UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, DC 20460

			OFFICE OF  PREVENTION, PESTICIDES,  AND TOXIC SUBSTANCES

 

March 7, 2007

MEMORANDUM:

Subject:	Transmittal of Octhilinone (OIT) RED Ecological Hazard and
Environmental Risk Assessment Chapter – Case Number 2475

		

		DP Barcode:

		PC Code:  099901

							

		

From:		Richard C. Petrie, Agronomist/Team 3 Leader

		OPP/AD/RASSB						

		Antimicrobial Division (7510P)

Thru:		Norm Cook.

		Chief, RASSB

		Antimicrobial Division (7510P)

To:		Mark Hartman, Chief

		RMB II

		Antimicrobial Division (7510P)

	Attached is the ecological hazard and environmental risk assessment RED
chapter for octhilinone (OIT).  

		

 

ECOLOGICAL HAZARD AND ENVIRONMENTAL 

RISK ASSESSMENT CHAPTER

Octhilinone (OIT)

PC Code 099901

CASE No.: 2475

04/05/07

Richard C. Petrie, Agronomist – Team 3 Leader

Antimicrobials Division

Office of Pesticide Programs

U.S. Environmental Protection Agency

1200 Pennsylvania Avenue, NW

Washington, DC 20460

Table of Contents

												        pg

Executive Summary
………………………………………………………………
……………… 1

Data Gaps
………………………………………………………………
………………………… 1

Label Hazard Statements/Use
Recommendations…………………………………………………
2

1.  Ecological Toxicity Data . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2  

A.  Toxicity to Terrestrial Animals . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . .2 

1.  Birds, Acute  . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . 3

2.  Birds, Subacute. . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . 4 

3.  Mammals, Acute and Chronic . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . .5  

B.  Toxicity to Aquatic Animals . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . .5 

1.  Freshwater Fish, Acute . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .5  

2.  Freshwater Invertebrates, Acute . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .7  

3.  Estuarine and Marine Organisms, Acute . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .8 

4.  Aquatic Organisms, Chronic . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .9 

C.  Toxicity to Plants . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

II.  Risk Assessment and Risk Characterization . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .11

A.  Environmental Fate Assessment Summary . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .. . . . .12 

B.  Environmental Exposure And Ecological Risk Assessment. . . . . . . .
. . . . . . . . .. . . . . . .12 

C.  Endangered Species Considerations . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .  . . . . . . . . . . .15

III.  Confirmatory Data Required. . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 16   

IV.  Label Hazard Statements for Terrestrial and Aquatic Organisms. . .
. . . . . . . .  . . . . . . . . . .17

V.  References . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . .  . . . . . . . . . . 18

LIST OF TABLES

																			    pg

Table 1 – Acute Oral Toxicity of Octhilinone to Birds. . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . .3 

				

Table 2 – Subacute Oral Toxicity of Octhilinone to Birds. . . . . . .
. . . . . . . . . . . . . . . . . . . . . . 4

Table 3 – Acute Toxicity of Octhilinone to Freshwater Fish. . . . . .
. . . . . . . . . . . . . . . . . . . . . 5

Table 4 – Acute Toxicity of Octhilinone to Freshwater Invertebrates. .
. . . . . . . . . . . . . . . . . . 7 

Table 5 – Acute Toxicity of Octhilinone to Estuarine and Marine
Organisms. . . . . . . . . . . . . .8

Table 6 – Chronic Toxicity of Octhilinone to Freshwater Organisms. . .
. . . . . . . . . . . . . . . . . 9

Table 7 – Toxicity of Octhilinone to Aquatic Plants. . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . .11

Table 8 -  Octhilinone “Down-the-Drain” Model
Results…………………………………….13

Table 9 -  Octhilinone Risk
Quotients………………………………………………………
…13

Table 10 -  Risk Presumption
Categories……………………………………………………
…14

	Ecological Hazard and Environment Risk Assessment

For Octhilinone (OIT)

Executive Summary:

		Octhilinone (OIT) is currently registered as an industrial mildewcide
and microbiocide.   Uses as a mildewcide, fungicide and bacteriocide are
mostly during the manufacturing processes, and include:  fabrics and
textiles (furniture, auto upholstery, footwear, carpet, carpet backing,
tents, awnings, canvas, linens, wall and window coverings, dust towels,
bedding, mattresses, pet bedding, synthetic brooms, mops, air filter
media), coatings (walls, paints, plasters, stuccos), sealants (grouts,
caulks, joint cements), adhesives (wallpaper pastes, gelatin and starch
based), rubber and plastics (latex, acrylic, styrene, butadiene,
polyvinyl chloride, polymethane, vinyl, foams), leather preservation
(wet processes), metalworking fluid preservation, hydraulic fluid
preservation, industrial process and water systems including air washer
water and flow-thru cooling towers, and wood preservation as an
antisapstain drench to debarked logs.  

	The Octhilinone industry task force has officially withdrawn the
once-through cooling tower use from their labels and has clarified that
the antifouling use on label 48302-12 is not an octhilinone label but a
DCOIT [4,5-Dichloro2-octyl-3(2H)-isothiazolone] label.  The octhilinone
task force is retaining the antisapstain wood preservation use on label
73612-1.  The antisapstain wood treatment use is a use having high
potential for environmental exposure thus requiring an ecological risk
assessment.  Octhilinone is stable and persistent in water under abiotic
conditions with a half life of > 30 days.  It is tightly bound to soil
particles and is microbially degraded in soil within 120 days. 
Octhilinone is not expected to bioaccumulate in aquatic organisms.  An
antisapstain wood treatment risk assessment was not possible. 
Outstanding data required to conduct modeling include those studies
listed below.  Due to persistence in soil and water, a Tier I
“Down–the-Drain” model assessment was conducted to simulate
industrial process waste water releases.

Data Gaps:  

	Confirmatory Data Required For Risk Assessment:

    Freshwater diatom (850.5400),

    Blue-green cyanobacteria (850.5400),

    Marine diatom (850.5400),

    Freshwater floating macrophyte duckweed (850.4400),

    Freshwater rooted macrophyte rice seedling emergence (850.4225),

    Freshwater rooted macrophyte rice vegetative vigor (850.4250),

    Wood leaching study (AWPA Method E11-06, Standard Method of
Determining         the Leachability of Wood Preservatives Immersed in
Water, AWPA, 2006),

8.)    Environmental runoff monitoring study instead of Tier I
antisapstain                                   model.

9.)     Residues in honey/beeswax and toxicity of treated wood residues
to bees -                         combination of Guidelines 860.1500 and
850.3030 (“Honey Bee Toxicity of                      Residues on
Foliage.”.  A combined study which addresses honey/beeswax residues   
      and acute toxicity of treated wood residues to bees is required if
bee hives are to be           constructed of treated wood, or if an
antimicrobial product is intended for                         
application to a bee hive; unless product labeling prohibits such uses.)
 

10.)   Soil Koc study (835.1220)

 

Label Hazard Statements/Use Recommendations

Octhilinone labels must state:  

“This pesticide is toxic to fish, aquatic invertebrates, oysters, and
shrimp.”

"Do not discharge effluent containing this product into lakes, streams,
ponds, estuaries, oceans, or other waters unless in accordance with the
requirements of a National Pollutant Discharge Elimination System
(NPDES) permit and the permitting authorities are notified in writing
prior to discharge.  Do not discharge effluent containing this product
to sewer systems without previously notifying the local sewage treatment
plant authority.  For guidance contact your State Water Board or
Regional Office of the EPA."

Antisapstain labels must state:  "Treated lumber must be stored under
cover, indoors, or at least 100 feet from any pond, lake, stream,
wetland, or river to prevent possible runoff of the product into the
waterway.  Treated lumber stored within 100 feet of a pond, lake,
stream, wetland, or river must be either covered with plastic or
surrounded by a berm to prevent surface water runoff into the nearby
waterway.  If a berm or curb is used around the site, it should consist
of impermeable material (clay, asphalt, concrete) and be of sufficient
height to prevent runoff during heavy rainfall events.”

The honey bee residue and toxicity test can be waived provided the label
is amended to prohibit the use of treated wood for beehive construction,
with a statement such as, “Wood treated with octhilinone shall not be
used in the construction of beehives.”

1.	Ecological Toxicity Data

	The toxicity endpoints presented below are based on the results of
ecotoxicity studies submitted to EPA to meet the Agency’s data
requirements for the uses of octhilinone.

	A.	Toxicity to Terrestrial Animals

(1)	Birds, Acute 

	In order to establish the toxicity of octhilinone to avian species, the
Agency requires an acute oral toxicity study using the technical grade
active ingredient (TGAI).  The preferred-test species is either mallard
duck (a waterfowl) or bobwhite quail (an upland game bird).  The results
of five acute oral toxicity studies, submitted for octhilinone, are
provided in the following table (Table 1).

	

Table 1.  Acute Oral Toxicity of Octhilinone to Birds

Species	

Chemical,

% Active Ingredient

(a.i.)

Tested	

Endpoint

(mg/kg)	

Toxicity Category	

Satisfies Guidelines/

Comments	

Reference

(MRID No.)

Bobwhite quail

(Colinus virginianus)	Octhilinone 98.5%	LD50 = 660

NOAEL = ND

(a.i.) 

	Slightly toxic	Yes

- 21-day test duration

- 19 weeks of age	416080-01

Bobwhite quail

(Colinus virginianus)	Octhilinone

95.9%	LD50 = 384

NOAEL = 171 

(a.i.)	Moderately toxic	Yes

- 14-day test duration

- 21 weeks of age	448590-01

Bobwhite quail

(Colinus virginianus)	Octhilinone

88.7%	LD50 = 346

(a.i.)	Moderately toxic	Yes

	00026809

Bobwhite quail

(Colinus virginianus)	Octhilinone

RH-893

(% purity unknown)	LD50 = 565 (M) and 498 (F) 	Slightly

toxic	No

	86-870001877

(Ecotox data)

Mallard duck

(Anas platyrhynchos)	Octhilinone

RH-893

(% purity unknown)	LD50  > 1000	Slightly

toxic	No

	86-870001877

(Ecotox data)



	

	Three acceptable acute oral toxicity studies on the Bobwhite quail
(416080-01, 448590-01, 00026809) indicate that octhilinone is moderately
to slightly toxic on an acute oral basis. The guideline requirement
OPPTS 850.2100/(71-1) is satisfied.  

(2)	Birds, Subacute

	A subacute dietary study using the TGAI may be required on a
case-by-case basis depending on the results of lower-tier ecological
studies and pertinent environmental fate characteristics in order to
establish the toxicity of a chemical to avian species.  This testing was
required for octhilinone.  The preferred-test species is either the
mallard duck or bobwhite quail.  The results of five subacute dietary
toxicity studies, submitted for octhilinone, are provided in the
following table (Table 2).

Table 2.  Subacute Oral Toxicity of Octhilinone to Birds

Species	

Chemical,

% Active Ingredient

(a.i.)

Tested	

Endpoint

(mg/kg)	

Toxicity Category	

Satisfies Guidelines/

Comments	

Reference

(MRID No.)

Bobwhite quail

(Colinus virginianus)	Octhilinone  

98.5%	LC50 (diet) = >3267

NOAEC = 1288

(a.i.)	Slightly toxic	Yes

-	8-day test duration

-	11 weeks of age	416080-02

Bobwhite quail

(Colinus virginianus)	Octhilinone 

96%	LC50 (diet) = 2542

NOAEC = 310 

(a.i.)	Slightly toxic	No

- 12-day test duration

- 10 days of age 

-  control mortality        20%

-  inadequate housing	439357-01

Bobwhite quail

(Colinus virginianus)	Octhilinone 

88.7%	LC50 (diet) >5620 

(a.i.)	Relatively nontoxic	Yes

-  8-day test duration	00026808

Mallard duck

(Anas platyrhynchos)	Octhilinone 

98.5%	LC50 (diet) = 1215

NOAEC = ND

(a.i.)	Slightly toxic	Yes

-  8-day test duration

-  5 days of age	416080-03

Mallard duck

(Anas platyrhynchos)	Octhilinone 

88.7%	LC50 (diet) = >5620

(a.i.)	Relatively nontoxic	Yes

	00026807



	The results from four acceptable studies (416080-02, 00026808,
416080–03, and 00026807) indicate that octhilinone is slightly to
relatively non-toxic to avian species through subacute dietary exposure.
These studies fulfill guideline requirements OPPTS 850.2100/ (71-2a –
Bobwhite quail and 71-2b – Mallard duck). 

 (3)	Mammals, Acute and Chronic Toxicity

Wild mammal testing is not required by the Agency.  In most cases, rat
and mice toxicity values obtained from studies conducted to support data
requirements for human health risk assessments are substituted for wild
mammal testing.  Refer to the human toxicology chapter of this RED for
the mammalian toxicity data summary.

	

B.	Toxicity to Aquatic Animals

	The Agency requested that aquatic toxicity studies be conducted with
octhilinone since, under typical use conditions, it is introduced into
the aquatic environment.

(1)	Freshwater Fish, Acute

	In order to establish the acute toxicity of octhilinone to freshwater
fish, the Agency requires freshwater fish toxicity studies using the
TGAI.  The preferred test species are rainbow trout (a coldwater fish)
and bluegill sunfish (a warmwater fish).  The results of 9 freshwater
fish acute studies submitted for octhilinone, 3 coldwater and 6
warmwater, are presented in Table 3.

 Table 3.  Acute Toxicity of Octhilinone to Freshwater Fish 

Species	

Chemical,

% Active Ingredient

(a.i.)

Tested	

Endpoint

(mg/L)	

Toxicity Category	

Satisfies Guidelines/

Comments	

Reference

(MRID No.)

Rainbow Trout (Oncorhynchus mykiss)	Octhilinone

98.5%	LC50 = 0.047

NOAEC = 0.023

(a.i.)	Very highly toxic	Yes

-	96-hr test duration

-	flow-through test system	416080-05

Rainbow Trout (Oncorhynchus mykiss)	Octhilinone

96%	LC50 = 0.05

LOEC = 0.05

NOEC = < 0.05

(a.i.)	Very highly toxic	No

-	96-hr test duration

-	static renewal test system

-  toxic effects and 

    death at all      

    treatment levels

-  small aquaria	439357-02

Rainbow Trout (Oncorhynchus mykiss ,formerly Salmo gairdneri)
Octhilinone

90%	LC50 = 0.0655

(a.i.)	Very Highly toxic	No

-  96-hr test duration

-  static test system	00026805

Bluegill sunfish (Lepomis macrochirus)	Octhilinone

98.5%	LC50 = 0.18 

(a.i.)	Highly toxic	Yes

-  96-hr

-  flow-through test system	416080-04

Bluegill sunfish (Lepomis macrochirus)	Octhilinone 96%	LC50 = 0.16

NOAEC = 0.07 

(a.i.)	Highly toxic	Yes

-	96-hr test duration

-	static renewal test system		439357-03

Bluegill

(Lepomis macrochirus)	Octhilinone

90%	LC50 = 0.196

(a.i.)	Highly toxic	No

-  96-hr test duration

-  static test system	00026805

Redear

(Lepomis macrochirus)	Octhilinone

90%	LC50 = 0.203

(a.i.)	Highly toxic	No

-  96-hr test duration

-  static test system	00026805

Fathead minnow

(Pimephales promelas)	Octhilinone

90%	LC50 = 0.140

(a.i.)	Highly toxic	No

-  96-hr test duration

-  static test system	00026805

Golden shiner

(Notemigonus crysoleucas)	Octhilinone

90%	LC50 = 0.154

(a.i.)	Highly toxic	No

-  96-hr test duration

-  static test system	00026805



	Freshwater acute toxicity tests indicate that octhilinone is very
highly toxic to the coldwater fish Rainbow trout and highly toxic to the
warmwater fish Bluegill sunfish on an acute basis.  Study 416080-05
fulfills the guideline requirement for the coldwater species and studies
439357-03 and 416080-04 fulfill the guideline requirement for a
warmwater fish species under OPPTS 850.1075 (72-1a&b).  Because acute
toxicity to fish is <1.0 mg/L the environmental hazard section of
octhilinone labels must state: “This pesticide is toxic to fish.”

	(2)	Freshwater Invertebrates, Acute

	The Agency requires a freshwater aquatic invertebrate study using the
TGAI to establish the acute toxicity to freshwater invertebrates.  The
preferred test species is Daphnia magna.  The results of three studies
submitted for octhilinone are provided in the following table (Table 4).

	Table 4.  Acute Toxicity of Octhilinone to Freshwater Invertebrates

 

Species	

Chemical,

% Active Ingredient

(a.i.)

Tested	

Endpoint

(mg/L)	

Toxicity Category	

Satisfies Guidelines/

Comments	

Reference

(MRID No.)

Waterflea (Daphnia magna)	Octhilinone

98.5%	EC50 = 0.32 

NOAEC = 0.21 (a.i.)	Highly toxic	Yes

-	48-hr test duration

-	flow-through test system 	416080-06

Waterflea (Daphnia magna)	Octhilinone

96%	EC50 = 0.107

NOAEC = 0.055 

(a.i.)	Highly toxic	No

-	48-hr test duration

-	static test system

-  total hardness 

    above guideline

-  small test aquaria	439357-04

Waterflea (Daphnia magna)	Octhilinone

88.7%	LC50 = 0.18

(a.i.)	Highly toxic	Yes

-  48-hr test                duration

-  static test system	00026806

(Ecotox data No. 86-870001884)



	The results of two core studies (416080-06 and 00026806) indicate that
octhilinone is highly toxic to freshwater invertebrates.  These studies
fulfill guideline requirement OPPTS 850.1010 (72.2a).  Because the acute
aquatic invertebrate toxicity value is < 1.0 mg/L, the environmental
hazard section of octhilinone labels must state:  “This pesticide is
toxic to aquatic invertebrates.”

(3)	Estuarine and Marine Organisms, Acute

	Acute toxicity testing with estuarine and marine organisms using the
TGAI is required when the end-use product is intended for direct
application to the marine/estuarine environment or effluent containing
the active ingredient is expected to reach this environment.  The
preferred fish test species is the sheepshead minnow.  The preferred
invertebrate test species are Mysid shrimp and Eastern oyster.  This
testing is required for octhilinone based on the chemical’s potential
to reach estuarine and marine environments.  The results of three
toxicity studies submitted for octhilinone are presented in Table 5.



Table 5.  Acute Toxicity of Octhilinone to Estuarine and Marine
Organisms 

Species	

Chemical,

% Active Ingredient

(a.i.)

Tested	

Endpoint

(mg/L)	

Toxicity Category	

Satisfies Guidelines/

Comments	

Reference

(MRID No.)

Sheepshead minnow (Cyprinodon variegatus)	Octhilinone

98.5%	LC50 = 0.16

NOAEC = 0.0.054

(a.i.)	Highly toxic	Yes

-	96-hr test duration 

-	flow-through test system 	416080-07

Mysid shrimp (Mysidopsis bahia)	Octhilinone

98.5%	LC50 = 0.071

NOAEC = <0.034

(a.i.)	Very highly toxic	Yes

-	96-hr test duration 

-	flow-through test system 	416080-08 

Eastern oyster (Crassostrea virginica)	Octhilinone  

98.5% 	LC50   >0.057

EC50  <0.013

NOAEC< 0.003	Very highly toxic	Yes

-	96-hr test duration 

-	flow-through test system	417007-01





	The results of the three core studies indicate that octhilinone is
highly toxic to estuarine/marine fish and very highly toxic to the
estuarine/marine invertebrates shrimp and oysters on an acute basis. 
The sheepshead minnow study (416080-07) fulfills the guideline
requirement OPPTS 850.1075/(72-3a) for an acute estuarine/marine fish
study.  The Mysid shrimp study (416080-08) fulfills the guideline
requirement OPPTS 850.1035/(72-3c) for an estuarine/marine shrimp study.
The Eastern oyster study (417007-01) fulfills the guideline requirement
OPPTS 850.1025/(72-3b) for an acute estuarine/marine mollusk study. 
Because estuarine/marine aquatic fish, mollusk, and shrimp acute
toxicity values are < 1.0 mg/L, the environmental hazard section of
octhilinone labels must state:  “This pesticide is toxic to oysters
and shrimp.”

    Aquatic Organisms, Chronic

	Chronic toxicity testing (fish early life stage and aquatic
invertebrate life cycle) is required for pesticides when certain
conditions of use and environmental fate apply.  The preferred
freshwater fish test species is the fathead minnow.  The preferred
freshwater invertebrate is Daphnia magna. This testing is required for
octhilinone.  The results of two toxicity studies submitted for
octhilinone are presented in Table 6.

Table 6.  Chronic Toxicity of Octhilinone to Freshwater Organisms

Species	

Chemical,

% Active Ingredient

(a.i.)

Tested	

Endpoint

(mg/L)	

Satisfies Guidelines/

Comments	

Reference

(MRID No.)

Fathead Minnow (Pimephales promelas)	Octhilinone

98.5%	LOAEC = ND 

NOAEC = ND 

MATC  >8.5 and < 0 .018; 0.012  geo. Mean

 (a.i.)

	No

-	35-day test duration

-	early-life stage

-  flow-through test    system                 -  relative S.D. for    
fish weight in         one  control            replicate                
 unacceptable          (53%)	419093-01

Waterflea 

(Daphnia magna)	Octhilinone

98.5%	NOAEC = 0.074

(a.i.)	No

-  21-day test             duration 

-  life-cycle 

-  flow-through test     system

-   MATC could           not be                    determined  

-   raw data missing	419094-01

	

The fathead minnow study (419093-01) does not fulfill the guideline
requirement for a fish early life stage toxicity test (72-4a/OPPTS
850.1400) due to missing raw data. The study on the waterflea
(419094-01) also does not fulfill the guideline requirement for a
chronic aquatic invertebrate because the maximum allowable toxicant
concentration (MATC) could not be determined (>0.074 mg/L).   Additional
chronic aquatic toxicity studies are not required to be repeated at this
time, but are held in reserve pending results of the Tier I risk
assessment for the treated lumber antisapstain use.

Toxicity to Plants

	Non-target plant phytotoxicity testing is required for pesticides when
certain conditions of use and environmental fate apply.  Octhilinone use
as an antisapstain wood treatment may result in chemical leachate from
treated wood into the aquatic environment.  Aquatic plant toxicity data
are necessary for a non-target plant risk assessment.  Testing is
conducted with one species of aquatic vascular plant (Lemna gibba) and
four species of algae:  (1) freshwater green alga, Selenastrum
capricornutum, (2) marine diatom, Skeletonema costatum, (3) freshwater
diatom, Navicula pelliculosa, and (4)  bluegreen cyanobacteria, Anabaena
flos-aquae.  The rooted aquatic macrophyte rice (Oryza sativa) is also
tested in seedling emergence and vegetative vigor tests.

	A freshwater algal growth study, that evaluated the toxicity of
octhilinone to green algae, was reviewed. Results of this study are
presented in Table 7.

Table 7.  Toxicity of Octhilinone to Aquatic Plants

Species	

Chemical,

% Active Ingredient

(a.i.)

Tested	

Endpoint 

(mg/L)	

Satisfies Guidelines/

Comments	

Reference

(MRID No.)

Green alga (Selenastrum capricornutum)	Octhilinone

99.2%	EC50 (120-hour, cell density) = 0.015)

NOEC (120-hour cell density) = <0.011	YES

-	growth inhibition

-	120-hr test duration

-	static test system

	440710-01



	Study 440710-01 is classified as acceptable and partially fulfills the
guideline requirements for a green algae toxicity test. (850.5400,
123-2).  Plants are the most sensitive species to octhilinone.  

The following confirmatory studies are required to conduct a Tier I risk
assessment for the treated lumber antisapstain use:

Three additional algal toxicity tests under 850.5400:  

	freshwater diatom (Navicula pelliculosa), 

	blue-green cyanobacteria (Anabeana flow-aquae), 

	marine diatom (Skeletonema costatum).  

Non-target aquatic macrophyte toxicity tests: 

	floating freshwater aquatic macrophyte duckweed (Lemna gibba) –
850.4400, 

	rooted freshwater macrophyte rice (Oryza sativa) – 850.4225 and
850.4250 

		(2 tests - seedling emergence and vegetative vigor).  

II		Risk Assessment and Characterization

	Octhilinone uses are classified as “indoor” with the exception of
the antisapstain wood treatment use.  An ecological risk assessment is
not typically conducted for “indoor” uses, however, due to the
persistence of OIT in soil and water, a Tier I “Down-the-Drain”
assessment was conducted to simulate industrial process waste water
releases.  A Tier I treated lumber antisapstain risk assessment cannot
be done until after receipt of a wood leaching study, soil Koc values,
and outstanding ecotoxicity data.  

	

     Environmental Fate Assessment Summary 

		Octhilinone is stable and persistent in water under abiotic conditions
with a half 	life of > 30 days.  A soil migration study showed that it
is not likely to migrate from the 	soil surface and does not show a
tendency to run-off with water. The estimated KOC of 	2120 indicates it
is likely to bind with soils strongly. With little tendency to migrate
and 	strong soil binding, it remains on the surface soils which may
result in contamination of 	surface water. Its degradation pathway
appears to be through microbial biodegradation in 	surface soils under
aerobic and anaerobic condition within120 days.  It is not likely to 
bioaccumulate in aquatic organisms.  The Agency has used the “Down-
the-Drain” model 	to estimate the EECs for this chemical from
industrial waste water discharges.

	See the Environmental Fate Science Chapter for additional details.

B.	Environmental Exposure and Ecological Risk Assessment

Antisapstain Wood Treatment Use:

A Tier I ecological risk assessment for the antisapstain wood treatment
use of octhilinone 	was not conducted due to missing data endpoints (see
Section III below).  Chronic fish 	and aquatic invertebrate studies have
been triggered due to the high toxicity of 	octhilinone to aquatic
organisms however these studies are held in reserve pending the 	results
of the Tier I antisapstain risk assessment. Outstanding plant toxicity
studies must 	be submitted as confirmatory studies prior to conducting
the Tier I antisapstain risk 	assessment (see Section III below).

An antisapstain environmental risk assessment was not conducted.  Soil
Koc and 	wood leaching rate data are required prior to the conduct of
the Tier I 	environmental risk assessment.  Surface water monitoring
data to obtain expected 	environmental concentrations (EECs) may be
submitted in lieu of the antisapstain 	model.

Industrial Process Waste Water Releases:

The high stability of octhilinone in water, and it’s long aerobic and
anaerobic ½ lives 	have triggered Tier I “Down-the-Drain” modeling
and risk assessment.  The EPA/Office 	of Water “Down-the-Drain”
model was utilized to provide expected environmental 	concentrations
(EEC’s) for octhilinone that may be flushed down-the-drain following
use 	following industrial applications. The “Down-the-Drain” model
has uncertainties as 	follows:  the model does not address the
possibility of degradation of the parent, does not 	estimate the
concentration of any degradates, and does not address actions to be
taken to 	avoid contamination of POWTs when a chemical remains in water
and does not 	biodegrade.

Table 8 – Octhilinone “Down –the –Drain” Model Results

Surface Water Conc.	Equation	 Results

CSM  - chronic	 HR  x  [1/QH ]  x (1-WWT) x CFI			

  ---------------------------------------

SDFM 

	6 x 10-3 µg/L

CSH  - acute	  HR  x [1/QH]  x (1-WWT) x CFI   	

-------------------------------------------		       

		SDFL 			7.8 x 10-2 µg/L



The “down-the-drain” model provides the following EEC’s:  

		acute – 	0.006 ppb  (0.000006 ppm)

		chronic - 	0.080 ppb  (0.00008 ppm)

These expected environmental concentrations (EEC’s) are worst-case
estimates assuming 100% of octhilinone produced for antimicrobial use is
discharged down the drain.  A worst-case scenario was used as a Tier I
assessment to generate risk quotients.  The model does not account for
formulation dilution of active ingredient or for reduced efficacy
following use

	Table 9 – Octhilinone Risk Quotients

      Species                                     Toxicity Value  (ppm) 
              RQ

Rainbow trout	0.05 LC50	0.0016

Daphnia magna acute

                           chronic	0.18 EC50

0.07  NOAEC	0.0004

0.00009

Sheepshead minnow	0.16 LC50	0.0005

Mysid shrimp	0.07 EC50	0.0014

Eastern oyster	>0.06 EC50	0.0013

Green algae	0.02 EC50	0.0040



	Risk characterization integrates the results of the exposure and
ecotoxicity data to evaluate the likelihood of adverse ecological
effects.  The means of this integration is called the quotient method. 
Risk quotients (RQs) are calculated by dividing exposure estimates by
acute and chronic ecotoxicity values.  

       

           RQ =   EXPOSURE/TOXICITY 

 

RQs are then compared to OPP's levels of concern (LOCs).  These LOCs are
used by OPP to analyze potential risk to nontarget organisms and the
need to consider regulatory action.  The criteria indicate that a
pesticide used as directed has the potential to cause adverse effects on
nontarget organisms.  LOCs currently address the following risk
presumption categories: (1) acute -- potential for acute risk to
non-target organisms which may warrant regulatory action in addition to
restricted use classification, (2) acute restricted use -- the potential
for acute risk to non-target organisms, but may be mitigated through
restricted use classification, (3) acute endangered species - endangered
species may be adversely affected by use but risk may be mitigated by
refined risk assessment or regulatory restrictions, (4) chronic risk -
the potential for chronic risk may warrant refined risk assessment
and/or regulatory action, (5) non-endangered plant risk – potential
for effects in non-target plants, and (6) endangered plant risk –
potential for effects in endangered plants.   Currently, EFED does not
perform assessments for chronic risk to plants, acute or chronic risks
to nontarget insects, or chronic risk from granular/bait formulations to
birds or mammals.

The ecotoxicity test values (measurement endpoints) used in the acute
and chronic risk quotients are derived from required studies.  Examples
of ecotoxicity values derived from short-term laboratory studies that
assess acute effects are: (1) LC50 (fish and birds), (2) LD50 (birds and
mammals), (3) EC50 (aquatic plants and aquatic invertebrates) and (4)
EC25 (terrestrial plants).  Examples of toxicity test effect levels
derived from the results of long-term laboratory studies that assess
chronic effects are: (1) LOAEC (birds, fish, and aquatic invertebrates),
and (2) NOAEC (birds, fish and aquatic invertebrates). For birds and
mammals, the NOAEC generally is used as the ecotoxicity test value in
assessing chronic effects, although other values may be used when
justified. However, the NOAEC is used if the measurement endpoint is
production of offspring or survival.

Risk presumptions and the corresponding RQs and LOCs are tabulated
below.

Table 10. Risk Presumption Categories

Risk Presumption for Terrestrial Animals	

LOC



  Acute: Potential for acute risk for all non-target organisms	

>0.5



  Acute Restricted Use: Potential for acute risk for all non-target
organisms, but may be mitigated through restricted use classification	

>0.2



  Acute Endangered Species: endangered species may be adversely affected
by use	

>0.1



  Chronic Risk: potential for chronic risk may warrant regulatory action


>1



Risk Presumption for Aquatic Organisms	

LOC



  Acute: Potential for acute risk for all non-target organisms	

>0.5



  Acute Restricted Use: Potential for acute risk for all non-target
organisms, but may be mitigated through restricted use classification	

>0.1



  Acute Endangered Species: endangered species may be adversely affected
by use	

>0.05



  Chronic Risk: potential for chronic risk may warrant regulatory action


>1



Risk Presumption for Terrestrial and Aquatic Plants	

LOC



  Potential for risk for all non-endangered and endangered plants   	

>1



	“Down-the-Drain” Model Conclusions for Industrial Waste Water

No acute, chronic, or endangered species LOCs are exceeded for aquatic
animals and green algae, however, the risk assessment is incomplete due
to missing non-target plant ecotoxicity endpoints.  Plants are the most
sensitive species tested, therefore, the full compliment of plant
toxicity tests are required to evaluate toxicity to other non-target
plant groups.   Terrestrial animals are not expected to be exposed to
residues greater than those predicted by the “down-the-drain” model.

      Endangered Species Considerations

Section 7 of the Endangered Species Act, 16 U.S.C. Section 1536(a)(2),
requires all federal agencies to consult with the National Marine
Fisheries Service (NMFS) for marine and anadromous listed species, or
the United States Fish and Wildlife Services (FWS) for listed wildlife
and freshwater organisms, if they are proposing an "action" that may
affect listed species or their designated habitat.  Each federal agency
is required under the Act to insure that any action they authorize,
fund, or carry out is not likely to jeopardize the continued existence
of a listed species or result in the destruction or adverse modification
of designated critical habitat.  To jeopardize the continued existence
of a listed species means "to engage in an action that reasonably would
be expected, directly or indirectly, to reduce appreciably the
likelihood of both the survival and recovery of a listed species in the
wild by reducing the reproduction, numbers, or distribution of the
species." 50 C.F.R. ( 402.02.

To facilitate compliance with the requirements of the Endangered Species
Act subsection (a)(2) the Environmental Protection Agency, Office of
Pesticide Programs has established procedures to evaluate whether a
proposed registration action may directly or indirectly reduce
appreciably the likelihood of both the survival and recovery of a listed
species in the wild by reducing the reproduction, numbers, or
distribution of any listed species (U.S. EPA 2004).  After the
Agency’s screening-level risk assessment is performed, if any of the
Agency’s Listed Species LOC Criteria are exceeded for either direct or
indirect effects, a determination is made to identify if any listed or
candidate species may co-occur in the area of the proposed pesticide
use.  If determined that listed or candidate species may be present in
the proposed use areas, further biological assessment is undertaken. 
The extent to which listed species may be at risk then determines the
need for the development of a more comprehensive consultation package as
required by the Endangered Species Act.

For certain use categories, the Agency assumes there will be minimal
environmental exposure, and only a minimal toxicity data set is required
(Overview of the Ecological Risk Assessment Process in the Office of
Pesticide Programs U.S. Environmental Protection Agency - Endangered and
Threatened Species Effects Determinations, 1/23/04, Appendix A, Section
IIB, pg.81).  Because OIT is persistent in water and soil, a Tier I
screening level assessment was conducted for OIT industrial waste water
discharges.  No acute, chronic, or endangered species LOCs are exceeded
for aquatic animals and green algae, however, the risk assessment is
incomplete due to missing non-target plant ecotoxicity endpoints.  The
green algae is the most sensitive species, therefore, the full
compliment of plant toxicity tests are required to confirm that green
algae is the most sensitive non-target plant species.   Terrestrial
animals are not expected to be exposed to residues greater than those
predicted by the “down-the-drain” model.  A No Effect determination
is made for terrestrial and aquatic animal species from “indoor” OIT
uses.  The Agency defers making an endangered species determination for
terrestrial and aquatic plants from “indoor” uses of OIT until after
receipt of outstanding data.

	A Tier I screening model to assess potential exposure from antisapstain
wood preservation uses of octhilinone was not conducted due to the lack
of data for octhilinone wood leaching rate and soil Koc’s.  An
environmental monitoring study of runoff from antisapstain treatment
facilities is suggested to address the potential risks and to provide
EECs for a risk assessment as an alternative to the antisapstain Tier I
model.  The Agency defers making a determination for the antisapstain
use of ochtilinone until additional data and modeling refinements are
available. At that time, the environmental exposure assessment of the
antisapstain use of octhilinone will be revised, and the risks to Listed
Species will be considered. 

III.	Confirmatory Data Required  For Risk Assessment:

1.)    Freshwater diatom (850.5400) using Navicula pelliculosa,

2.)    Blue-green cyanobacteria (850.5400) using Anabaena flow-aquae,

3.)    Marine diatom (850.5400) using Skeletonema costatum,

4.)    Freshwater floating macrophyte duckweed (850.4400) using Lemna
gibba,

5.)    Freshwater rooted macrophyte rice seedling emergence (850.4225)
using Oryza                sativa,

6.)    Freshwater rooted macrophyte rice vegetative vigor (850.4250)
using Oryza sativa,

7.)    Wood leaching study (AWPA Method E11-06, Standard Method of
Determining               the Leachability of Wood Preservatives
Immersed in Water, AWPA, 2006),

8.)    Environmental runoff monitoring study instead of Tier I
antisapstain model,

9.)    Residues in honey/beeswax and toxicity of treated wood residues
to bees -                         combination of Guidelines 860.1500 and
850.3030 (“Honey Bee Toxicity of                      Residues on
Foliage.”.  A combined study which addresses honey/beeswax residues   
      and acute toxicity of treated wood residues to bees is required if
bee hives are to be           constructed of treated wood, or if an
antimicrobial product is intended for                         
application to a bee hive; unless product labeling prohibits such uses.)
 

10.)  Soil Koc study (835.1220).

IV.	 Label Hazard Statements for Terrestrial and Aquatic Organisms and
Use                              Recommendations

Octhilinone labels must state:  

“This pesticide is toxic to fish, aquatic invertebrates, oysters, and
shrimp.”

"Do not discharge effluent containing this product into lakes, streams,
ponds, estuaries, oceans, or other waters unless in accordance with the
requirements of a National Pollutant Discharge Elimination System
(NPDES) permit and the permitting authorities are notified in writing
prior to discharge.  Do not discharge effluent containing this product
to sewer systems without previously notifying the local sewage treatment
plant authority.  For guidance contact your State Water Board or
Regional Office of the EPA."

Antisapstain labels must state:  

"Treated lumber must be stored under cover, indoors, or at least 100
feet from any pond, lake, stream, wetland, or river to prevent possible
runoff of the product into the waterway.  Treated lumber stored within
100 feet of a pond, lake, stream, wetland, or river must be either
covered with plastic or surrounded by a berm to prevent surface water
runoff into the nearby waterway.  If a berm or curb is used around the
site, it should consist of impermeable material (clay, asphalt,
concrete) and be of sufficient height to prevent runoff during heavy
rainfall events.”

	Optional:

“Wood treated with octhilinone shall not be used in the construction
of beehives.”

 V.  REFERENCES

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Five Species of Freshwater Fishes.  Unpublished data. Conducted by
Bionomics, Inc. for Rohm and Haas Company.  

00026806.  1979. Acute Toxicity of RH-893 Technical to the Water Flea
(Daphnia magna).  Lab Report No. BW-79-7-503. Unpublished data.
Conducted by Bionomics, Inc. for Rohm and Haas Company.  

00026807.  1979. Eight-day Dietary LC50 – Mallard Duck RH-893
Technical (79P-251) Final Report.  Unpublished data. Conducted by
Wildlife International. Ltd. for Rohm and Haas Company.  

00026808.  1979. Eight-day Dietary LC50 – Bobwhite Quail RH-893
Technical (79P-253) Final Report.  Unpublished data. Conducted by
Wildlife International. Ltd. for Rohm and Haas Company.  

00026809.  1979. Acute Oral LD50 – Bobwhite Quail RH-893 Technical
(79P-252) Final Report.  Unpublished data. Conducted by Wildlife
International. Ltd. for Rohm and Haas Company.  

86-870001877.  Gough, B.J. and T.E. Shellenberger.  1971.  Acute
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AWPA.  2006.  Book of Standards.  American Wood Preservers’
Association, Birmingham, Alabama.

MRID 416080-01.  Pedersen, C.A.. 1990.  Octhilinone – 21-Day Acute
Oral LD50  Study in Bobwhite Quail. Rohm and Haas Report No. 90RC-0020. 
Unpublished data. Conducted by Bio-Life Associates, Ltd. for Rohm and
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MRID 416080-02.  Pedersen, C.A.. 1990.  Octhilinone – 8-Day Acute
Dietary LC50 Study in Bobwhite Quail. Rohm and Haas Report No.
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Rohm and Haas Company.

MRID 416080-03.  Pedersen, C.A.. 1990.  Octhilinone – 8-Day Acute
Dietary LC50 Study in Mallard Ducklings. Rohm and Haas Report No.
90RC-0022.  Unpublished data. Conducted by Bio-Life Associates, Ltd. for
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MRID 416080-04.  Sousa, J.V. 1990.  Octhilinone – Acute Toxicity to
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MRID 416080-05.  Sousa, J.V. 1990.  Octhilinone – Acute Toxicity to
Rainbow Trout (Oncorhynchus mykiss) Under Flow-Through Conditions. Lab
Report No. 90-7-3367.  Unpublished data. Conducted by Springborn
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MRID 416080-06.  McNamara, P.C. 1990.  Octhilinone – Acute Toxicity to
Daphnids (Daphnia magna) During a 48-Hour Flow-Through Exposure. Lab
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MRID 416080-07.  Sousa, J.V. 1990.  Octhilinone – Acute Toxicity to
Sheepshead Minnow (Cypridon variegatus) Under Flow-Through Conditions.
Lab Report No. 90-7-3375.  Unpublished data. Conducted by Springborn
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MRID 416080-08.  Sousa, J.V. 1990.  Octhilinone – Acute Toxicity to
Mysid Shrimp (Mysidopsis bahia) Under Flow-Through Conditions. Lab
Report No. 90-7-3383.  Unpublished data. Conducted by Springborn
Laboratories for Rohm and Haas Company.

MRID 417007-01.  Dionne, E.  1990.  Mollusc 96-Hour Flow-Through Shell
Deposition Study.

Unpublished data. Conducted by Springborn Laboratories, Inc. for Rohm
and Haas Company.

MRID 419093-01.  Sousa, J.V. 1991. Octhilinone – Toxicity Test with
Fathead Minnow (Pimephales promelas) Embryos and Larvae. Lab. Report No.
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MRID 419094-01.  McNamara, P.C. 1991. Octhilinone – The Chronic
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MRID 439357-01.  Wyness, L.E. 1995.  N-Octylisothiazolone (OIT):
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MRID 439357-02.  Wyness, L.E.  1995. N-Octylisothiazolone (OIT):  Acute
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MRID 439357-03.  Wyness, L.E.  1995. N-Octylisothiazolone (OIT):  Acute
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MRID 439357-04.  Wyness, L.E.  1995. N-Octylisothiazolone (OIT): 
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MRID 448590-01.  Rodgers, M.  1999.  Acticide OIT:  Acute Oral Toxicity
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GmbH/Acti-Chem Specialties, Inc. 

MRID#: 447232-01. Hydrolytic Stability Study of Octhilinone (
14C)-Acticie OIT), 1999, by Dr. T. Lucas Submitted by:  Acti-Chem
Specialties Inc., 56 Quarry Rd., Trumbull, CT: 06611-4816. Performing
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Germany. Laboratory Report #: 1509-1154-069

Rohm& Haas Technical Reports on Environmental Fate Studies. Reports#s:
23-71-4, 23-72-3, 3923-74-38,  3923-75-3, and 3923-75-11

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