Re: Fwd: Sodium hypochlorite and Zebra -Quagga Mussels Uses C) 

Joan Harrigan -Farrelly to: Keith Pitts 10/18/2012 03:53PM 

Cc: Amy Roberts, Jonathan Birdsong, John Fournier, William Jordan, 

Mike Mendelsohn 

History: This message has been forwarded . 

Keith, 

Greetings. Here is the information I was able to find on the zebra and quagga mussel that was added to 

the sodium hypochlorite label. 

Regards, 

Joan 

zebra and quagga mussels. 10.17.2012.docx 

Joan Harrigan Farrelly 

US Environmental Protection Agency 

Director, Antimicrobials Division 

Office of Pesticide Programs 

1200 Pennsylvania Ave. N.W. Mailcode 7510P 

Washington, DC 20460 

Physical Address 

One Potomac Yard 

2777 Crystal Dr. 

Arlington, VA 22202 

Phone: 703-603-8914 

Keith Pitts Joan and Steven, I hope all is well with you. Ha ... 

From : Keith Pitts <kpitts@marronebio.com> 

10/08/2012 07:36:04 PM 

To: Joan Harrigan-Farrelly/DC/USEPA/US@EPA, Steven Bradbury/DC/USEPA/US@EPA 

Cc: 

Date: 

Subject: 

Amy Roberts <ARoberts@TSGUSA.COM>, John Fournier <jfournier@marronebio.com>, Jonathan 

Birdsong <jbirdsong@bwstrategies.com> 

10/08/2012 07:36PM 

Fwd: Sodium hypochlorite and Zebra-Quagga Mussels Uses 

Joan and Steven, I hope all is we ll with you. Have you been able to 

find anything out about 

the zebra and quagga mussel use that was added to a sodium 

hypochlorite label? thanks, 

Keith 

---------- Forwarded message ----------
From: Keith Pitts <kpitts@marronebio.com> 

Date: Tue, Sep 25, 2012 at 2:51 PM 

Subject: Sodium hypochlorite and Zebra-Quagga Mussels Uses 

To: bradbury.steven@epamail.epa.gov, Harrigan-Farrelly.joan@epa.gov 

Cc: Amy Roberts <ARoberts@tsgusa.com>, John Fournier 

<jfournier@marronebio.com> 

Dear Steven and Joan, 

In August 2012, while researching approaches to address NPDES 

permitting requirements for Zequanox, we encountered sodium 

hypochlorite product labels that included zebra mussel control uses . 

The EPA database indicates the Antimicrobial Division approved the 

new use sometime in 2010. The new zebra and quagga mussels uses 

appear to be 20-40 times the previously assessed and registered 

treatment concentration (for disinfection) and much longer treatment 

durations than EPA has previously evaluated. 

After our collective experience with Zequanox, I would expect the new 

use to require a new risk assessment since chlorine treatments at 

efficacious concentrations are between dozens and thousands of times 

more toxic than Zequanox treatments, and treatment times are 

significantly longer than the 6-8 hours typically needed for pipe 

anti-fouling treatments using Zequanox. However, the EPA database 

does not provide any indication that any data to support the new use 

was submitted to EPA 

MBI did make multiple EPA contacts to understand a bit more about how 

these mussel-control uses had been added to the product label. On a 

cursory level, the informal feedback is that no new data was submitted 

to support these new uses on the sodium hypochlorite label (attached). 

MBI staff contacted EPA Ombudsmen and the Antimicrobials Division, via 

Sharon Carlisle and Sherada Hobgood, on August 17th to inquire as to 

whether or not EPA had completed additional risk assessments on 

chlorine or if these mussel-control uses had been allowed on product 

labels in error. To date, we haven't received a response to the 

inquiry. Could OPP review this situation and let us know has 

transpired? 

Please let me know if you need any additional information from us. 

Thanks for your help. Keith 

Keith Pitts 

Vice President, Regulatory and Government Affairs 

Marrone Bio Innovations 

2121 Second St., Ste B-107 

Davis, CA 95618 

Office: 530-750-2800 ext. 212 

Mobile: 240-463-4357 

kpitts@marronebio.com 

www.marronebioinnovations.com 

This message and any associated attachments are confidential and 

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P.S. Please consider the environment - do you really need to print this 

email? 

Keith Pitts 

Vice President, Regulatory and Government Affairs 

Marrone Bio Innovations 

2121 Second St., Ste B-107 

Davis, CA 95618 

Office: 530-750-2800 ext . 212 

Mobile: 240-463-4357 

kpitts@marronebio . com 

www.marronebioinnovations.com 

This message and any associated attachments are confidential and 

intended solely for the use of the individual(s) or entity to whom it 

is addressed. If you are not the intended recipient you are hereby 

notified that any dissemination, copying or distribution of this 

message or attachments associated with this message, is strictly 

prohibited. If you have received this email in error please delete it. 

Although this email and any attachments are believed to be free of 

viruses or other defects, it is the responsibility of the recipient 

to ensure that it is virus free and no responsibility is accepted by 

Marrone Bio Innovations, Inc. or its affiliates. 

P.S. Please consider the environment - do you really need to print this 

email? 

[attachment "Sodium Hypochlorite- 12.5 Bacticide.pdf" deleted by Joan 

Harrigan-Farrelly/ DC / USEPA/ US] 
Dear KeithBelow is a response to your September 25 email raising questions concerning the Antimicrobials 

Division registration of a sodium hypochlorite product that included zebra mussel and quagga 

mussel control uses. Specifically, you asked that we explain the basis for what appeared to be 

different approaches used by AD and the Biopesticides and Pollution Prevention Division toward 

the chlorine-based product and another product, Zequanox, approved by BPPD for a similar use. 

Sodium Hypochlorite Molluscacides 

Let me begin with some historical information on EPA's registration of sodium hypochlorite 

products. For many decades, sodium hypochlorite labels have contained instructions for outdoor 

aquatic use sites such as cooling towers. AD records indicate that zebra mussels were first listed 

as pests on sodium hypochlorite product labels in 1997 (EPA Reg. No. 813-15). At that time, 

EPA approved an increased use rate of 20 ppm, compared to 10 ppm for the slimicide and 

algicide uses. Quagga mussels appear to have been added later; use rates and sites are the same 

as for zebra mussels and quagga mussels. The product label that was attached to your email 

(EPA Reg. No. 72315-6) first had zebra and quagga mussels added in 2008. 

Throughout the time that the agency has registered sodium hypochlorite products for outdoor 

use, we have recognized that sodium hypochlorite is toxic to aquatic organisms. As explained in 

more detail below, OPP's approach to the regulation of these products rests on our conclusion 

that risk was adequately mitigated by the use of the following precautionary labeling and 

requirement for NPDES permitting: 

ENVIRONMENTAL HAZARDS 

This product is toxic to fish. Do not discharge into lakes, streams, ponds or public 

waterways unless in accordance with a NPDES permit. For guidance, contact the 

regional office of the U.S. Environmental Protection Agency. " 

As you are aware, "[a]n NPDES permit will generally specify an acceptable level of a pollutant 

or pollutant parameter in a discharge (for example, a certain level of bacteria) ... " 

http://cfpub.epa.gov/npdes/faqs.cfm?program id=45. "When assessing point source discharges 

to determine whether controls based on water quality standards are necessary, an NPDES 

permitting authority should conduct an analysis to determine whether the discharge causes, has 

the "reasonable potential" to cause, or contributes to an excursion of any water quality criteria in 

the receiving water." http://cfpub.epa.gov/npdes/wqbasedpermitting/wqoverview.cfm 

The Agency published the Ambient Water Quality Criteria for Chlorine in January 1985. 

Extensive non-target aquatic organism data were used to set the water quality criteria and these 

criteria impact NPDES permit requirements. "Thirty-three freshwater species in 28 genera have 

been exposed to TRC [(Total Residual Chlorine)] and the acute values range from 28 ~giL for 

Daphnia magna to 710 ~giL for the threespine stickleback. Fish and invertebrate species had 

similar ranges of sensitivity. Freshwater chronic tests have been conducted with two invertebrate 

and one fish species, and the chronic values for these 3 species ranged from less than 3.4 to 26 

~giL, with acute-chronic ratios from 3.7 to greater than 78. The acute sensitivities of 24 species 
of saltwater animals in 21 genera have been determined for CPO [(Chlorine Produced 

Oxidants)], and the LC50s range from 26 f.lg/L for the eastern oyster to 1,418 f.lg/L for a mixture 

of two shore crab species. This range is very similar to that observed with freshwater species, 

and fish and invertebrate species had similar sensitivities. Only one chronic test has been 

conducted with a saltwater species, Menidia peninsulae, and in this test the acute-chronic ratio 

was 1.162. The available data also indicate that aquatic plants are more resistant to chlorine than 

fish and invertebrate species. 

The procedures described in the "Guidelines for Deriving Numerical National Water Quality 

Criteria for the Protection of Aquatic Organisms and Their Uses" indicate that except possibly 

where a locally important species is very sensitive, freshwater aquatic organisms and their uses 

should not be affected unacceptably if the four-day average concentration of total residual 

chlorine does not exceed 11 f.lg/L more than once every three years on the average and if the onehour average concentration does not exceed 19 f.lg/L more than once every three years on the 

average. 

The procedures described in the "Guidelines for Deriving Numerical National Water Quality 

Criteria for the Protection of Aquatic Organisms and Their Uses" indicate that except possibly 

where a locally important species is very sensitive, saltwater aquatic organisms and their uses 

should not be affected unacceptably if the four-day average concentration of chlorine-produced 

oxidants does not exceed 7.5 f.lg/L more than once every three years on the average and if the 

one-hour average concentration does not exceed 13 f.lg/L more than once every three years on the 

average." p. 17-18. See 

http://water.epa.gov/scitechfswguidance/standards/upload/2001 10 12 criteria ambientwqc chl 

orine1984.pdf . 

Pseudomonas flourescens molluscacides 

BPPD decided to impose specific data requirements on Zequanox because the active ingredient, 

Pseudomonasfluorescens CL 145A, raises unique risk considerations that differ from 

conventional (chemical) pesticides. A particular concern is that the active ingredient is a living 

bacterium that could proliferate in the environment. The use patterns for Ps. fluorescens CL 

145A may result in discharges of Ps. fluorescens CL 145A into water, with concomitant 

exposure to non-target aquatic organisms. Ps. fluorescens is an opportunistic fish pathogen, and 

therefore, applications of the end-use products could present risks to fish, and perhaps other 

nontarget aquatic organisms (e.g., early-stage larval or "veliger" mussels/bivalves). BPPD 

determined that the application for registration of Pseudomonasfluorescens CL 145A did not 

adequately address the Tier 1 data requirements for non-target aquatic organisms. Additionally, 

EPA could not adequately estimate the potential exposure to nontarget aquatic organisms. 

Therefore, BPPD concluded that it could not make the FIFRA determination (i.e., no 

unreasonable adverse effects to the environment) without 1) the inclusion of appropriate 

mitigation measures as terms of registration (i.e., discharge limitations and monitoring), and 2) 

the requirement that MBI submit additional non-target studies to enable EPA to complete its risk 

assessment for the active ingredient and confirm that use in accordance with label directions will 

not result in unreasonable adverse effects to the environment. 
Conclusion 

In sum, while sodium hypochlorite products and Zequanox are approved for use against zebra 

and quagga mussels, at the time EPA was considering the two applications, the agency had far 

more data on chlorine toxicity and exposure in aquatic environments than on Ps. Fluorescens 

CL145A. Moreover, regulatory controls, in the form of a requirement for an NPDES permit to 

cover a discharge, existed at the time of the sodium hypochlorite registrations. OPP regarded 

the NPDES permit program as capable of addressing the aquatic risks for chlorine discharges 

because EPA had established chlorine water quality criteria levels, which were linked to those 

permits for point source discharge. Although Ps. Fluorescens CL145A molluscacide uses would 

also require NPDES permits, we are not aware of water quality criteria levels being available for 

Ps. flourescens. Thus, EPA needed data to support the specific discharge levels that were 

established via the terms of the Pseudomonas flourescens molluscacide registrations. 

You may obtain additional background information from the Sodium and Calcium Hypochlorite 

1986 Registration Standard, 1992 Reregistration Eligibility Document, and 2012 Registration 

Review Final Work Plan. Should you have any further questions, please contact Mike 

Mendelsohn, Acting Chief of Regulatory Management Branch II, at (703) 308-8715 or 

mendelsohn.mike @epa. gov. 

Best Regards, 

Joan