U.S. EPA, TSCA Inventory Representation for Certain Chemical Substances Containing Varying Carbon Chain Lengths (Alkyl Ranges Using the CX-Y Notation) (1995) (ELR Order No. AD-4000)

• Author: Carolyne R. Hathaway/William K. Rawson/Ann Claassen/Julia A. Hatcher
• Pages: 307-314

TSCA Inventory Representation for Certain Chemical Substances Page 307

Toxic Substances Control Act

Inventory Representation for Certain

Chemical Substances Containing

Varying Carbon Chain Lengths (Alkyl

Ranges Using the CX-Y Notation)

I. Introduction

is paper explai ns the conventions that are applied

to certain li stings of chemical substances conta ining

ranges of alk yl chain lengths (i.e., carbon chai ns of

varying leng ths) for the Chemical Substance Inventory

that is mainta ined by the U.S. Environmental Protec-

tion Agency (EPA) under the Toxic Substances Con-

trol Act (TSCA). is paper i s restricted to substances

using the general a lkyl range notation of the type C X-Y,

described in (1), below. e conventions applicable to

this typ e of substa nce have been i n place essentially

unchanged since t he inception of the Inventory. e

Agency’s goal in developing t his paper is to make it

easier for the users of the Inventory to inter pret list ings

that include alk yl ranges and to understand how new

substances should be identi ed for Inventory inclu sion.

Fundamental to al kyl group nomenclature and to the

Inventory as a whole is the principle that entries on

the Inventory are interpreted as preci sely descriptive

as possible for the commercial c hemica l substance, as

reported by the submitter. e following di scussion

assumes thi s principle.

Carbon chain s of var ying lengths are present in thou-

sands of Inventory chemica ls and are described by the

use of four dierent ty pes of Inventory representations.

ese types a re:

(1) General alk yl range notation of the type CX-Y

for substances derived f rom natura l sources and

synthetics;

(2) Soap and Detergent Manufac turers Association

(SDA) descriptors of the type CX-Y for sub-

stances derived from nat ural fats and oils and

their synthetic subst itutes;

(3) Natural source de scriptors; and,

(4) Other, including EPA-American Petroleum

Institute (API) pet roleum proces s stream

terms.

ey are furt her described as follows:

(1) e subject of this paper is alkyl rang e notation

of the type CX-Y. Carbon c hains in this notation are

represented by the nomenclature CX-Y where X is the

smallest ca rbon chain to be included in the range and

Y is the largest ch ain. e Agency uses the CX-Y nota-

tion to describe the carb on chai ns in the large number

of substances for which t he SDA, natura l product and

API systems are not appropriate or applicable. e sub -

stances descr ibed by thi s notation may be derive d from

a source not described in SDA nomenclature, be puri-

ed to enhance one or more of the alk yl chains from

a natural source or be de rived from two or more inter-

changeable source s. is paper presents the accepted

practices governing t he use of this notation, along with

the nomenclature for the modic ations that are found

in Inventory substances .

Example 1. Alcohols, C 7-9-branched

CASRN 68551-09-7*

(2) e SDA system of naming chemical sub stances

derived from natural f ats and oils and their synthetic

equivalents was develope d by EPA and the Soap and

Detergent Manufactu rers Association. (See references,

for complete details.) e name for each subs tance

using the SDA system includes one of 27 alk yl descrip-

tors developed for the alk yl groups found in exten-

sively- used fats and oils derived from nat ural plant and

animal sourc es and their synthetic equivalents. SDA

nomenclature is limited to the fat s, oils and synthetic

equivalents of the specic pla nt and animal sources

listed in the SDA procedures; a lkyl groups derived

from other sources are not covered by the SDA nomen-

clature. e SDA name for a substanc e includes the

alkyl desc riptor, a functional ity des criptor and a sa lt

descriptor (if required) inserted in t he appropriate SDA

Substance Denit ion Format. Becau se alkyl descrip-

tors are used instead of spe cic sources, manufacturers

may have some limited exibilit y to switch from one

source to another under SDA nomenclature as long as

the alkyl r ange descriptor encompasses the alkyl ra nge

of the fats and oils from the se cond source.

Example 2. A mines, tri-C6-12-alk yl

CASRN 68 038-01-7*

e denition associated w ith th is name is:

“is substanc e is identied by SDA Substa nce

Name: C6-C12, tria lkyl amine and SDA Report-

ing Number: 13-044 -00. Consult SDA Sub-

stance Identication Proce dure.”

NOTICE: e policies set out in this doc ument are

not nal Agency a ction, but are intended solely a s

guidance. ey a re not intended, nor can they be relied

upon, to create any rights enforceable by a ny part y in

litigation with the United States. E PA ocials may

decide to follow the guidanc e provided in t his docu-

ment, or to act at variance with t his guidance, based

on an analysis of spe cic circumstances.