Regulatory Status
For full compliance data across 55 jurisdictions, use the Substance Compliance tool.
Safety Data
Calculate MoS for your specific formulation with the MoS Calculator.
Expert Verdict
CI 42100 is an anionic sulfonated triphenylmethane dye authorized under EU Annex IV for rinse-off cosmetics only; leave-on applications are prohibited in the EU. The ingredient has no FDA cosmetic color additive listing and is not authorized for use in US cosmetics.
Regulatory Flags
Frequently Asked Questions
Is CI 42100 (Acid Green 9 / Steel Blue) safe in cosmetics?
CI 42100 is an anionic sulfonated triphenylmethane dye authorized under EU Annex IV for rinse-off cosmetics only; leave-on applications are prohibited in the EU. The ingredient has no FDA cosmetic color additive listing and is not authorized for use in US cosmetics. The EU classifies CI 42100 (Acid Green 9 / Steel Blue) as "restricted". Safety rating: MODERATE.
Is CI 42100 (Acid Green 9 / Steel Blue) allowed in the EU?
CI 42100 (Acid Green 9 / Steel Blue) EU regulatory status: restricted. Maximum allowed concentration: Annex IV, Entry IV/64; restricted to rinse-off applications only. No maximum concentration specified for permitted rinse-off applications.. This is based on EU Regulation 1223/2009 and its amendments.
What does CI 42100 (Acid Green 9 / Steel Blue) do in cosmetics?
CI 42100 (Acid Green 9 / Steel Blue) functions as: Colorant. Synthetic triphenylmethane dye (Acid Green 9 / Steel Blue). Water-soluble anionic sulfonated triphenylmethane dye. Permitted under EU Annex IV for rinse-off cosmetic applications only.. It is classified as a cosmetic ingredient in our database. CAS number: 4857-81-2.
What is the Margin of Safety for CI 42100 (Acid Green 9 / Steel Blue)?
not established The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.
Compliance Tools
Check CI 42100 (Acid Green 9 / Steel Blue) compliance across multiple jurisdictions:
Related Ingredients
Is CI 42100 (Acid Green 9 / Steel Blue) in Your Products?
Scan any product label with Piro — our free ingredient scanner. Point your camera at the ingredients list and get instant safety scores for every ingredient.
Try Piro Free →Analyze Your Full Ingredient List
Paste any INCI list into the Decoder for instant safety analysis, or calculate the Margin of Safety for CI 42100 (Acid Green 9 / Steel Blue) in your formulation.