					   January 11, 2005

MEMORANDUM

Subject:		Product Chemistry Science Chapter for Didecyl Dimethyl
Ammonium Chloride   (DDAC)

To:		A .Najm Shamim,  Risk Assessor for DDAC 

Regulatory Management Branch II

Antimicrobials Division (7510C) 

	And

Tracy Lantz, CRM for DDAC RED

Regulatory Management Branch I

Antimicrobials Division (7510C)

From:		Chris Jiang, Chemist

Product Science Branch

Antimicrobials Division (7510C)

Thru:		Karen P. Hicks, CTT Team Leader 

              Product Science Branch

              Antimicrobials Division (7510C)

                           Michele Wingfield, Branch Chief

             Product Science Branch

             Antimicrobials Division (7510C)

DP Barcode:	D323311					Chemical Code:		069149	

EPA Reg. No.:	3377-42						MRID #(s: 		44520301

											44520302

											44520303

Enclosed is the Science Chapter for Didecyl Dimethyl Ammonium Chloride
Reregistration Eligibility Decision (RED).

Science Chapter on for Didecyl Dimethyl Ammonium Chloride (MRID #(s: 
44520301, 44520302, 44520303)

Product Chemistry

Case Overview

Chemical Overview

The main ingredient covered for this Science Chapter is:  Didecyl
Dimethyl Ammonium Chloride

Chemical Name:			Didecyl dimethyl ammonium chloride

Common/Trade Names:		Di-n-decyl dimethyl ammonium chloride, DDAC  

Chemical Family:			Quaternary amines

CAS Registry Number:		7173-51-5

OPP Chemical Code:		069149

Molecular Formula:		R2C2H6NCl (R = n-decyl)

Molecular Weight:		362.08

SCIENCE ASSESSMENT

The Agency thoroughly reviewed the registrants( submissions (in-house
literature) for the purpose of 

determining the reregistration eligibility of didecyl dimethyl ammonium
chloride for use in wood preservatives, in agricultural premises and
equipment, in industrial processes and water systems, and in commercial,
institutional, and residential premises.

Product Chemistry Assessment

The physical and chemical characteristics of didecyl dimethyl ammonium
chloride are described below.

Technical Grade Active Ingredient (TGAI):

Chemical Name:			Didecyl dimethyl ammonium chlorideMolecular Wt.		
362.08

Color:				100 APHA units

Physical State:			Liquid

Odor:				Ethanolic

*Melting Point:			228.81 oC

Boiling Point:			Please provide boiling point data

Could not be established because test article is a multi-component
system with each component boiling at a different temperature?

Density:				0.9216 g/cm3 at 25 oC

Water Solubility:			Completely soluble

*Vapor Pressure:			2.33 x 10-11 mm Hg			

Dissociation Constant:		Not applicable

*log Kow:			4.6581

pH:				6.31

Stability:			Stable with respect to metal, nonmetal, temperature, and
light

Oxidizing/Reducing Potential:	Not applicable as product does not contain
oxidizers or reducers

Flash Point:			38.0 oC

Explodability:			Not applicable for liquids which are not potentially
explosive

Viscosity:			28.35 cSt at 25 oC

Miscibility:			Not applicable as product is not to be mixed with
petroleum solvents

Corrosion Characteristics		Corrosive to stainless steel and no corrosion
to HDPE

Dielectric breakdown voltage:	Not applicable as product is not to be
used near electrical equipment

*-Values obtained from EpiSuite

     Didecyl Dimethyl ammonium chloride

PRODUCT CHEMISTRY

 BIBLIOGRAPHY

US EPA(s MRID #: 44520301, Albemarle DAQ-1010-5 Biocide—Product
Chemistry, (1998) Albemarle Corp., Lab Project Number 8382-139 Quat 10,
Albemarle Corporation.

US EPA(s MRID #: 44520302, Tolbert, A., Product Chemistry Chemical
Characterization for Determining 

Identity and Purity of  50% Di-N-Decyl Dimethyl Ammonium Chloride,
(1998), Lab Project Number Quat 10B, Albemarle Corporation.

US EPA(s MRID #: 44520303, Tolbert, A., Product Chemistry Chemical
Characterization for Determining

the Physical and Chemical Properties, and Accelerated Storage Stability
of 50% Di-N-Decyl Dimethyl Ammonium Chloride, (1998), Lab Project Number
Quat 10A, Albemarle Corporation.

	EPISuite  Property Assessment Program

Appendix I:  Impurities evolved during the manufacture of Didecyl
dimethyl ammonium chloride

Chemical name

Methyl chloride

Di-n-decylmethyl amine 



Di-n-decylmethyl amine-hydrochloride



Methanol

No percentages of these impurities are given.

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