Document ID: EPA-HQ-OPP-2006-0338-0019
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-12-29T05:00Z

DRAFT

Didecyl Dimethyl Ammonium Chloride (DDAC)

Risk Assessment

(DP Barcode 069149)

Office of Pesticide Programs

Antimicrobials Division

U.S. Environmental Protection Agency

2777 South Crystal Drive

Arlington, VA 22202

Date: July 31, 2006

TABLE OF CONTENTS 

  TOC \o "1-5" \h \z \u    HYPERLINK \l "_Toc128911774"  1.0	 EXECUTIVE
SUMMARY	  PAGEREF _Toc128911774 \h  3  

  HYPERLINK \l "_Toc128911775"  2.0	 PHYSICAL AND CHEMICAL PROPERTIES	 
PAGEREF _Toc128911775 \h  7  

  HYPERLINK \l "_Toc128911776"  3.0	 ENVIRONMENTAL FATE	  PAGEREF
_Toc128911776 \h  8  

  HYPERLINK \l "_Toc128911777"  4.0	 HAZARD CHARACTERIZATION	  PAGEREF
_Toc128911777 \h  10  

  HYPERLINK \l "_Toc128911778"  4.1 	Hazard Profile	  PAGEREF
_Toc128911778 \h  10  

  HYPERLINK \l "_Toc128911779"  4.2	FQPA Considerations	  PAGEREF
_Toc128911779 \h  12  

  HYPERLINK \l "_Toc128911780"  4.3 	Dose-Response Assessment	  PAGEREF
_Toc128911780 \h  12  

  HYPERLINK \l "_Toc128911781"  4.4	Endocrine Disruption	  PAGEREF
_Toc128911781 \h  14  

  HYPERLINK \l "_Toc128911782"  5.0	EXPOSURE ASSESSMENT AND
CHARACTERIZATION	  PAGEREF _Toc128911782 \h  14  

  HYPERLINK \l "_Toc128911783"  5.1	Summary of Registered Uses	  PAGEREF
_Toc128911783 \h  14  

  HYPERLINK \l "_Toc128911784"  5.2	Dietary Exposure and Risk	  PAGEREF
_Toc128911784 \h  14  

  HYPERLINK \l "_Toc128911785"  5.3	Drinking Water Exposures and Risks	 
PAGEREF _Toc128911785 \h  16  

  HYPERLINK \l "_Toc128911786"  5.4	Residential Exposure/Risk Pathway	 
PAGEREF _Toc128911786 \h  16  

  HYPERLINK \l "_Toc128911787"  6.0	AGGREGATE RISK ASSESSMENT AND RISK
CHARACTERIZATION	  PAGEREF _Toc128911787 \h  20  

  HYPERLINK \l "_Toc128911788"  6.1	Acute and Chronic Aggregate Risks	 
PAGEREF _Toc128911788 \h  20  

  HYPERLINK \l "_Toc128911789"  6.2	Short- and Intermediate-Term
Aggregate Exposures and Risks	  PAGEREF _Toc128911789 \h  21  

  HYPERLINK \l "_Toc128911790"  7.0	 CUMULATIVE EXPOSURE AND RISK	 
PAGEREF _Toc128911790 \h  23  

  HYPERLINK \l "_Toc128911791"  8.0	OCCUPATIONAL EXPOSURE ASSESSMENT	 
PAGEREF _Toc128911791 \h  24  

  HYPERLINK \l "_Toc128911792"  8.1	Occupational Handler Exposures	 
PAGEREF _Toc128911792 \h  24  

  HYPERLINK \l "_Toc128911793"  8.2  	Occupational Post-application
Exposures	  PAGEREF _Toc128911793 \h  26  

  HYPERLINK \l "_Toc128911794"  8.3 	Wood Preservation	  PAGEREF
_Toc128911794 \h  27  

  HYPERLINK \l "_Toc128911795"  8.3.1 	Non-Pressure Treatment Scenarios
(Handler and Post-application)	  PAGEREF _Toc128911795 \h  27  

  HYPERLINK \l "_Toc128911796"  8.3.2	Pressure Treatment Scenarios
(Handler and Post-Application)	  PAGEREF _Toc128911796 \h  30  

  HYPERLINK \l "_Toc128911797"  8.4	Data Limitations/Uncertainties	 
PAGEREF _Toc128911797 \h  31  

  HYPERLINK \l "_Toc128911798"  9.0	INCIDENT REPORTS	  PAGEREF
_Toc128911798 \h  32  

  HYPERLINK \l "_Toc128911799"  10.0	ENVIRONMENTAL RISKS	  PAGEREF
_Toc128911799 \h  33  

  HYPERLINK \l "_Toc128911800"  11.0	REFERENCES	  PAGEREF _Toc128911800
\h  36  

  HYPERLINK \l "_Toc128911801"  APPENDIX A: Master DDAC Label	  PAGEREF
_Toc128911801 \h  41  

 

1.0		EXECUTIVE SUMMARY

	This document provides a risk assessment for the Group I Quat Cluster. 
The Group I Quat Cluster is a group of structurally similar quaternary
ammonium compounds (“quats”) that are characterized by having a
positively charged nitrogen covalently bonded to two alkyl group
substituents (at least one C8 or longer) and two methyl substituents. 
In finished form, these quats are salts with the positively charged
nitrogen (cation) balanced by a negatively charged molecule (anion). 
The anion for the quats in this cluster is chloride or bromide. In this
document, the Group I Quat Cluster will be referred to as DDAC (didecyl
dimethyl ammonium chloride).

	DDAC is the active ingredient in numerous types of products.  The
products are mainly disinfectants and deodorants that are used in
agricultural, food handling, commercial/ institutional/industrial,
residential and public access, and medical settings. Examples of
registered uses for DDAC in these settings include application to indoor
and outdoor hard surfaces (e.g., walls, floors, tables, toilets, and
fixtures), eating utensils, laundry, carpets, agricultural tools and
vehicles, egg shells, shoes, milking equipment, humidifiers, medical
instruments, human remains, ultrasonic tanks, reverse osmosis units, and
water storage tanks. There are also DDAC-containing products that are
used in residential and commercial swimming pools, in aquatic areas such
as decorative ponds and decorative fountains, and in industrial process
and water systems such as re-circulating and once through cooling water
systems, drilling muds and packer fluids, oil well injection and
wastewater systems. Additionally, DDAC-containing products are used for
wood preservation through non-pressure and pressure-treatment methods. 
There are registered uses for fogging in occupational settings. 
Products containing DDAC are formulated as liquid ready-to-use, soluble
concentrate, pressurized liquid, and water soluble packaging. The
percentage of DDAC in the various end-use products ranges from 0.08% to
80% DDAC.  Residential products such as EPA Reg. No. 10324-69 range up
to 50% DDAC for swimming pools and spas.    

	The durations and routes of exposure evaluated in this assessment
include short-term (ST), intermediate-term (IT), and in some instances
long-term (LT) inhalation exposures, ST dermal exposures, and ST oral
exposures.  The ST inhalation endpoint and the ST oral endpoint are
based on a NOAEL of 10 mg/kg/day from a prenatal developmental toxicity
study in rats.  The LOAEL (20 mg/kg/day) was based largely on increased
incidence of skeletal variations in females.  This developmental study,
along with a developmental study in rabbits do not indicate increased
susceptibility in rats or rabbits from in utero and postnatal exposures
to DDAC.  The IT/LT inhalation endpoint is also confirmed by a NOAEL of
10 mg/kg/day but from a chronic toxicity study in dogs. No short-term
dermal endpoint for systemic effects was selected for DDAC, since no
systemic effects were identified.  However, a short-term dermal
irritation endpoint was identified. The short-term dermal endpoint for 
DDAC (2 mg/kg/day which is equivalent to 8 μg/cm2) was determined from
a LOAEL of 6 mg/kg/day based on increased clinical and gross findings
(erythema, edema, exfoliation, excoriation, and ulceration). A 21-day
dermal toxicity study was also conducted using a 0.13% ai formulation.
No short-term dermal endpoint was identified for this formulation
because no irritation or systemic effects were identified up to and
including the limit dose of 1,000 mg/kg/day. Intermediate- or long-term
dermal irritation endpoints were not identified for DDAC.  Because the
effect to the skin is localized skin irritation, a skin concentration
(μg/cm2) of exposure, rather then a dose (mg/kg/day) was used to assess
the dermal risk concerns.  No body weight is needed for the dermal
irritation endpoint, since no systemic dose is calculated.  Since the
toxicological endpoint for inhalation is female-specific, a body weight
of 60 kilograms is used in the assessment.  This represents the body
weight of an adult female. The Agency’s level of concern (LOC) for
occupational and residential DDAC inhalation and oral exposures is 100
(i.e., a margin of exposure (MOE) less than 100 exceeds the Agency’s
level of concern). The level of concern is based on 10x for interspecies
extrapolation and 10x for intraspecies extrapolation.  The level of
concern for the dermal route of exposure is a target MOE of 10 (i.e., 3X
intraspecies variation and 3X interspecies extrapolation). 

	The acute toxicity categories (Tox Cat) for DDAC include:  acute oral
(Tox Category II), acute dermal (Tox Category III), acute inhalation
(Tox Category II) and primary eye and skin irritation (Tox Category  I).
 DDAC is not a dermal sensitizer.

Dietary Risk Summary

	DDAC can be used as a disinfectant or sanitizer on counter tops,
utensils, appliances, tables, refrigerators, on animal premises and/or
farms, and in mushroom premises.  The use of DDAC as an antimicrobial
product on food or feed contact surfaces, agricultural commodities, and
application to food-grade eggs may result in pesticide residues in human
food.  Residues from treated surfaces, such as utensils, countertops,
equipment, and appliances can migrate to food coming into contact with
the treated and rinsed surfaces and can be ingested by humans.

	The results of the indirect food contact (i.e., countertops and
utensils) assessment indicate no risks of concern.  The acute and
chronic dietary risks are the same because they are based on the same
NOAEL.  For indirect food contact exposures, the percent of the acute
and chronic population adjusted dose occupied (%aPAD or cPAD) is 3.3
percent for adults and 13.3 percent for children.  For direct
applications to food, the % aPAD and cPAD for all individual uses and
populations is less than or equal to 1.  For the direct food contact as
well as the indirect food contact the risks are not of concern.  The
drinking water exposures from DDAC uses are negligible and are not
quantifiable.  

Residential Risk Summary

Dermal

	For the residential handler dermal exposure and risk assessment, dermal
risks were calculated by comparing residues on the surface of the skin
to the short-term dermal irritation endpoints.    Additional dermal
toxicity studies could provide a better characterization of the
relationship between percent DDAC in a formulation and dermal
irritation.  Residues on the surface of the skin (dermal irritation
exposure) were determined using hand unit exposures from CMA and/or PHED
adjusted for the surface area of the hand (mg/lb ai/cm2), application
rates, and use amounts. The dermal MOEs were above the target MOE of 10
for all scenarios except for the spray applications to carpets and the
heavy duty cleaning rate (0.02 lb ai per  gallon) for mopping and
wiping. 

	The residential post-application dermal risks were assessed by
comparing the surface residue on the skin (dermal skin irritation
exposure) to the short-term dermal endpoint. It was assumed that during
the exposure period the skin repeatedly contacts the treated surface
until a steady-state concentration of residues is achieved on the skin.
For residential scenarios, the post-application dermal MOEs were above
the target MOE of 10 for the laundered clothing (assuming 1% residue
transfer) but below the target MOE for the following:

Wearing clothes treated with a fabric spray: ST dermal MOE = <1 using  a
100% clothing to skin transfer factor and the MOE = 8 using a 5%
clothing to skin transfer factor.

There are no wipe data available to assess the children’s dermal
contact to treated decks and/or play sets.  Based on hand measurements
of workers at the treatment plants, dermal MOEs range from 3 to 13 with
considerable uncertainties, and therefore a wipe study is warranted.  

Inhalation

		For the residential handler inhalation assessment, the inhalation
risks were calculated by comparing the daily doses to the short-term
inhalation endpoint.  The inhalation MOEs were above the target MOE of
100 for all scenarios.

		For the residential post-application inhalation exposure and risk
assessment, the MOEs were below the target MOE of 100 for the following
scenario: 

Humidifier: ST/IT 8-hr Inhalation MOE = 27 for adults and 8 for
children; ST/IT 24-hr Inhalation MOE = 11 for adults and 5 for children

Incidental Oral

		For the residential post-application incidental oral assessment, the
MOEs were above the target MOE of 100 for all scenarios.

Aggregate Risk Summary

	The acute and chronic dietary aggregate risk assessment includes direct
and indirect food contact uses.  There are no drinking water exposures
as a result of DDAC applications.  The acute and chronic endpoints are
based on the same NOAEL value.  Based on the results of the acute and
chronic aggregate assessment, the % aPAD and cPAD for adults and
children are 3.8% and 14%, respectively.  Therefore, the acute and
chronic dietary aggregate risks are not of concern (i.e., less then 100
% of aPAD and/or cPAD).

	The DDAC toxicity endpoints for the chronic dietary and the
intermediate-term incidental oral are based on the same toxic effect
(and same study), and therefore, these two dietary routes of exposure
are aggregated.  On the other hand, the dermal and inhalation routes of
exposure are based on different toxic effects, and therefore, these two
routes of exposure are not aggregated.  However, the dermal route of
exposure is aggregated among those dermal exposure scenarios that are
believed to co-occur.  In addition, the inhalation route of exposure is
also aggregated among the inhalation exposure scenarios that are
believed to co-occur. The aggregate risks are not of concern for adults
for the oral and inhalation routes. However, the adult dermal MOE for
the heavy duty cleaning products are all of concern by themselves.  As
an aggregate, the adult dermal MOE is less than the target MOE of 10 for
the general cleaning rate (aggregate MOE = 7) and for the heavy duty
cleaning rate (aggregate MOE = 1).  For children, the oral aggregate
(dietary and intermediate-term ingestion for children at day care
centers) is 270.  The children aggregate MOE for the dermal route is 42,
and therefore, not of concern.  No children aggregate inhalation
scenarios were determined to co-occur.  It is important to note,
however, that some of the individual risks for scenarios not included in
the aggregate are of concern by themselves (e.g., the humidifier use and
the fabric spray for clothing).

Occupational Risk Summary

Dermal

DDAC dermal irritation exposures and risks were not estimated for
occupational handler exposures.  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 containing concentrations of DDAC
that result in classification of category I, II, or III for skin 
irritation potential will be long-sleeve shirt, long pants, shoes,
socks, chemical-resistant gloves, and chemical-resistant apron.  Once
diluted, if the concentration of DDAC in the diluted solution would
result in classification of toxicity category IV for skin irritation
potential, then the chemical-resistant gloves and chemical-resistant
apron can be eliminated for applicators and others exposed to the
dilute. Note that chemical-resistant eyewear will be required if the
end-use product is classified as category I or II for eye irritation
potential. 

	Dermal irritation exposures are assumed to be negligible for all
post-application occupational scenarios, except those associated with
wood preservation. As with occupational handlers, dermal irritation
exposures and risks from post-application activities in a wood
preservation treatment facility will be mitigated using default personal
protective equipment requirements based on the toxicity of the end-use
product.  For construction workers handling treated wood the MOEs range
from 3 to 13 with a target MOE of 10. A wipe study on treated wood will
be needed to assess the potential exposure to handling treated wood.

Inhalation

	For the occupational handler inhalation exposure and risk assessment,
the MOEs were above the target MOE of 100 for all scenarios.  

	For the occupational inhalation post-application exposure and risk
assessment, the MOEs were above the target MOE of 100 for all scenarios
except for fogging in a food processing plant.  The 8-hr MOE from
starting 2 hours after application (i.e., 2 hour re-entry interval) is
8.

Environmental Fate and Ecological Risk: AD Specific Uses

The results of the dietary avian studies indicate that DDAC is
practically non-toxic to both mallard duck and bobwhite quail.  In the
Acute oral studies, the chemical was found to be moderately toxic to
bobwhite quail.  The results from freshwater fish acute toxicity studies
demonstrated that DDAC was moderately  to highly toxic.  DDAC is very
highly toxic to freshwater aquatic invertebrates.  DDAC is very highly
toxic to mysid shrimp a marine/estuarine invertebrate.  DDAC is toxic to
freshwater alga at microgram concentrations.

Data Gaps:

The following data requirements are outstanding for the currently
registered uses of DDAC:

850.4225 - Non-target plant phytotoxicity testing (seedling emergence
test using rice).

850.1035 - Acute Sheepshead minnow testing

850.1300 - Fish-Early Life Stage

850.1400 - Aquatic Invertebrate Life Cycle

850.4400 – Aquatic Plant Growth

850.1950 – Aquatic Field Monitoring

850.4250 – Vegetative Vigor using Rice

850.3030 – Honey Bee Toxicity Studies

Monitoring/Tier II modeling of once-through cooling tower use to
establish EEC’s for risk assessment.

Environmental Fate and Eco Risks: Agricultural Premises:

	The Environmental Fate and Effects Division (EFED) has evaluated the
outdoor use of the quaternary ammonium compounds, didecyl ammonium
chlorides (DDAC), being considered for reregistration by the
Antimicrobial Division (AD) (DP Barcode D325481).  Although primarily
used as antimicrobial agents, DDAC is labeled for use in puddles and
decorative pools to control algae.  This use is intended for waterbodies
generally disconnected from the greater watershed and will not likely
result in exposure to nontarget aquatic species.  It is possible these
uses will result in exposure to amphibians utilizing these waterbodies
for some portion of their lifecycle (e.g. reproduction) and to birds and
mammals utilizing these waterbodies for drinking water.  At the maximum
label rate, 3 ppm initially followed by weekly 1.5 ppm treatments, there
are no LOC exceedances, assuming the toxicity of DDAC is similar to that
of ADBAC.  However, due to the persistence of DDAC, it is possible that
concentrations of DDAC in some waterbodies treated over time could
become harmful to animals utilizing these waterbodies.

2.0	 PHYSICAL AND CHEMICAL PROPERTIES

	The Group I Quat Cluster is a group of structurally similar quaternary
ammonium compounds (“quats”) that are characterized by having a
positively charged nitrogen covalently bonded to two alkyl group
substituents (at least one C8 or longer) and two methyl substituents. 
In finished form, these quats are salts with the positively charged
nitrogen (cation) balanced by a negatively charged molecule (anion). 
The anion for the quats in this cluster is chloride or bromide. In this
document, the Group I Quat Cluster will be referred to as DDAC (didecyl
dimethyl ammonium chloride).

	Currently, there are 5 active ingredients identified by the Agency that
are registered and included in Case Number 3003.  Table 2.1 below
provides the common chemical name, active ingredient code, CAS number,
chemical structure and number of registered product for each compound.  

 	R1 = C8 (variable %)

 	R = C12 (5%)

       C14 (90%)

       C16 (5%)

69173	68607-28-3	Oxydiethylenebis (alkyl*) dimethyl ammonium chloride

R=C12 (40%)

      C14 (50%)

      C16  (10%)

		Table 2.2 provides the physical/chemical characteristics that have
been reported for DDAC.

Table2.2.  Physical/Chemical Properties of DDAC

Parameter	

DDAC

Molecular Weight	362.08

Density	0.9216 g/cm3 at 25 C

Boiling Point	NA

Water Solubility	Completely soluble

Vapor Pressure	2.33E-11 mmHg

3.0		ENVIRONMENTAL FATE

	DDAC is used primarily as a disinfectant, sanitizer, or as a
microbiocide/microbiostat.  It also serves as an algaecide,
bacteriocide/bacteriostat, fungicide/fungistat, insecticide, miticide,
virucide, and tuberculocide.  Use sites for DDAC include agricultural
premises and equipment, food handling, commercial, industrial and
institutional settings, residential areas or areas of public access,
kennels, medical facilities, swimming pools, aquatic areas, and
industrial water systems.   DDAC is also used as a wood preservative. 
Some of the required guideline studies for an environmental fate
assessment have been submitted.  The Agency is using these environmental
fate studies for fate assessment of DDAC to fulfill the reregistration
requirements.

	DDAC has been shown to be hydrolytically stable under abiotic and
buffered conditions over the pH 5-9 range.  The calculated half-lives
for DDAC were 368 days at pH 5, 194 days at pH 7 (TRIS), 175 days at pH
7 (HEPES), and 506 days at pH 9.  DDAC is stable to photodegradation in
pH 7 buffered aqueous solutions; even in the presence of a
photosensitizer (acetone), degradation is minimal with a calculated
half-life of 227 days.  DDAC is photolytically stable in soil with a
calculated half-life of 132 days.

	Aquatic metabolism studies under aerobic and anaerobic conditions
indicate that DDAC is stable to microbial degradation.  The calculated
aerobic and anaerobic half-lives of 14C-DDAC in flooded river water are
180 days and 261 days, respectively.  Similarly, DDAC was found to be
stable with very little degradation in aerobic soils during a year-long
metabolism study.  The calculated half-life for aerobic soil degradation
was 1,048 days.  However, a report on the biodegradability of DDAC
prepared by the Registrant concluded that the degree of DDAC
biodegradability is variable and is influenced by the chemical
concentration, alkyl chain length, the presence of anionic moieties and
the quantity and characteristics of the microbial population.  
According to this report, DDAC is biodegradable and environmentally
acceptable.  This report was based on information from the open
literature, unpublished sources, and meeting proceedings and has not
been reviewed by the Agency.  

	DDAC is immobile in soil. A soil mobility study reviewed by the Agency
shows that DDAC has a strong tendency to bind to sediment/soil with
Freundlich Kads values of 1,095, 8,179, 3,279, and 30,851 in sand, sandy
loam, silty clay loam, and silt loam soils, respectively.  Because of
its strong adsorption to soils, DDAC is not expected to contaminate
surface and ground waters.

	Bioaccumulation of DDAC in freshwater fish is not likely to occur. 
Mean steady state bioconcentration factors for DDAC were determined to
be 38X, 140X, and 81X in the edible, nonedible, and whole body fish
tissue, respectively.  During depuration, 57%, 67%, and 71% of the
residues that accumulated in the edible, whole body, and nonedible
tissues, respectively, were eliminated.  DDAC is not expected to pose a
concern for bioconcentration in aquatic organisms.

	Information on the aqueous availability of DDAC from wood indicates
that the use of DDAC as a wood preservative may result in minimal
releases to the environment.

	The Environmental Fate and Effects Division (EFED) has evaluated the
outdoor use of the quaternary ammonium compounds, didecyl ammonium
chlorides (DDAC), being considered for reregistration by the
Antimicrobial Division (AD) (DP Barcode D325481).  Although primarily
used as antimicrobial agents, DDAC is labeled for use in puddles and
decorative pools to control algae.  This use is intended for waterbodies
generally disconnected from the greater watershed and will not likely
result in exposure to nontarget aquatic species.  It is possible these
uses will result in exposure to amphibians utilizing these waterbodies
for some portion of their lifecycle (e.g. reproduction) and to birds and
mammals utilizing these waterbodies for drinking water.  At the maximum
label rate, 3 ppm initially followed by weekly 1.5 ppm treatments, there
are no LOC exceedances, assuming the toxicity of DDAC is similar to that
of ADBAC.  However, due to the persistence of DDAC, it is possible that
concentrations of DDAC in some waterbodies treated over time could
become harmful to animals utilizing these waterbodies.

4.0		HAZARD CHARACTERIZATION

4.1 	Hazard Profile  tc "3.1 Hazard Profile " \l 2 

DDAC was assigned a Toxicity Category II from results of two acute oral
toxicity studies in rats, MRIDs 41394404 [65% a.i.; LD50 = 262 mg/kg
(combined)] and 42296101 [80% a.i.; LD50 = 238 mg/kg (combined)].  DDAC
was assigned  Toxicity Category III from two acute dermal toxicity
studies in rabbits, MRIDs 42053801 [65% a.i.; LD50 = 2930 mg/kg
(combined)] and 00071158 [50% a.i.; LD50 = 4350 mg/kg (combined)].  For
acute inhalation toxicity (MRID 00145074; TRID 455201010), DDAC (purity
not reported) is assigned a Toxicity Category II (LC50 = 0.07 mg/L). 
For primary eye irritation, DDAC was found to be corrosive (Toxicity
Category I) in two primary eye irritation studies in rabbits, MRIDs
41394404 [65% a.i.] and 42161602 [80% a.i].  For primary dermal
irritation, DDAC (80% a.i.) was found to be corrosive (Toxicity Category
I) in a primary dermal irritation study in rabbits (MRID 42161601).  For
dermal sensitization, DDAC was found to be a non-sensitizer in two
dermal sensitization studies in guinea pigs (MRID 42161603 [80% a.i.])  
(MRID 46367601 [purity not reported]).

For subchronic toxicity, the database includes a 90-day oral toxicity
test in rats (MRID 40966302), a 90-day oral study in dogs (MRID
40262901), and a 90-day dermal toxicity study in rats (MRID 41305901). 
In the 90-day rat oral feeding study (MRID 40966302), incidence of gross
pathological observations and non-neoplastic lesions, including a higher
incidence of glycogen depletion in the liver and contracted spleens were
observed.  In the 90-day dog feeding study (MRID 40269201), no
treatment-related clinical chemistry, hematology, urinalysis, or
pathological findings were observed.  In the 90-day dermal toxicity test
in rats (MRID 41305901), systemic toxicity was not observed and clinical
and gross findings (erythema, edema, exfoliation, excoriation and
ulceration) were limited to the treated skins.

For developmental toxicity, the data from two developmental toxicity
studies, one in the rat (MRID 41886701, range-finder MRID 42746901) and
another in the rabbit (MRID 41018701), do not indicate   SEQ CHAPTER \h
\r 1 increased susceptibility in rats or rabbits from in utero and
postnatal exposure to DDAC.  In the rat developmental toxicity study
(MRID 41886701), developmental toxicity (skeleton variations) was
observed only at treatment levels which also resulted in maternal
toxicity (audible respiration).  In the rabbit developmental toxicity
study, developmental toxicity (decreased fetal body weight and increased
number of dead fetuses) occurred at levels which also resulted in
maternal toxicity (hypo activity, audible respiration, and decreased
body weight gain).  

For reproductive toxicity, the toxicity database for DDAC includes a
2-generational reproductive toxicity study in rats (MRID 41804501).  In
this study, effects in offspring (decreased pup body weight/weight gain)
occurred at the same dose level as maternal effects (decreased maternal
body weight/weight gain and food consumption).

In a 1-year dog feeding study (MRID 41970401), beagle dogs were given
doses of 0, 3, 10, or 20/30 mg/kg/day in the diet.  Treatment-related
clinical signs (soft/mucoid feces, emesis) were observed frequently in
high-dose animals, and total cholesterol levels were significantly
decreased in high-dose females.

DDAC was not carcinogenic when administered in the diet in 2-year
chronic/ carcinogenicity studies in rats (MRID 41965101) and mice (MRID
41802301).  In the rat study, an increase in incidence of interstitial
cell adenomas in the testes were reported, but the incidence was with in
the range of historical controls.  In the mouse study, no
treatment-related effects were noted in the incidence of clinical signs,
deaths, and gross and histopathological observations.

For mutagenicity, DDAC was negative in a battery of tests.  In the Ames
test (MRID 40282201, supplemental information MRID 44005801); DDAC was
not mutagenic with or without metabolic activation.  In a forward gene
mutation test (MRID 93014008, reformat of 40895202), DDAC was negative
for induction of gene mutations in CHO cells at the HGPRT locus with and
without metabolic activation.  In an in vitro chromosome aberration test
(MRID 41252601),   SEQ CHAPTER \h \r 1 DDAC did not induce chromosome
aberration in the Chinese hamster ovary (CHO) cells with or without
metabolic activation.  In an unscheduled DNA synthesis (UDS) assay (MRID
93014007, reformat of 40895201), DDAC did not cause UDS in primary rat
hepatocytes.

Although there are no neurotoxicity studies available in the database,
the available toxicity for DDAC show no evidence for neurotoxic effects.

  SEQ CHAPTER \h \r 1 In a rat pharmacokinetics/ metabolism study (MRID
41617101 and addendum MRID 41385101), single oral doses of 14C- DDAC (5
or 50 mg/kg) or repeated doses (34 ppm of DDAC in the diet for 14 days
and then one single dose of 5 mg/kg of 14C- DDAC) were given to both
male and female rats.  DDAC was mostly excreted in the feces within 3
days principally as parent compound and metabolites.  The elimination
pattern and metabolic profile was not substantially altered by the dose
or exposure duration.  Male and female rats showed similar elimination
patterns, but females metabolized DDAC more extensively than males. 
Four major metabolites were identified as oxidation products with
oxidation confined to the decyl side chains.

The acute toxicity data for DDAC are summarized below in Table 4.1
(USEPA, 2006).

Table 4.1   Acute Toxicity Profile for DDAC

Guideline Number	Study Type/ Test substance (% a.i.)	MRID Number/
Citation	Results	Toxicity Category

870.1100

(§81-1)	Acute oral, rat

(Purity 65%)	MRID 41394404	  SEQ CHAPTER \h \r 1 LD50 =262 mg/kg
(combined)	II

870.1100

(§81-1)	Acute oral, rat

(Purity 80%)	MRID 42296101	  SEQ CHAPTER \h \r 1 LD50 =238 mg/kg
(combined)	II

870.1200

(§81-2)	Acute dermal, rabbit

(Purity 65%)	MRID 42053801	  SEQ CHAPTER \h \r 1 LD50 =2930 mg/kg
(combined)	III

870.1300

(§81-3)	Acute inhalation, rat

 (Purity not reported)	MRID 00145074

TRID 455201010	  SEQ CHAPTER \h \r 1 LC50 = 0.07 mg/L (combined)	II

870.2400

(§81-4)	Primary eye irritation, rabbit (Purity 80% a.i.)	MRID 42161602	
 SEQ CHAPTER \h \r 1 Corrosive.	I

870.2500

(§81-5)	Primary dermal irritation, rabbit (Purity 80%)	MRID 42161601
Corrosive.	I

870.2600

(§81-6)	Dermal sensitization, guinea pigs (Purity 80%)	MRID 46367601
Not a sensitizer.	NA

4.2	FQPA Considerations  tc "3.2   FQPA Considerations " \l 2  

	Under the Food Quality Protection Act (FQPA), P.L. 104-170, which was
promulgated in 1996 as an amendment to the Federal Insecticide,
Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug and
Cosmetic Act (FFDCA), the Agency was directed to "ensure that there is a
reasonable certainty that no harm will result to infants and children"
from aggregate exposure to a pesticide chemical residue.  The law
further states that in the case of threshold effects, for purposes of
providing this reasonable certainty of no harm, "an additional tenfold
margin of safety for the pesticide chemical residue and other sources of
exposure shall be applied for infants and children to take into account
potential pre- and post-natal toxicity and completeness of the data with
respect to exposure and toxicity to infants and children. 
Notwithstanding such requirement for an additional margin of safety, the
Administrator may use a different margin of safety for the pesticide
residue only if, on the basis of reliable data, such margin will be safe
for infants and children."

The Agency (USEPA, 2006) has decided that the FQPA safety factor be
removed for DDAC, based upon the existence of a complete developmental
and reproductive toxicity database and the lack of evidence for
increased susceptibility in these data.  

4.3 	Dose-Response Assessment  tc "3.3 Dose-Response Assessment " \l 2  

	Table 4.2 summarizes the toxicological endpoints for DDAC (USEPA,
2006).  

  SEQ CHAPTER \h \r 1 

Table 4.2  Summary of Toxicological Endpoints for DDAC

Exposure

Scenario	Dose Used in Risk Assessment

(mg/kg/day)	Target MOE/UF,

Special FQPA SF

for Risk Assessment	Study and Toxicological Effects

Acute Dietary

(Females 13-50)	NOAEL(developmental) = 10 mg/kg/day

	FQPA SF = 1

UF = 100 (10x inter-species extrapolation, 10x intra-species variation)
Prenatal Developmental Toxicity - Rat

MRID 41886701

LOAEL = 20 mg/kg/day based on increased incidence of skeletal
variations.

	Acute RfD = 0.1 mg/kg/day (for Females age 13-50)

Acute Dietary

(general population)	An acute dietary endpoint was not identified in the
data base.  This risk assessment is not required

Chronic Dietary

(general population)

	NOAEL = 10

mg/kg/day	FQPA SF = 1

UF = 100 (10x inter-species extrapolation, 10x intra-species variation
Chronic Toxicity Study - Dog

MRID 41970401

LOAEL = 20 mg/kg/day based on increased incidence of clinical signs in
males and females and decreased total cholesterol levels in females. 

	Chronic RfD = 0.1 mg/kg/day

Dermal, Short-Term (technical a.i.)

 

NOAEL = 2 

UF = 100Based on increased dermal clinical and gross findings

Rat 90-day Dermal Study

MRID 413059-01

Non-Dietary Exposures

Incidental Oral

Short-Term	NOAEL

(developmental) = 10 mg/kg/day

	Target MOE = 100 (10x inter-species extrapolation, 10x intra-species
variation)

FQPA SF = 1

	Prenatal Developmental Toxicity - Rat

MRID 41886701

LOAEL = 20 mg/kg/day based on increased incidence of skeletal
variations.

Incidental Oral

Intermediate-Term	NOAEL  = 10 mg/kg/day

	Target MOE = 100 (10x inter-species extrapolation, 10x intra-species
variation)

FQPA SF = 1	Chronic Toxicity Study - Dog

MRID 41970401

LOAEL = 20 mg/kg/day based on increased incidence of clinical signs in
males and females and decreased total cholesterol levels in females. 

Dermal, Short-term (formulated product 0.13% a.i.)	No endpoint
identified.  No dermal or systemic effects identified in the 21-day
dermal toxicity study (MRID 45656601) up to and including the limit dose
of 1000 mg/kg/day

Dermal, Short-term	NOAEL(dermal) = 2 mg/kg/day

(8 µg/cm2)b	Target MOE = 10 (3x inter-species extrapolation, 3x
intra-species variation)

	90-day Dermal Toxicity - Rat

MRID 41305901

LOAEL = 6 mg/kg/day based on increased clinical and gross findings
(erythema, edema, exfoliation, excoriation, and ulceration)

Dermal, Intermediate- and Long-term 	No appropriate endpoint identified.

Inhalation, Short-Term

	NOAEL b  = 10 mg/kg/day

	Target MOE = 100 (10x inter-species extrapolation, 10x intra-species
variation)

FQPA SF = 1	Prenatal Developmental Toxicity - Rat

MRID 41886701

LOAEL = 20 mg/kg/day based on increased incidence of skeletal
variations.

 Inhalation, Intermediate- and Long-Term

	NOAEL c = 10

mg/kg/day	Target MOE = 100 (10x inter-species extrapolation, 10x
intra-species variation)

FQPA SF = 1	Chronic Toxicity Study - Dog

MRID 41970401

LOAEL = 20 mg/kg/day based on increased incidence of clinical signs
males and females and decreased total cholesterol levels in females. 

UF = uncertainty factor, FQPA SF = special FQPA safety factor, NOAEL =
no observed adverse effect level, LOAEL = lowest observed adverse effect
level, PAD = population adjusted dose (a = acute, c = chronic), RfD =
reference dose, MOE = margin of exposure, LOC = Level of concern, NA =
Not Applicable.

 a Short-term dermal endpoint = (2 mg/kg rat x 0.2 kg rat x 1000 ug/mg)
/ 50cm2  area of rat dosed = 8 µg/cm2 .

 b An additional UF of 10x is used for route extrapolation from an oral
endpoint to determine if a confirmatory study is warranted.  

4.4	Endocrine Disruption

	  SEQ CHAPTER \h \r 1 EPA is required under the FFDCA, as amended by
FQPA, to develop a screening program to determine whether certain
substances (including all pesticide active and other ingredients) “may
have an effect in humans that is similar to an effect produced by a
naturally occurring estrogen, or other such endocrine effects as the
Administrator may designate.”  Following recommendations of its
Endocrine Disruptor and Testing Advisory Committee (EDSTAC), EPA
determined that there was a scientific basis for including, as part of
the program, the androgen and thyroid hormone systems, in addition to
the estrogen hormone system.  EPA also adopted EDSTAC’s recommendation
that the Program include evaluations of potential effects in wildlife. 
For pesticide chemicals, EPA will use FIFRA and, to the extent that
effects in wildlife may help determine whether a substance may have an
effect in humans, FFDCA authority to require the wildlife evaluations. 
As the science develops and resources allow, screening of additional
hormone systems may be added to the Endocrine Disruptor Screening
Program (EDSP).

5.0	EXPOSURE ASSESSMENT AND CHARACTERIZATION  tc \l1 "4.0	RESIDENTIAL
EXPOSURE ASSESSMENT 

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

	For dietary uses, DDAC can be used as a disinfectant or sanitizer on
counter tops, utensils, appliances, tables, refrigerators, and in
mushroom premises.  The use of DDAC as an antimicrobial product on food
or feed contact surfaces, agricultural commodities, and application to
food-grade eggs may result in pesticide residues in human food. 
Residues from treated surfaces, such as utensils, countertops,
equipment, and appliances can migrate to food coming into contact with
the treated and rinsed surfaces and can be ingested by humans.

	Products containing DDAC can also be used as general cleaners,
disinfectants, and deodorizers. These products are primarily for use on
indoor surfaces such as hard floors, carpets, walls, bathroom fixtures,
trash cans, toilet bowls, and household contents.  Additionally, other
uses in the home include liquid laundry deodorizers that are added to
the final rinse of the wash cycle, algaecide/bactericides that are added
to portable humidifiers and swimming pools, and deodorizers that are
sprayed on fabric.  Residents may also be exposed to items that have
been treated with DDAC in occupational settings, such as dimensional
lumber for decks and play sets. Appendix A presents a summary of all
exposure scenarios that may occur in residential settings based on
examination of product labels.

	5.2	Dietary Exposure and Risk 

	In the absence of data on DDAC residues on treated food contact
surfaces, the Agency estimated residue levels that may occur in food
from the application rates on food contact surfaces.  Dietary exposures
from application to food grade eggs and mushroom houses are expected to
be much lower than the dietary exposures resulting from the surface
disinfectant and sanitizing uses; therefore, these uses were not
assessed separately.

	To estimate the Estimated Daily Intake (EDI) to treated food contact
surfaces and food utensils, an FDA (FDA, 2003) screening - level
assessment model was used in lieu of residue data.  The maximum
application rate for DDAC in food handling establishments from the
various labeled ready-to-use products is 0.0043 pounds per gallon of
treatment solution.  The EDI calculations presented in this assessment
assumes that food can contact 2,000 cm2 or 4,000 cm2 (50% and 100% of
the FDA worst case scenario) of treated surfaces, and that 10% of the
pesticide migrate to food. The use of the 10% transfer rate, instead of
the use of a 100% transfer rate that is used in the FDA Sanitizer
Solution Guidelines, requires the submission of confirmatory data to
establish the reliability of the use of the 10% transfer rate.  These
daily estimates were conservatively used to assess both acute and
chronic dietary risks.  None of the calculated percent acute population
adjusted dose (% aPAD) or chronic (% cPAD) estimates exceeded 100%.  The
estimated EDI, % aPAD, and % cPAD for food contact surfaces are
presented in Table 5.1.  Note:  The NOAEL for both the acute and chronic
dietary endpoints are the same so only one % PAD is reported (i.e., aPAD
and cPAD are identical).  The results indicate that for the aggregate
risks the adult %aPAD and %cPAD is 2.8% for males and 3.3% for females,
and for children 13.3%.

	For DDAC treatments of food processing plants, the application rates
are similar to food handling establishments presented in Table 5.1, and
hence the exposure, EDIs, DDDs, and % aPAD and cPADs are also similar.

Table 5.1: Calculated EDIs, aPAD, and cPAD for Utensils and Countertops

Exposure Group	Utensils	Countertops	Aggregate

	EDI (mg/day)	DDD (mg/kg/d)	% PADa	EDI (mg/day)	DDD (mg/kg/d)	% PADa	EDI
(mg/p/d)	DDD (mg/kg/d)	% PADa (mg/kg/d)

Adult males	0.0959	0.00137	1.37	0.103	0.00147	1.47	0.199	0.00284	2.84

Adult females	0.0959	0.00160	1.60	0.103	0.00172	1.72	0.199	0.00332	3.32

Children	0.0959	0.00639	6.39	0.103	0.00687	6.87	0.199	0.0133	13.3

       % PAD = exposure (DDD) /(aPAD or cPAD) x 100. The acute and
chronic population average dose is the same;          therefore the %
PADs are the same.  	

	EDI is the estimated daily intake (mg/day).

		DDD is the dietary daily dose (mg/kg/day).

	The maximum application rate for DDAC for bottling/packing of food is
0.0020 lbs a.i per gallons of treatment solution.  EDI values were
calculated using an approach similar to that used for treated
food-contact surfaces and food utensils.  Exposure was assumed to occur
through the ingestion of three food products that might be packaged with
treated material: milk, egg products, and beverages (alcoholic and
non-alcoholic).  The calculated %aPAD and %cPAD did not exceed 100%. 
The results of the EDI and % cPAD are presented in Table 5.2.

Table 5.2:  Calculated EDIs, aPAD, and cPAD for Representative Dairy and
Beverage Consumption

Food Type	Exposure Group	EDI (mg/p/d)	DDD (mg/kg/d)	% PAD

(aPAD & cPAD)

Milk 	Adult Male	0.00451	6.44x10-5	0.0644

	Adult Female

7.52x10-5	0.0752

	Childa	0.00290	1.94x10-4	0.194

Egg product	Adult Male	8.10x10-9	1.16x10-10	1.16x10-7

	Adult Female

1.35x10-10	1.35x10-7

	Child a	5.22x10-9	3.48x10-10	3.48x10-7

Beverages, non-alcoholic	Adult Male	0.0230	3.29x10-4	0.329

	Adult Female

3.84x10-4	0.384

	Childa	0.0148	9.90x10-4	0.990

Beverages, alcoholic, beer	Adult Male	2.91x10-4	4.16x10-6	0.00416

	Adult Female

4.85x10-6	0.00485

5.3	Drinking Water Exposures and Risks  tc "5.4	Drinking Water Exposures
and Risks " \l 2 

	The only DDAC outdoor uses are as an algaecide in decorative pools and
for oil field operations which are considered to be contained. 
Therefore, the DDAC contributions to drinking water exposure are
considered to be negligible and are not quantified.  

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

	The exposure scenarios assessed in this document for the representative
antimicrobial uses selected by the Agency to represent the residential
risks include:

Indoor hard surfaces (e.g., mopping, wiping, trigger pump sprays);

Carpets;

Swimming pools;

Wood preservative;

Textiles (e.g., diapers treated during washing and clothes treated with
fabric spray); and

Humidifiers.

Exposure Data and Assumptions

	The residential handler scenarios were assessed to determine dermal and
inhalation exposures.  The scenarios were assessed using PHED and CMA
data. Specific surrogate data used in determining the dermal and
inhalation exposures are reported below:

    

For the mopping, wiping, low pressure hand wand, and liquid pour in
swimming pool the CMA data were used; and

For aerosol spray and trigger pump scenarios the PHED data were used.

 

	The quantities handled/treated were estimated based on information from
various sources, including the Antimicrobial Division’s estimates. 

For mopping scenarios, it is assumed that 1 gallon of diluted solution
is used.

For wiping and trigger pump spray scenarios, it is assumed that 0.5
liter (0.13 gal) of diluted solution is used.

For low pressure hand wand, it was assumed that 2 gallons are used in
all indoor applications.

For liquid pour in swimming pool scenario, it was assumed that a
residential pool contains 20,000 gallons of water.

For liquid pour in humidifier scenario, it was assumed that a humidifier
with a 11 gallon tank would be treated, based on Holmes Model#
HM4600-U-11. This humidifier releases 11 gallons/1,700 ft2/24 hours
(http://www.holmesproducts.com/estore/product.aspx?CatalogId=3&CategoryI
d=1120&ProductId=582). 

	Post-application scenarios have been developed that encompass multiple
products, but still represent a high end exposure scenario for all
products represented.  Post-application scenarios assessed include
crawling on treated hard surfaces, carpets, and treated lumber such as
decks/play sets (dermal and incidental oral exposure to children),
wearing treated clothing from wash treatment and from a direct clothing
spray treatment (dermal exposure to adults and children and incidental
oral exposure to children), using portable humidifiers (adult and child
inhalation exposure), and swimming in treated pools (adult and child
incidental ingestion). 

Since no toxicological endpoint of concern was identified for dermal
systemic adverse effects, post-application dermal risks were assessed
using the toxicological endpoint of concern for dermal irritation. The
residential post-application dermal risks were assessed by comparing the
surface residue on the skin (dermal skin irritation exposure) to the
short-term dermal irritation endpoint. It was assumed that during the
exposure period, the skin repeatedly contacts the treated surface until
a steady-state concentration of residues is achieved on the skin. 

The duration of exposure for most homeowner exposures is believed to be
best represented by the short-term duration (1 to 30 days).  The reason
that short-term duration was chosen to be assessed is because the
different handler and post-application scenarios are assumed to be
episodic, not daily.  In addition, homeowners are assumed to use
different products with varying activities, not exclusively DDAC treated
products.

Risk Characterization

	A summary of the residential handler inhalation risks are presented in
Table 5.3.  Although the inhalation endpoint represents short-,
intermediate-, and long-term durations, the exposure duration of most
homeowner applications of cleaning products is believed to be best
represented by the short-term duration.  The inhalation toxicological
endpoint is based on an oral study because a route-specific inhalation
study is not available.  The calculated inhalation MOEs are above the
target MOE of 100.  The dermal MOEs are presented in Table 5.4.  The
dermal MOEs were above the target MOE of 10 for all scenarios evaluated
except for the spray applications to carpets and the heavy duty cleaning
rate (0.02 lb ai/gallon) for mopping and wiping.

.

Table 5.3 Short-Term Residential Handler Inhalation Exposures and MOEs

Exposure Scenario

Application Method	Application Method	Application Ratea (lb ai/gallon)
Quantity Handled/ Treated per dayb (gallons)	

Unit Exposure

(mg/lb a.i.)	Daily Dose (mg/kg/day) c	MOE d 

(Target MOE = 100)

Application to indoor hard surfaces	Mopping	0.020	1	2.38	0.00079	13,000

	Wiping	0.020	0.13	67.3	0.0029	3,400

	Trigger Spray	0.020	0.13	2.4	0.00010	96,000

Application to Carpets	Low Pressure Spray	0.0088	2	0.681	0.012	50,000

Application to Swimming Pools	Liquid Pour	0.0000244	20,000	0.00346
0.00002	510,000

Application to Humidifiers	Liquid Pour	0.0043	11	1.89	0.0015	6,700

a	Application rates are the maximum application rates determined from
EPA registered labels for DDAC.

b	Amount handled per day values are estimates or label instructions.	

c	Daily dose (mg/kg/day) = [unit exposure (mg/lb a.i.) x application
rate (lb ai/gal) x quantity treated (gal/day) x absorption factor (1.0
for  inhalation)]/ Body weight (60 kg for inhalation).

d	MOE = NOAEL / Absorbed Daily Dose.  [Where short-term NOAEL = 10
mg/kg/day for inhalation]. Target MOE = 100.

	

Table 5.4 DDAC Short-Term Residential Handler Dermal Risks

Exposure Scenario	Application Method	Application Ratea 

(lb ai/gal)	Quantity Handled/ Treated per dayb (gallon)	Hand Unit
Exposure Adjusted for Surface Area

(mg/lb ai/cm2)c	

Dermal Skin Irritation Exposure d

((g/cm2)	MOE e

(Target MOE = 10)

Application to indoor hard surfaces	Mopping	0.0043	1	0.063	0.273	29

0.02

	1.27	6

	Wiping	0.0043	0.13	1.341	0.750	11

0.02

	3.49	2

	Trigger Spray	0.0043	0.13	0.129	0.072	110

0.02

	0.34	24

Application to Carpets	Low Pressure Spray	0.0088	2	0.161	2.832	3

Humidifier	Liquid Pour	0.0043	11	0.000239	0.011	710

Application to swimming pools	Liquid Pour	0.000017	20,000	0.000239	0.08
98

a	Application rates are the maximum application rates determined from
EPA registered labels for DDAC.

μg/lb ai/cm2) = Unit Exposure (mg/lb ai/cm2) x Application Rate (lb
ai/gal) x Quantity Treated (gal/day) x 1,000 μg/mg

e 	MOE = NOAEL (μg/cm2)/ Dermal Skin Irritation Exposure (μg/cm2). 
[Where short-term dermal NOAEL = 8 µg/cm2]. Target MOE = 10.

	A summary of the residential post application are presented in Table
5.5.  Although the inhalation endpoint represents short-, intermediate-,
and long-term durations, the exposure duration of most homeowner
applications of cleaning products is believed to be best represented by
the short-term duration.  The inhalation toxicological endpoint is based
on an oral study because a route-specific inhalation study is not
available.  The calculated incidental oral MOEs are above the target MOE
of 100.  The dermal MOEs are above the target MOE for all scenarios
except for the laundered clothing.  The inhalation MOEs are above the
target MOE of 100 for all scenarios, except the humidifier.  The 24-hour
inhalation MOEs for adults and children are 11 and 5, respectively.  

Table 5.5.  Short-term Residential Post Application Risks for Adults and
Children.

Exposure Scenario	Dermal MOE

(Target 

MOE =10)

	Incidental Ingestion MOE

 (Target MOE = 100)	Inhalation MOE (Target = 100)

Child playing on floor	33	760	NA

Child playing on carpet	45	520	NA

Clothing

(Laundered – 1% transfer)	690 adults and children	2,600	NA

Clothing

(Fabric spray – 5% transfer)	8	150

	Child playing on decks/play sets	Range from 3 to 13	360

(high end)	NA

Swimming	NA	Ranges from 330 to 4,000 for adults and children	NA

Humidifiers	NA	NA	Adult 11 (24-hrs)

	Child 5 (24-hrs)

NA = not assessed because negligible exposure is assumed by that route
for the exposure scenario of concern.

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

	In order for a pesticide registration to continue, it must be shown
that the use does not result in “unreasonable adverse effects on the
environment”. Section 2 (bb) of FIFRA defines this term to include
“a human dietary risk from residues that result from a use of a
pesticide in or on any food inconsistent with standard under section
408...” of FFDCA.  Consequently, even though no pesticide tolerances
have been established for DDAC, the standards of FQPA must still be met,
including “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).  Aggregate risk assessment were conducted for
short-term (1-30 days), intermediate-term (1-6 months) and chronic
(several months to lifetime) exposures. 

	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.

6.1	Acute and Chronic Aggregate Risks  tc "6.1	Acute and Chronic
Aggregate Risks " \l 2 

	The acute and chronic aggregate risk assessment includes dietary and
drinking water exposures.  No drinking water exposures were identified
for DDAC.  Acute and chronic dietary risk estimates from direct and
indirect food uses are presented in Section 5.2.  Table 6.1 presents a
summary of these exposures, including the aggregate indirect and direct
dietary exposure (all direct and indirect food contact exposures). 
Based on the results of the acute and chronic aggregate assessment, the
% aPAD and % cPAD for adults and children are 3.8% and 14%,
respectively.  Therefore, the acute and chronic dietary risks are not of
concern (i.e., less then 100 % of aPAD and cPAD).

Table 6.1  DDAC Acute and Chronic Aggregate Exposures and Risks (aPAD
and cPAD)

Exposure Routes	Acute and Chronic Dietary Exposures (mg/kg/day)

	Indirect Dietary  Exposuresa	Direct Food Contact Dietary Exposuresa
Drinking Water Exposures 	Aggregate Dietary Exposuresb	% aPAD and cPAD

(MOE)

Adults

Oral Ingestion	0.0033	0.00046	None	0.00376	3.8

(2,700)

Children

Oral Ingestion	0.013	0.0012	None	0.0142	14

(700)

a Dietary (indirect + direct food contact) exposures are presented in
Tables 5.1 and 5.2.

b Aggregate Dietary Exposures = indirect dietary + direct food contact +
drinking water exposures.

c %aPAD and cPAD (percent acute or chronic population adjusted dose) =
aggregate exposures / (a PAD or cPAD) x 100.  Where aPAD and cPAD =
NOAEL 10 mg/kg/day / 100x uncertainty factor = 0.1 mg/kg/day.  MOE =
NOAEL of 10 mg/kg/day / aggregate dietary exposures mg/kg/day.

 	6.2	Short- and Intermediate-Term Aggregate Exposures and Risks  tc
"6.2	Short- and Intermediate-Term Aggregate Exposures and Risks " \l 2 

	Short- and intermediate-term aggregate exposures and risks were
assessed for adults and children that could be exposed to DDAC residues
from the use of products in non-occupational environments.  The short-
and intermediate-term aggregate risks account for pesticide exposures
from the diet, drinking water, and residential uses.  The following list
summarizes all of the potential sources of DDAC exposures for adults and
children.

Adult DDAC exposure sources:

handling of cleaning products containing DDAC as an active ingredient
during wiping, mopping, and spraying activities;

applying DDAC as an air deodorizer using an aerosol spray;

applying DDAC to carpets using a low pressure sprayer;

applying DDAC to swimming pools via open pouring;

applying DDAC to humidifiers via open pouring;

contacting pressure treated wood;

wearing treated clothing; 

use of DDAC in humidifiers; and

eating food having DDAC residues from indirect or direct food contact.

	

Child DDAC exposure sources:

post-application exposures to cleaning product residues containing DDAC
that are used on hard surfaces (e.g, floors/carpets);

breathing air treated with a humidifier;

swimming in treated pools;

contacting pressure treated wood;

wearing treated clothing/diapers;

eating food having DDAC residues from indirect or direct food contact. 

	The use patterns of the products and probability of co-occurrence must
be considered when selecting scenarios for incorporation in the
aggregate assessment.  Table 6.2 summarizes the scenarios included in
the short- and intermediate-term aggregate assessments.

Table 6.2 Exposure Scenarios Included in the Aggregate Assessments

	Short-term (ST) Aggregate	Intermediate-Term (IT) Aggregate

Adults	chronic dietary (direct and indirect)

handling cleaning products (wipe + trigger pump spray) 

wearing treated clothing

humidifier	

Oral:  ST and IT endpoints are the same for both durations. 

Dermal:  ST endpoint only.

Inhalation:  All durations same endpoint.

Children	chronic dietary – (direct and indirect)

post-application to cleaning product on carpets (dermal and oral)

wearing treated clothing

humidifier	Oral:  ST and IT endpoints are the same for both durations. 

Dermal:  ST endpoint only.

Inhalation:  All durations same endpoint.

The chronic dietary exposures were used in both the short- and
intermediate-term aggregate assessment because chronic dietary exposures
occur nearly every day (as opposed to acute dietary exposures occurring
on a one-time basis).  Therefore, short- or intermediate-term
non-dietary exposures have a much higher probability to co-occur with
the chronic dietary intake.  	

Cleaning activities in a residential setting occur on a short-term
basis.  However, the DDAC-containing cleaning products are also labeled
for use in institutional settings such as day-care facilities where
cleaning activities can occur on an intermediate-term basis.  Therefore,
children could have exposure to cleaning product residues on a more
continuous basis in a day care facility, thus, these post-application
scenarios were included in the intermediate-term aggregate assessment.	

	The DDAC toxicity endpoints for the chronic dietary and the
intermediate-term incidental oral are based on the same toxic effect
(and same study), and therefore, these two dietary routes of exposure
are aggregated.  On the other hand, the dermal and inhalation routes of
exposure are based on different toxic effects, and therefore, these two
routes of exposure are not aggregated.  However, the dermal route of
exposure is aggregated among those dermal exposure scenarios that are
believed to co-occur.  In addition, the inhalation route of exposure is
also aggregated among the inhalation exposure scenarios that are
believed to co-occur.  Aggregate risks were calculated using the total
MOE approach outlined in OPP guidance for aggregate risk assessment
(August 1, 1999, Updated “Interim Guidance for Incorporating Drinking
Water Exposure into Aggregate Risk Assessments”).  Table 6.3 presents
a summary of the short-term aggregate risks (i.e., MOEs). Only the
short-term aggregate is presented because the endpoints for incidental
oral as well as inhalation are identical for the short- and
intermediate-term durations.  Only a short-term dermal endpoint was
identified (i.e., no intermediate- and/or long-term dermal endpoints
were identified).  

	The aggregate risks are not of concern for adults for any of the three
routes of exposure except for the dermal exposure.  The adult dermal MOE
for the heavy duty cleaning product rate indicates that the MOE is 1
which is less than the target MOE of 10. The general cleaning rate has
an aggregate MOE of 7 for the combined mopping, wiping and  spraying.
For children, the oral aggregate (dietary and intermediate-term
ingestion for children at day care centers) is 270.  The children
aggregate MOE for the dermal route is 42, and therefore, not of concern
.  No children aggregate inhalation scenarios were determined to
co-occur.  It is important to note, however, that some of the individual
risks for scenarios not included in the aggregate are of concern by
themselves (e.g., the humidifier use and the fabric spray for clothing).
 However, the dermal contribution from the fabric spray would not be
combined with the dermal exposure to children playing on treated
carpets.  These two scenarios are not combined because the dermal
endpoint of irritation is from a localized skin exposure and the skin
exposed to the treated clothing would not also be exposed to the treated
carpet.

Table 6.3  Short- and Intermediate-term Aggregate Risk (MOE) Assessment
for DDAC

Exposure Routes	Chronic Dietary 

MOE	Cleaning Product MOEs

(Adult Applicators & Children Playing)	Humidifier

MOE	Wearing Treated Clothing

MOE	Route-Specific

Aggregate

MOE

Adults

Oral Ingestion	2,700	NA	NA	NA	2,700

Dermal

	NA	29 (mop)	11 (wipe)	110 (spray)	NA	690	7

Dermal

(Heavy duty cleaning rate)

6

 (mop)	2

 (wipe)	24

 (spray)

	1

Inhalation	NA	13,000

(mop)	3,400 (wipe)	96,000 (spray)	Not included, risk of concern	NA	2,600

Children

Oral Ingestion	700	520

(IT hand-to-mouth carpets)	NA	2,600 

(IT Laundered)	270

Dermal	NA	45 (playing on carpets, 5% residue transfer)	NA	690
(Laundered)	42

Inhalation	NA	NA	Not included, risk of concern	NA	No co-occurrence

Aggregate MOE = 1/((1/MOEsame route) + (1/MOE same route) + etc)

7.0		CUMULATIVE EXPOSURE AND RISK tc "6.0	CUMULATIVE EXPOSURE AND RISK" 

		Another standard of section 408 of the FFDCA which must be considered
in making an unreasonable adverse effect determination is that the
Agency considers "available information” concerning the cumulative
effects of a particular pesticide's residues and "other substances that
have a common mechanism of toxicity.” 

		Unlike other pesticides for which EPA has followed a cumulative risk
approach based on a common mechanism of toxicity, EPA has not made a
common mechanism of toxicity finding as to DDAC and any other substances
and DDAC does not appear to produce a toxic metabolite produced by other
substances.  For the purposes of this tolerance action, therefore, EPA
has not assumed that DDACs has a common mechanism of toxicity with other
substances.  For information regarding EPA’s efforts to determine
which chemicals have a common mechanism of toxicity and to evaluate the
cumulative effects of such chemicals, see the policy statements released
by EPA’s Office of Pesticide Programs concerning common mechanism
determinations and procedures for cumulating effects from substances
found to have a common mechanism on EPA’s website at   HYPERLINK
"http://www.epa.gov/pesticides/cumulative/" 
http://www.epa.gov/pesticides/cumulative/ .

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

	Potential occupational handler exposure can occur in various use sites,
which include: agricultural premises, industrial processes and water
systems, food handling premises, commercial/institutional/industrial
premises, medical premises, swimming pools, and aquatic areas. 
Additionally, occupational exposure can occur during the preservation of
wood. For the preservation of wood, the procedure for treatment can
occur in different ways, such that multiple worker functions were
analyzed. Due to the complexity of the wood preservative analysis, the
results for handler and post-application exposures are presented
separately in Section 8.3.

8.1	Occupational Handler Exposures

DDAC dermal irritation exposures and risks were not estimated for
occupational handler exposures.  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 containing concentrations of DDAC
that result in classification of category I, II, or III for skin
irritation potential will be long-sleeve shirt, long pants, shoes,
socks,  chemical-resistant gloves, and chemical-resistant apron.  Once
diluted, if the concentration of DDAC in the diluted solution would
result in classification of toxicity category IV for skin irritation
potential, then the chemical-resistant gloves and chemical-resistant
apron can be eliminated for applicators and others exposed to the
dilute. Note that chemical-resistant eyewear will be required if the
end-use product is classified as category I or II for eye irritation
potential. 

	

	Inhalation exposures and risks were presented based on the oral
toxicity endpoint (i.e., route-specific inhalation study not available).
 The surrogate unit exposure values were taken from the proprietary
Chemical Manufacturers Association (CMA) antimicrobial exposure study
(USEPA, 1999b: DP Barcode D247642) or from the Pesticide Handler
Exposure Database (USEPA, 1998).   The specific inhalation unit
exposures and quantity of DDAC handled are provided in the Occupational
and Residential Exposure chapter for DDAC.

	The inhalation MOEs were calculated for the short- and
intermediate-term durations for occupational handlers using the oral
endpoint. 

 Risk Characterization

	The resulting inhalation exposures and MOEs for the representative
occupational handler scenarios are presented in Table 8.1. The
calculated MOEs were above the target MOE of 100 for all scenarios,
except for once-through cooling water, metering pump: using the average
flow rate for high flow streams (153 MGD) the ST inhalation MOE= 91 for
initial applications.

Table 8.1 Short- , Intermediate- and Long-Term Inhalation Risks
Associated with Occupational Handlers

Exposure Scenario	

Method of Application	

Inhalation Unit Exposure

(mg/lb a.i.) 	Application Rate	Quantity Handled/ Treated per day	

Inhalation  Daily Dose (mg/kg/day)a	

Inhalation 

MOEb, c 

(Target MOE = 100)

Agricultural Premises and Equipment (Use Site Category I)

Application to hard surfaces, equipment, and vehicles 	Mop	2.38	0.0094
lb ai/gal	2 gallons	0.0075	13,000

	High pressure/high volume spray	0.12	0.0094 lb ai/gal	40 gallons
0.00075	13,000

	Low pressure handwand	0.681	0.0094 lb ai/gal	40 gallons	0.0043	2,300

	Trigger pump sprayer	1.3	0.0094 lb ai/gal	0.26 gallons	0.000052	190,000

	Wipe	67.3	0.0094 lb ai/gal	0.26 gallons	0.0027	3,600

Fogging (mix/load only)	Liquid pour	1.89	1.88E-05 lb/ft3	150,000 ft3
0.089	110

  SEQ CHAPTER \h \r 1 Food Handling/Storage Establishments Premises And
Equipment	 (Use Site Category II)

Application to indoor hard surfaces	Low pressure handwand	0.681	0.0200
lb ai/gal	2 gallons	0.00045	22,000

	Mop	2.38	0.0200 lb ai/gal	2 gallons	0.0016	6,300

	Wipe	67.3	0.0200 lb ai/gal	0.26 gallons	0.0058	1,700

	Trigger pump sprayer	1.3	0.0200 lb ai/gal	0.26 gallons	0.00011	89,000

	Immersion, Flooding, Circulation	1.89	0.00196 lb ai/gal	2 gallons
0.00012	81,000

  SEQ CHAPTER \h \r 1 Commercial, Institutional and Industrial Premises
and Equipment (Use Site Category III )

Application to indoor hard surfaces	Low pressure handwand	0.681	0.0200
lb ai/gal	2 gallons	0.00045	22,000

	Mop	2.38	0.0200 lb ai/gal	2 gallons	0.0016	6,300

	Wipe	67.3	0.0200 lb ai/gal	0.26 gallons	0.0058	1,700

	Trigger pump sprayer	1.3	0.0200 lb ai/gal	0.26 gallons	0.00011	89,000

	Liquid pour	1.89	0.0043 lb ai/gal	2 gallons	0.00027	37,000

Application to carpets	Liquid pour	0.00346	0.102 lb ai/gal	32 gallons
0.00019	53,000

Medical Premises and Equipment (Use Site Category V)

Application to hard surfaces	Mop	2.38	0.0200 lb ai/gal	45 gallons	0.036
280

Industrial Processes and Water Systems (Use Site Category VIII)

Small process water systems: Recirculation cooling tower	Liquid pour
0.45	4.17 lb ai/gal product	2.5 gallons	0.078	130

	Metering pump	 0.00432	Initial Dose (ST): 1.50E-03lb ai/gal water
20,000 gallons	0.0022	ST = 4,600

	Maintenance Dose (IT): 1.50E-04lb ai/gal water	20,000 gallons	0.00022
IT =46,000

Oil field operations - drilling mud and packing fluids	Liquid pour
0.00346	1.50 lb ai/gal product	5.6 gallons	0.00048	ST = 21,000

2.8 gallons	0.00024	IT = 41,000

Once-through Cooling Water System - Power plant	Metering pump 	0.000265
Slug Dose (ST): 4.89E-5 lb ai/gal water	5,900,000 gallons	0.0013	ST=2300

	Initial Dose (ST): 4.89 E-5 lb ia/gal water	153,000,000 gallons	0.033
ST=91

Swimming Pools (Use Category X)d

Application to swimming pools	Liquid pour	0.00346	Heavy algae Dose (ST):

0.000017 lb ai/gal	200,000 gallons	0.00020	ST= 15,000

	Maintenance Dose (IT/LT):

0.00000417 lb ai/gal	200,000 gallons	0.000048	IT=210,000

	ST = short-term,  IT = intermediate-term, LT = long-term, N/A= No data
available

a	Daily dose (mg/kg/day) = [unit exposure (mg/lb a.i.) x absorption
factor (1.0 for inhalation) x application rate x quantity treated / Body
weight (60 kg for inhalation).

	b	MOE = NOAEL  (mg/kg/day) / Absorbed Daily Dose [Where NOAEL = 10
mg/kg/day for all inhalation exposure durations].  Target MOE = 100.

	c	The MOEs refer to short-term and intermediate-term duration unless
indicated otherwise.

	d.	The swimming pool scenario also represents the decorative
pond/fountain scenario in the aquatic area use site category because the
application rates are very similar.

8.2  	Occupational Post-application Exposures

	Except for the post-application scenarios assessed for fogging and wood
preservatives (Section 8.3), occupational post-application dermal and
inhalation exposures are assumed to be negligible.

Fogging (Food Processing Plant and Hatchery) 

	Post-application inhalation exposures only were assessed for entry into
a building (hatchery and food processing plant) after a fogging
application, because dermal post application is presumed to be
negligible.  The inhalation exposure assessment was conducted using the
Multi-Chamber Concentration and Exposure Model (MCCEM v1.2).   MCCEM
estimates average and peak indoor air concentrations of chemicals
released from products or materials in houses, apartments, townhouses,
or other residences. Although the data libraries contained in MCCEM are
limited to residential settings, the model can be used to assess other
indoor environments.  MCCEM has the capability to estimate inhalation
exposures to chemicals, calculated as single day doses, chronic average
daily doses, or lifetime average daily doses. (All dose estimates are
potential doses; they do not account for actual absorption into the
body.)

	The product, EPA Reg # 10324-80 (3.3% ai) with a maximum application
rate of 0.0065 lb ai/gal, was assessed for fogging use in a food
processing plant. The label states to fog one quart of the diluted
product per 1,000 cubic feet. All labels which can be used for fogging
in food processing areas indicate that all personnel must vacate the
room during fogging and for a minimum of 2 hours after fogging.
Therefore, exposure was calculated for a person entering the food
processing plant 2 hours after all the applied fogger has been deployed.

	The MOE for fogging in the food processing plant (2-hr re-entry
interval) was below the target MOE of 100.  For fogging in hatcheries,
the 8-hr MOE is 120 immediately after fogging and 6,600 after a 2 hour
REI.  The risks of concern for the food processing plant are attributed
to the low air changes per hour assumed (i.e., 0.18 ACH as a default
parameter in MCCEM to represent low air flow) in the assessment.  This
assessment can be refined with additional information on air flows in
food processing plants.  For the poultry barn, ventilation rate was
obtained from Jacobson (2005).  The assessment for food processing
plants could be refined if a more accurate ventilation rate could be
obtained.  	

8.3 	Wood Preservation

	DDAC is used in products that are intended to preserve wood through
both non-pressure treatment methods and pressure treatment methods. 
Section 8.3.1 presents the exposure analysis for the handler and
post-application scenarios for non-pressure treatment scenarios and
Section 8.3.2 presents the exposure analysis for the handler and
post-application scenarios for pressure treatment scenarios. 

	Dermal irritation exposures from post-application activities in the
wood preservation treatment facility will be mitigated using default
personal protective equipment requirements based on the toxicity of the
end-use product.  Therefore, only inhalation exposures and risks are
presented.

	8.3.1 	Non-Pressure Treatment Scenarios (Handler and Post-application)

	The proprietary study, “Measurement and Assessment of Dermal and
Inhalation Exposures to Didecyl Dimethyl Ammonium Chloride (DDAC) Used
in the Protection of Cut Lumber (Phase III)” (Bestari et al., 1999,
MRID 455243-04) identified various worker functions/positions for
individuals that handle DDAC-containing wood preservatives for
non-pressure treatment application methods and for individuals that
could then come into contact with the preserved wood. The worker
functions/positions identified in the DDAC study are presented below.  

Handler:

Blender/spray operators are workers that add the wood preservative into
a blender/sprayer system for composite wood via closed-liquid pumping.

Diptank Operators can be in reference to wood being lowered into the
treating solution through an automated process (i.e., elevator diptank,
forklift diptank).  This scenario can also occur in a smaller scale
treatment facility in which the worker can manually dip the wood into
the treatment solution.

Chemical operators for a spray box system consist of chemical operators,
chemical assistants, chemical supervisors, and chemical captains.  These
individuals maintain a chemical supply balance along with flushing and
cleaning spray nozzles. 

Post-application: 

Graders, positioned right after the spray box, grade dry lumber by hand
(i.e. detect faults).  In the DDAC study, graders graded wet lumber;
therefore, the exposures to graders using DDAC are worst-case scenarios.
   

Millwrights repair all conveyer chains and general up-keep of the mill. 

Clean-up crews perform general cleaning duties at the mill.

Trim saw operators operate the hula trim saw and consist of operators
and strappers. In the DDAC study, hula trim saw operators handled dry
lumber. 

Construction workers install treated plywood, oriented strand board,
medium density fiberboard, and others.  

	The blender/spray operator position was assessed using CMA unit
exposure data and the remaining handler and post-application positions
were assessed using data from the DDAC study (Bestari et al., 1999). 

Blender/Spray Operators

Table 8.2 provides the inhalation doses and MOEs for the workers adding
the preservative to the wood slurry.  The inhalation MOE is above the
target MOE of 100 for short-, intermediate-, and long-term inhalation
exposures (MOE = 280).

Table 8.2  Short-, Intermediate-, and Long-Term Inhalation Exposures and
MOEs for Blender/Spray Operator

Exposure Scenario

	Inhalation Unit Exposurea

(mg/lb ai)	Application Rate

(% ai in solution/

day)	Wood Slurry Treatedb

(lb/day)	Daily Dosec (mg/kg/day)	ST/IT/LT 

MOEd 

(Target MOE = 100)

Occupational Handler

Blender/spray operator	0.000403	3	178,000	0.036	280

ST =	Short-term duration; IT =	Intermediate-term duration; and LT =
long-term.

Inhalation unit exposure: Baseline.	

b.	Wood slurry treated = (8 batches/day x 7,000 gallons/batch x 0.003785
m3/gallon x 380 kg/m3 x 2.2 lb/kg)	

c.	Daily Dose = unit exposure (mg/lb ai) x App Rate (% ai/day) x
Quantity treated (lb/day) x absorption factor (100% for inhalation) / BW
(60 kg)

d.	MOE = NOAEL (mg/kg/day)/ Daily dose [Where ST/IT/LT NOAEL = 10
mg/kg/day for inhalation. Target MOE = 100.

Chemical Operators, Graders, Millwrights, Clean-up Crews, and Trim Saw
Operators

Table 8.3 provides the short-, intermediate-, and long-term inhalation
doses and MOEs for chemical operators, graders, millwrights, clean-up
crews, and trim saw operators.  The inhalation MOEs are above the target
MOE of 100 for all worker functions. Any dermal irritation exposures
from post-application activities will be mitigated using default
personal protective equipment requirements based on the toxicity of the
end-use product.

Table 8.3 Short-, Intermediate, and Long-Term Inhalation Exposures and
MOEs for Wood Preservative Chemical Operators, Graders, Trim Saw
Operators, and Clean-Up Crews (Handler and Post-application Activities)

Exposure Scenarioa 

(number of volunteers)	Inhalation UEb 

(mg/day)	Conversion Ratioc	Daily Dosed

(mg/kg/day)	MOEe (Target MOE = 100)

Occupational Handlers

Chemical Operator (n=11)	0.0281	NA	0.000468	21,000

Occupational Post-Application

Grader (n=13)	0.0295	NA	0.000491	20,000

Trim Saw (n=2)	0.061	NA	0.00101	9,900

Millwright (n=3)	0.057	NA	0.00095	11,000

Clean-Up (n=6)	0.60	NA	0.0101	990

ST = 	Short-term duration, IT = Intermediate-term duration, LT =
Long-term duration

a.	The exposure scenario represents a worker wearing short-sleeved
shirts, cotton work trousers, and cotton glove dosimeter gloves under
chemical resistant gloves. Volunteers were grouped according to tasks
they conducted at the mill.

b.	Inhalation unit exposures are from Bestari et. al. (1999).  Refer to
Table E-1 in Appendix E for the calculation of the inhalation exposures.
Inhalation exposure (mg/day) was calculated using the following
equation: Air concentration (μg/m3) x Inhalation rate (1.0 m3/hr) x
Sample duration (8 hr/day) x Unit conversion (1 mg/1000 μg).  The
inhalation rate is from USEPA, 1997.

c.	A conversion ratio is not needed because the maximum % active
ingredient in the product is the same as the % active ingredient in the
DDAC study.  

d.	Daily dose (mg/kg/day) = exposure (mg/day) x absorption factor (100%
for inhalation)/body weight (60 kg). 

e.			MOE = NOAEL (mg/kg/day)/ Daily dose [Where inhalation NOAEL = 10
mg/kg/day]. Target MOE = 100.

Diptank Operators

	Exposures to diptank operators were also assessed using the data from
the DDAC study (Bestari et al., 1999). The diptank scenario assessment
was conducted differently than for the other job functions because the
concentration of DDAC in the diptank solution was provided.  The
exposure data for diptank operators were converted into (unit exposures(
in terms of mg a.i. for each 1% of concentration of the product.  Table
8.4 provides the short-, intermediate- and long-term inhalation dose and
MOEs for diptank operators. The inhalation MOE is above the target MOE
of 100 and, therefore, is not of concern.

Table 8.4 Short-, Intermediate-, and Long-Term Inhalation Exposures and
MOEs for Diptank Operator (Handler Activity)

Exposure Scenarioa

(number of replicates)	Inhalation Unit Exposureb

(mg DDAC/1% solution)	App Rate

(% a.i. in solution/ day)	Daily Dosec

(mg/kg/day)	MOEd

Occupational Handler

Dipping, with gloves (n=7)	0.046	3	0.0023	4,300

a 	The exposure scenario represents a worker not wearing a respirator.

b	Inhalation unit exposures are from DDAC study (MRID 455243-04). Refer
to Table E-2 in Appendix E for inhalation unit exposure calculations.
Inhalation exposure (mg) was calculated using the following equation:
Air concentration (mg/m3) x Inhalation rate (1.0 m3/hr) x Sample
Duration (8 hr).  The inhalation rate is from USEPA, 1997.

c	Daily dose (mg/kg/day) = unit exposure (mg/1% ai solution) x percent
active ingredient in solution  (3% ai) x absorption factor (100% for
inhalation) / body weight (60 kg).

d			MOE = NOAEL (mg/kg/day) / Daily dose [Where inhalation NOAEL = 10
mg/kg/day. Target MOE = 100.

Construction workers

	Potential risks resulting from construction worker dermal contact with
DDAC-treated wood are assessed in the same manner as potential risks
resulting from children’s dermal contact with DDAC-treated play sets
and decks. The risks were calculated using a range of worker residue
data for hands available in the DDAC exposure study for contacting dry
lumber. Hand residue data from the end stacker, stickman, and tallyman
workers were used because of the possibility of the contact with dry
treated wood. The range of hand residue values from these data (0.6 up
to 3 ug/cm2) was assumed to be the dermal skin irritation exposure.  The
dermal MOEs assuming this exposure range from 3 to 13.  A wood wipe
study is needed to refine the risk estimates.

8.3.2	Pressure Treatment Scenarios (Handler and Post-Application)

	DDAC may be used to treat wood and wood products using pressurized
application methods such as double vacuum. According to the product
labels, the maximum retention rate is 0.6 lb/ft3. An application rate
was not provided on the product labels; therefore, an application rate
of 3% ai solution was used in this assessment, based on the master
label. DDAC-specific exposure data are not available for assessment of
pressure treatment exposure.  Therefore, the assessment relies on
surrogate chromated copper arsenate (CCA) data (ACC, 2002b) and was
based on the approach used in a previous exposure assessment (USEPA,
2003b).  

	The estimated inhalation exposures and risks for DDAC are presented in
Table 8.5.  The calculated inhalation MOEs are above the target MOE of
100 for all scenarios. 

Table 8.5  Short-, Intermediate-, and Long-Term Inhalation Exposures and
MOEs for Pressure Treatment Handler and Post-application Scenarios

Exposure Scenario	Inhalation Unit Exposurea

(μg As/ppm) 	Application Rate 

(% ai solution)	Absorbed Daily Dosesb 

(mg/kg/day)	Inhalation MOEsc

(Target MOE = 100)

Occupational Handler

Treatment Operator (TO)	0.00257	3	0.0013	7,800

Treatment Assistant (TA)	0.000802	3	0.00040	25,000

Occupational Post-application

All (Tram setter, stacker operator, loader operator, supervisor, test
borer, and tallyman) 	0.00160	3	0.00080	13,000

a. 	Unit exposure values taken from CCA study and are shown in Table
6.11.

 (μg As/ppm) x [% DDAC in solution (3) x 10,000 (parts per million
conversion)] x (0.001 mg/μg) x absorption factor (100% for inhalation)
/ Body weight (60 kg).

c.			MOE = NOAEL (mg/kg/day) / Daily dose [Where inhalation NOAEL = 10
mg/kg/day for all durations. Target MOE = 100.

	

8.4	Data Limitations/Uncertainties tc \l2 "6.3	Data
Limitations/Uncertainties 

	There are several data limitations and uncertainties associated with
the occupational handler and post-application exposure assessments. 
These include:

Surrogate dermal and inhalation unit exposure values were taken from the
proprietary Chemical Manufacturers Association (CMA) antimicrobial
exposure study (USEPA, 1999b: DP Barcode D247642) or from the Pesticide
Handler Exposure Database (USEPA, 1998).  Since the CMA data are of poor
quality, the Agency requests that confirmatory data be submitted to
support the occupational scenarios assessed in this document.

  SEQ CHAPTER \h \r 1 Unit exposures are not available for some of the
specific scenarios that are prescribed for DDAC including open loading
into oil-well/field environments 

The CMA data used for oil-well uses are based on open pouring of a
material preservative.  Although these data are only represented by 2
replicates each, the exposure values are similar to open loading of
pesticides in PHED. Furthermore, there are no representative unit
exposure data for chemical metering into secondary recovery oil
operations.  Since the volume of water being treated in secondary
recovery 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 if the open pour handling activities for the other oil well
operations resulted in MOEs that are not of concern, then the MOEs for
the closed system chemical metering into secondary recovery operations
would also be not of concern.  The Agency requests that confirmatory
data be conducted to show that this is accurate.

For the wood preservative pressure treatment scenarios, CCA exposure
data were used for lack of DDAC-specific exposure data.  Limitations and
uncertainties associated with the use of these data include:

The assumption was made that exposure patterns for workers at treatment
facilities using CCA and DDAC would be similar to exposure patterns for
workers at treatment facilities using DDAC, and therefore the exposures
could be used as surrogate data for workers that treat wood with DDAC. 

For environmental modeling, it was assumed that the leaching process
from the DDAC treated wood would be similar to that of CCA and DDAC. 
However, due to the lack of real data for DDAC -treated wood, it is not
possible to verify this assumption. 

The quantities handled/treated were estimated based on information from
various sources, including HED’s Standard Operating Procedures (SOPs)
for Residential Exposure Assessments (USEPA, 2000 and 2001), and
personal communication with experts.  In particular,   SEQ CHAPTER \h \r
1 the use information for oil-well uses and cooling water tower uses are
based on personal communication with biocide manufacturers for these
types of uses. 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.  In certain cases,
no standard values were available for some scenarios.  Assumptions for
these scenarios were based on AD estimates and could be further refined
from input from registrants.  

The percent active ingredient in solution for the pressure treatment of
lumber needs to be refined by the registrant.  The labels only provided
a retention rate.  For this assessment, the application rate on the
master label was used, which is the same as the application rate for
non-pressure treatment of lumber. 

9.0	INCIDENT REPORTS

To review the evidence of health effects in humans resulting from
exposure to QAC as stated in the PR Notice 88-1 (February 26, 1988), the
Agency has clustered Quats into four categories:

Group I.  	Alkyl or hydroxyalkyl (straight chain) substituted quats;

Group II	Non-halogenated benzyl substituted quats;

Group III. 	Di- and tri-chlorobenzyl substituted quats; and

Group IV.	Quats with unusual substituents 

However for the available incident information, it is difficult to
differentiate the specific members of the Quats involved in each
incident.  Therefore, all the Quats are discussed together.	

 tc "8.0	INCIDENTS"   SEQ CHAPTER \h \r 1 The Agency consulted the
following databases for poisoning incident data for DDAC:

OPP Incident Data System (IDS) - The Incident Data System of The Office
of Pesticide Programs (OPP) of the Environmental Protection Agency (EPA)
contains reports of incidents from various sources, including
registrants, other federal and state health and environmental agencies
and individual consumers, submitted to OPP since 1992.  Reports
submitted to the Incident Data System represent anecdotal reports or
allegations only, unless otherwise stated.  Typically no conclusions can
be drawn implicating the pesticide as a cause of any of the reported
health effects.  Nevertheless, sometimes with enough cases and/or enough
documentation risk mitigation measures may be suggested. 

  SEQ CHAPTER \h \r 1 California Department of Pesticide Regulation
(1982-2004) - California has collected uniform data on suspected
pesticide poisonings since 1982.  Physicians are required, by statute,
to report to their local health officer all occurrences of illness
suspected of being related to exposure to pesticides.  The majority of
the incidents involve workers.  Information on exposure (worker
activity), type of illness (systemic, eye, skin, eye/skin and
respiratory), likelihood of a causal relationship, and number of days
off work and in the hospital are provided.

  SEQ CHAPTER \h \r 1 National Pesticide Telecommunications Network
(NPTN) - NPTN is a toll-free information service supported by OPP.  A
ranking of the top 200 active ingredients for which telephone calls were
received during calendar years 1984-1991, inclusive, has been prepared. 
The total number of calls was tabulated for the categories human
incidents, animal incidents, calls for information, and others 

 Published Incident Reports - Some incident reports associated with
Quats related human health hazard are published in the scientific
literature.

There are many incident reported associated with exposure to end-use
products containing Quats.  Dermal, ocular and inhalation are the
primary routes of exposure.  Most of the incidences are related to
irritation.  Allergic type reactions have also been reported in some
incidents.   Although risk associated with eye exposure is not assessed
in the risk assessment process, symptoms associated with eye are most
commonly reported associated with Quats exposure.  The most common
symptoms reported for cases of ocular exposure were eye
irritation/burning, eye pain, conjunctivitis, swelling eye and swelling
of eyelid.  

The most common symptoms reported for cases of inhalation exposure were
respiratory irritation/burning, irritation to mouth/throat/nose,
coughing/choking, chest pain, disorientation, dizziness, shortness of
breath.

The most common symptoms reported for cases of dermal exposure were skin
irritation/burning, rash, itching, and blistering.  Allergic type
reactions including hives and allergic contact dermatitis, have also
been reported. 

Although oral exposure is considered a minor route of exposure for Quats
use, irritation to mouth/throat/nose, vomiting/nausea/abdominal pain,
dizziness, and headache have been reported in the cases of ingestion.

ENVIRONMENTAL RISKS

The results of the dietary avian studies indicate that DDAC is
practically non-toxic to both mallard duck and bobwhite quail.  In the
Acute oral studies, the chemical was found to be moderately toxic to
bobwhite quail.  The results from freshwater fish acute toxicity studies
demonstrated that DDAC was moderately  to highly toxic.  DDAC is very
highly toxic to freshwater aquatic invertebrates.  DDAC is very highly
toxic to mysid shrimp a marine/estuarine invertebrate.  DDAC is toxic to
freshwater alga at microgram concentrations.

Data Gaps:

The following data requirements are outstanding for the currently
registered uses of DDAC:

850.4225 - Non-target plant phytotoxicity testing (seedling emergence
test using rice).

850.1035 - Acute Sheepshead minnow testing

850.1300 - Fish-Early Life Stage

850.1400 - Aquatic Invertebrate Life Cycle

850.4400 – Aquatic Plant Growth

850.1950 – Aquatic Field Monitoring

850.4250 – Vegetative Vigor using Rice

850.3030 – Honey Bee Toxicity Studies

Monitoring/Tier II modeling of once-through cooling tower use to
establish EEC’s for risk assessment.

Tier I once-through cooling tower modeling indicates that DDAC use will
result in acute and chronic risk to all non-endangered and
endangered/threatened aquatic organisms at all dosages modeled: 32 ppm
and 63 ppm for continuous dosing and 1000 ppm and 1800 ppm for
intermittent dosing.  

The high vs medium vs low water flow rate is based on size of the
facility.  Generally, higher flow (e.g., > 1000 MGD) would use more
chemical than smaller facilities, but the pattern does not hold true
across the board, probably because model input values are based on
different receiving water (“reach”) data for individual facilities. 
This model uses 7Q10 rainfall conditions, which is essentially the
worst-case drought of a 10 year period.  Variables such as stream flow
rate and DDAC dissipation, degradation, and 1/2 life were not considered
in this Tier I model but should be considered in higher tier modeling. 
Field monitoring is suggested in the absence of higher Tier modeling. 
Risk mitigation recommendations should be based on dosing method (e.g.
intermittent vs continuous) and application rate instead of facility
size, however, risk mitigation is not recommended at this time.

Wood Treatment Use:

The maximum amount of leachate from treated wood per the Krahn and
Strub, 1990 model totaled 18.97 ppb.  The lowest predicted amount of
leachate was 4.7 ppb and the highest amount was 113.8 ppb. 
Non-endangered/threatened aquatic species (fish and invertebrates) are
not expected to be adversely affected - acute or chronic toxicity -
based on LOCs above.  Endangered/threatened fish (freshwater warm water
species) are not expected to be adversely affected by the wood treatment
use.  However, green alga non-endangered/threatened species, and
freshwater fish coldwater species, freshwater and marine aquatic
invertebrates, and green algae endangered/threatened species are at risk
from the wood treatment use.  

Due to the extreme sensitivity of freshwater and marine aquatic
invertebrates to DDAC, methods such as indoor or covered wood storage
and/or containment of runoff water via berms or plastic barriers in
outdoor storage areas are suggested.  DDAC is tightly adsorbed to clay
and organic matter which greatly reduces potential for DDAC to leach
downward through soil to groundwater, and will serve to reduce surface
runoff as well. 

Endangered Species Concerns:

	DDAC uses that have potential for direct release into the environment
or runoff to surface waters include once-through cooling tower and wood
treatment uses respectively.  These uses are considered to be
representative of having worst-case potential for impacting the
environment.  Therefore, these sites were modeled. 

 

The “best case” once-through cooling tower scenario using 1/2 the
maximum recommended label dosage intermittently applied in a low water
flow resulted in LOC exceedances for all aquatic organisms used in the
model, including freshwater fish, green alga, freshwater invertebrates,
and marine invertebrates.  The agency is not aware of any endangered or
threatened green algae.  Because DDAC is rapidly adsorbed to organic
materials and clay, impacts to aquatic organisms may be less than
modeled.  Aerobic aquatic metabolism study on DDAC (MRID# 422538-03)
provides a sediment half-life of 60 years.  There is a potential for
sediment concentrations to reach toxic levels over time (aerobic soil
metabolism half-life of 2.8 years, MRID# 422538-01).  The once-through
cooling tower model does not account for degradation and therefore,
further assessment is required prior to making an agency endangered
species determination.

	Endangered/threatened coldwater fish species, marine and freshwater
invertebrates, and green algae species are expected to be adversely
affected by the wood treatment use.  Impacts from the wood treatment use
are not expected to occur as long as precautions are taken to prevent
leaching when wood is stored outdoors. 

	The Environmental Fate and Effects Division (EFED) has evaluated the
outdoor use of the quaternary ammonium compounds, didecyl ammonium
chlorides (DDAC), being considered for reregistration by the
Antimicrobial Division (AD) (DP Barcode D325481).  Although primarily
used as antimicrobial agents, DDAC is labeled for use in puddles and
decorative pools to control algae.  This use is intended for waterbodies
generally disconnected from the greater watershed and will not likely
result in exposure to nontarget aquatic species.  It is possible these
uses will result in exposure to amphibians utilizing these waterbodies
for some portion of their lifecycle (e.g. reproduction) and to birds and
mammals utilizing these waterbodies for drinking water.  At the maximum
label rate, 3 ppm initially followed by weekly 1.5 ppm treatments, there
are no LOC exceedances, assuming the toxicity of DDAC is similar to that
of ADBAC.  However, due to the persistence of DDAC, it is possible that
concentrations of DDAC in some waterbodies treated over time could
become harmful to animals utilizing these waterbodies.

11.0	REFERENCES tc \l1 "7.0	REFERENCES 

American Chemistry Council (ACC). 2002a.  Assessment of Potential
Inhalation and Dermal Exposure Associated With Pressure Treatment of
Wood with Arsenical Wood Products.  MRID 4550211-01.

American Chemistry Council (ACC). 2002b.  An Analysis of the Training
Patterns and Practices of Competitive Swimmers.  Prepared by Richard
Reiss.  Sciences International, Inc. Alexandria, Virginia.  December 9,
2002.

  SEQ CHAPTER \h \r 1 Bestari KT, Macey K, Soloman KR, Tower N. 1999. 
Measurement and Assessment of Dermal and Inhalation Exposures to Didecyl
Dimethyl Ammonium Chloride (DDAC) Used in the Protection of Cut Lumber
(Phase III). MRID 455243-04.

  SEQ CHAPTER \h \r 1 CEC, 2001.  Residential Manual for Compliance with
California’s 2001 Energy Efficiency Standards. 
http://www.energy.ca.gov/title24/residential_manual/index.html, viewed
January 2005.

DOE.  1997.  Energy Information Administration: Profile of Commercial
Buildings in 1995. 
http://www.eia.doe.gov/emeu/cbecs/char95/profile.html

FDA. 2003.  “Sanitizing Solutions:	Chemistry Guidelines for Food
Additive Petitions.” 

  GOTOBUTTON BM_1_ http://www.cfsan.fda.gov/~dms/opa-cg3a.html.   Last
accessed June 9, 2003.

  SEQ CHAPTER \h \r 1 Freeman, N , Jimenez M, Reed KJ,Gurunathan S,
Edwards RD, Roy A, Adgate JL, Pellizzari ED, Quackenboss J, Sexton K,
Lioy PJ, 2001.  Quantitative analysis of chilren’s microactivity
patterns:  The Minnesota Children’s Pesticide Exposure Study.  Journal
of Exposure Analysis and Environmental Epidemiology.  11(6): 501-509.

Helwig, D. (2003) Personal Communication between D. Helwig (Johnson
Diversy, Inc) and K. Riley (Versar, Inc.), November 11, 2003.

HERA, 2003.  Human and Environmental Risk Assessment, Guidance Document
Methodology, April 22, 2002
(http://www.heraproject.com/files/Guidancedocument.pdf).

HERA, 2005.  Human and Environmental Risk Assessment, Guidance Document
Methodology, February 2005 (http://www.heraproject.com).

MCCEM V 1.2  The Multi-Chamber Concentration and Exposure Model (MCCEM)
Model Version 1.2. Prepared for the US EPA Office of Pollution
Prevention and Toxics. Prepared by Versar, Inc. and Wilkes Technologies,
LLC.

Jacobson, Larry. 2005.  Professor and Extension Engineer at University
of Minnesota.

SIMetric. 2005.    HYPERLINK
"http://www.simetric.co.uk/si_materials.htm" 
http://www.simetric.co.uk/si_materials.htm   Last viewed November 9,
2005.

USAID. 2005. “ANNEX III: Recommended Energy Allowance Tables.”
November 2005.   HYPERLINK
"http://www.usaid.gov/our_work/humanitarian_assistance/ffp/crg/annex-3.h
tm" 
http://www.usaid.gov/our_work/humanitarian_assistance/ffp/crg/annex-3.ht
m .  Last viewed January 23, 2006. 

USEPA.  Undated.  RISK.  Version 1.9.27.  Developed by Dr. Les Sparks of
USEPA/NRMRL/ APPCD.

USEPA. 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 1996.   Data Collection Period
October 1992 - September 1994 . 

USEPA.  1997.  Exposure Factors Handbook. Volume I-II.  Office of
Research and Development.  Washington, D.C.  EPA/600/P-95/002Fa. August
1997.

USEPA. 1998. PHED Surrogate Exposure Guide. Estimates of Worker Exposure
from the Pesticide Handler Exposure Database Version 1.1.   Washington,
DC:  U.S. Environmental Protection Agency.

  SEQ CHAPTER \h \r 1 USEPA. 1999.  Evaluation of Chemical Manufacturers
Association Antimicrobial Exposure Assessment Study (Amended on 8
December 1992).  Memorandum from Siroos Mostaghimi, PH.D., USEPA to
Julie Fairfax, USEPA. Dated November, 4 1999.  DP Barcode D247642.

USEPA.  2000.  Residential SOPs.  EPA Office of Pesticide Programs,
Health Effects Division. Dated April 5, 2000.

USEPA.  2001.  HED Science Advisory Council for Exposure. Policy Update,
November 12.  Recommended Revisions to the Standard Operating Procedures
(SOPs) for Residential Exposure Assessment, February 22, 2001. 

 

USEPA. 2003b.  Assessment of the Proposed Bardac Wood Preservative
Pressure Treatment Use.  Memorandum from Tim Leighton and Siroos
Mostaghimi.  February 11, 2003.

USEPA. 2004.  Occupational and Residential Exposure Assessment for
Carboquat WP-50.  Memorandum from Siroos Mostaghimi, USEPA to Welma
Noble, USEPA.   Dated November 4, 2004. DP Barcodes D303714 and D303938.

USEPA. 2006.  Didecyl dimethyl benzyl ammonium chloride (DDAC) –
Report of the Antimicrobials Division Toxicity Endpoint Committee (ADTC)
and the Hazard Identification Assessment Review Committee (HIARC). 
January 9, 2006.

Toxicology References

41394404 (MRID) Myers, R.; Christopher, S. (1989) NP-1 Plus
(Concentrate): Acute Toxicity and Primary Irritation Studies: Lab
Project Number: 52- 642. Unpublished study prepared by Bushy Run
Research Center. 31 p.

42296101 (MRID) Morris, T. (1992) Acute Oral Toxicity in Rats--Median
Lethal Dosage Determination with Didecylammoniumchloride (DDAC): Lab
Project Number: 91-8114-21 (A). Unpublished study prepared by Hill Top
Biolabs, Inc. 153 p.

42053801 (MRID) Myers, R.; Christopher, S. (1991) Sapstain Control
Chemical NP-1: Acute Percutaneous Toxicity Study in the Rabbit: Lab
Project Number: 54-588. Unpublished study prepared by Bushy Run Research
Center (BRRC). 17 p.

00071158 (MRID) Nitka, S.; Palanker, A.L.; Lally, E.; et al. (1980)
Acute Dermal LDI50^ in Rabbits (FIFRA): Experiment Reference No.
8044-10. Final rept. (Unpublished study received Feb 2, 1981 under
6836-51; prepared by Consumer Product Testing Co., Inc., sub- mitted by
Lonza, Inc., Fair Lawn, N.J.; CDL:244350-A)

00145074 (MRID) Dudek, R. (1984) Four Hour Acute Aerosol Inhalation
Toxicity Study in Rats of Micro Emulsion Concentrate-Type A: Toxigenics
Study No. 420-1485. Unpublished study prepared by Toxigenics, Inc. 44 p.

42161602 (MRID) Morris, T. (1991) Primary Eye Irritation Study in
Rabbits with Didecyldimethylammoniumchloride (DDAC): Lab Project Number:
91-8114-21 C. Unpublished study prepared by Hill Top Biolabs, Inc. 30 p.

42161601 (MRID) Morris, T. (1991) Primary Skin Irritation Study in
Rabbits with Didecyldimethylammoniumchloride (DDAC): Lab Project Number:
91-8114-21 B. Unpublished study prepared by Hill Top Biolabs, Inc. 29 p.

42161603 (MRID) Morris, T. (1991) Photoallergy Study in Guinea Pigs with
Didecyldimethylammoniumchloride (DDAC): Lab Project Number: 91-8114-21
D. Unpublished study prepared by Hill Top Biolabs, Inc. 77 p.

46367601 (MRID) Merkel, D. (2004) Dermal Sensitization Test in Guinea
Pigs (Buehler Method): Bardac 2280. Project Number: 15512, P328/TRS.
Unpublished study prepared by Product Safety Labs and Food Products
Laboratory and Precision Analytical Services, Inc. 25 p.

40565301 (MRID) Rose, G. (1988) Acute Toxicology (EP): HS-Sanitizing
Carpet Shampoo: Laboratory Project ID B 6-27. Unpublished study prepared
by Envirocon. 21 p.

41105801 (MRID) Rose, G. (1989) Acute Toxicology (EP): HS-Sanitizing
Carpet Shampoo: Project ID: B6-27. Unpublished study prepared by
Envirocon. 36 p.

45656601 (MRID) Henwood, S. (2001) 21-Day Dermal Toxicity Study with
SS0853.01 in Rats: Final Report: Lab Project Number: 6114-398: DRD:
SSBTS00.040-52068. Unpublished study prepared by Covance Laboratories
Inc. 538 p. {OPPTS 870.3200}

40966302 (MRID) Van Miller, J. (1988) Ninety-day Dietary Subchronic Oral
Toxicity Study with Didecyldimethylammoniumchloride in Rats: Laboratory
Project ID: 51-506. Unpublished study prepared by Bushy Run Research
Center, Union Carbide. 262 p.

40262901 (MRID) Bailey, D. (1975) 90-day Feeding Study in Dogs with a
Quaternary Ammonium Sanitizer: Bardac-22: Laboratory Project ID: 2224a.
Unpublished study prepared by Food & Drug Research Laboratories, Inc. 89
p.

41305901 (MRID) Gill, M; Van Miller, J. (1989) Ninety-day Subchronic
Dermal Toxicity Study with Didecyldimethylammonium chloride in Rats: Lab
Project Number: 51-554. Unpublished study prepared by Bush Run Research
Center, Union Carbide. 244 p.

41886701 (MRID) Neeper-Bradley, T. (1991) Development Toxicity
Evaluation of Didecyldimethylammoniumchloride Administered by Gavage to
CD (Sprague-Dawley) Rats: Lab Project Number: 53-534. Unpublished Study
prepared by Bushy Run Research Center. 282 p.

42746901 (MRID) Neeper-Bradley, T. (1993) Developmental Toxicity Dose
Range-Finding Study of Didecyldimethylammoniumchloride Administered by
Gavage to CD (Sprague-Dawley) Rats: Lab Project Number: 53-533.
Unpublished study prepared by Bushy Run Research Center. 106 p.

41018701 (MRID) Tyl, R. (1989) Developmental Toxicity Study of
Didecyldimethylammonium chloride Administered by Gavage to New Zealand
White Rabbits: Project ID: 51-590. Unpublished study prepared by Bushy
Run Research Center. 164 p.

41804501 (MRID) Neeper-Bradley, T. (1991) Two-Generation Reproduction
Study in Sprague-Dawley (CD) Rats with Didecyldimethylammonium chloride
Administered in the Diet: Lab Project Number: 52-648. Unpublished study
prepared by Bushy Run Research Ctr. 758 p.

41970401 (MRID) Schulze, G. (1991) Chronic Oral Toxicity Study of
Didecyldimethylammonium chloride in Dogs: Final Report: Lab Project
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Inc. 335 p.

41965101 (MRID) Gill, M.; Chun, J.; Wagner, C. (1991) Chronic Dietary
Toxicity/On- cogenicity Study with Didecyldimethyl-ammoniumchloride in
Rats: Lab Project Number: 53/566. Unpublished study prepared by Bushy
Run Research Center. 1649 p.

41802301 (MRID) Gill, M.; Hermansky, S.; Wagner, C. (1991) Chronic
Dietary Oncogenicity Study with Didecyldimethylammonium chloride in
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Salmonella/Mammalian--Microsome Assay with Bardac 22. Unpublished study
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44005801 (MRID) Schoenig, G. (1996) Response to EPA Data Evaluation
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93014007 (MRID) Schoenig, G. (1990) Lonza Inc Phase 3 Summary of MRID
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40895202 (MRID) Young, R. (1988) Mutagenicity Test on Didecyldimethyl
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Study No. 10141-0-435. Unpublished study prepared by Hazleton
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41252601 (MRID) Holmstrom, M.; Leftwich, D.; Leddy, I. (1986) PO151:
Chromosomal Aberrations Assay with Chinese Hamster Ovary Cells in vitro:
Proj. No. 735717. Unpublished study prepared by Lonza Inc. 36 p.

93014008 (MRID) Schoenig, G. (1990) Lonza Inc Phase 3 Summary of
40895202. Mutagenicity Test on Didecyldimethylammoniumchloride in the
CHO/ HGPRT Forward Mutation Assay: Project No. 10141-0-435. Prepared by
Hazleton Laboratories America, Inc. 17 p.

40895201 (MRID) Cifone, M. (1988) Mutagenicity Test on
Didecyldimethylammonium Chloride in the Rat Primary Hepatocyte
Unscheduled DNA Synthesis Assay: HLA Study No. 10141-0-447. Unpublished
study prepared by Hazleton Laboratories America, Inc. 60 p.

41617101 (MRID) Selim, S. (1989) Absorption, Distribution, Metabolism
and Excretion Studies of Didecyldimethylammoniumchloride (DDAC): Lab
Project Number: P01421. Unpublished study prepared by Biological Test
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41385101 (MRID) Lin, P.; Selim, S. (1989) Addendum to Report Entitled
Absorption, Distribution, Metabolism and Excretion Studies of
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P01421. Unpublished study prepared by Biological Test Center. 269 p.

USEPA (2000): Didecyl Dimethyl Ammonium Chloride (DDAC) – Report of
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014099.

USEPA (2000): Didecyl Dimethyl Ammonium Chloride: Toxicology Review.  DP
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INCIDENCE REPORTS REFERENCES

Dibo, M.  and Brasch, J.  2001.  Occupational allergic contact
dermatitis from N,N-bis93-aminoprpyl)dodecylamine and
dimethyldidecylammonium chloride in two hospital staff.  Contact
Dermatitis.  45(1):40.

Mehler, L. 2005.  Personal Communication.  California Department of
Pesticide Regulation

Oriandini, A.; Viotti, G.  Martinoli, C; and Magno, L.  1990.  Allergic
Contact Conjunctivities from synthetic detergenets in nurse.  Contact
Dermatitis.  23:  376-377.

Preller, L.; Doekers, G.; Heederik, D.; Vermulen, R.; Vogelzang, P.F.J,
and Boleij, J. S.M.  1996. Disinfinfectant use as a risk factor for
atopic sensitization and symptoms consistent with asthma: an
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Shmunes, E. and Levy, E.J.  1972.  Quaternary ammonium compound contact
dermatitis from deodorant.  Arch Dermatol.  105(1) 91-93.

APPENDIX A: Master DDAC Label

EPA Reg Number used for Max. Appl. Rate	Use Site	Treatment Site/Surfaces
Method of Application	Notes	Freq of Application

Industrial processes and water systems

1839-129	Industrial Recirc Water Systems 	Cooling Towers (including
evaporative condensers, dairy sweetwater systems, cooling canals,
pasteurizers, tunnel coolers and warmers)	Pour/metered	1839-129 (50% ai)
	Weekly

10707-46	cooling water, disposal water, oil field operations	 	slug
treatment	 	 

1839-151	Oil Field water flood or salt water disposal	oil field water
disposal systems	pour/metered	1839-151	As needed

1839-179	Oil Field	injection and wastewater	continuous injection	Blend
with ADBAC	As needed

1839-179	Oil Field	injection and wastewater	batch treatment	Blend with
ADBAC	As needed

1839-179	Oil Field	packer fluids	 	Blend with ADBAC	As needed

1839-179	Oil Field	drilling muds	 	Blend with ADBAC	As needed

Swimming Pools

10324-69	Swimming Pool 	 	pour	 	Once               weekly

1839-133	Outside Spas/Whirlpools/Hot Tub Bath	 	pour	 	Weekly

Aquatic Areas

499-482	greenhouse/nurseries, golf courses, recreational parks,
amusement parks, universities, cemeteries	decorative fountains,
decorative pools, ponds, water displays, standing waters	dribble, spray
ring	Blend with ADBAC	As needed

499-482	greenhouse/nurseries	irrigation system, watering lines, drip
lines, emitters, watering nozzles, and hoses	immersing or running thru
system	Blend with ADBAC	As needed

 Wood Treatment	 	 	 	 	 

6836-212	Pressure Treatment	 	 	3% ai soln	As needed

6836-212	Double vacuum	 	 	3% ai soln	As needed

6836-212	Dip/Spray surface treatment	 	 	3% ai soln	As needed

Agricultural Premises and Equipment

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lants, rendering plants, fishery/milk/citrus/wine/ice cream/ potato
processing plants, 	water softners and reverse osmosis units	pour	 	As
needed

10324-117	bottling and beverage plants, breweries, tobacco,  egg
processing plants, meat/poultry processing plants, rendering plants,
fishery/milk/citrus/wine/ice cream/ potato processing plants, 	boots and
shoes	immersion	Blend with ADBAC	As needed

1839-173	dairies, beverage, and food processing plants	floors, walls,
countertops, appliances (microwaves, refrigerators, stove tops,
freezers, coolers), chairs, tables, shelves,  racks, carts, telephones,
door knobs, storage areas, potato storage areas, food storage areas,
garbage storage areas, cutting boards, tanks, exhaust fans, refrigerator
bins, refrigerated storage/display equipment, storage tanks, coolers,
ice chests, garbage cans/pails	fogging	Blend with ADBAC	As needed

10324-80	food processing plants, food service areas, institutional
kitchens, industrial/hospital caferias, school lunchrooms, dairies, and
packing plants	air ducts	spray, brush,mop, wipe, ULV or mist generating,
automated spray	odor causing bacteria, fungi	6 months

Clean/Deodorization

1839-167	Water/Smoke restoration (institutional, industrial, hospital)
carpets, carpet cushion, sub floors, drywall, trim, farm lumber,
tackless strip and paneling	Pour, brush, spray	Blend with ADBAC	As
needed

1839-167	Sewer backup/river flood cleanup,  (clean water source)
carpets, carpet cushion, sub floors, drywall, trim, farm lumber,
tackless strip and paneling	spray	Blend with ADBAC	As needed

1839-167	garbage storage areas, pet areas, garbage bins & cans	 	 
Blend with ADBAC	As needed

  

71814-1	hospitals	Medical waste	pour	blend w/ ADBAC	Poured into machine

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