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Federal regulations · Through 2026-08-25 · Newer source version available

40 CFR 721.1660: Benzidine-based chemical substances.

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Where this section sits in the code
  1. Title 40—Protection of Environment
  2. CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY
  3. SUBCHAPTER R—TOXIC SUBSTANCES CONTROL ACT
  4. PART 721—SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES
  5. Subpart E—Significant New Uses for Specific Chemical Substances

(a) Chemical substances and significant new uses subject to reporting. (1) The benzidine-based chemical substances listed in Table 1 and Table 2 of this section are subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section.

Table 1—Benzidine-Based Chemical Substances

CAS or accession No. C.I. name C.I. No. Chemical name

117-33-9 Not available Not available 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-[2-[4'-[2-(4-hydroxyphenyl)diazenyl][1,1'-biphenyl]-4-yl]diazenyl]-

65150-87-0 Not available Not available 1,3,6-Naphthalenetrisulfonic acid, 8-hydroxy-7-[2-[4'-[2-(2-hydroxy-1-naphthalenyl)diazenyl][1,1'- biphenyl]-4-yl]diazenyl]-, lithium salt (1:3)

68214-82-4 Direct Navy BH 22590 2,7-Naphthalenedisulfonic acid, 5-amino-3-[2-[4'-[2-(7-amino-1-hydroxy-3-sulfo-2- naphthalenyl)diazenyl][1,1'-biphenyl]-4- yl]diazenyl]-4-hydroxy-, sodium salt (1:2)

72379-45-4 Not available Not available 2,7-Naphthalenedisulfonic acid, 4-amino-5- hydroxy-3-[2-[4'-[2-[2-hydroxy-4-[(2- methylphenyl)amino]phenyl]diazenyl][1,1'- biphenyl]-4-yl]diazenyl]-6-(2-phenyldiazenyl)-

Accession No. 21808 CAS No. CBI (NA) CBI CBI 2,7-Naphthalenedisulfonic acid, 4-amino-5- hydroxy [[[(substituted phenylamino)] substituted phenylazo] diphenyl]azo-, phenylazo-, disodium salt. (generic name)

Accession No. 24921 CAS No. CBI CBI 4-(Substituted naphthalenyl )azo diphenylyl azo-substituted carbopolycycle azo benzenesulfonic acid, sodium salt. (generic name)

Accession No. 26256 CAS No. CBI (NA) CBI CBI 4-(Substituted phenyl)azo biphenylyl azo- substituted carbopolycycloazo benzenesulfonic acid, sodium salt. (generic name)

Accession No. 26267 CAS No. CBI (NA) CBI CBI 4-(Substituted phenyl)azo biphenylyl azo - substituted carbopolycycle azo benzenesulfonic acid, sodium salt. (generic name)

Accession No. 26701 CAS No. CBI (NA) CBI CBI Phenylazoaminohydroxynaphthalenylazobiphenylazo substituted benzene sodium sulfonate. (generic name).

Table 2—Benzidine-Based Chemical Substances

CAS No. C.I. name C.I. No. Chemical name

92-87-5 Benzidine Not available [1,1′-Biphenyl]-4,4′-diamine.

531-85-1 Benzidine · 2HCl Not available [1,1′-Biphenyl]-4,4′-diamine, dihydrochloride.

573-58-0 C.I. Direct Red 28 22120 1- Naphthalenesulfonic acid, 3,3′-[[1,1′-biphenyl]-4,4′-diylbis(azo)]bis[4-amino-, disodium salt.

1937-37-7 C.I. Direct Black 38 30235 2,7-Naphthalenedisulfonic acid, 4-amino-3-[[4′-[(2,4-diaminophenyl) azo][1,1′-biphenyl]-4- yl]azo]-5-hydroxy-6-(phenylazo)-, disodium salt.

2302-97-8 C.I. Direct Red 44 22500 1-Naphthalenesulfonic acid, 8,8′-[[1,1′-biphenyl]-4,4′-diylbis(azo)]bis[7-hydroxy-, disodium salt.

2429-73-4 C.I. Direct Blue 2 22590 2,7-Naphthalenedisulfonic acid, 5-amino-3-[[4′-[(7-amino-1-hydroxy-3-sulfo-2-naphthalenyl)azo][1,1′-biphenyl]-4-yl]azo]-4-hydroxy-, trisodium salt.

2429-79-0 C.I. Direct Orange 8 22130 Benzoic acid, 5-[[4′-[(1-amino-4-sulfo-2-naphthalenyl) azo][1,1′-biphenyl]-4-yl]azo]-2- hydroxy-, disodium salt.

2429-81-4 C.I. Direct Brown 31 35660 Benzoic acid, 5-[[4′-[[2,6-diamino-3-[[8-hydroxy-3,6-disulfo-7-[(4-sulfo-1-naphthalenyl)azo]-2- naphthalenyl]azo]-5-methylphenyl]azo][1,1′- biphenyl]-4-yl]azo]-2-hydroxy-, tetrasodium salt.

2429-82-5 C.I. Direct Brown 2 22311 Benzoic acid, 5-[[4′-[(7-amino-1-hydroxy-3-sulfo-2-naphthalenyl) azo][1,1′-biphenyl]-4-yl]azo]-2-hydroxy-, disodium salt.

2429-83-6 Direct Black 4 30245 2,7-Naphthalenedisulfonic acid, 4-amino-3-[[4′-[(2,4-diamino-5-methylphenyl)azo][1,1′-biphenyl]-4-yl]azo] -5-hydroxy-6-(phenylazo)-, disodium salt.

2429-84-7 C.I. Direct Red 1 22310 Benzoic acid, 5-[[4′-[(2-amino-8-hydroxy-6-sulfo-1-naphthalenyl)azo][1,1′-biphenyl]-4-yl]azo]-2-hydroxy-, disodium salt.

2586-58-5 C.I. Direct Brown 1:2 30110 Benzoic acid, 5-[[4′-[[2,6-diamino-3-methyl-5-[(4-sulfophenyl)azo]phenyl]azo][1,1′-biphenyl]-4- yl]azo]-2-hydroxy-, disodium salt.

2602-46-2 C.I. Direct Blue 6 22610 2,7-Naphthalenedisulfonic acid, 3,3′-[[1,1′-biphenyl]-4,4′-diylbis(azo)]bis[5-amino-4-hydroxy-, tetrasodium salt.

2893-80-3 C.I. Direct Brown 6 30140 Benzoic acid, 5-[[4′-[[2,4-dihydroxy-3-[(4-sulfophenyl) azo]phenyl]azo][1,1′-biphenyl]-4- yl]azo]-2-hydroxy-, disodium salt.

3530-19-6 C.I. Direct Red 37 22240 1,3-Naphthalenedisulfonic acid, 8-[[4′-[(4-ethoxyphenyl)azo][1,1′-biphenyl]-4-yl]azo]-7-hydroxy-, disodium salt

3567-65-5 C.I. Acid Red 85 22245 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-[[4′-[[4-[[(4-methylphenyl)sulfonyl]oxy]phenyl]azo][1,1′-biphenyl]-4-yl]azo]-, disodium salt.

3626-28-6 C.I. Direct Green 1 30280 2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-3-[[4′-[(4-hydroxyphenyl)azo][1,1′- biphenyl]-4- yl]azo]-6-(phenylazo)-, disodium salt.

3811-71-0 C.I. Direct Brown 1 30045 Benzoic acid, 5-[[4′-[[2,4-diamino-5-[(4-sulfophenyl) azo]phenyl]azo][1,1′ biphenyl]-4- yl]azo]-2-hydroxy-, disodium salt.

4335-09-5 C.I. Direct Green 6 30295 2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-6-[[4′-[(4-hydroxyphenyl)azo][1,1′-biphenyl]-4- yl]azo]-3-[(4-nitrophenyl)azo]-, disodium salt.

6358-80-1 C.I. Acid Black 94 30336 2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-3-[[4′-[[4-hydroxy-2-[(2- methylphenyl)amino]phenyl]azo] [1,1′- biphenyl]-4-yl]azo]-6-[(4-sulfophenyl) azo]-, trisodium salt.

6360-29-8 C.I. Direct Brown 27 31725 Benzoic acid, 5-[[4′-[[4-[(4-amino-7-sulfo-1-naphthalenyl)azo]-6-sulfo-1-naphthalenyl]azo][1,1′-biphenyl]-4-yl] azo]-2- hydroxy-, trisodium salt.

6360-54-9 C.I. Direct Brown 154 30120 Benzoic acid, 5-[[4′-[[2,6-diamino-3-methyl-5-[(4-sulfophenyl)azo]phenyl] azo][1,1′-biphenyl]-4-yl]azo]-2- hydroxy-3-methyl-, disodium salt.

8014-91-3 C.I. Direct Brown 74 36300 Benzoic acid, 3,3′-[(3,7-disulfo-1,5-naphthalenediyl)bis [azo(6-hydroxy-3,1-phenylene)azo[6(or7)-sulfo-4,1-naphthalenediyl]azo[1,1′-biphenyl]-4,4′-diylazo]]bis[6-hydroxy-, hexasodium salt.

16071-86-6 C.I. Direct Brown 95 30145 Cuprate(2-), [5-[[4′-[[2,6-dihydroxy-3-[(2-hydroxy-5-sulfophenyl)azo]phenyl] azo][1,1′- biphenyl]-4-yl]azo]-2-hydroxybenzoato(4-)]-, disodium salt.

(2) The significant new uses are:

(i) For each of the chemical substances listed in Table 2 of this section, any use other than use as a reagent to test for hydrogen peroxide in milk; a reagent to test for hydrogen sulfate, hydrogen cyanide, and nicotine; a stain in microscopy; a reagent for detecting blood; an analytical standard; and, additionally for Colour Index (C.I.) Direct Red 28 (Congo Red) (CAS No. 573-58-0), an indicator dye.

(ii) For the chemical substances listed in Table 1 of this section: Any use.

(b) Specific requirements. The provisions of subpart A of this part apply to this section except as modified by this paragraph (b).

(1) Revocation of certain notification exemptions. The provisions of § 721.45(f) do not apply to this section. A person who imports or processes a chemical substance identified in paragraph (a)(1) of this section as part of an article for a significant new use described in paragraph (a)(2) of this section is not exempt from submitting a significant new use notice.

(2) [Reserved]

Collected 2026-08-27T02:26:04Z. Source file · JSON

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