WRITER’S DIRECT DIAL 1330 Connecticut Avenue, NW

202.419.5166 Washington, DC 20036-1795

Tel 202.429.3000

Fax 202.429.3902

steptoe.com

April 13, 2010

Ms. Joan Harrigan-Farrelly

Joan Harrigan-Farrelly, Director USEPA Headquarters

Antimicrobials Division Ariel Rios Building 1200 Pennsylvania Ave. NW

Mail Code: 7510P Washington, DC 20460

Subject: EPA should Ignore Ashland’s Untimely Attempt to Distort the Science Underlying Nalco’s Use of Bleach pl us Halogen Stabilizers

Dear Ms. Harrigan-Farrelly:

I am writing on behalf of Nalco in response to the March 25, 2010 letter from Dr. Donald Penner that was submitted by Ashland. First, it is important to point out that Dr. Penner is not an expert in the area of chlorine chemistry, or in th e application of such chemistry to industrial or similar systems. Instead, Dr. Penner’s expertise is in the area of weed science, includ ing the reaction be tween glyphosate and products such as ammonium sulfate that result in a chemical change to the glyphosate molecule.

Dr. Penner asserts that Nalco’s use of stabilizer s is not analogous to the agricultural use of adjuvants because Nalco’s system involves a “reaction vessel” instead of tank mixing. However, this is simply incorrect. First, contrary to Dr. Penner’s assertion, there is no “reac tion tank” involved in the application process for halogens in pulp and paper systems. The registered sodium hypochlorite is directly into the process, along w ith a stabilizer and pH adujster. All mixing occurs in-line.

An agricultural spray tank typically serves to dilute the pesticide(s) and other materials being applied and to allow any reaction between adjuvants and pesticides to occur. A mix tank therefore contains a significant amount of water, and the chemi cals are mixed in the tank pr ior to application. TheMs. Joan Harrigan-Farrelly April 13, 2010 Page 2

additional w ater is needed to ensure adequate and appropriate dilution, and ther efore adequate coverage with the mixture over a large area. When chemicals are added to water based systems such as pulp and paper, however, there is no need for extra water to en sure coverage. The water itself is what is being treated, and there is a single in-lin e point at which chemicals are introduc ed to the system to be treated. Thus, as Nalco explained at the meeting on February 16, there is no “reaction tank” in Nalco’s system. In Nalco’s applications that ut ilize ammonium sulfate and urea, these stabilizers are added to the feedline that is used to deliver EPA-registered so dium hypochlorite to paper mill process for the purpose

of microbial control. Th e in-line blending uses a static mixer or tee-mixer to ensure adequate mixing. However, there is no reaction tank and no way to dis tinguish that the Nalco ap proach is fundamentally different from the tank mix (i.e. spray tank) used to apply stabilized pesticides to crops.

Second, Dr. Penner’s focus on “tank mixing” is mi splaced. EPA has never stated that adjuvants are limited to those products that are mixed in a ta nk prior to application. Th e ASTM definition cited by Dr. Penner is not referenced in any EPA regulatio n or guidance. ASTM E 1519-05 simply defines an adjuvant as ‘a material added to a tank mix to ai d or modify the action of an agrichemical, or the physical characteristics of the mixture’. While the ASTM standard was developed specifically for agricultural adjuvants, Nalco’s use of ammonium sulfate and urea are c onsistent with this definition. The ammonium sulfate and urea modify the action the sodium hypochlorite, so that it is less reactive to allow the chlorine residual to pers ist longer in the treated water system . Increased chlo rine persistence allows the chlorine to provide the intended level of control of microbial growth and deposit formation

This is similar to the definition of “extender” in the ASTM standard, where ex tended is defined as “a

material that increases the effective life of an agrichemical after application.”.

Third, contrary to Dr. Penner’s comments, reactions do take place in the spray tank equipment used to apply conventional chemicals. If reactions did not take place in the spray tank, there would be no reason to use the ‘water conditioners’ with post emergence herbicides. The ASTM definition for ‘water conditioning agent’ as used with agicultura l chemicals specifically identifi es that it is to reduce or eliminate antagonism in the water us ed for application, i.e., in the spray tank. Moreover, Dr. Penner provides no support for his assertion that “Adjuvants by definition do not undergo [] reactions.” Letter at p. 2. There is no regulatory definition for adjuva nts, and the available standard for agrichemical adjuvants neither includes nor excludes such reactions.

Fourth, Dr. Penner’s focus on the formation of “covalent bonds” is misplaced. ASTM E 1519- 05 defines an adjuvant as ‘a materi al added to a tank mix to aid or m odify the action of an agrichemical, or the physical characteristics of the mixture’. In this definition there is no exclusion of specific

reactions or chemical bonds. The well-known, well-understood, and long practiced use of nitrogen to stabilize halogen chemistry in wate r treatment depends upon ensuring that the majority of the halogen is

in the combined form. That is the intent of the use of stabilizers, to pr event the degradation or conversion of the highly reactive ha logen into unreactive forms. Free halogen can and is quickly consumed in systems, which can result in the need for significantly higher amounts that would need to be applied to ensure adequate micr obial control before the free haloge n is consumed (i.e., converted to forms that have no activity against microorganisms). However, the ex tent of stabilization has neverMs. Joan Harrigan-Farrelly April 13, 2010 Page 3

been a basis for determining whethe r separately added non-biocidal comp onents are or are not pesticides requiring registration

Furthermore, Dr. Penner is inaccurate when he st ates that the reaction of ammonium sulfate/urea

with chlorine is an irreversible reaction. While covalent bonds do form between chlorine and ammonia or urea, resulting in the formation of monochloramine and chlorourea, these are not permanent covalent bonds and hydrolysis is well documented. 1 In fact, Ashland acknowledged and documented dissociation constants in their February 16, 2010 presentation to EPA. Hydrolysis consta nts are dependent not only on the source of the nitrogen, but also on the con centration of the chlorina ted-nitrogen compound, the

ratio of chlorine:nitr ogen, pH, and temperature. 1 Hydrolysis of monochlor amine to HOCl increases in

weak solutions. 2 In the case of chlorourea, free resi duals are minimal allowing for enhanced compatibility with functional chemicals used in th e papermaking process and enhanced persistence of the chlorine residual. Hydrolysis of chlorourea and the role of HOCl in disinfection are indicated based

on the observation of overstab ilization of chlorourea in the presence of excess stabilizer according to the principle of Le Chatelier. 3

Finally, the regulatory and polic y issues raised by Nalco in its December 2007 petition and reiterated since that time are not specific to Nalc o’s products. Dr. Penner cl early was not been made aware of the materials presented at the February 16 meeting, the sc ope of the issues, the regulatory background, history and implications, and the set of issues that Nalco has presented. Dr. Penner’s paper therefore should not be gi ven any weight by EPA.

Sincerely,

Elizabeth Anne Brown, Ph.D. Sr. Technical and Regulatory Analyst

1 Morris, J.D. “Kinetics of reactions between aqueous chlorine and nitrogen compounds”, in “Principles and Applications of Water Chemistry”’ Faust, S.D., Hunter, J.V., Eds.; John Wiley and Sons, New York (1967).

2 White, G.C. “Handbook of Chlorination” ; John Wiley and Sons, New York. 1999.

3 Williams, D.E., E.D. Elder, and S.D. Worley. Is free halogen necessary for disinfection? Appl.

Environ. Microbiol. 54:2583-2585.