Is Potassium Hydroxide safe in cosmetics?
Potassium Hydroxide has a safety rating of "MODERATE" in our database. EU status: restricted. US status: permitted. 4 toxicological study endpoint(s) are available in our database.
Potassium Hydroxide
Also known as: KCl, [KCl], Potassium chloride (KCl), EC No.: 231-211-8, Caswell No. 686 (+15 more)
INCI: POTASSIUM HYDROXIDE
Potassium Hydroxide (CAS 7447-40-7) is a cosmetic cosmetic ingredient functioning as Strong alkali used in cuticle remover formulations at 2–5%. Dissolves dead. NOAEL 1820 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: restricted, max Regulated as alkaline agent; EU cosmetic regulations require pH and concentration control for alkaline products. Cuticle remover-specific formulations must be assessed for skin safety at use concentration/pH. Not for use on broken or irritated skin.. Industrial safety data is also available in the chemical safety dat
Function
Strong alkali used in cuticle remover formulations at 2–5%. Dissolves dead cuticle tissue via alkaline hydrolysis of peptide bonds in the stratum corneum proteins of the cuticle. Caustic — strict pH control and precise concentration are essential for safe use. Also used as a pH adjuster in cosmetic formulations at much lower concentrations.
Editorial assessment
MODERATE
Preliminary editorial note — not a computed safety verdict.
Regulatory Status
EU EU Status
restricted
EU Max Conc.
Regulated as alkaline agent; EU cosmetic regulations require pH and concentration control for alkaline products. Cuticle remover-specific formulations must be assessed for skin safety at use concentration/pH. Not for use on broken or irritated skin.
US US Status
permitted
US Notes
FDA GRAS for direct food use under 21 CFR 184.1631. No separate cosmetic approval system; cosmetic use governed by general FD&C Act safety provisions. CIR Expert Panel (2021, Int J Toxicol 40(2_suppl):16S-35S) concluded safe as used when formulated to be non-irritating. Not a sunscreen active.
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Potassium Hydroxide.
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
4 study endpoints found for Potassium Hydroxide. 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 | 195 mg/kg bw/day | oral | dog | Short Term Toxicity | COSMOS DB |
| NOAEL | 235 mg/kg bw/day | oral | mouse | Developmental | COSMOS DB |
| NOAEL | 310 mg/kg bw/day | oral | rat | Developmental | COSMOS DB |
| NOAEL | =310 mg/kg bw/day | oral | Rat | developmental | ECHA |
GHS Hazard Classification
Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.
Short-term Exposure Effects
The substance is irritating to the eyes and respiratory tract. Ingestion of large amounts could cause effects on the cardiovascular system. This may result in cardiac dysrhythmia.
Routes of Exposure
The substance can be absorbed into the body by ingestion.
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for Potassium Hydroxide across SCCS product categories, with measured dermal absorption where available.
EPA ToxValDB — Toxicity Values
6 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).
| Endpoint | Value | Species | Route | Duration | Source |
|---|---|---|---|---|---|
| LEL | =40 mg/kg-day | Human | oral | short-term | EFSA |
| NOAEL | =310 mg/kg-day | Rat | oral | - | ECHA |
| NOAEL | =310 mg/kg-day | Rat | oral | - | ECHA |
| NOAEL | >141.96 mg/kg-day | Rat | oral | chronic | ECHA |
| LD50 | =1500 mg/kg | Mouse | oral | - | ChemIDplus |
| LD50 | =2600 mg/kg | Rat | oral | - | ChemIDplus |
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.
Additional Jurisdictional Restrictions (1)
| Jurisdiction | Status | Max % | Product Type |
|---|---|---|---|
| AU | restricted | - | specific uses |
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Chemical reaction regulator
Filler
Flavouring and nutrient
Processing aids not otherwise specified
Thickening agent
Viscosity modifier
pH regulating agent
Regulatory List Membership (2)
EPA Safer Chemical Ingredients List (SCIL)
FDA Substances Added to Food (EAFUS)
Editorial summary
Preliminary editorial summary for Potassium Hydroxide — not a computed safety verdict. See the sourced toxicological data above.
Regulatory Flags
eu-restricted
cir-approved
sccs-opinion
gras-fda
irritant
epa_safer_alternative
fda_food_additive
jecfa_safe
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to Potassium Hydroxide by CAS number or substance name.
Studies
4
Lowest NOAEL
195 mg/kg bw/day
Highest NOAEL
310 mg/kg bw/day
COSMOS DB
ECHA
Known Synonyms
KCl
[KCl]
Potassium chloride (KCl)
EC No.: 231-211-8
Caswell No. 686
Chloride of potash
Dipotassium dichloride
EINECS 231-211-8
EPA Pesticide Chemical Code 013904
Kalcorid
Kaon-Cl TABS
Kay Ciel
KCl-retard Zyma
Klor-Lyte
Natural sylvite
Potassium muriate
K-Predne-dome
Slow-K tablets
Tripotassium trichloride
Kaon Cl
Chemical Function
Viscosity modifier
Filler
Regulatory Lists
inert_ingredient; Pesticides
Europe; supplements
Europe; food_additive; supplements
animal_products
food_additive; Substances Added to Food (formerly EAFUS) (2/2019)
SCIL (9/2019)
Canada; pharmaceutical
Canada; pharmaceutical
fracking; water
inert_ingredient; non_food_use; Pesticides
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
POTASSIUM CHLORIDE
ChEMBL ID
CHEMBL1200731
Max Phase
4
Adverse Event Associations
8747
SOURCE
EFSA / FDA GRAS
food_additives
Food Safety Data
Same-CAS food additive or FDA GRAS records from the core public database.
Food Name
Potassium chloride
ADI
NOT LIMITED mg/kg bw
Food Category
preservative
Frequently Asked Questions
Is Potassium Hydroxide allowed in the EU?
Potassium Hydroxide EU regulatory status: restricted. Maximum allowed concentration: Regulated as alkaline agent; EU cosmetic regulations require pH and concentration control for alkaline products. Cuticle remover-specific formulations must be assessed for skin safety at use concentration/pH. Not for use on broken or irritated skin.. This is based on EU Regulation 1223/2009 and its amendments.
What does Potassium Hydroxide do in cosmetics?
Potassium Hydroxide functions as: Strong alkali used in cuticle remover formulations at 2–5%. Dissolves dead cuticle tissue via alkaline hydrolysis of peptide bonds in the stratum corneum proteins of the cuticle. Caustic — strict pH control and precise concentration are essential for safe use. Also used as a pH adjuster in cosmetic formulations at much lower concentrations.. It is classified as a cosmetic ingredient in our database. CAS number: 7447-40-7.
What is the NOAEL for Potassium Hydroxide?
The NOAEL (No Observed Adverse Effect Level) for Potassium Hydroxide is 195 mg/kg bw/day based on a Short Term Toxicity study via oral route in dog. A total of 4 study endpoints are available. Source: COSMOS DB.
Is Potassium Hydroxide used outside cosmetics?
Potassium Hydroxide 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
Check Potassium Hydroxide compliance across multiple jurisdictions:
Ingredient Decoder
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82 Allergen Checker
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Substance Compliance
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MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
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