Guanine

INCI: GUANINE

CAS Number
73-40-5
Function
Opacifying agent; colorant (pearlescent/iridescent effect)
Safety Rating
EXCELLENT

Regulatory Status

🇪🇺 EU Status permitted
🇺🇸 US Status permitted
US Notes Permitted — permanently listed, exempt from certification; approved for cosmetics generally including eye area under 21 CFR 73.2329

For full compliance data across 55 jurisdictions, use the Substance Compliance tool.

Safety Data

Margin of Safety (MoS)
adequate
Dermal Absorption
negligible
Sensitization
none

Calculate MoS for your specific formulation with the MoS Calculator.

Expert Verdict

GHS R36/37/38 applies to pure powder occupational handling only. No consumer-level concerns at cosmetic use concentrations. Fish-scale–derived guanine may present allergen labeling issues for fish-allergic consumers; voluntary disclosure recommended.

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Concern Level: Low

Regulatory Flags

potential-allergen colorant eu_cosing_listed

Frequently Asked Questions

Is Guanine safe in cosmetics?

GHS R36/37/38 applies to pure powder occupational handling only. No consumer-level concerns at cosmetic use concentrations. Fish-scale–derived guanine may present allergen labeling issues for fish-allergic consumers; voluntary disclosure recommended. The EU classifies Guanine as "permitted". Safety rating: EXCELLENT.

Is Guanine allowed in the EU?

Guanine EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.

What does Guanine do in cosmetics?

Guanine functions as: Opacifying agent; colorant (pearlescent/iridescent effect). It is classified as a cosmetic ingredient in our database. CAS number: 73-40-5.

What is the Margin of Safety for Guanine?

adequate 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.

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