Also known as: 3-Acetyl-6-methyl-2,4-pyrandione, 3-Acetyl-6-methyl-2H-pyran-2,4(3H)-dione, DHS, Geogard 111A, Dehydracetic acid (+15 more)
INCI: DEHYDROACETIC ACID
Dehydroacetic Acid (CAS 520-45-6) is a cosmetic preservative functioning as Preservative; broad-spectrum antimicrobial (bacteria, fungi, yeasts). EU Regulation 1223/2009 status: restricted, max 0.6%. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety, pharmaceutical, and food safety data.
US NotesPermitted without specific cosmetic concentration cap under FDA. Listed in FDA Inactive Ingredients Database for topical use. No specific MoCRA restriction. Sodium dehydroacetate (the sodium salt form) is the most commonly used form in cosmetic formulations.
For full compliance data across multiple jurisdictions, use the
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Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Dehydroacetic Acid.
Calculate MoS for your specific formulation with the
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Sensitization Profile
Contact sensitization data for Dehydroacetic Acid based on clinical patch test studies and IFRA standards.
Sensitization Rate
low
Allergen Class
preservative
EU Allergen Listed
no
Patch Test Positive Rate
0.1%
Cross-reactivity Group
none
Reaction Type
contact-dermatitis
Source: ESSCA; IVDK; NACDG
Dermal Penetration Profile
Skin absorption and penetration characteristics of Dehydroacetic Acid, relevant to systemic exposure and MoS calculations.
Absorption %
6-12%
Penetration Level
stratum-corneum
Penetration Depth
stratum corneum/epidermis
Molecular Weight
168.1 Da
Log P
0.52
Systemic Absorption
minimal
Topical Bioavailability
4-10%
Safety Margin Factor
moderate
Vehicle Dependent
Yes — absorption varies by formulation
Source: SCCS Opinion
EPA ToxValDB — Toxicity Values
2 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).
Endpoint
Value
Species
Route
Duration
Source
LD50
=1330 mg/kg
Mouse
oral
-
ChemIDplus
LD50
=500 mg/kg
Rat
oral
-
ChemIDplus
EU CLP Annex VI Harmonized Classification
Legally binding harmonized classification per Regulation (EC) No 1272/2008 (CLP) Annex VI.
Signal Word
Warning
Pictograms
Harmful / Irritant
Hazard Class and Category
Acute Tox. 4 *
Hazard Statements
H302Harmful if swallowed
Inserted via ATP: CLP00
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
1,000 - 10,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
Hazard classification:Restricted (Annex XVII)
Expanded Jurisdictional Detail
Additional regulatory detail beyond the 7-jurisdiction summary: Saudi SFDA, Korea MFDS, ASEAN ACD, Japan/Korea, Brazil/India, and cross-jurisdictional restriction entries.
JPKR Japan/Korea Cosmetics
Japan (Positive (Preservative)): max 0.50
Korea (Restricted): max 0.6
Japan (Restricted): max 0.50%
Additional Jurisdictional Restrictions (5)
Jurisdiction
Status
Max %
Product Type
JP
restricted
0.50%
All cosmetics
CN
permitted_preservative
0.6
All cosmetics
IN
permitted_preservative
0.6
all cosmetics
BR
permitted_preservative
0.6
0.6% as acid; prohibited in sprayable systems
ASEAN
permitted_preservative
0.6% as acid
All products
Typical Use Concentrations
Reported concentration ranges per product category from SCCS/CIR/industry sources.
Product Category
Typical Range
Max Reported
Source
Face Cream
0.1–0.6
0.6
CIR Safety Assessment
Function Categories & List Membership
Cosmetic/Chemical Function Categories
AntioxidantBiocideFragrancePreservative
Regulatory List Membership (3)
EPA Safer Chemical Ingredients List (SCIL)FDA Substances Added to Food (EAFUS)Consumer Product Chemical
Editorial summary
Preliminary editorial summary for Dehydroacetic Acid — not a computed safety verdict. See the sourced toxicological data above.
inert_ingredient; non_food_use; Pesticidesactive_ingredient; Europe; Pesticidesdetected; Europe; Personal care - sexual wellnessdetected; Europe; Personal care - sexual wellnessEurope; Personal care - sexual wellnessEurope; Personal care - body hygiene - hand soapCEDIfood_additive; Substances Added to Food (formerly EAFUS) (2/2019)SCIL (9/2019)consumer_product
Australian Status
AICIS status:listed
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical and food safety data.
SOURCEChEMBL / DrugCentral / FAERSDB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Dehydroacetic Acid has a safety rating of "GOOD" in our database. EU status: restricted. US status: permitted.
Is Dehydroacetic Acid allowed in the EU?
Dehydroacetic Acid EU regulatory status: restricted. Maximum allowed concentration: 0.6%. This is based on EU Regulation 1223/2009 and its amendments.
What does Dehydroacetic Acid do in cosmetics?
Dehydroacetic Acid functions as: Preservative; broad-spectrum antimicrobial (bacteria, fungi, yeasts). It is classified as a Preservative in our database. CAS number: 520-45-6.
Is Dehydroacetic Acid used outside cosmetics?
Dehydroacetic Acid also appears in industrial chemical safety, pharmaceutical, and food safety data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Compliance Tools
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