Ingredient Dictionary

OXALIC ACID

Oxalic acid is an alpha,-dicarboxylic acid that is ethane substituted by carboxyl groups at positions 1 and 2.

Korean limit: 5%

OXALIC ACID Molecular structure — Molecular structure

Definition

Oxalic acid is an alpha,-dicarboxylic acid that is ethane substituted by carboxyl groups at positions 1 and 2. It has a role as a plant metabolite, a human metabolite and an algal metabolite. It is a conjugate acid of an oxalate and an oxalate(1-).

Source: PubChem

US FDA substance register · UNII 9E7R5L6H31 · registered name Oxalic acid · single chemical substance

Source: US FDA Unique Ingredient Identifier (UNII)

Cosmetic roles

Binds metal ions to prevent spoilageCHELATING

Safety & regulatory references

Restricted: China · South Korea · United Kingdom

Source: ASEAN Cosmetic Directive · EU Cosmetics Regulation · MFDS (Korea) cosmetic regulatory information · UK cosmetics regulations (OPSS)

Argentina · Brazil

Field of application and/or use : Professional products for hair treatment
Maximum concentration permitted at final product : 5%
Use conditions and warnings that must appear on the label : For Professional use only

ASEAN

Field of application and/or use : Hair care products
Maximum authorised concentration in the finished cosmetic product : 5%
Conditions of use and warning which must be printed on the labels : For professional use only

European Union

Product Type, body parts : Hair products
Maximum concentration in ready for use preparation : 5%
Other : Professional use
Wording of conditions of use and warnings : For professional use only

Source: MFDS (Korea) cosmetic regulatory information

Not classified under Korea’s toxic-substance GHS list · existing chemical substance

Source: Korea toxic substances GHS register (NIER)

EU Cosmetics Regulation, Annex III (restricted substances), entry 3 · maximum concentration 5% · applies to Hair products

Source: EU restricted substances (Annex III)

Restriction III/3

Source: EU CosIng ingredient list

More data — names, identifiers, properties, test records, literature

Official labels & definitions

JCIA labelling name シュウ酸: 本品は、次の化学式で表されるジカルボン酸である。

Source: JCIA labelling names (Japan)

Names & identifiers

OXALIC ACIDINCI옥살릭애씨드Korean label name (MFDS standard)Ethanedioic acidSynonymOXALIC ACID, ITS ESTERS AND ALKALINE SALTSSynonymシュウ酸Japanese labelling name

CAS No.chemical registry number: 144-62-7
EC No.EU chemical inventory number: 205-634-3
DTXSIDUS EPA chemical ID: DTXSID0025816
DTXCIDUS EPA compound ID: DTXCID805816

IUPAC: Oxalic acid
Molecular formula: C2H2O4
Molecular weight: 90.034 g/mol

Measured properties

Appearance: Oxalic acid is an odorless white solid. Sinks and mixes with water. (USCG, 1999) · Dry Powder, Other Solid, Large Crystals, CBI, Liquid
Odour: Odorless. · odourless
Boiling point: Sublimes (NIOSH, 2024) · sublimes
Melting point: 372 °F (Decomposes) (NTP, 1992) · 189.5 dec °C
Solubility: 50 to 100 mg/mL at 75 °F (NTP, 1992) · 220000 mg/L (at 25 °C)
Density: 1.9 at 59 °F (USCG, 1999) - Denser than water, will sink · 1.90 @ 17 DEG/4 °C, ALPHA
Stability: OXALIC ACID CAN BE DEHYDRATED BY CAREFUL DRYING @ 100 °C, BUT LOSSES OCCUR THROUGH SUBLIMATION /OXALIC ACID DIHYDRATE/
Dissociation constant: pKa 1: 1.46, pKa 2: 4.40
Colour: white
pH: 1.3
Melting/freezing point: 189.5 ℃
Flammability (solid, gas): not flammable
Vapour pressure: 0.54 ㎜Hg (105℃)
Water solubility: 22 g/100㎖ (25℃)
Relative density: 1.9 ( @ 17 DEG/4 DEG C)
n-Octanol/water partition coefficient (Kow): -0.7 (23 °C, pH&amp, lt, 2 )
Auto-ignition temperature: (&amp, gt, 400 ℃ at atmospheric pressure)
Molecular weight: 90.04

Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.

Source: PubChem · KOSHA safety data sheets (Korea)

What products actually use it for

What the 27 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.

Cleaning agent5
pH regulating agent4
Processing aids not otherwise specified3
Corrosion inhibitor3
Tanning agents not otherwise specified2
Surfactant (surface active agent)2
Photosensitive agent2
Chelating agent1

5 other uses

Reducing agent1
Monomers1
Catalyst1
Fragrance1
Fixing agent (mordant)1

Source: US EPA CompTox dashboard

Irritation and sensitisation studies

7 skin studies and 5 eye studies are on record.

Classed as moderate2Classed as low2

The studies disagree (the most common conclusion covers 50%), so they do not establish that this ingredient is irritating. These tests are on the raw material itself; irritation at the amount in a finished product is a different question.

See all 12 studies

Category 2
Skin Irritation · Screening
Skin corrosion/irritation - Category 2
Skin Irritation · Screening
Skin corrosion - category 1B
Skin Irritation · Screening
Classification not possible
Skin Sensitization · Screening
Studies Indicate No Significant Irritation
skin irritation: in vivo · Screening · OECD Guideline 404 (Acute Dermal Irritation / Corrosion) according to
Not likely to be sensitizing
skin sensitisation: in vivo (LLNA) · Screening · according to OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Category 8.2C (Category 1C)
Skin Irritation · Read Across
Category 8.3A (Category 1)
Eye Irritation · Read Across
Category 1
Eye Irritation · Screening
Serious eye damage/eye irritation - Category 1
Eye Irritation · Screening
Severe Irritation
eye irritation: in vivo · Screening · OECD Guideline 405 (Acute Eye Irritation / Corrosion) according to other guideline: guideline by the French Authorities for the testing of cosmetics and toiletries according to other guideline: guideline by the Association Francaise de Normalisation (AFNOR) for the testing of chemicals according to
Corrosive or Irritation Persists for > 21 days
eye irritation: in vivo · Screening · OECD Guideline 405 (Acute Eye Irritation / Corrosion) according to