- beauty
- industrial
Guanine
CAS 73-40-5 · 20/100 · High conf.
Also registered as 13 other CAS numbers
71660-36-1 · 492-33-1 · 8039-79-0 · 11006-44-3 · 15986-36-4 · 37432-34-1 · 54435-87-9 · 66224-64-4 · 69257-39-2 · 158475-99-1 · 929247-29-0 · 934585-79-2 · 936902-27-1
Concern score
20/100Minor concern based on regulatory listings.
High confidence
Guanine in plain language
On cosmetic ingredient lists it appears as “CI 75170”.
Also known as CI 75170 · 2-Amino-1,7-dihydro-6H-purin-6-one · 2-AMINOHYPOXANTHINE · 2-Amino-1,9-dihydro-6H-purin-6-one · 2-amino-1,7-dihydropurin-6-one · C.I. no. 75170 (guanine)
Show all 27 names
2-Amino-1,7-dihydro-6H-purin-6-one; Guanine · 2-Amino-6-hydroxy-1H-purine · 2-Amino-6-hydroxypurine · 2-amino-3,7-dihydropurin-6-one · 6-Hydroxy-2-aminopurine · 6H-Purin-6-one, 2-amino-1,7-dihydro- · 6H-Purin-6-one, 2-amino-1,9-dihydro- · C.I. Natural White 1 · CI Natural white 1 · Dew Pearl · Guanin · Guanine (CI 75170) · Guanine enol · Hypoxanthine, 2-amino- · Mearlmaid · Natural pearl essence · Natural white 1 · Naturon · Pearl essence · Stella Polaris · guanine sigma grade
Used in cosmetics as a colourant and an opacifier. Guanine is a natural purine.
- Colorant
- Opacifying
- Colourant
- Opacifier
- Minor concern: no hazard classifications on record. It is listed for cosmetic use in the EU.
What the listings say
Permitted, with conditions — Guanine appears on published "allowed" regulatory lists rather than on a restriction list.
2-Amino-1,7-dihydro-6H-purin-6-one is listed in Annex IV of the EU Cosmetics Regulation (EC) 1223/2009 (colorants allowed in cosmetic products).
The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.
Regulation
No restrictions found. Guanine appears in these published regulatory listings.
- EU Annex IV — permitted colorant
- EU permitted colorant
- Found in consumer products
- Beauty
- Industrial
EUECallowed_listedAnnex IV of EU Cosmetics Regulation (EC) 1223/2009: colorants allowed in cosmetic products.
- Annex IV of EU Cosmetics Regulation (EC) 1223/2009: colorants allowed in cosmetic products.Source →
USEPAcommercial use observedEPA CPDat observed this chemical in 73 composition records across product categories including Laboratory supplies, Construction, Personal care. EPA CPDat classifies this chemical for functional uses including Dye, Opacifer.
- EPA CPDat observed this chemical in 73 composition records across product categories including Laboratory supplies, Construction, Personal care. EPA CPDat classifies this chemical for functional uses including Dye, Opacifer.Source →
USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
- openFDA substance registry classifies this ingredient as chemical.Source →
Expert safety opinions
No expert opinion on file for Guanine. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.
SCCS
EU Scientific Committee on Consumer Safety
No SCCS opinion on file.
CIR
Cosmetic Ingredient Review (US expert panel)
No CIR safety assessment on file.
Evidence & sources
No graded research studies for Guanine yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.
Where this comes from
- Open →
CosIng
regulatory · updated 2026-09-23
- Open →
EU CosIng Cosmetics Regulation Annexes
regulatory · updated 2020-08-14
- Open →
EPA Chemical and Products Database
exposure · updated September 2013
- Open →
EPA DSSTox Identifiers
chemistry · updated 2025-12-29
- Open →
FDA GSRS UNII
registry · updated 2026-02-26
- Open →
openFDA Substance
registry · updated 2026-05-24
- Open →
PubChem Live Enrichment
chemistry · updated 2026-05-17
Reference links (2)
ncithesaurus.nci.nih.gov
Suitability
Context-specific fit derived from published classifications and the current ingredient evidence profile.
Food use
Food-use source coverage is present in the current record.
The ingredient appears in food-oriented source coverage or allowed-use references, which makes food use easier to support than a context with no domain signal at all.
Fragrance avoidance
No fragrance-linked caution surfaced in the current profile.
This ingredient does not currently read as a fragrance-linked driver in the published evidence and hazard profile.
Where it has been recorded
How often EPA CPDat has listed Guanine in a product composition. These are source records, not Greenveil catalog products.
Source records
73
Named organisations
6
Laboratory suppliesConstructionPersonal care
Typical roles
ColorantOpacifyingColourantOpacifier
Found in these products
Cosmetic and personal-care products that list Guanine are shown first. Their ingredient lists include Guanine; each product's own rating depends on its whole formula, so it is shown on the product page, not here.
