Page 2 of 12

into terrestrial and aquatic environments. DHMP is slightly toxic to avian species on an 

acute oral basis and practically nontoxic to avian species on subacute dietary basis; 

practically non-toxic to mammals on an acute oral basis; practically nontoxic to slightly 

toxic to freshwater fish; and slightly toxic to aquatic invertebrates. For the ecological 

risk assessment, including an endangered species assessment for all uses, the Agency 

requires needing the algal toxicity data.

Introduction

1H-Pyrazole-1-methanol, 3,5-dimethy (Busan 1104) is also known as 

dimethyl1hydroxymethylpyrazole (DMHMP). DMHMP technical (93%) is a white solid 

granule with no odor, is highly soluble in water (49.4 g/l) and has a vapor pressure of 

2.55 x 10-3 mm Hg at 20°C. The first product containing DMHMP as an active 

ingredient was registered in the United States in 1996 for use as a material preservative. 

Currently there is only one end-use product registered with DMHMP as an active 

ingredient for the material preservative uses listed in Table 1. The product is registered

for use as a preservative for emulsion paints, adhesives, latex emulsions, liquid polishes 

and waxes, detergents, paper making chemicals and coating. A Reregistration Eligibility 

Decision (RED) has not been issued by EPA for DMHMP because the initial registration 

date was after the November 1984, the mandated cutoff for initiation of the RED process.

Table 1. Registered Product of DMHMP

Registration

No.

Registration

Name

Company

Name

Formulation

Type

% of Active

Ingredient

1448-351 BUSAN 1104 Buckman 

Laboratories Inc.

Ready-to-Use 

Solution 93

EPA Reg. No. 1448-351

BUSAN 1104

BUSAN is a registered trademark.

Active Ingredient:

IH-Pyrazole-1 -methanol, 3,5-dimethyl...93%

Busan 1104 is a preservative that is effective for the protection of emulsion paints, 

adhesives, latex emulsions, and liquid polishes and waxes.

EMULSION PAINTS: For in-can preservation of emulsion paints, including acrylic, 

butadiene-stryene and PVA paints, add 0.025 to 0.4% (250 to 4,000 ppm) Busan 1104 

based on the total weight of the formulation. The preservative can be added to the paint 

or any aqueous raw materials incorporated into the paint.

ADHESIVES: To protect adhesives, including natural gums, natural latex, PVA 

emulsions, synthetic gums, starched based adhesives (including non-converted tapioca, 

corn, and potato starches) and animal glues (including those derived from hide, bone, 
Page 3 of 12

fish, blood or gelatin) or other adhesives, add 0.05 to 0.4% Busan 1104 based on the total 

weight of the formulation.

LATEX EMULSIONS: For the preservation of styrene-butadiene, PVA, acrylic and 

vinyl chloride, or other latex emulsions, add 0.02 to 0.3% Busan 1104 based on the total 

weight of the emulsion.

POLISHES AND WAXES: To preserve water-based polishes and waxes in-can during 

storage, add 0.02 to 0.3% Busan 1104 based on the total weight of the product.

PAPERMAKING CHEMICALS AND COATINGS: To control the bacterial 

degradation of paper coatings, size press solutions, wet-end starch slurries, wet-end 

cooked starch, and other formulations used in papermaking, add 0.05 to 0.4% (500 to 

4,000 ppm) Busan 1104 based on the total weight of the formulation. For pigment slurries

(including clay, titanium dioxide, and calcium carbonate based slurries) add 0.03 to 0.3% 

(300 to 3,000 ppm) Busan 1104 based on the total weight of the formulation.

DETERGENTS: To prevent bacterial degradation during storage and to increase shelf 

life of biodegradable surfactants, add 0.05 to 0.5% (500 to 5,000 ppm) Busan 1104 by 

weight of the formulation.

The Agency has conducted a review of the available product chemistry, 

environmental fate, and ecotoxicity data for DMHMP. The findings are summarized

below.

A. Product Chemistry Summary of DMHMP (93% TGAI)

Common Name: 1H-Pyrazole-1-methanol, 3,5-dimethyl-l;

Chemical Name: 3,5-Dimethyl-1-(hydroxymethyl)pyrazole

3,5-Dimethyl-1-hydroxymethylpyrazole (DMHMP)

3,5-Dimethylpyrazole-1-methanol

3,5-Dimethyl-1H-pyrazole-1-carbinol

Trade and Other Names: BL-1104; DMHMP

IUPAC Name: (3,5-dimethyl-1H-pyrazol-1-yl)methanol

OPP Chemical Code: 129074

CAS Registry Number: 85264-33-1

Case: 5035

Chemical Family: Pyrazole

Alcohol

Molecular Formula: C6H10N2O

Molecular weight: 126.1582 g/mole

Molecular Structure:
Page 4 of 12

Color: White

Physical State: Solid, granular

Odor: None

Stability: Stable (to heat)

Sensitive to sunlight & metal ions.

This material is stable if stored under proper 

conditions..

Reactive with oxidizing agents.

Oxidation/Reduction: Not an oxidizer or reducing agent. Do not contain 

oxidizing or reducing agents.

Flammability: Not applicable for products which do not contain 

combustible liquids.

Flash Point: 87.3°C (>212 °F)

Explodability: Contains no explosive ingredients.

Storage Stability: Stable: 3 month sample shows no degradation

Accelerated storage stability (thermal stability) 

shows no degradation.

Miscibility: Not applicable for products not intended to be 

diluted with petroleum solvents.

Corrosion Characteristics: Not corrosive to packaging material. No corrosion 

of metals.

Dielectric breakdown voltage: Not applicable for products not intended to be used 

around electrical equipment

pH: Not applicable for solids.

UV/Visible absorption: Not Reported.

Viscosity: Not applicable for solid products.

Melting point: 77 °C (sublimes)
Page 5 of 12

Boiling Point: Not applicable.

Density: 1.183 g/cc

Dissociation Constant: pK = 11.4

Log Ko/w: 0.9294

Solubilities: 49.4 g/l

Fat Solubility: 14.3 g/kg (± 18% dependent on 

temp. & stirring).

Vapor Pressure: 3.4 x 10-3 hPa at 20°C

2.55 x 10-3 mm Hg (0.00255 mm Hg)

Henry's Law Constant: 3.586E-008 atm-m3/mole (Source: EPI Suite)

Enforcement Analytical

Method: HPLC (uses UV detection system)

Estimated Koc: 22.34 L/kg (Source: EPI Suite)

All product chemistry data requirements have been satisfied for the active 

ingredients DMHMP. (Source: MRIDs 41832501 to -04).

B. Environmental Fate Summary

No risk assessment was performed for DMHMP at the time of the registration.

The Agency has since reviewed two environmental fate studies for DMHMP, as 

summarized in Table 2. The Agency's conclusions for the degradation, studies are as 

follows.

Degradation Studies (Abiotic)

a. Hydrolysis 

Does not hydrolyze in aqueous buffered pH 5, 7, 9 solutions that were incubated 

in darkness at 25°C for 30 days. The study is acceptable (MRID No. 41831301).

b.Photodegradation in water

Does not photodegrade in aqueous buffered pH 5 solution but appeared to have 

photodegraded slightly in buffered pH 7 and 9 solutions during 30 days of 12 

hour/day irradiation with a xenon light at 25°C. Slightly degrades in pH of 7 & 9 

(MRID Nos. 41831302 & 42363901).
Page 6 of 12

Table 2. Environmental Fate Data Summary for DMHMP

OPP Guideline Fate Studies Half-Life Degradates Study Status

161-1

Hydrolysis

(30 days at 25°C)

pH 5

pH 7

pH 9

Stable

Stable

Stable

None

None

None

Acceptable

MRID 41831301

161-2

Aqueous Photolysis

(30 days at 25°C)

pH 5

pH 7

pH 9

Stable

Slightly degrades

Slightly degrades

None

None

None

Acceptable

MRIDs 41831302

42363901

The Agency did not conduct an environmental fate assessment for DMHMP

because of lack of data. However, the Agency needs to conduct an environmental fate 

assessment for material preservatives (including DMHMP) that may potentially pass 

through waste water treatment plants (WWTPs) and may be discharged into terrestrial 

and aquatic environments. For this assessment the Agency anticipates needing those data 

outlined on page 9 of this document.

Water Quality

DMHMP is not identified as a cause of impairment for any water bodies listed as 

impaired under section 303(d) of the Clean Water Act, based on information provided at 

the Agency’s National Pesticides Cause of Impairment of Waters website (searched April 

7, 2011)1. In addition, no Total Maximum Daily Loads (TMDL) have been developed 

for DMHMP, based on information provided at the Agency’s National Pesticide TMDL 

web site (searched April 7, 2011)2

http://www.epa.gov/owow/tmdl/

. More information on impaired water bodies and 

TMDLs can be found at . The Agency invites 

submission of water quality data for this pesticide. To the extent possible, data should 

conform to the quality standards in Appendix A of the OPP Standard Operating 

Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s 

Registration Review Risk Assessment and Management Process (see: 

http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1-sop.pdf ), in order to 

ensure they can be used quantitatively or qualitatively in pesticide risk assessments.

C. Ecological Effects Summary

No ecological risk assessment was performed for DMHMP at the time of the 

registration. Available ecotoxicity guideline studies and the results are summarized in 

 1 . http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885 2

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_p

ollutant_group_name=PESTICIDES
Page 7 of 12

Table 2. The Agency's conclusions for the terrestrial and aquatic effects studies are as 

follows.

a. Toxicity to Terrestrial Animals

Birds, Acute and Subacute

DMHMP is slightly toxic to avian species on an acute oral basis (LD50 759 

mg/kg) and practically nontoxic to avian species on subacute dietary basis

(LC50 >5620 ppm).

Toxicity to Mammals

DMHMP is practically non-toxic to mammals on an acute oral basis.

There is currently no 2-generation rat reproduction study but in the human 

health scoping document it has been identified as a data gap.

b. Toxicity to Aquatic Animals

Freshwater Fish and Invertebrates

DMHMP is practically nontoxic to rainbow trout (LC50 123 ppm), slightly 

toxic to bluegill sunfish (LC50 78 ppm) and slightly toxic to aquatic 

invertebrates (EC50 31.7 ppm).

c. Toxicity to Aquatic Plants

Freshwater Algae

No algal toxicity data have been submitted. For the ecological risk 

assessment, including an endangered species assessment for all uses, the 

Agency anticipates needing the algal toxicity data outlined on page 9 of 

this document.

Table 3. Ecotoxicity Data Summary for DMHMP

MRID No GUIDE

LINE

COMMON

NAME

TAXONOMIC

NAME

TEST

TYPE

% 

AI

STUDY

TIME

DOSE

TYPE

TOXI

CITY

TOX

LEVEL NOEL STUDY STATUS

TOX 

CATEGORY

Avian Acute Oral Toxicity

41832201 850.2200

(71-1)

Bobwhite 

quail

Colinus 

virginianus

O 99 14 day LD50 759 mgk 292 Acceptable Slightly 

toxic

Avian Subacute Dietary Toxicity

41832001 850.2200

(71-2a)

Mallard 

duck

Anas 

platyrhynchos

D 99 8 day LC50 >5620 ppm 1000 Acceptable Practically 

nontoxic

41832002 850.2200

(71-2b)

Bobwhite 

quail

Colinus 

virginianus

D 99 8 day LC50 >5620 ppm 3160 Acceptable Practically 

nontoxic
Page 8 of 12

MRID No GUIDE

LINE

COMMON

NAME

TAXONOMIC

NAME

TEST

TYPE

% 

AI

STUDY

TIME

DOSE

TYPE

TOXI

CITY

TOX

LEVEL NOEL STUDY STATUS

TOX 

CATEGORY

Freshwater Fish Acute Toxicity

41832302 850.1075

(72-1)

Rainbow 

trout

Oncorhynchus 

mykiss

S 99 96 hr LC50 123 ppm 56.6 Acceptable Practically 

nontoxic

41832301 850.1075

(72-1)

Bluegill 

sunfish

Lepomis 

macrochirus

S 99 96 hr LC50 78 ppm 34.5 Acceptable Slightly 

toxic

Freshwater Invertebrate Acute Toxicity

41832303 850.1010

(72-2)

Water 

flea

Daphnia 

magna

S 99 48 hr EC50 31.7 ppm 24 Acceptable Slightly 

toxic

 Mammalian Acute Oral Toxicity

41832101 81-1 Rat ----- ----- --- ----- LD50 2600 mg/kgbw ----- Acceptable Practically 

non- toxic 

III

Test Type—O: oral; D: dietary; S: static.

Tox Level—mgk: milligrams per kilogram-body weight; ppm: parts per million (equivalent to milligrams per kilogram-diet (mg/kg-diet) for 

dietary exposure and milligrams per liter (mg/L) for aquatic exposures)

Categories of acute toxicity for aquatic organisms (U.S. EPA, 2004) based on EC50/LC50(mg/L): < 0. 1 very highly toxic; 0.1-1 highly toxic; 

>1-10 moderately toxic; >10-100 slightly toxic; >100 practically nontoxic.

Categories of acute toxicity to terrestrial animals, avian and mammalian (U.S. EPA, 2004). LC50 (ppm): < 50 very highly toxic; 50 - 500 

highly toxic; 501 – 1000 moderately toxic; 1001-5000 slightly toxic; >5000 practically non-toxic. LD50 (mg/kg bw): < 10 very highly toxic; 

10 - 50 highly toxic; 51 - 500 moderately toxic; 501-2000 slightly toxic; >2000 practically non-toxic.

Adverse Ecological Incidents

There are no reported incidents in the Agency's Ecological Incident Information 

System (EIIS) regarding DMHMP. The absence of documented incidents does not 

necessarily mean that such incidents did not occur.

Ecological Effects Risk Assessment

An ecological risk assessment was not conducted on the DMHMP’s use patterns 

described in this document. DMHMP uses that have potential for environmental 

exposure are material preservatives discharges. The Agency needs to conduct 

environmental fate and ecological risk assessments for material preservatives that 

potentially pass through waste water treatment plants (WWTPs) and may be discharged 

into terrestrial and aquatic environments. For this ecological risk assessment, including 

an endangered species assessment for all uses, the Agency anticipates needing the algal 

toxicity data outlined on page 9 of this document.

The Agency has not conducted a risk assessment for DMHMP that supports a 

complete endangered species effects determination. The ecological risk assessment 

planned during registration review will allow the Agency to determine whether 1HPyrazole-1-methanol, 3,5-dimethyl-’s use has “no effect or “may affect” federally listed 

threatened or endangered species (listed species) or their designed critical habitats. When 

an assessment concludes that a pesticide’s use “may affect” a listed species or its 

designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife 

Service and/or National Marine Fisheries Services (the Services), as appropriate.
Page 9 of 12

Environmental Fate and Ecotoxicity Data Gaps and Anticipated Work

Environmental fate and ecological risk assessments have not been conducted for 

DMHMP. The Agency needs to conduct environmental fate and ecological risk 

assessments for material preservatives that potentially pass through waste water treatment 

plants (WWTPs) and may be discharged into terrestrial and aquatic environments. 

Therefore, the Agency anticipates needing the proposed environmental fate and 

ecotoxicity data for DMHMP and/or any of its major degradation products that are of 

potential concern for all registered uses of DMHMP. The following environmental fate 

and ecotoxicity data are needed to conduct an environmental fate and ecological risk 

assessment:

• The Agency anticipates needing the following data to conduct a complete 

environmental fate assessment for material preservative uses:

o (GLN 850.6800) Modified Activated Sludge Respiration Inhibition;

o (GLN 835.3110) Ready biodegradability, (GLN 835.3220) Porous Pot 

Test, or (GLN 835.3280) Simulation Tests to Assess the Biodegradability 

of Chemicals Discharged to Wastewater3

.

• The Agency anticipates needing the following algal toxicity data in order to 

conduct a complete ecological risk assessment, including an endangered 

species assessment:

o (GLN 850.5400) Algal toxicity (Tier II) using freshwater green alga, 

Selenastrum capricornutum.

 3 The results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which of these 

biodegradation tests are required. If the ASRI test EC50 is less than or equal to 20 mg/L, then either the 

Biodegradation in Activated Sludge Study or the Porous Pot Test is required. If the ASRI test EC50 is 

greater than 20 mg/L, then the applicant must choose either: (i) Ready Biodegradability or (ii) 

Biodegradation in Activated Sludge or the Porous Pot Test. If the antimicrobial passes the ready 

biodegradability study, then no further testing is required. If, however, the antimicrobial fails the ready 

biodegradability study, then the Biodegradation in Activated Sludge or the Porous Pot study is required.
Page 10 of 12

Appendix A. Environmental Fate Guideline Study Justifications

Guideline Number: 850.6800; OECD 209

Study Title: Modified Activated Sludge, Respiration Inhibition Test for Sparingly Soluble 

Chemicals; Activated Sludge Respiration Inhibition Test

Rationale for Requiring the Data

An activated sludge, respiration inhibition test (ASRI) is needed to identify whether this pesticide could 

harm activated sludge microorganisms found in biological wastewater treatment systems. The Agency 

will use these data to determine the potential impact of this chemical on waste water treatment plants 

(WWTPs) as a result of respiration inhibition of activated sludge microorganisms. This test is also 

necessary to enable EPA to establish correct concentrations for use in the biodegradability test, if that 

test is determined to be adequate for assessing biodegradation potential. Furthermore, the results of the 

Activated Sludge Respiration Inhibition Test (ASRI) determine which biodegradation test is required. If 

the ASRI test EC50 is less than or equal to 20 mg/L, then either the Biodegradation in Activated Sludge 

Study or the Porous Pot Test is required. If the ASRI test EC50 is greater than 20 mg/L, then the applicant 

must choose either: (i) Ready Biodegradability or (ii) Biodegradation in Activated Sludge or the Porous Pot 

Test. If the antimicrobial passes the ready biodegradability study, then no further testing is required. If, 

however, the antimicrobial fails the ready biodegradability study, then the Biodegradation in Activated 

Sludge or the Porous Pot study is required.

Practical Utility of the Data

1. How will the data be used?

The data will be used to assess potential adverse effects to activated sludge microorganisms. In addition, 

the data will be used to determine whether or not label restrictions are needed. The study will identify the 

inhibitory effect of this chemical on the treatment plant’s microorganisms’ respiration at different 

concentrations of the test substance and will identify the EC50, the effective concentration of the test 

substance at which the respiration rate is 50% of that shown by the control under conditions in this 

guideline. The data will also determine suitable non-inhibitory concentrations to be used in 

biodegradability tests.

2. How could the data impact the Agency’s future decision-making?

If the data indicate a high degree of activated sludge respiration inhibition, a more rigorous test for 

biodegradation in wastewater treatment will be required than the ready biodegradability test. Also, if a 

high degree of respiration inhibition is demonstrated and biodegradation and/or sorption is indicated to be 

negligible, the Agency may require label restrictions or mitigation measures to insure that activated sludge 

microorganisms will not be adversely impacted.
Page 11 of 12

Guideline Numbers: 835.3110, 835.3220, or 835.3280

Study Titles: Ready Biodegradability, Porous Pot Test, or Simulation Tests to Assess the 

Biodegradability of Chemicals Discharged to Wastewater (also referred to as Biodegradation in 

Activated Sludge), respectively

Rationale for Requiring the Data

For antimicrobial chemicals that go down-the-drain and reach a WWTP, as part of its screening-level 

environmental fate assessment, EPA will analyze the potential impact of the antimicrobial chemical on the 

microorganisms in the biological treatment processes of a WWTP. Biodegradation is an important 

environmental pathway in which the antimicrobial is broken down by bacteria. This study results supply

information on the rate of biological breakdown and the completeness of the degradation to carbon dioxide 

and water. A ready biodegradability study would allow the Agency to determine whether or not the 

chemical achieves ‘‘pass levels’’ for ready biodegradability (e.g., 70% removal of dissolved organic 

carbon). The results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which of these 

three biodegradation tests are required. If the ASRI test EC50 is less than or equal to 20 mg/L, then either 

the Biodegradation in Activated Sludge Study or the Porous Pot Test is required. If the ASRI test EC50 is 

greater than 20 mg/L, then the applicant must choose either: (i) Ready Biodegradability or (ii) 

Biodegradation in Activated Sludge or the Porous Pot Test. If the antimicrobial passes the ready 

biodegradability study, then no further testing is required. If, however, the antimicrobial fails the ready 

biodegradability study, then the Biodegradation in Activated Sludge or the Porous Pot study is required.

Practical Utility of the Data

1. How will the data be used?

The data from a biodegradation study will be used to determine the percent removal of the antimicrobial as 

a result of biodegradation of the antimicrobial by activated sludge microorganisms. Percent removal via 

biodegradation is a key input used to determine concentrations of the antimicrobial in surface water 

immediately downstream of wastewater treatment plants. The concentrations of antimicrobial pesticide 

immediately downstream of wastewater treatment plants are used to assess exposure and risk to non-target 

endangered and non-endangered species. Exposure data are integral parts of the risk equation for 

determining the impact of pesticides to beneficial non-target organisms through direct exposure from their 

food sources and habitat.

In addition, the data will be used to determine whether or not additional studies and/or label restrictions 

are needed. If the chemical does not achieve a ‘‘pass level’’ for ready biodegradability, then the Agency 

would determine that the chemical has the potential to pass through the WWTP and therefore may be 

discharged in to the aquatic environment potentially resulting in exposure to non-target species. This 

determination would trigger further data requirements to assess the chemical’s impact on the aquatic 

environment upon release.

2. How could the data impact the Agency’s future decision-making?

If the chemical is found to be readily biodegraded, then activated sludge microorganisms would be 

identified as highly biodegradable (90% removal via biodegradation). This result would be used in 

conjunction with wastewater treatment plant influent volume and measurement endpoints for aquatic 

organisms to determine concentrations of antimicrobial pesticide downstream of wastewater treatment 

plants. If high inhibition of activated sludge microorganisms (i.e., EC50 less than or equal to 20 mg/L) is 

determined in an activated sludge respiration inhibition test, then higher-tiered wastewater treatment plant 

(WWTP) biodegradation studies and/or an activated sludge sorption isotherm study may be triggered. If 

results of higher-tier WWTP biodegradation tests indicate low or negligible removal by biodegradation, the 

risk assessments for this chemical would reflect the magnitude of potential risk derived from the chemical’s 

lack of biodegradability. The risk assessment may result in the Agency requiring label restrictions that 

would be necessary for the products to meet the “no unreasonable adverse effects” requirements of FIFRA 

(e.g., changes to the directions for disposal).
Page 12 of 12

In addition, EPA is required by section 7(a)(2) of the ESA to ensure that any action it authorizes or takes 

“...is not likely to jeopardize the continued existence of any endangered or threatened species or result in 

the destruction or adverse modification of critical habitat” and to use the best scientific data available” in 

carrying out this obligation. The data EPA intends to call in are necessary to inform the determination 

required by the ESA as to whether continued registration of a pesticide is not likely to jeopardize the 

species or its critical habitat. Absent this data EPA may not be able to conclude that this pesticide will not 

harm endangered species and may therefore need to consider other limitations on the use of the pesticide in 

order to fulfill the Agency’s statutory obligations under the ESA. The lack of these data will limit the 

flexibility that the Agency and registrants have in coming into compliance with the ESA and could result in 

use restrictions which are unnecessarily severe.

Appendix B: Ecological Guideline Study Justifications

Guideline Number: 850.5400

Study Title: Algal toxicity (Tier II) using freshwater green alga, Selenastrum capricornutum

Practical Utility of the Data

1) What is the value of the study?

As part of an initial risk assessment, one indicator plant species is tested for phytotoxicity. This study 

would allow the Agency to categorize DMHMP as toxic or non-toxic to plants. If toxic, additional higher 

tier plant tests would be needed. An endangered species assessment for endangered or threatened plants is 

not possible without this study.

2) How would the data be used?

This study would be used to evaluate the toxicity of DMHMP to non-target plants in terrestrial and aquatic 

ecosystems.

3) How could the data affect the risk assessment?

Adverse effects to non-target plants in terrestrial and aquatic ecosystems may result in mitigation to protect 

species at risk. Mitigation might include reduced label dosages, neutralization of effluents prior to

discharge into water, restrictions on use in sensitive ecosystems or where endangered species are present, or 

other mitigation measures.

4) What is triggering the need for this data?

Increased concern from state regulators and the public to evaluate impacts on WWTP operations, 

endangered species, and persistence in the environment, since initial registration, have triggered the need 

for this study. Green algae are critical to ecosystem health and productivity.