UVCB: Class 2 substance of unknown or variable composition
The presence of "UVCB" indicates the substance is a Class 2 substance within the UVCB group, i.e. those with "unknown" or "variable composition," "complex reaction products" and "biological materials."
18,201 substances carry it in the July 2026 release, of which 9,116 are designated active.
What it obliges
Care with identity. A UVCB has no definite molecular formula, so its identity rests on the process and the feedstock. Two suppliers can ship materially different material under one CAS number.
Substances carrying UVCB
Showing 100 of 18,201, active substances first. Search the full Inventory for a specific one.
| CAS number | Substance | Status | Other flags |
|---|---|---|---|
| 1191284-28-2 | Propanenitrile, 3-amino-, N,N-bis(hydrogenated tallow alkyl) derivs. | Active | PMN S 5E |
| 119209-70-0 | Rosin, polymer with formaldehyde, glycerol and 4-(1,1,3,3-tetramethylbutyl)phenol | Active | FRI PMN XU Y1 |
| 1264747-45-6 | Phenol, reaction products with 1-bromo-4-phenoxybenzene and 1,1'-oxybis[4-bromobenzene], brominated | Active | PMN S 5E |
| 1333523-10-6 | 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1-dodecanethiol, N-(hydroxymethyl)-2-methyl-2-propenamide and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl methacrylate, 2,2'-[1,2-diazenediylbis(1-methylethylidene)]bis[4,5-dihydro-1H-imidazole] hydrochloride (1:2)-initiated | Active | PMN S 5E |
| 1772607-28-9 | Fatty acids, tall-oil, polymers with acrylic acid and styrene, tert-Bu peroxide-initiated | Active | PMN S 5E |
| 1884578-89-5 | Amines, N'-[3-[(3-aminopropyl)amino]propyl]-N,N-bis(hydrogenated tallow alkyl)trimethylenedi- | Active | PMN S 5E |
| 100402-91-3 | Oxirane, 2-[[3-(trimethoxysilyl)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)) | Active | PMN S 5E |
| 100486-94-0 | Hexanedioic acid, polymer with N1-(2-aminoethyl)-1,2-ethanediamine, 2-butene-1,4-diol, 1,6-diisocyanatohexane, 1,2-ethanediol, 1,3-isobenzofurandione, 2-methyloxirane, oxirane and sodium sulfite (1:1), 2-(2-butoxyethoxy)ethanol-blocked | Active | FRI PMN XU |
| 100916-02-7 | Castor oil, polymer with polymethylenepolyphenylene isocyanate and polypropylene glycol | Active | FRI PMN XU |
| 101316-90-9 | Ethene, 1,1,2,2-tetrafluoro-, oxidized, polymd., reduced, Me esters, reduced, acrylates | Active | FRI PMN XU |
| 1017237-78-3 | 2-Propenoic acid, 2-[methyl[(1,1,2,2,3,3,4,4,4-nonafluorobutyl)sulfonyl]amino]ethyl ester, telomer with 3-mercapto-1,2-propanediol, 2-methyloxirane polymer with oxirane di-2-propenoate, and 2-methyloxirane polymer with oxirane mono-2-propenoate, tert-Bu 2-ethylhexaneperoxoate-initiated | Active | PMN SP 5E |
| 102322-80-5 | 2-Propenoic acid, 2-methyl-, methyl ester, homopolymer, reaction products with ammonia | Active | FRI PMN XU |
| 102343-97-5 | Benzene, ethenyl-, homopolymer, sulfonated | Active | FRI PMN XU |
| 102763-23-5 | Propanedioic acid, 1,3-diethyl ester, reaction products with 1,6-diisocyanatohexane homopolymer, ethyl acetoacetate, 2-ethyl-1,3-hexanediol and 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane homopolymer | Active | FRI PMN XU |
| 102782-61-6 | Siloxanes and Silicones, di-Me, 3-hydroxypropyl Me | Active | FRI PMN XU |
| 102782-92-3 | Siloxanes and Silicones, 3-[(2-aminoethyl)amino]propyl Me, di-Me, methoxy-terminated | Active | FRI PMN XU |
| 102782-93-4 | Siloxanes and Silicones, di-Me, lauryl Me, Me myristyl | Active | FRI PMN XU |
| 102782-97-8 | Siloxanes and Silicones, di-Me, 3-(2-oxiranylmethoxy)propyl group-terminated | Active | FRI PMN XU |
| 102900-02-7 | Alcohols, C6-10, ethoxylated propoxylated, fumarated, sodium salts | Active | FRI PMN XU |
| 102900-03-8 | Oxirane, 2-methyl-, polymer with oxirane, ether with 1,2-propanediol (2:1), polymer with 1,3-diisocyanatomethylbenzene, nonylphenol-blocked | Active | FRI PMN XU |
| 103170-26-9 | Cyclohexane, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethyl-, homopolymer, Me Et ketone oxime-blocked | Active | FRI PMN XU |
| 103621-98-3 | Fatty acids, soya, polymers with benzoic acid, glycerol, pentaerythritol, phthalic anhydride and tall-oil fatty acids | Active | FRI XU Y1 |
| 104133-73-5 | Amines, tallow alkyl, reaction products with bisphenol A diglycidyl ether, ethoxylated | Active | FRI PMN XU |
| 104376-75-2 | Poly(oxy-1,2-ethanediyl), .alpha.-phenyl-.omega.-hydroxy-, styrenated | Active | FRI PMN XU |
| 106232-85-3 | Alkanes, C18-20, chloro | Active | PMN S 5E |
| 1065544-88-8 | Formaldehyde, polymers with acetone-phenol reaction products and phenol, sodium salts | Active | PMN S 5E |
| 1072227-60-1 | Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts | Active | PMN S 5E |
| 1078142-02-5 | 1,3,5-Triazine, 2,4,6-trichloro-, polymer with piperazine, reaction products with morpholine | Active | PMN S 5E |
| 1078712-88-5 | Thiols, C4-20, .gamma.-.omega.-perfluoro, telomers with acrylamide and acrylic acid, sodium salts | Active | PMN S SP |
| 1078715-61-3 | 1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-[2-[(.gamma.-.omega.-perfluoro-C4-20-alkyl)thio]acetyl] derivs., inner salts | Active | PMN S SP |
| 1078715-83-9 | Phenol, 2-[[[3-(dimethylamino)propyl]amino]methyl]-6-methyl-, 4-polybutene derivs. | Active | PMN S 5E |
| 109037-68-5 | Amines, N,N'-ditallow alkyl[1,2-ethanediylbis(imino-3,1-propanediyl)]di-, ethoxylated propoxylated | Active | FRI PMN XU |
| 109037-71-0 | Siloxanes and Silicones, 3-aminopropyl Me, lauryl Me, Me 2-phenylpropyl | Active | FRI PMN XU |
| 109961-31-1 | Fatty acids, C18-unsatd., dimers, polymers with dodecylphenol, formaldehyde, maleic anhydride, pentaerythritol and rosin | Active | FRI XU Y1 |
| 109961-32-2 | Fatty acids, dehydrated castor-oil, polymers with benzoic acid, glycerol, pentaerythritol, phthalic anhydride and soya fatty acids | Active | FRI XU Y1 |
| 109961-35-5 | Fatty acids, tall-oil, polymers with adipic acid, isophthalic acid, neopentyl glycol, trimellitic anhydride and trimethylolethane | Active | FRI XU Y1 |
| 109961-36-6 | Fatty acids, tall-oil, polymers with benzoic acid, isophthalic acid, linoleic acid and pentaerythritol | Active | FRI XU Y1 |
| 109961-41-3 | Siloxanes and Silicones, di-Me, polymers with Ph silsesquioxanes, hydroxy-terminated | Active | FRI PMN XU |
| 109961-42-4 | 2-Propenenitrile, polymer with 1,2,4-triethenylcyclohexane, hydrolyzed | Active | FRI PMN XU |
| 109981-10-4 | 2-Propenoic acid, 2-methyl-, C12-15-alkyl esters, polymers with N-[3-(dimethylamino)propyl]-2-methyl-2-propenamide and Me methacrylate | Active | FRI PMN XU |
| 110015-93-5 | 2-Propenoic acid, 2-methyl-, C12-20-alkyl esters, polymers with isodecyl methacrylate, Me methacrylate and vinylpyrrolidone | Active | FRI PMN XU |
| 110475-02-0 | Siloxanes and Silicones, di-Me, [[(3-aminopropyl)dimethoxysilyl]oxy]-terminated | Active | FRI PMN XU |
| 110475-03-1 | Siloxanes and Silicones, di-Me, Me 3-[[(1-oxooctadecyl)amino]propyl | Active | FRI PMN XU |
| 110475-04-2 | Siloxanes and Silicones, di-Me, Me 3,3,3-trifluoropropyl, hydroxy- and vinyl group-terminated | Active | FRI PMN XU |
| 110615-50-4 | 1,3-Propanediol, 2-ethyl-2-(hydroxymethyl)-, polymer with 1,1'-methylenebis[4-isocyanatobenzene], cresol-, phenol- and xylenol-blocked | Active | FRI PMN XU |
| 110720-64-4 | Siloxanes and Silicones, 3-aminopropyl Me, Me stearyl | Active | FRI PMN XU |
| 110775-80-9 | Siloxanes and Silicones, di-Me, di-Ph, polymers with Me Ph silsesquioxanes, hydroxy-terminated | Active | FRI PMN XU |
| 111353-95-8 | Fatty acids, C18-unsatd., dimers, polymers with adipic acid, ethylene glycol, isophthalic acid, neopentyl glycol, propylene glycol and terephthalic acid | Active | FRI XU Y1 |
| 113221-69-5 | 2-Propenoic acid, ethyl ester, polymer with ethenyl acetate and 2,5-furandione, hydrolyzed | Active | FRI PMN XU |
| 113355-05-8 | Siloxanes and Silicones, di-Me, polymers with Me Ph silsesquioxanes, hydroxy-terminated | Active | FRI PMN XU |
| 114553-41-2 | Siloxanes and Silicones, di-Me, 3-(2-hydroxyethoxy)propyl group-terminated, polymers with adipic acid, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol and 1,1'-methylenebis[4-isocyanatobenzene] | Active | FRI PMN XU |
| 114553-48-9 | Propanoic acid, 3-hydroxy-2-(hydroxymethyl)-2-methyl-, polymer with 1,6-diisocyanatohexane, Me Et ketone oxime-blocked, compds. with triethylamine | Active | FRI PMN XU |
| 114793-01-0 | 1,2-Ethanediol, polymer with 1,3-diisocyanatomethylbenzene, 2-ethyl-1-hexanol- and methanol-blocked | Active | FRI PMN XU |
| 115001-58-6 | Acetic acid ethenyl ester, homopolymer, hydrolyzed, reaction products with 4-methylene-2-oxetanone | Active | FRI PMN XU |
| 115019-51-7 | Fatty acids, C8-18 and C18-unsatd., diesters with polyethylene glycol ether with bisphenol A (2:1) | Active | FRI PMN XU |
| 115271-30-2 | Hexanedioic acid, polymer with 1,4-butanediol, 1,6-diisocyanatohexane, 1,2-ethanediamine, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane, .alpha.,.alpha.'-[(1-methylethylidene)di-4,1-phenylene]bis[.omega.-hydroxypoly[oxy(methyl-1,2-ethanediyl)]] and 2-methyloxirane, polyethylene-polypropylene glycol mono-Bu ether-blocked | Active | FRI PMN XU |
| 115323-07-4 | Fatty acids, tall-oil, polymers with benzoic acid, Me methacrylate, pentaerythritol, phthalic anhydride, styrene and trimethylolethane | Active | FRI PMN XU |
| 115487-49-5 | Siloxanes and Silicones, Me hydrogen, Me Ph, (dimethylsilyl)oxy-terminated | Active | FRI PMN XU |
| 115487-50-8 | Cashew, nutshell liq., polymer with epichlorohydrin and formaldehyde | Active | FRI PMN XU |
| 115606-51-4 | Siloxanes and Silicones, 3-aminopropyl Me, di-Me, Me 3-[(1-oxooctadecyl)amino]propyl | Active | FRI PMN XU |
| 115606-52-5 | Siloxanes and Silicones, di-Me, lauryl Me, Me 3-mercaptopropyl, Me 2-phenylpropyl | Active | FRI PMN XU |
| 116597-52-5 | Fatty acids, tall-oil, polymers with Me methacrylate, pentaerythritol, phthalic anhydride, soybean oil, styrene and trimethylolpropane | Active | FRI XU Y1 |
| 116597-55-8 | Fatty acids, dehydrated castor-oil, polymers with benzoic acid, pentaerythritol, phthalic anhydride and tall-oil fatty acids | Active | FRI XU Y1 |
| 116810-47-0 | Siloxanes and Silicones, di-Me, 3-hydroxypropyl group-terminated, diesters with 2-oxepanone homopolymer acetate | Active | FRI PMN XU |
| 116998-33-5 | Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-phenoxy-, styrenated, ammonium salts | Active | PMN S 5E |
| 117500-34-2 | 1,3-Benzenedicarboxylic acid, polymer with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 1,6-hexanediol, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane and 2,2,4(or 2,4,4)-trimethyl-1,6-hexanediol, acetone oxime-blocked | Active | FRI PMN XU |
| 117584-36-8 | Poly(oxy-1,2-ethanediyl), .alpha.,.alpha.'-phosphinicobis[.omega.-hydroxy-, di-C12-15-alkyl ethers | Active | FRI PMN XU |
| 117584-37-9 | Fatty acids, sunflower-oil, polymers with benzoic acid, pentaerythritol, phthalic anhydride and trimethylolpropane | Active | FRI PMN XU |
| 118439-11-5 | 1,2-Propanediol, polymer with 2,4-diisocyanato-1-methylbenzene and 2-methyloxirane, Me Et ketone oxime-blocked | Active | FRI PMN XU |
| 118685-25-9 | Formaldehyde, polymer with 2-methylphenol, Bu ether | Active | PMN S |
| 119040-02-7 | Siloxanes and Silicones, di-Me, Me vinyl, [(triethenylsilyl)oxy]-terminated | Active | FRI PMN XU |
| 119185-04-5 | Fatty acids, C18-unsatd., dimers, polymers with dicyclopentadiene, fumaric acid, maleic anhydride, rosin and soybean oil | Active | FRI PMN XU |
| 119185-05-6 | 1,3-Propanediol, 2-ethyl-2-(hydroxymethyl)-, polymer with 1,3-diisocyanatomethylbenzene and .alpha.-hydro-.omega.-hydroxypoly(oxy-1,4-butanediyl), caprolactam-blocked | Active | FRI PMN XU |
| 119185-06-7 | Poly[oxy(methyl-1,2-ethanediyl)], .alpha.,.alpha.',.alpha.''-1,2,3-propanetriyltris[.omega.-hydroxy-, polymer with .alpha.-hydro-.omega.-hydroxypoly[oxy(methyl-1,2-ethanediyl)] and 1,1'-methylenebis[4-isocyanatobenzene], Me Et ketone oxime-blocked | Active | FRI PMN XU |
| 119275-52-4 | Siloxanes and Silicones, di-Me, Me trifluoropropyl, hydroxy-terminated | Active | FRI PMN XU |
| 119275-53-5 | 1-Butene, polymer with 2-butene and 2-methyl-1-propene, epoxidized | Active | FRI PMN XU |
| 119345-05-0 | Phenol, polymer with 3a,4,7,7a-tetrahydro-4,7-methano-1H-indene, glycidyl ether | Active | FRI PMN XU |
| 119345-06-1 | Phenol, polymer with 1,3-cyclopentadiene, 2-methyl-1,3-butadiene and 3a,4,7,7a-tetrahydro-4,7-methano-1H-indene, glycidyl ether | Active | FRI PMN XU |
| 122335-03-9 | Soybean oil, polymer with diethylene glycol and phthalic anhydride | Active | FRI PMN XU |
| 1227870-90-7 | Oxirane, 2-methyl-, polymer with 2,4-diisocyanato-1-methylbenzene, 2-methyloxirane polymer with oxirane ether with 1,2,3-propanetriol (3:1), and oxirane, cashew nutshell liq.- and Pr alc.-blocked | Active | PMN SP 5E |
| 1245553-85-8 | Glycerides, mixed acetyl and lauroyl | Active | PMN S 5E |
| 124578-11-6 | 2,5-Furandione, polymers with hydrogenated butadiene-styrene polymer | Active | FRI PMN XU |
| 125904-11-2 | Benzene, ethenyl-, ar-bromo derivs. | Active | PMN S 5E |
| 1267611-06-2 | Paraffin waxes (lignocellulosic), hydrotreated, C5-40-branched, cyclic and linear | Active | PMN S 5E |
| 1267611-11-9 | Distillates (lignocellulosic), hydrotreated, C8-26-branched, cyclic and linear | Active | PMN S 5E |
| 1267611-14-2 | Kerosine (lignocellulosic), hydrotreated, C8-16-branched, cyclic and linear | Active | PMN S 5E |
| 1267611-35-7 | Naphtha (lignocellulosic), hydrotreated, C5-12-branch, cyclic and linear | Active | PMN S 5E |
| 1267611-71-1 | Residual oils (lignocellulosic), hydrotreated, C20-40-branch, cyclic and linear | Active | PMN S 5E |
| 1267611-99-3 | Distillates (lignocellulosic), C5-40 | Active | PMN S 5E |
| 1275611-61-4 | Benzenesulfonic acid, dimethyl-, mono-C11-16-sec-alkyl derivs., sodium salts | Active | PMN S 5E |
| 1279108-20-1 | Hexane, 1,6-diisocyanato-, homopolymer, .alpha.-[1-[[[3-[[3-(dimethylamino)propyl]amino]propyl]amino]carbonyl]-1,2,2,2-tetrafluoroethyl]-.omega.-(1,1,2,2,3,3,3-heptafluoropropoxy)poly[oxy[trifluoro(trifluoromethyl)-1,2-ethanediyl]]-blocked | Active | PMN S 5E |
| 130353-62-7 | Benzenesulfonamide, 2-methyl-, reaction products with bisphenol A-epichlorohydrin polymer and 4-methylbenzenesulfonamide | Active | PMN S 5E |
| 136504-96-6 | 1,3-Propanediamine, N1,N1'-1,2-ethanediylbis-, polymer with 2,4,6-trichloro-1,3,5-triazine, reaction products with N-butyl-2,2,6,6-tetramethyl-4-piperidinamine | Active | PMN S 5E |
| 1372804-76-6 | Alkanes, C14-16, chloro | Active | PMN S 5E |
| 1375604-06-0 | Amides, from ammonia-ethanolamine reaction by-products and branched and linear C16-18 and C18-unsatd. fatty acids, hydrochlorides | Active | PMN S |
| 1400260-68-5 | Amides, C16-18 and C18-unsatd., branched and linear, N-[2-[[2-[(2-aminoethyl)amino]ethyl]amino]ethyl], trihydrochlorides | Active | PMN S |
| 1400260-69-6 | Amides, C16-18 and C18-unsatd., branched and linear, N-[2-[[2-[[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]amino]ethyl], tetrahydrochlorides | Active | PMN S |
| 1400263-22-0 | Amides, from ammonia-ethanolamine reaction by-products and tall oil, hydrochlorides | Active | PMN S |
| 1401974-24-0 | Alkanes, C22-30-branched and linear, chloro | Active | PMN S 5E |
| 1402738-52-6 | Alkanes, C24-28, chloro | Active | PMN S 5E |
From the EPA non-confidential TSCA Inventory, July 2026 release. EPA also maintains a confidential portion it does not publish, so a substance absent from this data is not thereby unflagged.