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]{.underline}**

> 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: R~2~C~2~H~6~NCl (R = n-decyl)

> Molecular Weight: 362.08

**[SCIENCE ASSESSMENT]{.underline}**

> 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 ^o^C

> 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/cm^3^ at 25 ^o^C

Water Solubility: Completely soluble

\*Vapor Pressure: 2.33 x 10^-11^ mm Hg

Dissociation Constant: Not applicable

\*log K~ow~: 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 ^o^C

Explodability: Not applicable for liquids which are not potentially
explosive

Viscosity: 28.35 cSt at 25 ^o^C

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.