure

Exposure Calculations 

	Short-term exposures – Short-term exposures for machinists were
assumed to pose potential risks due to dermal irritation.  Short-term
exposure estimates based on surface area were derived using the
following equation: 

	PE = % ai x FT

	         			

where: 

PE		=	Potential exposure (mg/cm2)

% ai	=	Fraction active ingredient in treated metalworking fluid
(unitless)

FT		=	Film thickness of paint on hands (mg/cm2)

The percent active ingredient in the treated fluid was assumed to be the
highest use rate for metalworking use scenarios (60 -600 ppm ai, or
0.006 - 0.06%, a.i. in treated metalworking fluid; Reg. No. 1448-217). 

It was assumed that exposure to a machinist’s hands would occur in the
absence of gloves.

For short-term duration exposures, the film thickness on the hands was
assumed to be 10.3 mg/cm2 (US EPA, 1992).  This film thickness is based
on a machinist completing a double dip in which both hands are immersed
and remain wet.  The film thickness was chosen because the dermal
endpoint for short-term durations is based on dermal irritation effects
and represents an estimate in the absence of more specific data

Results

	Table 6.3 shows the calculation of the dermal doses and dermal MOEs for
a machinist working with metal fluids. The MOE value at the low
application rate is above the target MOE of 100 and therefore not a
concern however, at the maximum application rate the MOE is below 100.

Table 6.3.  Short- term Dermal Exposures and MOEs for Machinist Exposure
to Metalworking Fluids



Exposure Scenario	

% ai	Film thickness (mg/cm2)	Exposure a

(mg ai/cm2)	Dermal MOE

 (Target MOE = 100) b

Machinist - two hand immersion	0.006	10.3	6.2E-04	200

	0.06	10.3	6.2E-03	20

a	For ST, exposures are calculated as a.i. per area of skin exposed
(mg/cm2) =  (% active ingredient x film thickness mg/cm2 (10.3 for ST
exposure).  

b	MOE = NOAEL (mg/cm2) / exposure (mg/cm2), Where: short-term NOAEL =
0.125 mg/cm2

Inhalation Exposures tc \l4 "6.2.2.2		Inhalation Risks 

	The screening-level intermediate and long term inhalation exposure
estimate for treated metalworking fluids have been developed using the
OSHA PEL for oil mist.  The equation used for calculating the inhalation
dose is:

PDR = PEL x IR x % ai x ED	

		BW

where:

PDR		=	Potential dose rate (mg/kg/day);

PEL		=	OSHA PEL (mg/m3);

IR		=	Inhalation rate (m3 /hr)

% ai		=	Fraction active ingredient in treated metalworking fluid
(unitless) 

ED		=	Exposure duration (hrs/day); 

BW		=	Body weight (kg)

Assumptions  

		

The high-end oil mist concentration is based on OSHA’s Permissible
Exposure Limit (PEL) of 5 mg/m3 (NIOSH, 1998).

The percent active ingredient was selected from the label that provides
an application rate for the non-concentrate fluid (EPA Registration No.
1448-217).

The inhalation rate for a machinist is 1.25 m3 /hr.

A machinist is exposed to the metalworking fluid 8 hours a day, for 5
days a week.

The body weight of an adult is 70 kg (US EPA 1997b).

Results

	Table 6.6 shows the calculation of the inhalation doses and MOEs for a
machinist working with metalworking fluids. The inhalation ST and IT/LT
MOE values for Busan 77 are above the target MOE of 100.  Furthermore,
these MOEs are also above 1,000 therefore a confirmatory inhalation
toxicity study is not warranted based on the results of this scenario.

Table 6.6.  Short-, Intermediate- and Long-Term Inhalation Exposures and
MOEs Associated with Metalworking Fluids Treated with Busan 77
(Machinist)

Exposure Scenario	% a.i.	OSHA PEL (mg/m3)	Inhalation rate

(m3/hr)	Exposure Duration (hrs/day)	Exposure (mg/kg/day)	

Inhalation MOEs

(Target MOE is 100) b





	

ST/IT/LT	

ST	IT	LT



Machinist	

0.06%	

5	

1.25	

8	

4.3E-04	

1,200,000	520,000	230,000



a Exposure (mg/kg/day) = % ai x OSHA PEL (mg/m3) x Inhalation rate
(m3/hr) x exposure duration (hr/day) / body weight (70 kg)

b  MOE = NOAEL (mg/kg/day) / exposure (mg/kg/day) [Where: ST NOAEL = 500
mg/kg/day, IT NOAEL = 221, LT NOAEL = 100 mg/kg/day] 

	6.7	Data Limitations/Uncertainties tc \l2 "6.8	Data
Limitations/Uncertainties 

	There are several data limitations and uncertainties associated with
the occupational handler exposure assessments which include the
following:

Surrogate dermal and inhalation unit exposure values were taken from the
proprietary CMA antimicrobial exposure study (US EPA 1999: DP Barcode
D247642). Most of the CMA data are of poor quality therefore, AD
requests that confirmatory monitoring data be generated to support the
values used in these assessments.  

The CMA unit exposure data used for the secondary recovery in oilfields
and water cooling tower operations are based on metering pump
applications made in a pulp and paper facilities.  Since the volume of
water being treated in secondary recovery and cooling water tower
operations is so large, the available CMA data can not be reliably
extrapolated because they are based on activities that handle much lower
volumes and possibly different techniques.  Therefore, it was assumed
that pulp and paper chemical metering applications, which are typically
large operations, can be representative of other large operations. 
Additional exposure data should be collected to confirm the estimates
for large scale applications 

The once through cooling water flow volumes for power generation are
large (e.g., 500 million gallons assessed).  It is unknown if these
utilities actually use Busan 77 but there are not label restrictions on
flow volumes.  Nonetheless, this screening-level assessment and the
inhalation risks are not of concern at these higher flows.

The use information for the pulp and paper/textile processing, materials
preservation, oil-well uses, and cooling water tower uses are based on
personal communication with the registrants.  The individuals contacted
have experience in these operations and their estimates are believed to
be the best available without undertaking a statistical survey of the
uses. 

7.0	REFERENCES tc \l1 "7.0	REFERENCES  

ACC. 2002. American Chemistry Council (ACC).  An Analysis of the
Training Patterns and Practices of Competitive Swimmers.  Prepared by
Richard Reiss.  Sciences International, Inc.  Alexandria, Virginia. 
December 19, 2002.

National Institute for Occupational Safety and Health (NIOSH). 1998.
Criteria for a Recommended Standard-Occupational Exposure to
Metalworking Fluids.  Department of Health and Human Services (DHHS)
NIOSH Publication #98-102.

U.S. Environmental Protection Agency (US EPA).  1987. Methods for
Assessing Exposure to Chemical Substances: Volume 7, Methods for
Assessing Consumer Exposure to Chemical Substances. Office of Toxic
Substances. EPA/560/5-85/007 

U.S. Environmental Protection Agency (US EPA).  1992.  A Laboratory
Method to Determine the Retention of Liquids on the Surface of Hands. 
Prepared by C. Cinalli, C. Carter, A. Clark, and D. Dixon, under EPA
Contract No. 68-02-4254.  EPA-747/R-92-003.  Exposure Evaluation
Division, Office of Pollution Prevention and Toxics.  September 1992.

U.S. Environmental Protection Agency (US EPA).  1996.  Office of
Research and Development, Descriptive Statistics Tables from a Detailed
Analysis of the National Human Activity Pattern (NHAPS) Data;
EPA/600/R-96/148, July.   Data Collection Period October 1992 -
September 1994.  

U.S. Environmental Protection Agency (US EPA).  1997a. Standard
Operating Procedures (SOPs) for Residential Exposure Assessments.  EPA
Office of Pesticide Programs Human Health Effects Division (HED). 
December 18, 1997.

U.S. Environmental Protection Agency (US EPA).  1997b. Exposure Factors
Handbook. Volume I-II.  Office of Research and Development.  Washington,
D.C.  EPA/600/P-95/002Fa.

U.S. Environmental Protection Agency (US EPA).  1999.  Evaluation of
Chemical Manufacturers Association Antimicrobial Exposure Assessment
Study.  Memorandum from Siroos Mostaghimi, Ph.D., USEPA, to Julie
Fairfax.

U.S. Environmental Protection Agency (US EPA).  2007. Exposure and Fate
Assessment Screening Tool (E-FAST) Version 2.0. Demonstration Manual.
Office of Pollution Prevention and Toxics Exposure Assessment Branch.
March 2007.

Versar. 2003.  User's Manual Swimmer Exposure Assessment Model
(SWIMODEL) Version 3.0. Prepared for US EPA Antimicrobials Division.
November 2003. 

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