Is Etidronic Acid safe in cosmetics?
Etidronic Acid has a safety rating of "GOOD" in our database. EU status: restricted. US status: permitted. 5 toxicological study endpoint(s) are available in our database.
Etidronic Acid
Also known as: Phosphonic acid, (1-hydroxyethylidene)bis-, 1,1,1-Ethanetriol diphosphonate, Phosphonic acid, P,P′-(1-hydroxyethylidene)bis-, 0-02-00-00171, BRN 1789291 (+15 more)
INCI: ETIDRONIC ACID
Etidronic Acid (CAS 2809-21-4) is a cosmetic cosmetic ingredient functioning as Chelating agent, perfume excipient. NOAEL 78 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: restricted, max 1.5% in hair care products; 0.2% in soap. 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.
View industrial chemical safety profile for CAS 2809-21-4 →
Auto-generated CPSR Part A draft with source citations
Cross-Vertical Regulatory Divergence
Etidronic Acid is classified GHS Danger (H290, H302, H314, H318, H413, H371) in the chemicals database but is restricted in EU cosmetics at max 1.5% in hair care products; 0.2% in soap.
Source: Cosmetics: ingredients.eu_status/eu_max; Chemicals: ghs_classifications.signal_word/hazard_statement_code
Function
Chelating agent, perfume excipient
Safety Rating
GOOD
Chemistry & Identifiers
IUPAC Name
(1-hydroxy-1-phosphonoethyl)phosphonic acid
InChIKey
DBVJJBKOTRCVKF-UHFFFAOYSA-N
Regulatory Status
EU EU Status
restricted
EU Max Conc.
1.5% in hair care products; 0.2% in soap
US US Status
permitted
US Notes
CIR Expert Panel (2017) concluded safe in present practices. No FDA restriction in cosmetics. Highest reported cosmetic use concentration was 0.9% (hair coloring); highest leave-on dermal exposure was 0.12% (fragrance).
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Etidronic Acid.
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
5 study endpoints found for Etidronic Acid. NOAEL (No Observed Adverse Effect Level) values are used to calculate the Margin of Safety per SCCS methodology.
| Endpoint | Value | Route | Species | Study Type | Source |
|---|---|---|---|---|---|
| NOAEL | 75 mg/kg bw/day | oral | dog | Subchronic | COSMOS_DB |
| NOAEL | 100 mg/kg bw/day | oral | rabbit | Developmental | COSMOS_DB |
| NOAEL | 250 mg/kg bw/day | oral | rat | Multigeneration Reproductive | COSMOS_DB |
| NOAEL | 330.3 mg/kg bw/day | oral | rat | Developmental | COSMOS_DB |
| NOAEL | 500 mg/kg bw/day | oral | rat | Chronic | COSMOS_DB |
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for Etidronic Acid across SCCS product categories, with measured dermal absorption where available.
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
10,000 - 100,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
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.
SA Saudi SFDA (III - Restricted)
Product type: (a) Hair product (b) Soap. Max: (a) 1.5% (as etidronic acid) (b) 0.2% (as etidronic acid).
BRIN Brazil/India Cosmetics
India: Restricted · max (a) 1.5% (as etidronic acid) (b) 0.2% (as etidronic acid)
Additional Jurisdictional Restrictions (2)
| Jurisdiction | Status | Max % | Product Type |
|---|---|---|---|
| AU | restricted | - | certain soaps |
| ASEAN | restricted | 1.5% (hair products); 0.2% (soap-based products) | Hair care; soap |
PubChem Annotations
Safety and regulatory annotations from PubChem (NCBI) aggregated sources.
Safety (1)
Carcinogen Classification
No indication of carcinogenicity to humans (not listed by IARC).
Source: Toxin and Toxin Target Database (T3DB)
Regulatory (1)
JECFA Evaluation
HEDP | 2004 | HEDP does not pose a safety concern at the levels of residue that are expected to remain on foods at the time of consumption | TRS 928-JECFA 63/26 | FAS 54-JECFA 63/87
Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Chelating agent
Corrosion inhibitor
Fragrance
Oxidizing agent
Processing aids not otherwise specified
Stabilizing agent
Regulatory List Membership (4)
IFRA Fragrance Transparency List
EPA Safer Chemical Ingredients List (SCIL)
FDA Substances Added to Food (EAFUS)
EU CosIng Cosmetics Ingredient Database
Expert Verdict
Expert safety assessment and concern-level summary for Etidronic Acid.
Regulatory Flags
eu-annex-iii-restricted
poor-biodegradability
not-cosmos-ecocert-eligible
cir-reviewed
chelating-agent
epa_safer_alternative
ifra_fragrance
fda_food_additive
eu_cosing_listed
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to Etidronic Acid by CAS number or substance name.
Studies
5
Lowest NOAEL
75 mg/kg bw/day
Highest NOAEL
500 mg/kg bw/day
COSMOS_DB
Known Synonyms
Phosphonic acid, (1-hydroxyethylidene)bis-
1,1,1-Ethanetriol diphosphonate
Phosphonic acid, P,P′-(1-hydroxyethylidene)bis-
0-02-00-00171
BRN 1789291
EINECS 220-552-8
Hydroxyethane-1,1-diphosphonic acid
(1-Hydroxyethylene)diphosphonic acid
1-Hydroxyethylidene-1,1-biphosphonate
(1-Hydroxyethylidene)diphoshonic acid
Phosphonic acid, 1-hydroxy-1,1-ethanediyl ester
UNII-M2F465ROXU
(1-Hydroxyethylidene)bis(phosphonic acid)
(Hydroxyethylidene)diphosphonic acid
1-Hydroxyethane-1,1-diphosphonate
1-Hydroxyethanediphosphonic acid
1-Hydroxyethylidene-1,1-bisphosphonate
EHDP
Ethane-1-hydroxy-1,1-bisphosphonate
Ethane-1-hydroxy-1,1-diphosphonate
Chemical Function
Chelating agent
Fragrance
Oxidizing agent
Stabilizing agent
Corrosion inhibitor
Regulatory Lists
Europe; Personal care; restricted
inert_ingredient; Pesticides
food_additive; Substances Added to Food (formerly EAFUS) (2/2019)
inert_ingredient; non_food_use; Pesticides
pharmaceutical
SCIL (9/2019)
Canada; pharmaceutical
IFRA Transparency
Australian Status
AICIS status: listed
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical and food safety data.
SOURCE
ChEMBL / DrugCentral / FAERS
DB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Compound
ETIDRONIC ACID
ChEMBL ID
CHEMBL871
Max Phase
4
Adverse Event Associations
26
SOURCE
EFSA / FDA GRAS
food_additives
Food Safety Data
Same-CAS food additive or FDA GRAS records from the core public database.
Food Name
1-HYDROXYETHYLIDENE-1,1-DIPHOSPHONIC ACID
Food Category
food_additive
Frequently Asked Questions
Is Etidronic Acid allowed in the EU?
Etidronic Acid EU regulatory status: restricted. Maximum allowed concentration: 1.5% in hair care products; 0.2% in soap. This is based on EU Regulation 1223/2009 and its amendments.
What does Etidronic Acid do in cosmetics?
Etidronic Acid functions as: Chelating agent, perfume excipient. It is classified as a cosmetic ingredient in our database. CAS number: 2809-21-4.
What is the NOAEL for Etidronic Acid?
The NOAEL (No Observed Adverse Effect Level) for Etidronic Acid is 75 mg/kg bw/day based on a Subchronic study via oral route in dog. A total of 5 study endpoints are available. Source: COSMOS_DB.
Is Etidronic Acid used outside cosmetics?
Etidronic 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.
Does Etidronic Acid have different safety status in cosmetics vs industrial chemicals?
Etidronic Acid is classified GHS Danger (H290, H302, H314, H318, H413, H371) in the chemicals database but is restricted in EU cosmetics at max 1.5% in hair care products; 0.2% in soap.
Compliance Tools
Check Etidronic Acid compliance across multiple jurisdictions:
Ingredient Decoder
Paste a full ingredient list for instant analysis
82 Allergen Checker
Check for EU declarable fragrance allergens
Substance Compliance
Check compliance across multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions
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