APPENDIX D 

EVALUATION OF RISKS FROM 

DEGRADATES, POLYOXYETHYLENEAMINE (POEA) AND R-11, AND 

ENDOCRINE DISRUPTING CHEMICALS 

DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

TABLE OF CONTENTS 

Page

Introduction..............................................................................................................................................................D-1

Potential Ecological Impacts of the Surfactant Polyoxyethyleneamine (POEA) and R-11.....................................D-1

Degradates ...............................................................................................................................................................D-2

Aquatic Toxicity Review.................................................................................................................................D-5

Human Health Toxicity Review ......................................................................................................................D-7

Conclusions .....................................................................................................................................................D-8

Potential Endocrine Disrupting Chemicals..............................................................................................................D-8

References..............................................................................................................................................................D-33

List of Tables 

D-1 Selected Toxicity Values for Polyoxyetheyleneamine...............................................................................D-3 

D-2 Review of AgDrift Results.........................................................................................................................D-3 

D-3 Polyoxyethyleneamine (POEA) Risk Quotients (RQs) for Aquatic Exposure ..........................................D-4 

D-4 Degradates Identified for Active Ingredients...........................................................................................D-10 

D-5 Listings of Endocrine Disrupting Potential of BLM Herbicides ..................................................... D-30

List of Figures 

D-1a Aquatic Toxicity – 2,4-D Toxicity Reference Values and Degradate Toxicity Data...............................D-21 

D-1b Aquatic Toxicity – 2,4-D Toxicity Reference Values and Degradate Toxicity Data...............................D-22 

D-2 Aquatic Toxicity – Diquat Toxicity Reference Values and Degradate Toxicity Data .............................D-23 

D-3a Aquatic Toxicity – Diuron Toxicity Reference Values and Degradate Toxicity Data.............................D-24 

D-3b Aquatic Toxicity – Diuron Toxicity Reference Values and Degradate Toxicity Data.............................D-25 

D-4 Aquatic Toxicity – Fluridone Toxicity Reference Values and Degradate Toxicity Data ........................D-26 

D-5 Aquatic Toxicity – Imazapyr Toxicity Reference Values and Degradate Toxicity Data.........................D-27 

D-6 Aquatic Toxicity – Metsulfuron Methyl Toxicity Reference Values and Degradate Toxicity Data........D-28 

D-7 Aquatic Toxicity – Triclopyr Toxicity Reference Values and Degradate Toxicity Data.........................D-29 

BLM Vegetation Treatments Using Herbicides D-i June 2007 

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DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

APPENDIX D 

EVALUATION OF RISKS FROM 

DEGRADATES, POLYOXYETHYLENEAMINE (POEA) AND R-11, AND 

ENDOCRINE DISRUPTING CHEMICALS 

Introduction 

This appendix was prepared in response to public

comments on the Draft PEIS. Specifically, this

appendix addresses three concerns raised by the public 

about the human health and ecological risk

assessments prepared for the PEIS: 

• Some surfactants may be more toxic to

aquatic receptors than the active ingredient in 

an herbicide. Using polyoxyethyleneamine 

(POEA) as an example, what are the potential

impacts of surfactants in Roundup Original®

and Honcho

®

 applied with glyphosate and R11? 

• The risk assessments only address the 

potential impacts of the active ingredients, 

what about the toxicity of degradates?

• The risk assessments did not identify 

endocrine disruption as a toxic endpoint. Are

any of the herbicides considered to be 

endocrine disrupting chemicals?

Potential Ecological Impacts 

of the Surfactant 

Polyoxyethyleneamine 

(POEA) and R-11 

The glyphosate ecological risk assessment (ERA) 

conducted by the U.S. Department of Agriculture

Forest Service (Forest Service; Syracuse 

Environmental Research Associates [SERA] 2003) 

identified the potential for ecological risks associated

with the use of a surfactant included in some

glyphosate formulations. This surfactant,

polyoxyethyleneamine (POEA), is an ethoxylated 

tallow amine on the U.S. Environmental Protection

Agency (USEPA) List 3 of Inert Ingredients of

Pesticides (Inerts of Unknown Toxicity). POEA by

itself is much more toxic to aquatic organisms than 

glyphosate. Therefore, there may be greater risk 

associated with applications of POEA-containing

glyphosate formulations than with applications of nonPOEA-containing glyphosate near aquatic systems. 

For this assessment, concentrations of POEA in a

hypothetical stream and pond resulting from an

application of Roundup Original®

 and/or Honcho®

were estimated and compared to toxicological values

for fish, aquatic invertebrates, and amphibians. 

Toxicity data for POEA were reviewed, and median

lethal concentration (LC50) values were identified for 

four groups of aquatic receptors: threatened,

endangered, and sensitive (TES) fish (represented by

the rainbow trout, Oncorhynchus mykiss); non-TES 

fish (represented by the bluegill and fathead minnow, 

Lepomis macrochirus and Pimephales promelas, 

respectively); non-TES invertebrates (represented by

the water flea, Daphnia pulex); and amphibians 

(represented by the African clawed frog, Xenopus 

laevis). Selected toxicity values for POEA are 

presented in Table D-1. 

The Forest Service glyphosate ERA (SERA 2003) and 

the herbicide labels for Honcho® and Roundup 

Original

® (both of which are Monsanto products that

may be used by the BLM) were reviewed to identify 

application rates and percent surfactant present in the

applied products. The ERA for glyphosate considered 

typical and maximum glyphosate application rates of 2

and 7 pounds (lbs) acid equivalent (a.e.)/acre 

(equivalent to 2.67 to 9.33 lbs active ingredient

(a.i.)/acre), respectively (SERA 2003). According to

BLM Vegetation Treatments Using Herbicides D-1 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

the Honcho® and Roundup Original® labels, each 

product contains 41% glyphosate and 8% surfactant by

weight, conservatively assumed to be 100% POEA. 

Therefore, for modeling purposes, the typical and

maximum application rates for POEA were calculated 

as 0.521 and 1.82 lbs/acre, respectively (41/8 or 5.125 

times less POEA per acre than glyphosate). In

addition, investigators have found POEA to be acutely

toxic to amphibians (Diamond and Durkin 1977; 

Howe et al. 2004; Relyea 2005). 

AgDrift results for the ERAs for herbicides evaluated 

by the BLM (see Appendix C of the PEIS) were

reviewed to select a conservative set of results that

could be used to estimate the POEA concentrations

deposited at varying distances from an application site.

The percent active ingredient remaining at each of the

evaluated distances (0, 25, 100, and 900 feet for 

ground applications, and 0, 100, 300, and 900 feet for

aerial applications) was determined, and the most 

conservative result from each scenario (i.e., the

maximum amount of active ingredient remaining at

900 feet) was selected for use in the POEA evaluation.

The selected results represented ground applications 

with a high boom, and aerial applications over nonforested areas. Table D-2 presents a summary of the 

most conservative AgDrift model results, as well as

average model results. 

The typical and maximum POEA application rates 

(0.521 and 1.82 lbs/acre, respectively) were modeled

for the hypothetical pond and stream (using the water 

body volumes and assuming an instantaneous 

concentration) and multiplied by the maximum percent

herbicide remaining at each distance (based on the

most conservative AgDrift modeling results presented

in Table D-2). These conservative pond and stream

concentrations were then compared against the toxicity 

data to generate risk quotients (RQs; Table D-3). 

The RQs were compared to the levels of concern 

(LOCs) from the BLM ERAs to identify scenarios that

could indicate the potential for risk to aquatic receptors

from POEA. RQs for stream scenarios were higher

than RQs for pond scenarios. The majority of the RQs 

were below the most conservative LOC of 0.05 (acute

endangered species). The majority of the RQs greater 

than 0.05 were generated at the point of application (0 

feet). A distance of 0 feet from the point of application 

is a highly conservative scenario in that it essentially

assumes a direct application to the water body with no

dilution or drift (i.e., drift distance equals 0 feet). This

scenario is highly unlikely under BLM application

practices. The stream and pond RQs for TES fish and 

the stream RQ for non-TES fish exposed to POEA 100 

feet from an aerial application at the maximum rate 

were also greater than the most conservative LOC

considered in the ERAs (0.05; acute endangered

species). This indicates that a buffer zone of greater 

than 100 feet is necessary for aerial applications of

POEA at the maximum rate in an area containing TES

fish species. 

As discussed under Mitigation in Chapter 2 of the

Final PEIS, the BLM would avoid using any

formulations with POEA, or seek to use the 

formulation with the lowest amount of POEA 

available, to reduce risks to aquatic organisms. It is 

also unlikely that the BLM would apply glyphosate

herbicides containing POEA in an area known to

contain endangered aquatic species, so comparisons to

the endangered species LOC may be overly

conservative. A comparison to the acute high risk LOC

of 0.5 may be more appropriate. The only RQs greater

than the LOC of 0.5 are generated in the stream at the 

point of application (0 feet) using the maximum

application rate. As stated previously, this scenario is

highly unlikely and assumes zero dilution and no drift 

(i.e., essentially direct application). However, even

under these conditions the RQs are quite low: 1.57 for

TES fish and 1.02 for non-TES fish. RQs for

invertebrates and amphibians are less than 0.5 under 

all scenarios.

This assessment indicates that even under conservative

conditions (scenarios with the most conservative

amount of drift, and herbicide applications at the

maximum rate) the potential risks to aquatic receptors 

from POEA are minimal under BLM application 

scenarios. However, because of lack of physical

chemical property information, POEA was not

modeled for leaching properties and runoff to water 

bodies and aquatic receptors. Therefore, there is some

uncertainty associated with that pathway. 

The adjuvant R-11 is a nonylphenol ethoxylate that is

acutely toxic to aquatic life, and is suspected to be an

endocrine-disrupting chemical (Bakke 2003, Stark and 

Walthall 2003). The BLM has decided to suspend the

use of R-11 in its herbicide applications. 

Degradates 

While it is preferable to estimate not just the risks from

the active ingredient of an herbicide, but also the

cumulative risks of all chemicals included in the 

applied formulation (i.e., inert ingredients, adjuvants,

BLM Vegetation Treatments Using Herbicides D-2 June 2007 

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DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

BL

Final Pr

M Vegetation Treatments Using Herbicides D-3 June 2007 

ogrammatic EIS

TABLE D-1 

Selected Toxicity Values for Polyoxyethyleneamine 

Common Name Scientific Name Endpoint 

Exposure 

Duration 

(hours) 

Concentration 

(mg/L)1 Source 

Rainbow trout, 

Donaldson trout Oncorhynchus mykiss LC50 96 0.68 Mayer and Ellersieck (1986) 

Bluegill Lepomis macrochirus LC50 96 1 Mayer and Ellersieck (1986) 

Fathead minnow Pimephales promelas LC50 96 1 Folmar et al. (1979) 

Water flea Daphnia pulex LC50 48 2.35 Moore et al. (1987) 

African clawed frog Xenopus laevis LC50 96 6.8 Perkins et al. (2000) 

1

 mg/L = Milligrams per liter. 

TABLE D-2 

Review of AgDrift Results 

Percent of Active Ingredient Remaining in Pond 

and Stream at Various Distances Distance From 1

Application (feet) Most conservative model results 2 Average model results 

Ground Application Stream Pond Stream Pond 

0 100 100 100 100 

25 1.88 2.67 1.87 1.08 

100 0.53 1.4 0.5 0.57 

900 0.05 0.22 0.04 0.09 

Aerial Application Stream Pond Stream Pond 

0 100 100 100 100 

100 7.75 5.4 7.18 4.92 

300 2.84 2.53 2.41 2.17 

900 1.23 1.17 1.06 1.02 

1

 Based on a review of AgDrift results for herbicides evaluated in the ERAs in Appendix C of the PEIS. 2

 The most conservative model results (i.e., maximum herbicide concentrations, as a percent of applied rate, from AgDrift model) were 

selected to estimate POEA concentrations in ponds and streams. 
TABLE D-3 

Polyoxyethyleneamine (POEA) Risk Quotients (RQs) for Aquatic Exposure 

Estimated POEA 

Concentrations (mg/L) TES Fish 1, 2 Non-TES Fish 3 Non-TES Invertebrates 4 

Application Method and 

Rate 

Distance 

From 

Application 

(feet) Stream Pond Stream RQ Pond RQ Stream RQ Pond RQ Stream RQ Pond RQ 

0 2.92E-016 5.84E-02 4.49E-01 8.98E-02 2.92E-01 5.84E-02 1.24E-01 2.49E-0

25 5.49E-03 1.56E-03 8.45E-03 2.40E-03 5.49E-03 1.56E-03 2.34E-03 6.64E-0

100 1.55E-03 8.18E-04 2.38E-03 1.26E-03 1.55E-03 8.18E-04 6.60E-04 3.48E-0

Ground

Application 

(high boom)

Typical Rate 900 1.46E-04 1.28E-04 2.25E-04 1.97E-04 1.46E-04 1.28E-04 6.21E-05 5.45E-0

0 1.02E+00 2.04E-01 1.57E+00 3.14E-01 1.02E+00 2.04E-01 4.34E-01 8.68E-0

25 1.92E-02 5.45E-03 2.95E-02 8.38E-03 1.92E-02 5.45E-03 8.17E-03 2.32E-0

100 5.41E-03 2.86E-03 8.32E-03 4.40E-03 5.41E-03 2.86E-03 2.30E-03 1.22E-0

Ground

Application 

(high boom)

Maximum Rate 900 5.10E-04 4.49E-04 7.85E-04 6.91E-04 5.10E-04 4.49E-04 2.17E-04 1.91E-0

0 2.92E-01 5.84E-02 4.49E-01 8.98E-02 2.92E-01 5.84E-02 1.24E-01 2.49E-0

100 2.26E-02 3.15E-03 3.48E-02 4.85E-03 2.26E-02 3.15E-03 9.62E-03 1.34E-0300 8.29E-03 1.48E-03 1.28E-02 2.28E-03 8.29E-03 1.48E-03 3.53E-03 6.30E-0

Aerial 

Application 

(non-forested)

Typical Rate 900 3.59E-03 6.83E-04 5.52E-03 1.05E-03 3.59E-03 6.83E-04 1.53E-03 2.91E-0

0 1.02E+00 2.04E-01 1.57E+00 3.14E-01 1.02E+00 2.04E-01 4.34E-01 8.68E-0

100 7.90E-02 1.10E-02 1.22E-01 1.69E-02 7.90E-02 1.10E-02 3.36E-02 4.68E-0300 2.90E-02 5.16E-03 4.46E-02 7.94E-03 2.90E-02 5.16E-03 1.23E-02 2.20E-0

Aerial 

Application 

(non-forested)

Maximum Rate 900 1.25E-02 2.39E-03 1.92E-02 3.68E-03 1.25E-02 2.39E-03 5.32E-03 1.02E-0

1 TES = Threatened, endangered, and sensitive species. 2 Toxicity value = 0.65 mg/L (96-hour LC50 for rainbow trout).3 Toxicity value = 1 mg/L (96-hour LC50 for bluegill and fathead minnow). 4 Toxicity value = 2.35 mg/L (48-hour LC50 for water flea). 5 Toxicity value = 6.8 mg/L (96-hour LC50 for frogs [Xenopus laevis]).6 Values given in scientific notation. For example, 2.92E-01 equals 0.292; 5.84E-02 equals 0.0584, etc. Shading and boldface indicates RQs greater than 0.05 (LOC for acute risk to endangered species – most conservative). Impacted stream volume is 254,460 liters (2 meters wide, 0.2 meter deep, 636 meters long). Impacted pond volume is 1,011,715 liters (1/4 acre pond, 1 meter deep). Assumes typical and maximum application rates of 0.521 lbs/acre and 1.82 lbs/acre for POEA. 

BLMVegetationTreatment Using Herbicides D-4 June 2007 

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DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

surfactants), doing so is impractical with currently

available models (e.g., GLEAMS) and toxicity

databases, which are designed to calculate

deterministic risk calculations (i.e., exposure

modeling, effects assessment, and risk calculations) for

a single active ingredient. 

To address this uncertainty, each ERA conducted by

the BLM included a semi-quantitative assessment of 

the potential impacts of inert ingredients, adjuvants,

and tank mixtures. This process included a review of 

Confidential Business Information (CBI) on inert 

compounds; a review of the adjuvants discussed on the

herbicide label, with a modeling effort designed to

assess the potential toxicity of adjuvants in surface

runoff; and a quantitative assessment of selected tank

mixes to evaluate the potential additive impacts of two

herbicides applied together. Although it is also

preferable to thoroughly evaluate the potential impacts 

of any chemicals produced over time during the

degradation of the active ingredient, an assessment of 

the effects of these degradates has not been feasible. 

In response to comments received on the Draft PEIS, 

an additional investigation was conducted to more 

thoroughly investigate the available information on

degradates and to assess whether it is likely for 

degradates to be more toxic than the parent compounds

(i.e., the active ingredients considered in the risk

assessments), and whether it is feasible to evaluate the

potential risk of degradates using the methods applied

to the active ingredient. The following observations

were made during this review: 

• Degradates are often not identified or named in

registration documents. The USEPA’s Pesticide

Fate Database (available online at

http://www.epa.gov/oppefed1/general/databasedes

cription.htm) contains data from studies submitted

by pesticide manufacturers in support of the

registration or re-registration of their pesticide

products. Of the 486 active ingredients listed in

the database in August 2006, only 189 ingredients 

included fate studies. 

• Degradates are often tentatively identified 

compounds. Even when the degradates are

identified, the physical and chemical 

characteristics of the compounds are often poorly

understood. For example, there is often little

information available about toxicity or fate and

transport of the degradate. Without this 

information, it is impossible to conduct a

meaningful exposure assessment. 

• Each active ingredient may break down into

multiple degradates with varying toxicological and

chemical properties. For the 19 active ingredients

considered in this section, over 100 potential 

degradates were identified from the available 

registration materials. Investigating the

characteristics of each of these degradates is an 

enormous task, and given the lack of available

information, a comprehensive quantitative

assessment is virtually impossible. 

The specific suite of degradates produced varies with

local environmental conditions, and the relative

importance of degradates is often very small (i.e., only

a few percent of the mass of the parent compound is

represented in a single degradate). Together, these two 

factors make accounting for the impact of the 

degradates very difficult. 

Table D-4 presents the names of the degradates

identified during a review of registration documents, 

discussions with the USEPA, and communications 

with herbicide manufacturers. When available,

additional information is also presented. In some

cases, the materials reviewed provided toxicity 

information or information regarding the percentage of 

the parent compound that degraded into a given

degradate and the length of time in which the

degradate was produced. The percentage of the parent

compound that degraded into the various degradates

ranged widely, from 0.3 to 80.7%. There was also a 

wide range of production times for the degradates (12 

hours to 365 days). 

After the degradates were identified by name, an

additional search was conducted for toxicity data.

Searches focused on aquatic toxicity data for

ecological receptors in the USEPA’s ECOTOX 

database and reference doses for humans (searched in 

various databases, including USEPA’s Integrated Risk 

Information System [IRIS], California EPA, and 

USEPA’s National Center for Environmental

Assessment). The results of these searches are 

discussed in the following subsections. 

Aquatic Toxicity Review

In an effort to assess the potential toxicity of

degradates to aquatic receptors, the USEPA’s 

ECOTOX database (http://cfpub.epa.gov/ecotox/) was 

searched for the degradates listed in Table D-4. This

database is a prime source of single chemical toxicity

data for a variety of ecological receptors. The database

BLM Vegetation Treatments Using Herbicides D-5 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

is maintained by the USEPA Office of Research and 

Development (ORD), and the National Health and 

Environmental Effects Research Laboratory’s 

(NHEERL’s) Mid-Continent Ecology Division

(MED). The focus of the toxicity data searches was on 

aquatic toxicity, in part because there is generally a 

wider body of toxicity testing conducted on aquatic 

species than on terrestrial species. In addition, due to 

similarities in testing methods and test organisms, it is

easier to compare different sets of aquatic toxicity test

results than to compare terrestrial tests conducted with

widely different species. In order for the comparisons 

between toxicity data to be meaningful, it would be

necessary to extrapolate the terrestrial toxicity test

results to the body weight of the surrogate bird and

mammal species selected for the development of

toxicity reference values (TRVs) in each of the 19 risk 

assessments, which would add additional layers of 

uncertainty associated with interspecies variation. 

Searches of the ECOTOX database identified relevant

aquatic toxicity data for 10 degradates. Toxicity data

were not considered relevant for comparison to the 

parent compound TRVs if the data were not presented

on a water concentration basis (i.e., tissue data were

not considered), if an effect concentration was not

reported (NR), or if both the test duration and test

endpoint were listed as NR in the database. The

remaining aquatic toxicity data were compared against

the aquatic TRVs selected for use in the BLM and 

Forest Service ERAs. These comparisons are

presented in Figures D-1 through D-7. It should be

noted that the values for the parent compounds

presented in the figures represent the individual TRVs 

selected from a wide range of aquatic toxicity data

reviewed during the ERA process. The full set of

toxicity data considered in the derivation of the TRVs

is presented in an appendix included with each ERA.

In some cases, too many degradate toxicity values 

were found to include all data labels in the figures. In

these cases, a set of representative labels are presented 

over the range of data points. 

In most cases, the toxicity data for the degradates and

the parent compound TRVs overlap and cover a

similar range of concentrations. The lowest TRVs

selected for diquat, diuron, imazapyr, and metsufuron 

methyl are below the lowest toxicity data point for the

associated degradates. The parent compound TRVs are

likely, therefore, to be sufficiently protective of 

potential aquatic impacts from degradates (see Figures

D-2, D-3a, D-5, and D-6). These examples show that

predicted risks for impacts due to degradates would 

likely be less than risks from the active ingredients

evaluated in the ERAs. 

The ECOTOX searches on degradates associated with

2,4-D, diuron, fluridone, and triclopyr identified

individual toxicity data points below some of the

TRVs for the active ingredients. In these cases, there

may be selected aquatic species that are more sensitive

to the degradate than to the active ingredient.

However, this information should be considered in the

context of the herbicide use practices, the

concentration of the degradate relative to the parent

compound, the process of degradate production, and 

the body of available toxicity data. For example,

although the toxicity review identified aquatic toxicity

data points for 3,4-dichlorobenzenamine (Figure D-3b; 

referred to as 3,4-dichloroaniline in Table D-4) below 

the TRVs for the parent compound (diuron), the

registration materials indicate that only 0.5% of the

parent compound degrades into 3,4-

dichlorobenzenamine. Therefore, the increased toxicity 

of the degradate is offset by the fact that only a minute

amount of the degradate is produced, which will likely

disperse rapidly in an active aquatic system. A similar 

case exists for fluridone and the degradate benzoic

acid (Figure D-4). There are also some uncertainties

associated with the lowest water flea toxicity values

identified for benzoic acid, since the toxicity endpoint 

is not defined. These toxicity values (1.95E-04 and 

1.22E-03 mg/L) are also dramatically lower than other 

water flea toxicity values identified for benzoic acid

(ranging from 146 mg/L to 1540 mg/L). Focusing on a 

single toxicity study may be overly conservative and

may not be representative of risks found in the field or

in other laboratory studies. 

The ECOTOX search also indicated that aquatic risks 

to sensitive salmonids may be slightly higher for a 

triclopyr degradate (Figure D-7) than for the active 

ingredient itself. However, this dataset is limited to a

series of studies presented in a single journal article in

1987. Aquatic risks associated with degradates of 2,4-

D may also be higher than predicted risks for the 

parent compound under some conditions. Figure D-4

indicates that selected toxicity data points for 2,4-

dichlorophenol and 4-chlorophenol are lower than the

TRVs selected for 2,4-D. However, as with other

degradates, the lowest toxicity data points may be 

overly conservative and may not represent the full

range of toxicity data available. There are several fish,

aquatic invertebrate, and aquatic macrophyte toxicity 

data points for 2,4-dichlorophenol and 4-chlorophenol,

that are within the 0.3 mg/L to 100 mg/L range

BLM Vegetation Treatments Using Herbicides D-6 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

selected for the 2,4-D TRVs. However, the presence of

lower toxicity data points for the degradates may 

indicate the need for additional caution when 2,4-D is

applied in the vicinity of a water body. There remains 

a great deal of uncertainty, though, since the 

registration materials did not report information on the 

production time or proportion of parent degrading for

2,4-dichlorophenol and 4-chlorophenol. 

Human Health Toxicity Review

A search for human health toxicity values was

conducted for the degradates listed in Table D-4. 

USEPA’s memorandum for the hierarchy of selection

of toxicity data (USEPA 2003) was followed. Sources 

of toxicity data searched included: 

1. Tier 1: The USEPA’s Integrated Risk Information 

System (IRIS; USEPA 2006a). This online

database (http://www.epa.gov/iris/) presents

toxicity data that are peer reviewed and generally

represent official USEPA position on the toxicity

of the chemicals. 

2. Tier 2: The USEPA’s Provisional Peer Reviewed 

Toxicity Values (PPRTVs). PPRTVs are available

from the National Center for Environmental 

Assessment with approval from a Superfund

Remedial Project Manager, and can often be found

in tables of compiled toxicity data, published by 

USEPA Region 3 (USEPA 2006b) or USEPA 

Region 9 (USEPA 2004a). 

3. Tier 3: Other Sources, including the Agency for

Toxic Substances (ATSDR) Minimal Risk Levels

(ATSDR 2005), California Environmental

Protection Agency values (CalEPA 2005a, 2005b)

and the Health Effects Summary Tables (USEPA 

1997). 

The focus of the search was to determine whether the 

degradates have toxicity values (such as no observed

adverse effect levels (NOAELs) or reference doses 

(RfDs)) that are derived by a regulatory agency.

Identification of these toxicity values for the

degradates would allow a comparison of toxicity with

the parent compound. General toxicology information 

was not compiled for the degradates, as general 

information would not allow for a direct comparison of 

the toxicity of the degradate to the RfD used in the

human health risk assessment for the parent chemical.

The majority of the degradates do not have toxicity

values derived by a regulatory agency. Only two of the

listed degradates, benzoic acid and 4-chlorophenol,

have relevant toxicity values, as discussed below. 

Benzoic Acid 

Benzoic acid is the only degradate of fluridone to have

a published human health toxicity value. No cancer 

slope factor is available from the sources searched.

Benzoic acid has an RfD of 4 mg/kg-day listed in IRIS 

(USEPA 2006a). This RfD is 50 times higher than the

RfD listed for fluridone (0.08 mg/kilogram [kg]-day),

which was also used as the Population Adjusted Dose

(PAD) for evaluating dietary pathways in the EIS risk

assessment. The higher RfD indicates that benzoic acid

is less toxic than fluridone. 

The BLM human health risk assessment (HHRA) for 

fluridone showed that fluridone risks could exceed the 

USEPA’s level of concern for all occupational

receptors under the accidental scenario, for an airplane 

mixer/loader under the routine use (maximum

application rate) scenario for intermediate- and longterm exposures, and for a helicopter mixer/loader

under the routine use (maximum application rate) 

scenario for long-term exposures. For public receptors, 

the HHRA showed that fluridone risks do not exceed 

the USEPA’s level of concern under the routine-use

typical application rate scenario, but could exceed the 

USEPA’s level of concern for a nearby resident (adult

and child) under the routine-use maximum application 

rate scenario, and for a nearby resident (adult and 

child), a berry picker (child) and a Native American 

(child) under the accidental scenarios. 

Since benzoic acid is 50-fold less toxic than fluridone,

it is likely that it would not show any risks above the

USEPA’s level of concern. The other herbicides

evaluated in the PEIS risk assessment that have higher

RfDs than fluridone did not show risks above the

USEPA’s level of concern.

4-Chlorophenol 

4-chlorophenol is a degradate of 2,4-D. Although this

chemical does not have a listed toxicity value from the 

sources searched, it is structurally similar to 2-

chlorophenol. Therefore, the RfD available for 2-

chlorophenol (0.005 mg/kg-day) from IRIS (USEPA

2006a) was used to evaluate 4-chlorophenol. The RfD

for 2-chlorophenol is one-half that of the current RfD 

for 2,4-D (0.01 mg,/kg-day), indicating that 4-

chlorophenol is twice as toxic as 2,4-D. No cancer

slope factor is available from the sources searched. 

BLM Vegetation Treatments Using Herbicides D-7 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

Because 2,4-D was included in the 1991 BLM EIS, an

updated risk assessment was not conducted for the

current PEIS. However, the Forest Service conducted a 

risk assessment for 2,4-D that uses the current

reference dose for 2,4-D (SERA 1998). Because 4-

chlorophenol is twice as toxic as 2,4-D, it is expected 

that, at the same exposure concentration, the risks from

4-chlorophenol would be twice those predicted in the

Forest Service risk assessment for 2,4-D. The Forest 

Service risk assessment for 2,4-D concluded that there

could be some risks to workers at the highest estimate 

of exposure, but that these could be controlled by

adequate protection. The risk assessment for 2,4-D

concluded that that there should be no risks to the 

public except under accidental scenarios or after

consumption of contaminated vegetables over several

months, which the risk assessment stated is unlikely. 

Degradation of 2,4-D yields only a fractional

percentage of 4-chlorophenol on a molar basis, and 4-

chlorophenol is degraded faster than 2,4-D. It is

unlikely that concentrations of 4-chlorophenol in the

environment produced from 2,4-D degradation would

be on the same order of magnitude as the 2,4-D.

Furthermore, according to the RED (USEPA 2005), 

the OPP Metabolism Assessment Review Committee 

(MARC) determined that all degradates of 2,4-D are 

not of risk concern due to low occurrence under 

environmental conditions, comparatively low toxicity,

or both. 

Conclusions 

Although a fully quantitative evaluation of the

potential risks associated with degradates using the 

methods followed for the active ingredient is not

possible, a limited semi-quantitative comparison of the 

toxicity values was possible for both ecological and

human health. The review of the relevant degradate 

toxicity information indicates that, in most cases where

information was available, the TRVs used in the ERAs

and the RfDs used in the human health risk assessment 

are protective of impacts (i.e., are low enough to

predict potential impacts) due to the identified

degradates. Most of the TRVs capture the full range of

data identified during the aquatic toxicity review for

the degradates, indicating that degradate toxicity is

addressed by these TRVs. 

The RfD identified for benzoic acid indicates that it is

far less toxic than the parent compound (fluridone).

There are a few exceptions where aquatic toxicity data

for the degradates is lower than the TRVs used in the

ERAs (2,4-D, diuron, fluridone, triclopyr) and one

case (2,4-D) where the RfD for the degradate is lower

than for the parent compound. There are some

uncertainties associated with the degradate toxicity

data in these examples (i.e., a surrogate RfD for 4-

chlorophenol was used; some low aquatic toxicity data

points appear to be outliers compared to the rest of the

degradate data set). In these cases, the use of the 

herbicide may warrant additional precautions. 

Potential Endocrine 

Disrupting Chemicals 

According to the World Health Organization (2002),

endocrine disrupters have been defined as exogenous

substances that alter function(s) of the endocrine 

system and consequently cause adverse health effects

in an intact organism or its progeny, or in

(sub)populations. Endocrine disrupters interfere with

the functioning of the endocrine system, in at least 

three possible ways:

• By mimicking the action of a naturallyproduced hormone, such as estrogen or

testosterone, and thereby setting off similar 

chemical reactions in the body; 

• by blocking the receptors in cells receiving

the hormones (hormone receptors), thereby 

preventing the action of normal hormones; or 

• by affecting the synthesis, transport,

metabolism and excretion of hormones, thus 

altering the concentrations of natural

hormones. 

During the toxicity review for the HHRAs and ERAs,

no endocrine disrupting effects were noted. For the 10

BLM ERAs, the toxicity review consisted of a

literature search and a review of USEPA registration

data. In order to further evaluate whether any of the

BLM herbicides have endocrine disruption effects, the 

BLM conducted a search of endocrine disrupter 

databases, including sources from the U.S., the

European Union, and Japan. The databases included

official government lists and lists published by

concerned citizen groups, such as the Pesticide Action 

Network. The results of this search are presented in

Table D-5. With the exception of 2,4-D and diuron,

none of the BLM herbicides were included among 

those associated with endocrine disrupting effects. As 

shown in the table, diuron and 2,4-D are listed by the

BLM Vegetation Treatments Using Herbicides D-8 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

BL

Final Pr

M Vegetation Treatments Using Herbicides D-9 June 2007 

ogrammatic EIS

European Commission Directorate-General for the 

Environment (2000) as Category 2 chemicals, meaning 

that there is evidence of the potential for the listed 

chemical to cause endocrine disruption. Diuron only 

appeared on a single list, so there is some uncertainty 

within the scientific community about this chemical’s 

status as an endocrine disruptor. 

Several other lists include 2,4-D as a potential or 

probably endocrine disrupting chemical. However, the 

Endocrine Disruptor Knowledge Base supported by 

the U.S. Food and Drug Administration’s National 

Center for Toxicological Research indicates that there 

are no reports in the scientific peer-reviewed literature 

of 2,4-D acting as an estrogen receptor binder. 

The USEPA Health Effects Division (HED) HHRA 

that was used in the RED, and a correction to the HED 

HHRA provided by the 2,4-D Industry Task Force, 

were reviewed. The HED HHRA and Task Force 

correction provided additional detail regarding the 

studies used to test for potential endocrine effects. In 

general, the studies cited as showing evidence of 

endocrine disruption effects were conducted using 

extremely high doses of 2,4-D, where often renal 

saturation or other systemic effects were noted. The 

findings of these studies, therefore, do not indicate that 

2,4-D has selective toxicity to the endocrine system. 

In the health risk assessment conducted to support the 

reregistration of 2,4-D (USEPA 2004c), the USEPA 

concluded that there is not sufficient evidence that 2,4-

D is an endocrine disrupting chemical. The USEPA 

did not conduct the health risk assessment using 

endocrine disruption endpoints. Since the current 

studies that showed evidence of endocrine effects were 

tested using doses above renal saturation, the USEPA 

did recommended formal testing of 2,4-D for 

endocrine endpoints. However, there is no standard 

protocol for determination of endocrine effects of 

chemicals. 

The lack of a standardized and broadly accepted set of 

protocols for identifying and quantifying potential 

endocrine effects has very important implications. The 

absence of such a test contributes to the development 

of several, potentially conflicting, summaries of 

potential endocrine disruptors. As importantly, in the 

absence of an agreed upon process to quantify doseresponse relationships, quantitative risk assessments 

are difficult and highly uncertain. 
TABLE D-4 

Degradates Identified for Active Ingredients 

Parent Compound Degradate Name // [Synonym] Mechanism of Production 

Estimated 

Proportion 

of Parent 

Produc

Tim

(Day

2,4-D 1,2,4-benzenetriol Not reported Not reported Not reported 2,4-D 2,4-dichlorophenol // [2,4-DCP] Not reported Not reported Not reported 2,4-D 2,4-dichloroanisole // [2,4-DCA] Not reported Not reported Not reported 2,4-D 4-chlorophenol Not reported Not reported Not reported 2,4-D Chlorohydroquinone // [CHQ] Not reported Not reported Not reported Bromacil 3-sec-butyl-6-methyluracil // [Metabolite F] Aerobic soil metabolism 0.70% 304 Bromacil 3-sec-butyl-6-methyluracil // [Metabolite F] Anaerobic aquatic metabolism 80.7% 304 Bromacil 5-bromo-3-(2-hydroxy-1-methylpropyl)-6- methyluracil // [Metabolite D] Aerobic soil metabolism 0.80% 304 Bromacil 5-bromo-3-(alpha-hydroxymethylpropyl)-6- methyluracil // [Metabolite C] Aerobic soil metabolism 1.5% 154 Bromacil 5-bromo-3-(alpha-hydroxymethylpropyl)-6- methyluracil // [Metabolite C] Aerobic soil metabolism 1.5% 184 Bromacil 5-bromo-3-sec-butyl-6-hyroxymethyluracil // [Metabolite A] Aerobic soil metabolism 0.60% 184 Bromacil 5-bromo-6-methyluracil // [Metabolite G] Aerobic soil metabolism 3.4% 304 Bromacil 8 unidentified degradates Photodegradation in water <8.1% Each 102 Bromacil Peak II Hydrolysis 3.90% 30 Bromacil Unknown I Photodegradation on soil <2.5% 30 Bromacil Unknown I Soil in dark <2.0% 30 Bromacil Unknown II Photodegradation on soil <2.5% 30 Bromacil Unknown II Soil in dark <2.0% 30 

BLMVegetationTreatment Using Herbicides D-10 June 2007 

FinalProgrammaticEIS
TABLE D-4 (Cont.) 

Degradates Identified for Active Ingredients 

Parent Compound Degradate Name // [Synonym] Mechanism of Production Estimated Proportion of Parent Pro

T

(D

Chlorsulfuron 2-amino-4-methoxy-6-methyl-1,3,5-triazine Aerobic soil metabolism 15% 50 Chlorsulfuron 2-chlorobenzenesulfonamide Aerobic soil metabolism 30-35% 50 Chlorsulfuron

2-chloro-N-[[(4-hydroxy-6-methyl-1,3,5-triazin-2-yl)-amino]carbonyl]benzenesulfonamide 

Aerobic soil metabolism 15% 50 

Chlorsulfuron Chlorosulfonamide Hydrolysis 33% 31 Chlorsulfuron Dihydroxy triazine Hydrolysis <10% 31 Chlorsulfuron Dihydroxy triazine Soil photodegradation <10% 65 Chlorsulfuron N-(2-chlorobenzenesulfonyl)carbamic acid Degradation on soil Not reported Chlorsulfuron O-desmethylchlosulfuron Hydrolysis 10% 31 Chlorsulfuron O-desmethylchlosulfuron Soil photodegradation <10% 65 Chlorsulfuron Ring-opened chlorosulfuron Hydrolysis 16% 31 Chlorsulfuron Triazine Hydrolysis <10% 31 Chlorsulfuron Triazine amine Soil photodegradation <10% 65 Chlorsulfuron Triazine urea Soil photodegradation <10% 65 Clopyralid 1Dicamba 2 3,6-dichlorosalicylic acid // [3,6-DCSA] Aerobic soil metabolism ≤14.5% 365 Diflufenzopyr 2 1-(3,5-difluorophenyl)urea // [M4] Aerobic soil metabolism of phenyl labeled diflufenzopyr 5.82% 312 Diflufenzopyr 2 2-acetylnicotinic acid // [M6] Aqueous photolysis of pyridine labeled Diflufenzopyr >6.4% 20 Diflufenzopyr 2 2-acetylnicotinic acid // [M6] Dark control for aqueous photolysis experiments Not reported 20 

BLMVegetationTreatment Using Herbicides D-11 June 2007 

FinalProgrammaticEIS
TABLE D-4 (

Cont.) 

Degradates I

dentified for Active Ingre

dients 

Parent Com

pound Degrad

ate Name // [Synon

y

m] Mechanism 

of Production 

Estimated 

Proportion 

of Parent 

Produ

Tim

(Da

Diflufenzopyr 2 2-acetylnicotinic acid // [M6] Aerobic soil metabolism of pyridine labeled difl

ufenzopyr 4.25

% 312 

Diflufenzopyr 2 3,5-difl

uoroaniline // [M2] Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6% 20 

Diflufenzopyr 2 3,5-difl

uoroaniline // [M2] Dark control for aqueous photol

ysis e

x

peri

ments Not reported 20 

Diflufenzopyr 2 3,5-difl

uoroaniline // [M2] Aerobic soil metabolism of phenyl labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 7-methylfuro[3,4-b]p

yridin-5(7h)-one // 

[M24]

Aqueous p

hotolysis of pyridi

ne

labeled difl

ufenzopyr >6.4% 20 

Diflufenzopyr 2 8-methylp

yrido[2,3-d]pyridazin-5(6h)-one // 

[M1]

Aqueous p

hotolysis of pyridi

ne

labeled difl

ufenzopyr >6.4% 20 

Diflufenzopyr 2 8-methylp

yrido[2,3-d]pyridazin-5(6h)-one // 

[M1]

Dark control for aqueousphotol

ysis e

x

peri

ments Not reported 20 

Diflufenzopyr 2 8-methylp

yrido[2,3-d]pyridazin-5(6h)-one // 

[M1]

Aerobic soil metabolism ofpyridine labeled difl

ufenzopyr 1.9 - 13.15% 312 

Diflufenzopyr 2 8-meth

ylpyri

do[2,3-d]p

yridazine-2,5(1h,6

h)-

dione // [M9]

Aerobic soil metabolism ofpyridine labeled difl

ufenzopyr 26

% 312 

Diflufenzopyr 2

N-(3,5-difluorophenyl)-7-methyl-5-oxo-5,7-dihy

drofuro[3,4-b]pyridine-7-carboxamide //

[M23]

Aqueous p

hotolysis of pyridi

ne

labeled difl

ufenzopyr >6.4% 20 

Diflufenzopyr 2

N-(3,5-difluorophenyl)-7-methyl-5-oxo-5,7-dihy

drofuro[3,4-b]pyridine-7-carboxamide //

[M23]

Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6% 20 

Diflufenzopyr 2

N-(3,5-difluorophenyl)-7-methyl-5-oxo-5,7-dihy

drofuro[3,4-b]pyridine-7-carboxamide //

[M23]

Aerobic soil metabolism ofphenyl labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2

N-(3,5-difluorophenyl)-8-methyl-5-oxop

yrido[2,3-d]pyridazine-6(5H)-

carboxamide // [M5] 

Aerobic soil metabolism ofphenyl labeled difl

ufenzopyr 3.89

% 312 

Diflufenzopyr 2

N-(3,5-difluorophenyl)-8-methyl-5-oxop

yrido[2,3-d]pyridazine-6(5H)-

carboxamide // [M5] 

Aerobic soil metabolism ofpyridine labeled difl

ufenzopyr 3.22

% 312 

Diflufenzopyr 2 N-(3,5-difluorophenyl)hydrazinecarboxamide // [M7] Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6% 20 

BLM Vegetation Treatment Using Herbicides D-12 June 2007 

Final Programmatic EIS
BLM Vegetation Treatment Using Herbicides D-13 June 2007 

Final Programmatic EIS

TABLE D-4 (

Cont.) 

Degradates I

dentified for Active Ingre

dients 

Parent Com

pound Degrad

ate Name // [Synon

y

m] Mechanism 

of Production 

Estimated 

Proportion 

of Parent 

Produ

Tim

(Da

Diflufenzopyr 2 P1 Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6% 20 

Diflufenzopyr 2 P11 Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6% 20 

Diflufenzopyr 2 P2 Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6.4% 20 

Diflufenzopyr 2 P5 Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6.4% 20 

Diflufenzopyr 2 P9 Aqueous p

hotolysis of 

p

henyl

labeled difl

ufenzopyr >6% 20 

Diflufenzopyr 2 P9 Dark control for aqueous photol

ysis e

x

peri

ments Not reported 20 

Diflufenzopyr 2 PH1 Aerobic soil metabolism of phenyl labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PH2 Aerobic soil metabolism of phenyl labeled difl

ufenzopyr 4.02

% 312 

Diflufenzopyr 2 PH3 Aerobic soil metabolism of phenyl labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PH4 Aerobic soil metabolism of phenyl labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PH5 Aerobic soil metabolism of phenyl labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PY1 Aerobic soil metabolism of pyridine labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PY2 Aerobic soil metabolism of pyridine labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PY3 Aerobic soil metabolism of pyridine labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PY4 Aerobic soil metabolism of pyridine labeled difl

ufenzopyr <2% 312 

Diflufenzopyr 2 PY5 Aerobic soil metabolism of pyridine labeled difl

ufenzopyr <2% 312 

Diquat 1,2,3,4-tetrah

y

dro-1-o

xopyri

do (1,2-

a)pyrazin-5-i

u

m

Photodegradation in water 12% 74 
TABLE D-4 (Cont.) 

Degradates Identified for Active Ingredients 

Parent Compound Degradate Name // [Synonym] Mechanism of Production 

Estimated 

Proportion 

of Parent 

Produ

Tim

(Da

Diquat 1,2,3,4-tetrahydro-1-oxopyrido [1,2-a] -5- pyrazinium Photodegradation 

70% degradation of parent, major degradate along with picolinic acid

21 

Diquat Picolinic acid Photodegradation

70% degradation of parent, major degradate along with 1,2,3,4-tetrahydro-1-oxopyrido [1,2-a] -5-pyrazinium

21 

Diquat Unknown compound Anaerobic aquatic metabolism 5% 270 Diuron 3,3',4,4'-tetrachloroazobenzene // [TCAB] Photodegradation in soil Not reported 173 Diuron 3,4-dichloroaniline // [3,4-DCA] Hydrolysis 0.50% 30 Diuron CO2 and 13 minor polar products Photodegradation in water Each <9% 15 Diuron Dichloroaniline // [DCA] Photodegradation in soil Not reported 173 Diuron N'-(3,4-dichlorophenyl)-N-methylurea // [DCPMU] Photodegradation in soil Not reported 173 Fluridone 1-methyl-3-(4-hydroxyphenyl)-5-[3- (trifluoromethyl)phenyl]-4-(1h)-pyridinone

Fish tissue residue(bioconcentration factor: edible0.23; Inedible 4.16; whole body3.07) 

Not reported 

Fluridone 3-(trifluoromethyl)benzoic acid Aqueous photolysis distilled water 24% 27 Fluridone 3-(trifluoromethyl)benzoic acid Aqueous photolysis lake water 33% 21 Fluridone Benzoic acid Aqueous photolysis distilled water 11% 7 Fluridone Benzoic acid Aqueous photolysis distilled water 0.30% 27 Fluridone Benzoic acid Aqueous photolysis lake water 40% 21 

BLMVegetationTreatment Using Herbicides D-14 June 2007 

FinalProgrammaticEIS
BLM Vegetation Treatment Using Herbicides D-15 June 2007 

Final Programmatic EIS

TABLE D-4 (

Cont.) 

Degradates I

dentified for Active Ingre

dients 

Parent Com

pound Degrad

ate Name // [Synon

y

m] Mechanism 

of Production 

Estimated 

Proportion 

of Parent 

Produ

Tim

(Da

Fluridone N-methylformamide Aqueous photolysis distilled water 36

% 27 

Fluri

done N-meth

ylformamide Aqueous p

hotolysis lake water 74% 27 

Fluri

done No degradates detected at DL of 1 p

p

b Field application Not reported Not report

Fluri

done No degradates detected at DL of 2 p

p

b Field application Not reported Not report

Fluri

done No degradates detected at DL of 5 p

p

b Field application Not reported Not report

Fluri

done No specific degra

date i

nformation fo

und Not reported Not reported Not report

Fluridone Review article, no ad

ditional i

nformatio

n. Not reported Not reported Not report

Glyphosate Alp

haa

mino-3-hy

drox

y-5-

methyl-4-

iso

xazole

propionic acid Aerobic soil metabolism Major Not report

Glyphosate Alp

haa

mino-3-hy

drox

y-5-

methyl-4-

iso

xazole

propionic acid Anaero

bic aquatic 

metabolism Major Not report

Glyphosate Alp

haa

mino-3-hy

drox

y-5-

methyl-4-

iso

xazole

propionic acid Aerobic aquatic metabolism Major Not report

Hexazinone 3-(2-h

y

droxycyclohexyl)-6-(di

meth

yl-amino1-methyl-1,3,5-triazine-2,4(1H,3H)-dio

ne 

Aerobic aquatic metabolism <7% Not report

Hexazinone 3-(4-ket

ycyclohexyl)-6-(di

meth

ylamino)-1-

methyl-1,3,5-triazine-2,4(1H,3H)-dio

ne 

Aerobic aquatic metabolism <7% Not report

Hexazinone 3-(cyclohexyl-6-(methylamino)-1-methyl- 1,3,5-triazi

ne-2,4(1H,3H)-dione Aerobic aquatic metabolism <7% Not report

Hexazinone 3-(ketocyclohexyl)-6-(di

meth

ylamino)-1-

methyl-1,3,5-triazine-2,4(1H,3H)-dio

ne 

Aerobic soil metabolism 10.9% Not 

report

Hexazinone 3-(ketocyclohexyl)-6-(di

meth

ylamino)-1-

methyl-1,3,5-triazine-2,4(1H,3H)-dio

ne 

Anaero

bic aquatic 

metabolism 25% Not 

report

Hexazinone 3-cyclohex

yl-1-methyl-1,3,5-triazine-2,4,6-

(1H,3H,5

H)-trione Anaero

bic aquatic 

metabolism 24% Not 

report

Hexazinone 3-hy

drox

y-cyclohexyl-6-(dimethylamino)-1-

methyl-1,3,5-triazine-2,4(1

H-3H)-dio

ne 

Aerobic soil metabolism 18.7% Not Repor
TABLE D-4 (Cont.) 

Degradates Identified for Active Ingredients 

Parent Compound Degradate Name // [Synonym] Mechanism of Production 

Estimated 

Proportion 

of Parent 

Produ

Tim

(Da

Hexazinone 3-hydroxy-cyclohexyl-6-(dimethylamino)-1-

methyl-1,3,5-triazine-2,4(1H-3H)-dione Anaerobic aquatic metabolism 5.5% Not report

Hexazinone Metabolite B Aerobic soil metabolism 2.3% Not 

report

Hexazinone Metabolite D Aerobic soil metabolism 4.8% Not 

report

Imazapic 2-[(1-carbamoyl-1,2-dimethylpropyl) carbamoyl]-5-methyl-nicotinic acid Aqueous photolysis 41.3% <0.5Imazapic 2-carbamoyl-5-methyl-3-nicotinic acid Aqueous photolysis 44.3% <0.5 Imazapic 2-carbamoyl-5-methyl-nicotinic acid Aqueous photolysis 12.9% <0.5 Imazapic 4

3,5-pyridinedicarboxylic acid, 2-4(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)- // [CL 312622] 

Aerobic soil metabolism <10% Not 

report

Imazapic 5-methyl-2,3-pyridine dicarboxylic acid Aqueous photolysis 13% <0.5 Imazapic 5-methyl-3-pyridine carboxylic acid Aqueous photolysis 29.9% <0.5 Imazapic 4

Nicotinic acid, 5-hydroxy-6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)- // [CL354825] 

Aerobic soil metabolism <10% Not 

report

Imazapyr Nicotinic acid Aqueous photolysis Not reported 3 - 5 Imazapyr Pyridine dicarboxylic acid Aqueous photolysis Not reported 3 - 5 Imazapyr Pyridine hydroxy-dicarboxylic acid Aqueous photolysis Not reported 3 - 5 Metsulfuron methyl 5 (4-Methoxy-6-methyl-1,3,5-triazin-2-yl]urea

Only seen in one field study where material balance was highly variable

Not reported 

BLMVegetationTreatment Using Herbicides D-16 June 2007 

FinalProgrammaticEIS
BLM Vegetation Treatment Using Herbicides D-17 June 2007 

Final Programmatic EIS TABLE D-4 (

Cont.) 

Degradates I

dentified for Active Ingre

dients 

Parent Com

pound Degrad

ate Name // [Synon

y

m] Mechanism 

of Production 

Estimated 

Proportion 

of Parent 

Produc

Time (D

Metsulfuron methyl 5 1,2-benzisothiazol-3(2h)-one, 1,1-dioxide Not reported Not reported 3 - 198 Metsulfuron methyl 6 2-(aminosulfonyl)benzoic acid Not reported Not reported 22 Metsulfuron methyl 6

2-[[(aminocarbonyl)amino]sulfon

yl] benzoic 

acid, methyl ester Not reported Not reported 9 - 57 

Metsulfuron methyl 7

2-[[[[(4-methoxy-6-methyl-1,3,5-triazi

n-2-

yl)amino]carbonyl]amino]sulfon

yl]benzoic

acid 

Only see

n above 10% in one 

field study where material balance was highl

y variable

Not reported 

Metsulfuron methyl 6 4-methoxy-6-methyl-1,3,5-triazin-2-amine Not reported Not reported 22 - 39 Metsulfuron methyl 6 Meth

yl 2-(aminosulfonyl)be

nzoate Not reported Not reported 2 - 29 

Metsulfuron methyl 8

Meth

yl 2-[[[[(4-methoxy-6-methyl-1,3,5-

triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoate 

Not reported Not reported 11 - 38 

Metsulfuron methyl 9

Meth

yl 2-[[[[(4-methoxy-6-methyl-1,3,5-

triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoate 

Not reported Not reported 28 - 30 

Metsulfuron methyl 10

Methyl 2-[[[[[[(acetyla

mino)carbonyl]amino]carbonyl]

amino]carbonyl]amino]sulfonyl]benzoate 

O

nly seen i

n one field study 

where material balance was hi

g

hly variable

Not reported Not repo

Metsulfuron methyl 5

Methyl 2-[[[[[amino(aminocarbonyl)amino]

meth

yl]ami

no]carbonyl]amino]sulfonyl]benzoate

Not reported Not reported 16 - 53 

Picloram 4-amino-2,3,5-trichloro p

yridine Aerobic soil metabolism Minor Not repo

Picloram 4-amino-3,5--dichloro-2-

p

yridinol Aerobic soil metabolism Minor Not repo

Sulfometuronmethyl 5 1,2-benzisothiazol-3(2h)-one, 1,1-dioxide Not reported Not reported 3 - 198 
TABLE D-4 (

Cont.) 

Degradates I

dentified for Active Ingre

dients 

Parent Com

pound Degrad

ate Name // [Synon

y

m] Mechanism 

of Production 

Estimated 

Proportion 

of Parent 

Prod

Time 

Sulfometuronmethyl 2-(aminosulfonyl)benzoic acid Not reported Not reported Not reSulfometuronmethyl 6 2-(aminosulfonyl)benzoic acid Not reported Not reported 22 Sulfometuronmethyl 6

2-[[(aminocarbonyl)amino]sulfon

yl] benzoic 

acid, methyl ester Not reported Not reported 9 - 57 

Sulfometuronmethyl 6 4,6-di

meth

yl-2-pyrimidinamine Not reported Not reported 48 

Sulfometuronmethyl 5 4,6-di

meth

yl-2-pyrimidinol Not reported Not reported 312 

Sulfometuronmethyl 6 Meth

yl 2-(aminosulfonyl)be

nzoate Not reported Not reported 2 - 29 

Sulfometuronmethyl 8

Methyl 2-[[[[(4,6-dimethyl-2-pyri

midinyl)amino]carbonyl]amino]= 

sulfonyl]benzoate

Not reported Not reported 20 - 2

Sulfometuronmethyl 

Meth

yl-2-(amino-sulfonyl)benzoate Not reported Not reported Not re

Sulfometuronmethyl 

Meth

yl-2-[[(aminocarbonyl)amino]sulfonyl]

benzoate Not reported Not reported Not re

Sulfometuronmethyl Saccharin Not reported Not reported Not reTebuthiuron 5-(1,1-dimethyleth

yl)-2 amino-1,3,4-

thiadiazol // [Compou

n

d 108] Aerobic soil metabolism Not reported Not re

Tebuthiuron 5-(1,1-dimethyleth

yl)-2 amino-1,3,4-

thiadiazol // [Compou

n

d 108] Aerobic aquatic metabolism Sum of 5 products = 4.8% 28 

Tebuthiuron 5-(1,1-dimethyleth

yl)-2 meth

ylamino-1,3,4-

thiadiazol // [Compou

n

d 107] Aerobic soil metabolism Not reported Not re

Tebuthiuron 5-(1,1-dimethyleth

yl)-2 meth

ylamino-1,3,4-

thiadiazol // [Compou

n

d 107] Aerobic aquatic metabolism Sum of 5 products = 4.8% 28 

BLM Vegetation Treatment Using Herbicides D-18 June 2007 

Final Programmatic EIS
TABLE D-4 (

Cont.) 

Degradates I

dentified for Active Ingre

dients 

Parent Com

pound Degrad

ate Name // [Synon

y

m] Mechanism 

of Production 

Estimated 

Proportion 

of Parent 

Prod

Time 

Tebuthiuron

N-[5-(1,1-di

meth

ylethyl)-1,3,4-thiadiazol-2-

y1]-

N-methylN'-hydroxymet

h

yl-urea // 

[Compou

n

d 109]

Anaero

bic soil metabolis

m

Sum of 3 products = 4.7% 60 

Tebuthiuron

N-[5-(1,1-di

meth

ylethyl)-1,3,4-thiadiazol-2-

y1]-

N-methylN'-hydroxymet

h

yl-urea // 

[Compou

n

d 109]

Aerobic aquatic metabolism Sum of 5 products = 4.8% 28 

Tebuthiuron N-[5-1(1,1-dimethylethyl)-1,3,4-thiadiazol-2-

y1]-N'-methylurea // [Compound 105] Aerobic soil metabolism Not reported Not re

Tebuthiuron N-[5-1(1,1-dimethylethyl)-1,3,4-thiadiazol-2-

y1]-N'-methylurea // [Compound 105] Anaero

bic soil metabolis

m

Sum of 3 products = 4.7% 60 

Tebuthiuron N-[5-1(1,1-dimethylethyl)-1,3,4-thiadiazol-2-

y1]-N'-methylurea // [Compound 105] Aerobic aquatic metabolism Sum of 5 products = 4.8% 28 

Tebuthiuron N-[5-1(1,1-dimethylethyl)-1,3,4-thiadiazol-2-

y1]-N-meth

ylurea // [Compound 104] Aerobic soil metabolism 6.9 270 

Tebuthiuron N-[5-1(1,1-dimethylethyl)-1,3,4-thiadiazol-2-

y1]-N-meth

ylurea // [Compound 104] Anaero

bic soil metabolis

m

Sum of 3 products = 4.7% 60 

Tebuthiuron N-[5-1(1,1-dimethylethyl)-1,3,4-thiadiazol-2-

y1]-N-meth

ylurea // [Compound 104] Aerobic aquatic metabolism Sum of 5 products = 4.8% 28 

Triclopyr Oxamic acid Photodegradation in water 16% 0.7 - 1Triclo

p

yr 3 (5/6)-chloro-3-h

y

drox

y-s-pyridi

none Photodegradation in water 17% 30 

Triclo

p

yr 3 3,5,6-trichloro-2-methoxypyridine // [TM

P] Aerobic soil metabolism 8% <30 

Triclo

p

yr 3 3,5,6-trichloro-2-pyridinol // [T

C

P] Aerobic soil metabolism 26% <30 

Triclo

p

yr 3 3,5,6-trichloro-2-pyridinol // [T

C

P] Aerobic aquatic metabolism <5% 30 

Triclo

p

yr 3 5-c

hloro-3,6-dih

y

drox

y-2-pyridinyloxyacetic

acid Photodegradation in water 48% 0.7 - 1

Triclo

p

yr 3 At least 15 non-volatile co

mpounds (not

identified) Photodegradation in water 10% total 30 

Triclo

p

yr 3 Dichloropyridinyloxyacetic acid, 2hydrox

y

ethyl ester Photodegradation in water 6% 30 

Triclo

p

yr 3 Organic volatiles Photodegradation in water 1.6% total 30 

BLM Vegetation Treatment Using Herbicides D-19 June 2007 

Final Programmatic EIS
TABLE D-4 (Cont.) 

Degradates Identified for Active Ingredients 

1 The BLM has discussed the formation and identification of clopyralid degradates with the herbicide’s manufacturer, D

AgroSciences has performed relevant tests of environmental degradation in aerobic soils using radio-labeled clopyralid. Thstudies was that clopyralid in aerobic soils had a short half life (i.e., 8 days) and that mineralization to carbon dioxide was with this finding, 74% of the applied radio label was found as carbon dioxide. Less than 10% of the applied parent was foupolar daughter compounds. No degradate was present at more than 8% of the parent compound’s mass. Nonextractable, bwith humic and fulvic acid fractions represented as much as 8% of applied radio-labeled material. Gdegradates, characterization was not attempted, consistent with USEPA guidelines. 

2 Diflufenzopyr and dicamba are the active ingredients in the herbicide Overdrive®, which was evaluated by the BLM. 7 Effects on morning glory observed at highest tested concentration (0.05 kg/ha). No effects observed on other plants. 6 No plant toxicity observed at highest concentration tested (2.0 kg/hectare [ha]). 9 Some effects observed on plants at highest concentration tested (0.05 kg/ha). 10 No plant toxicity observed at highest concentration tested (0.1 kg/ha). 4 Not toxic, rat LD50 oral >2,000 mg/kg. 5 Not tested. Not considered herbicidal. 3 Also includes triclopyr acid. 8 Herbicidal. 

BLMVegetationTreatment Using Herbicides D-20 June 2007 

FinalProgrammaticEIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-1a

Aquatic Toxicity – 2,4-D Toxicity Reference Values and Degradate Toxicity Data 

var. unicellular algae NR 

NOEC

crayfish 7 d LC100

crayfish 10 d NR

goldfish 5 h LC50

goldfish 96 h LC50

goldfish 8 h LC50

green algae 48 h NR

water flea 7 d LC50

flagellate euglenoid 72 h NR

duckweed 72 h LC50

duckweed 10 d NR

blue-green algae NR LOEC

green algae 4 h EC50

green algae 7 d NR

green algae 48 h EC50

ciliate 46 h EC50

green algae 72 h NR

green algae 120 mi NR

crayfish 90 mi NR

fathead minnow 2.5 h NR

midge 24 h NR

green sunfish acute NOEC

bluegill chr. NOEC

bullfrog acute LC50

var. aq. invert acute NOEC

var. aq. invert chr. NOEC

var. aq. macrophytes NR 

EC50

crayfish 48 h LC100

water flea 48 h LC50 water flea 24 h LC50

0.0001

0.001

0.01

0.1

1

10

100

1000

10000

2,4-D 2,4-Dichlorophenol

log c

oncentration (mg/L)

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

NR indicates duration or endpoint not reported.

BLM Vegetation Treatments Using Herbicides D-21 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-1b

Aquatic Toxicity – 2,4-D Toxicity Reference Values and Degradate Toxicity Data 

bullfrog acute LC50

rotifer 48 h EC50

rotifer 48 h NOEC

goldfish 5 h NR

goldfish 2.5 h LC50

goldfish 5 h LC50

goldfish 23 mi LT50

goldfish 26 mi LT50

green algae 2 h NR

sand shrimp 96 h LC50

water flea 24 h EC50

water flea 21 d NOEC

water flea 48 h EC50

water flea 21 d NOEC

hydra 6 d LOEC

hydra 6 d LOEC

duckweed 72 h LC50

rainbow trout 85 d LOEC

green algae 96 h EC50

scud 10 d NR

green sunfish acute NOEC

bluegill chr. NOEC

var. aq. invert acute NOEC

var. aq. invert chr. NOEC

var. unicellular algae NR 

NOEC

var. aq. macrophytes NR 

EC50

water flea 24 h EC50

water flea 24 h EC50

hydra 2 h EC50

guppy 96 h LC50

green algae 72 h EC50

water flea 96 h NR

0.0001

0.001

0.01

0.1

1

10

100

1000

2,4-D 4-Chlorophenol

log concentrati

on (mg/L)

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

NR indicates duration or endpoint not reported.

BLM Vegetation Treatments Using Herbicides D-22 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-2 

Aquatic Toxicity – Diquat Toxicity Reference Values and Degradate Toxicity Data 

duckweed 14 d NOAEL

duckweed 14 d EC50

duckweed life cycle NOAEL

amphipod 48 h EC50

walleye 96 h LC50

frog 16 d NOAEL

rainbow trout 96 h LC50

striped barnacle 24 h LOEC

ciliate 60 h EC50

rainbow trout NR NOAEL

fathead minnow 34 d NOAEL

0.0001

0.001

0.01

0.1

1

10

100

1000

Diquat 2-Pyridinecarboxylic acid *

log concentration (

mg/L)

* Synonym for picolinic acid

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

NR indicates duration or endpoint not reported.

BLM Vegetation Treatments Using Herbicides D-23 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-3a

Aquatic Toxicity – Diuron Toxicity Reference Values and Degradate Toxicity Data 

scud 96 h EC50

green algae NR EC50

daphnid 28 d NOAEL

green algae 96 h NOAEL

bullfrog 21 d NOAEL

bluegill 96 h LC50

cutthroat trout 96 h NOAEL

scud ~24 h ET50

scud ~24 h ET50

scud ~24 h ET50

scud NR ET50

scud ~24 h ET50

cutthroat trout 96 h LC50 scud 24 h NOEC

fathead minnow chr. NOAEL

bullfrog 21 d LC50

fathead minnow chr. NOAEL

rotifer 24 h LC50

scud 24 h LOEC

rainbow trout 48 h LC0

rainbow trout-48 h LC100

medaka-28 d NR

0.0001

0.001

0.01

0.1

1

10

100

Diuron Dichloroaniline Bis(3,4-

dichlorophenyl)diazene*

log c

oncentration (mg/L)

* Synonym for 3,3',4,4'-Tetrachloroazoxybenzene

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

NR indicates duration or endpoint not reported.

BLM Vegetation Treatments Using Herbicides D-24 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-3b

Aquatic Toxicity – Diuron Toxicity Reference Values and Degradate Toxicity Data 

scud 96 h EC50

green algae NR EC50

daphnid 28 d NOAEL

fathead minnow chr. NOAEL

green algae 96 h NOAEL

bullfrog 21 d NOAEL

bluegill 96 h LC50

cutthroat trout NOAEL

aquatic sowbug 19 d MATC

copepod 5 d EC50

ciliate 96 h NOEC

pond snail 16 d EC50

pond snail 48 h LC50

green algae 4 d EC50

green algae 7 d NOEC

green algae 24 h EC50

green algae 72 h EC50

mayfly 28 d MATC

rainbow trout 24 h NOEC

rainbow trout 18 d MATC

rainbow trout 28 d NOEC

rotifer 5 mi EC50

rotifer 300 mi EC50

water flea 21 d LOEC

water flea 42 d LOEC

water flea 48 h LC50

zebra danio 42 d LOEC

cutthroat trout 96 h LC50

bullfrog 21 d LC50

fathead minnow chr. NOAEL

green algae 24 h NOEC

guppy 14 d LOEC

mayfly 28 d LOEC

perch 6.6 d LT50

rotifer 30 mi EC50

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

10

100

1000

Diuron 3,4-Dichlorobenzenamine *

log concentrati

on (mg/L)

* Synonym for 3,4-dichloroaniline

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

BLM Vegetation Treatments Using Herbicides D-25 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-4 

Aquatic Toxicity – Fluridone Toxicity Reference Values and Degradate Toxicity Data 

midge 30 d NOAEL

channel catfish 96 h LC50

blue-green algae 14 d EC50

blue-green algae 3 h EC50

blue-green algae 5 h EC50

blue-green algae 5 h EC50

blue-green algae 3 h EC50

water flea 24 h EC0

water flea 24 h EC100

water flea 48 h NR

water flea 24 h NR

bluegill 96 h LC0

green algae NR LOEC

midge 48 h LC50

pondweed 37 d EC50

pondweed 37 d NOAEL

fathead minnow life cycle 

NOAEL

rainbow trout 96 h LC50

rainbow trout 96 h NOAEL

goldfish 0.48 h LT50

water flea 24 h EC50

clawed toad 96 h EC50

clawed toad 96 h LC50

zebra mussel 48 h NR

0.0001

0.001

0.01

0.1

1

10

100

1000

10000

Fluridone Benzoic acid

log concentration (mg/L)

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

BLM Vegetation Treatments Using Herbicides D-26 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-5 

Aquatic Toxicity – Imazapyr Toxicity Reference Values and Degradate Toxicity Data 

silver barb acute/chr. LC50

ciliate 60 h EC50

northern squawfish 24 h NR

var. fish species acute NOEC

fathead minnow chr. NOEC water flea acute NOEC

water flea chronic NOEC

green algae acute/chr. EC50

green algae acute/chr. NOEC

duckweed acute/chr. EC25

chinook salmon 24 h NR coho salmon 24 h NR

northern squawfish 24 h NR rainbow trout 24 h NR

0.001

0.01

0.1

1

10

100

1000

10000

Imazapyr 3-Pyridinecarboxylic acid *

log concentration (mg/L)

* Synonym for nicotinic acid

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

NR indicates duration or endpoint not reported.

BLM Vegetation Treatments Using Herbicides D-27 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

FIGURE D-6

Aquatic Toxicity – Metsulfuron Methyl Toxicity Reference Values and Degradate Toxicity Data 

rainbow trout acute NOEC

rainbow trout chr. NOEC

bluegill chr. NOEC

green algae NR NOEC

duckweed acute NOEC

protozoan 35 h NR

bluegill acute NOEC

water flea acute NOEC

water flea chr. NOEC

green algae NR NOEC

0.0001

0.001

0.01

0.1

1

10

100

1000

10000

Metsulfuron methyl 1,2-Benzisothiazol-3-(2H)-one, 1,1-Dioxide

log concentration (

mg/L)

clawed toad-96 h EC50

(0.01289 - 0.0189; N=21)

clawed toad-96 h LC50

(0.01303 - 0.01867;

N=20)

clawed toad-96 h LOEC

(0.013 - 0.019; N=7)

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.

NR indicates duration or endpoint not reported.

BLM Vegetation Treatments Using Herbicides D-28 June 2007 

Final Programmatic EIS
DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

BL

Final Pr

M Vegetation Treatments Using Herbicides D-29 June 2007 

ogrammatic EIS

FIGURE D-7

Aquatic Toxicity – Triclopyr Toxicity Reference Values and Degradate Toxicity Data 

fathead minnow acute LD50

1000

mayfly acute LC50

algae acute/chr. NOEC

pink salmon 96 h LC50

fathead minnow chr. NOEC

water flea chr. NOEC

coho salmon 96 h LC50 chum salmon 96 h LC50

rainbow trout 96 h LC50

rainbow trout 96 h LC50

chinook salmon 96 h LC50

0.1

1

10

100

Triclopyr 3,5,6-Trichloro-2(1H)-pyridinone *

log concentration (mg/L)

Note: 

Same LC50 values observed

at 24, 48, and 72 hours

* Synonym for 3,5,6-trichloro-2-pyridinol

Label represents test organism, test duration, and endpoint.

Not all test organism names listed due to lack of space.
TABLE D-5

Listings of Endocrine Disrupting Potential of BLM Herbicides 

Herbicide 

Benbrook

List 

Colborn

List 

Endocrine

Disruptor

Knowledge Base 

(EDKB)1

European

Priority List2

Fluoride 

Action Net

Pesticide 

Project3

Illinois 

EPA List 

Keith 

List 

Na

Insti

Enviro

St

2,4-D Yes Yes

Not an active 

estrogen receptor 

binder 

Category 2 NL Probable Yes L

Bromacil NL NL No Data NL NL NL NL NChlorsulfuron NL NL No Data NL NL NL NL NClopyralid NL NL No Data NL NL NL NL NDicamba NL NL No Data NL NL NL NL NDiflufenzopyr NL NL No Data NL NL NL NL NDiquat NL NL No Data NL NL NL NL NDiuron NL NL No Data Category 2 NL NL NL NFluridone NL NL No Data NL NL NL NL NGlyphosate NL NL No Data NL NL NL NL NHexazinone NL NL No Data NL NL NL NL NImazapic NL NL No Data NL NL NL NL NImazapyr NL NL No Data NL NL NL NL NMetsulfuron methyl NL NL No Data NL NL NL NL NPicloram NL NL No Data NL NL NL NL NSulfometuron methyl NL NL No Data NL NL NL NL NTebuthiuron NL NL No Data NL NL NL NL NTriclopyr NL NL No Data NL NL NL NL N

BLMVegetationTreatment Using Herbicides D-30 June 2007 

FinalProgrammaticEIS
TABLE D-5 (Cont.) 

Listings of Endocrine Disrupting Potential of BLM Herbicides

1 Endocrine Disruptor Knowledge Base (EDKB) is a database of endocrine disruption effects reported in scientific literature and 

disruptors. 

2 Category 2 = Evidence of potential to cause endocrine disruption. 3 Only lists fluorinated/fluoride pesticides. 

NL = Not listed. Benbrook List = Benbrook, C.M. 1996. Growing Doubt: A Primer on Pesticides Identified as Endocrine Disruptors and/or Rep

National Campaign for Pesticide Policy Reform. Washington, D.C. Colborn List = Colborn, T., D. Dumanoski, and J.P. Myers. 2006. Our Stolen Future: A List of Endocrine-disrupting Com

2, 2007. Available at: http://www.ourstolenfuture.org/Basics/chemlist.htm. 

Endocrine Disruptor Knowledge Base (EDKB). 2006. U.S. Food and Drug Administration’s National Center for ToxicologicaMay 2, 2007. Available at: http://edkb.fda.gov/webstart/edkb/index.html. 

European Priority List = European Commission Directorate-General for the Environment. 2000. Towards the Establishment 

Substances for Further Evaluation of Their Role in Endocrine Disruption. BKH Consulting Engineers and TNO Nutrition and FoMay 2, 2007. Available at: http://ec.europa.eu/environment/docum/01262_en.htm. 

Fluoride Action Net Pesticide Project = Fluoride Action Network. ND. Suspected Endocrine Disruptors: Fluorinated & Fluorid

May 2, 2007. Available at: http://www.fluoridealert.org/pesticides/effects.suspected.endocrine.htm. 

Illinois EPA List = Illinois EPA. 1997. Endocrine Disruptors Strategy. (Table 1: Preliminary List of Chemicals Associated with Effects in Animals and Humans or In Vitro). Springfield, Illinois. Keith List = Keith, L.H. 1997. Environmental Endocrine Disruptors: A Handbook of Property Data. Wiley Interscience. New Y

National Institute for Environmental Studies: Ministry of the Environment of Japan. 2004. Endocrine Disrupting ChemicalJune 2006. Pesticide Action Network. 2005. Pesticide Action Network Pesticides Database. Accessed June 2006. Available at: 

http://docs.pesticideinfo.org/Index.html.

BLMVegetationTreatment Using Herbicides D-31 June 2007 

FinalProgrammaticEIS

DEGRADATES, POEA, AND ENDOCRINE DISRUPTORS

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