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HC Blue No. 1
AKA “HC Blue 1, HC Blue Number 1, NCI-C04159, 2'-((4-(Methylamino)-3-nitrophenyl)imino)diethanol, 1-Methylamino-2-nitro-4-(bis-2-hydroxyethyl)aminobenzene, Ethanol”
Synthetic
Ingredient Facts
Hc blue no. 1
AKA: HC Blue 1, HC Blue Number 1, NCI-C04159, 2'-((4-(Methylamino)-3-nitrophenyl)imino)diethanol, 1-Methylamino-2-nitro-4-(bis-2-hydroxyethyl)aminobenzene, Ethanol
Synthetic · Hair Dyeing · EWG: 4
Synthetic
Colorant
Synthetic
Clean
A synthetic blue colorant that delivers vibrant, long-lasting color to hair. Creates rich blue tones that resist fading with each wash.
Solubility less than 0.1 mg/mL at 64 °F (NTP, 1992)
Formula
C11H17N3O4
Mol. Weight
255.27
CAS #
173994-75-7, 102767-27-1
Form
Powder
State
Hc blue 1 appears as dark blue microcrystals or dark purple powder. (NTP, 1992)
See origin →
Functions
Hair Dyeing
Colorant
Gives the product its color. Purely aesthetic — makes the formula look good in the jar but does nothing for your skin.
Colors Hair
Traditional Use
HC Blue No. 1 is a synthetic aromatic amide dye developed in the 20th century specifically for hair coloring applications. It was created to provide a direct dye option for semi-permanent and permanent hair color formulations.
Skin Types
●all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Caution
EWG
4
CIR
Safe w/Qualifications
Pregnancy
Caution
CIR Safety Findings
medical-approval
all-shades-safe
Regulatory Status
USA✔ permitted
EU✔ permitted
JAPAN✔ permitted
CANADA✔ permitted
HC Blue No. 1.
IARC monographs on the evaluation of carcinogenic risks to humans, 1993
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Occupational allergic contact dermatitis caused by coconut fatty acids diethanolamide.
Aalto-Korte K, Pesonen M, Kuuliala O, Suuronen K
Contact dermatitis, 2014
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Occupational allergic contact dermatitis caused by coconut fatty acids diethanolamide.
Aalto-Korte K, Pesonen M, Kuuliala O, Suuronen K
Contact dermatitis, 2014
→
Occupational allergic contact dermatitis caused by coconut fatty acids diethanolamide.
Aalto-Korte K, Pesonen M, Kuuliala O, Suuronen K
Contact dermatitis, 2014
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Final report on the safety assessment of 3-methylamino-4-nitrophenoxyethanol as used in hair dyes.
Becker LC, Cosmetic Ingredient Review Expert Panel
International journal of toxicology, 2008
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Allergic contact dermatitis from trideceth-2-carboxamide monoethanolamine (MEA) in a hair dye.
Bowling JC, Scarisbrick J, Warin AP, Downs AM
Contact dermatitis, 2002
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Allergic contact dermatitis from trideceth-2-carboxamide monoethanolamine (MEA) in a hair dye.
Bowling JC, Scarisbrick J, Warin AP, Downs AM
Contact dermatitis, 2002
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Explaining skin permeation of 2-butoxyethanol from neat and aqueous solutions.
Bunge AL, Persichetti JM, Payan JP
International journal of pharmaceutics, 2012
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Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final amended report on the safety assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
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Effects of ethanol and diclofenac on the organization of hydrogenated phosphatidylcholine bilayer vesicles and their ability as skin carriers.
Castangia I, Manca ML, Matricardi P, Catalán-Latorre A, Nácher A et al.
Journal of materials science. Materials in medicine, 2015
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Screening of yeasts for the production of 2-phenylethanol (rose aroma) in organic waste-based media.
Chreptowicz K, Sternicka MK, Kowalska PD, Mierzejewska J
Letters in applied microbiology, 2018
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Final Amended Report on the Safety Assessment of 2,4-Diaminophenoxyethanol HCl and 2,4-Diaminophenoxyethanol Sulfate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Final Amended Report on the Safety Assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl Thioglycolate, Glyceryl Thioglycolate, Isooctyl T
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Final Report on the Safety Assessment of 2,4-Diaminophenoxyethanol Dihydrochloride
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of 3-Methylamino-4-Nitrophenoxyethanol as Used in Hair Dyes
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of Butoxyethanol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of Ethoxyethanol and Ethoxyethanol Acetate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of HC Blue No. 1
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of Phenoxyethanol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Final Report on the Safety Assessment of Potassium-Coco-Hydrolyzed Animal Protein and Triethanolamine-Coco-Hydrolyzed Animal Protein
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Final Report on the Safety Assessment of Triethanolamine, Diethanolamine, and Monoethanolamine
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Final Report: Amended Safety Assessment of 2,4-Diaminophenoxyethanol HCl and 2,4-Diaminophenoxyethanol Sulfate as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Safety Assessment of Diethanolamides as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Safety Assessment of Diethanolamine and Its Salts as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Safety Assessment of Ethanolamides as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Safety Assessment of Ethanolamine and Ethanolamine Salts as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Safety Assessment of Triethanolamine and Triethanolamine-Containing Ingredients as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
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Tentative Report: Amended Safety Assessment of Butoxyethanol as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
2,4-Diaminophenoxyethanol HCl
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
2,4-Diaminophenoxyethanol Sulfate
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
3-Methylamino-4-Nitrophenoxyethanol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Butoxyethanol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Ethanolamine
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Ethanolamine HCl
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Ethanolamine Thioglycolate
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Lysophosphatidylethanolamine
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Phenoxyethanol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Triethanolamine
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Phenoxyethanol Safety Assessment
Cosmetic Ingredient Review Expert Panel
International Journal of Toxicology, 2019
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Safety review of phenoxyethanol when used as a preservative in cosmetics.
Dréno B, Zuberbier T, Gelmetti C, Gontijo G, Marinovich M
Journal of the European Academy of Dermatology and Venereology : JEADV, 2019
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Safety review of phenoxyethanol when used as a preservati...
B Dréno, T Zuberbier, C Gelmetti, G Gontijo, M Marinovich
Journal of the European Academy of Dermatology and Venereology : JEADV, 2019
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Chemical characterization and antimicrobial activities of Citrus aurantifolia peel oils and Ocimum sanctum ethanolic extract.
Duangsombat P, Waranuch N, Pitaksuteepong T
PloS one, 2025
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Chemical characterization and antimicrobial activities of Citrus aurantifolia peel oils and Ocimum sanctum ethanolic extract.
Duangsombat P, Waranuch N, Pitaksuteepong T
PloS one, 2025
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2,4-Diaminophenoxyethanol HCl
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
2,4-Diaminophenoxyethanol Sulfate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
Butoxyethanol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
Diethanolamine
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
ethanol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
Ethanolamine
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
Ethoxyethanol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
HC Blue No. 1
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
Phenoxyethanol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
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Triethanolamine
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
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Safety Assessment of Diethanolamine and Its Salts as Used...
Monice M Fiume, Bart Heldreth, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen + 6 more
International journal of toxicology, 2017
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Safety Assessment of Diethanolamine and Its Salts as Used...
Monice M Fiume, Bart Heldreth, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen + 6 more
International journal of toxicology, 2017
→
Safety Assessment of Diethanolamine and Its Salts as Used...
Monice M Fiume, Bart Heldreth, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen + 6 more
International journal of toxicology, 2017
→
Safety assessment of triethanolamine and triethanolamine-containing ingredients as used in cosmetics.
Fiume MM, Heldreth B, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2013
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Detection of fatty acid ethyl esters in skin surface lipids as biomarkers of ethanol consumption in alcoholics, social drinkers, light drinkers, and t
González-Illán F, Ojeda-Torres G, Díaz-Vázquez LM, Rosario O
Journal of analytical toxicology, 2011
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2-Amino-1,2-bis(4-methoxyphenol) ethanol and its salts
Health Canada
Health Canada Cosmetic Ingredient Hotlist
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2,4-Diaminophenylethanol and its salts
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Butoxyethanol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Ethoxyethanol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Ethoxyethanol acetate
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Methoxyethanol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
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Methoxyethanol acetate
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Tribromoethanol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Final report on the safety assessment of ethoxyethanol and ethoxyethanol acetate.
Johnson W Jr, Cosmetic Ingredient Review Expert panel
International journal of toxicology, 2002
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Final report on the safety assessment of ethoxyethanol and ethoxyethanol acetate.
Johnson W Jr, Cosmetic Ingredient Review Expert panel
International journal of toxicology, 2002
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In vivo and in vitro inhibitory activity of an ethanolic extract of Sargassum fulvellum and its component grasshopper ketone on atopic dermatitis.
Kang BK, Kim MJ, Kim KB, Ahn DH
International immunopharmacology, 2016
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Direct synthesis of dimethyl carbonate from methanol and carbon dioxide over CeO2(X)-ZnO(1-X) nano-catalysts.
Kang KH, Joe W, Lee CH, Kim M, Kim DB et al.
Journal of nanoscience and nanotechnology, 2013
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Formation and inhibition of N-nitrosodiethanolamine in cosmetics under pH, temperature, and fluorescent, ultraviolet, and visual light.
Lim DS, Lim SK, Kim MK, Kwon YC, Roh TH et al.
Journal of toxicology and environmental health. Part A, 2018
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Can 1% chlorhexidine diacetate and ethanol stabilize resin-dentin bonds?
Manso AP, Grande RH, Bedran-Russo AK, Reis A, Loguercio AD et al.
Dental materials : official publication of the Academy of Dental Materials, 2014
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Allergic contact dermatitis caused by cocamide diethanolamine.
Mertens S, Gilissen L, Goossens A
Contact dermatitis, 2016
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Anti-senescence and anti-apoptotic effects of immature Citrus unshiu peel ethanol extract on ultraviolet B-irradiated skin keratinocytes.
Piao MJ, Kang KA, Fernando PDSM, Herath HMUL, Senavirathna HMMM et al.
Toxicological research, 2025
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Antioxidant screening and phenolic content of ethanol extracts of selected Baja California Peninsula macroalgae.
Tenorio-Rodriguez PA, Murillo-Álvarez JI, Campa-Cordova ÁI, Angulo C
Journal of food science and technology, 2017
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Skin-permeable gold nanoparticles with modifications azelamide monoethanolamine ameliorate inflammatory skin diseases.
Zhao H, Zhao H, Tang Y, Li M, Cai Y et al.
Biomarker research, 2024
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Skin-permeable gold nanoparticles with modifications azelamide monoethanolamine ameliorate inflammatory skin diseases.
Zhao H, Zhao H, Tang Y, Li M, Cai Y et al.
Biomarker research, 2024
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Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR