What does the restriction note for POTASSIUM SULFITE mean?

The restriction field for POTASSIUM SULFITE reads: III/99 V/9. This is the restriction note from the CosIng inventory. For authoritative conditions and limits, always refer to the linked annex entries.

What function does POTASSIUM SULFITE serve in cosmetics?

According to the EU CosIng inventory, POTASSIUM SULFITE carries the following function designation(s): ANTIOXIDANT, HAIR WAVING OR STRAIGHTENING, PRESERVATIVE, REDUCING.

How do I check if my formula contains POTASSIUM SULFITE?

Use the INCI Checker to screen a full ingredient list across selected markets, or use the substance market comparison to review this identity across all supported market datasets.

InventoryRef 3703111/08/2020

POTASSIUM SULFITE

Potassium sulphite

POTASSIUM SULFITE is linked to 2 EU annex records on this page. Inventory note: III/99 V/9.

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Regulatory evidence by market

This matrix separates verified ingredient rules from sources that are mapped but not yet imported. No imported rule does not mean the ingredient is permitted.

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Market	Evidence status	Records	Source language
European Union	Evidence linked Restricted entry found Open this evidence	2	English and EU languages
Great Britain	Source mapped Official source mapped; ingredient rule not imported	0	English
Canada	Source mapped Official source mapped; ingredient rule not imported	0	English and French
New Zealand	Evidence linked Permitted list with conditions Open this evidence	1	English
ASEAN	Source mapped Official source mapped; ingredient rule not imported	0	English and national languages
China	Source mapped Official source mapped; ingredient rule not imported	0	Chinese with selected English material
Japan	Source mapped Official source mapped; ingredient rule not imported	0	Japanese; official English translation available
South Korea	Source mapped Official source mapped; ingredient rule not imported	0	Korean with some English names
United States	Source mapped Official source mapped; ingredient rule not imported	0	English
Australia	Source mapped Official source mapped; ingredient rule not imported	0	English
Brazil	Source mapped Official source mapped; ingredient rule not imported	0	Portuguese with INCI crosswalks
India	Source mapped Official source mapped; ingredient rule not imported	0	English and Hindi
Saudi Arabia	Source mapped Official source mapped; ingredient rule not imported	0	Arabic and English

Chemical identity and properties

PubChem 2D chemical structure for CAS 10117-38-1

CAS 10117-38-1PubChem CID 24958

Potassium Sulfite

IUPAC name: dipotassium;sulfite

Molecular formula: K2O3S
Molecular weight: 158.26 g/mol
Exact mass: 157.88422800 Da
Topological polar surface area: 82.4 Å²
Hydrogen-bond donors: 0
Hydrogen-bond acceptors: 4
Covalent units: 3
Defined stereocentres: 0

Also known as

Dipotassium sulfitePotassium sulphiteSulfurous acid, dipotassium saltPotassium sulfite (K2SO3)UNII-015KZC652ESulfurous acid, potassium saltHSDB 5052015KZC652E

16 more reported names

EINECS 233-321-1DIPOTASSIUM SULPHITEPOTASSIUM SULFITE [MI]INS NO.225POTASSIUM SULFITE [FCC]POTASSIUM SULFITE [HSDB]INS-225EC 233-321-1E-225RefChem:175607POTASSIUM SULFITE [INCI]PotassiumsulfiteSulfurous acid, potassium salt (1:2)Potassium sulfite(IV)KaliumsulfitE225

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

EPA DTXSID:DTXSID80889532

Evidence from additional scientific databases

NIH PubChem PUG-View

Exact identifier match24958

Attributed physical-property, hazard, environmental and use annotations.

Physical Description: Liquid Source: EPA Chemical Data Reporting (CDR)
Physical Description: Dihydrate: White solid; Slowly oxidized by air to sulfate; [Merck Index] White powder; [MSDSonline] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Solubility: White crystals or crystalline powder; sol in about 3.5 parts water; decomposed by diluted acids with evolution of sulfur dioxide; pH about 8 /dihydrate/ Source: Hazardous Substances Data Bank (HSDB)
Solubility: White-yellowish, hexagonal form; insol in ammonia; slightly sol in alcohol /dihydrate/ Source: Hazardous Substances Data Bank (HSDB)

Note: This chemical does not meet GHS hazard criteria for 81.5% (242 of 297) of all reports. Source: European Chemicals Agency (ECHA)
Signal: Warning Source: European Chemicals Agency (ECHA)
GHS Hazard Statements: H315 (16.5%): Causes skin irritation [Warning Skin corrosion/irritation]; H319 (18.2%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H335 (16.2%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation] Source: European Chemicals Agency (ECHA)
Precautionary Statement Codes: P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
ECHA C&L Notifications Summary: Aggregated GHS information provided per 297 reports by companies from 10 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 242 of 297 reports by companies.; There are 7 notifications provided by 55 of 297 reports by companies with hazard statement code(s).; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
Signal: Danger Source: Hazardous Chemical Information System (HCIS), Safe Work Australia
GHS Hazard Statements: H302: Harmful if swallowed [Warning Acute toxicity, oral]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation] Source: Hazardous Chemical Information System (HCIS), Safe Work Australia
Precautionary Statement Codes: P264, P264+P265, P270, P280, P301+P317, P305+P354+P338, P317, P330, and P501 (click each P-code to see the statement) Source: Hazardous Chemical Information System (HCIS), Safe Work Australia

Cosmetic Ingredient Review Finding(s): Safe in the present practices of use and concentration. Ingredient, concentration, and use information are available in documents discoverable at https://cir-reports.cir-safety.org Source: Cosmetic Ingredient Review (CIR)

Consumer Uses: Etching agent; Soil amendments (fertilizers) Source: EPA Chemical Data Reporting (CDR)

Industry Uses: Reducing agent; Soil amendments (fertilizers) Source: EPA Chemical Data Reporting (CDR)

Cosmetic Ingredient Review Link: CIR ingredient: Potassium Sulfite Source: Cosmetic Ingredient Review (CIR)
Sources/Uses: Used in photography, food and cosmetics (preservative and antioxidant), and drugs (cathartic and diuretic); [HSDB] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Industrial Processes with risk of exposure: Photographic Processing [Category: Other] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Uses: Photography; preservative and antioxidant in foods Source: Hazardous Substances Data Bank (HSDB)
Uses: Medication: cathartic, diuretic Source: Hazardous Substances Data Bank (HSDB)
Uses: COMPONENT OF PHOTOGRAPHIC DEVELOPERS; FOOD ADDITIVE (EG, PRESERVATIVE & ANTIOXIDANT); INGREDIENT IN COSMETICS (EG, HAIR PREPARATIONS) Source: Hazardous Substances Data Bank (HSDB)

Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record

Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.

Additional source coverage and match status

Source	Result	Checked
EMBL-EBI ChEBI	No exact record	2026-08-31
NIH PubChem PUG-View	Exact match	2026-08-31

A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Inventory details for POTASSIUM SULFITE

INCI name

POTASSIUM SULFITE

Description

Potassium sulphite

Record provenance

Inventory reference: 37031
Imported identity: POTASSIUM SULFITE
Source update: 11/08/2020

European Commission CosIng source notes

Annex records for POTASSIUM SULFITE

Annex III Restriction reference

Entry 99

Inorganic sulfites and bisulfites (12)

Annex V Restriction reference

Entry 9

SODIUM SULFITE / AMMONIUM BISULFITE / AMMONIUM SULFITE / POTASSIUM SULFITE / POTASSIUM hydrogen SUL…

CAS: 7757-83-7 / 10192-30-0 / 10196-04-0 / 10117-38-1 / 7773-03-7 / 7631-90-5 / 7681-57-4 / 16731-55-8

EC: 231-821-4 / 233-469-7 / 233-484-9 / 233-321-1 / 231-870-1 /231-548-0 / 231-673-0 / 240-795-3

Key data

CAS

10117-38-1 / 23873-77-0

233-321-1 / -

Restriction

III/99 V/9

Function

ANTIOXIDANT: Inhibiting reactions promoted by oxygen, thus avoiding oxidation and rancidity.
HAIR WAVING OR STRAIGHTENING: Modifying the chemical structure of the hair, allowing it to be set in the style required (permanent waves or hair straightening).
PRESERVATIVE: Exclusively or mainly intended to inhibit the development of micro-organisms in the cosmetic product. All authorised preservatives are substances in the positive list of Annex V to the Cosmetics Regulation 1223/2009.
REDUCING: Changing the chemical nature of another ingredient by adding hydrogen (or removing oxygen).

Official EU ingredient-name evidence

The ingredient name exactly matches the official 2025 EU glossary of common ingredient names.

#22766 · POTASSIUM SULFITE

The 2 markets that hold a rule for this substance do not classify it the same way.

restricted: European Union
permitted on a positive list: New Zealand

See every substance the markets disagree about

Ingredients with overlapping formulation functions

OLIGOPEPTIDE-30ANTIOXIDANT, CHELATING, HAIR CONDITIONING, REDUCING, SKIN PROTECTING

P-HYDROXYANISOLEANTIOXIDANT, REDUCING

PHALAENOPSIS APHRODITE CALLUS EXTRACTANTIOXIDANT, REDUCING, SKIN PROTECTING

POTASSIUM METABISULFITEHAIR WAVING OR STRAIGHTENING, PRESERVATIVE, REDUCING

POTASSIUM TETRATHIONATEREDUCING

RH-POLYPEPTIDE-28REDUCING, SKIN CONDITIONING

RH-POLYPEPTIDE-60REDUCING, SKIN CONDITIONING

S-DNA APTAMER-2ANTIOXIDANT; REDUCING; SKIN PROTECTING; UV FILTER; pH ADJUSTERS

Additional official and scientific sources

11 external databases to check this identity in

Each link searches that source for this identity. What each source is, and its legal weight

ECHA CHEM / Information on chemicals PubChem PUG REST EU Safety Gate cosmetic product alerts ECHA CHEM US EPA CompTox Cosmetic Ingredient Review safety assessments FDA Global Substance Registration System ILO/WHO International Chemical Safety Cards Japan NITE-CHRIP NIOSH Pocket Guide to Chemical Hazards OECD eChemPortal

How POTASSIUM SULFITE appears in the CosIng inventory

The CosIng inventory lists POTASSIUM SULFITE as a cosmetic ingredient and this page links it to 2 annex records. The inventory entry captures names and identifiers, while the annex records show where the substance is prohibited, restricted or positively listed in EU cosmetics law.

POTASSIUM SULFITE is also tagged with 4 cosmetic functions in the official data. Function labels describe intended use, but they do not replace regulatory review of linked annex records before formulation or labelling work.

Frequently asked questions

POTASSIUM SULFITE appears in the EU CosIng inventory and has linked annex records. Check the annex records above for applicable restrictions, concentration limits and conditions of use. Annex II listing means prohibited; Annex III means restricted; Annexes IV, V and VI mean permitted under specified conditions.

The restriction field for POTASSIUM SULFITE reads: "III/99 V/9". This is the restriction note recorded in the CosIng inventory for this ingredient. For authoritative conditions and limits, always refer to the linked annex entries above.

According to the EU CosIng inventory, POTASSIUM SULFITE carries the following function designation(s):

CAS 10117-38-1 / 23873-77-0 may appear across multiple EU annex records. Viewing the CAS lookup page shows all Annex II–VI entries sharing this identifier, which is useful for identifying cross-annex regulatory status of the same chemical substance.

Use the INCI Checker to screen a full ingredient list across selected markets, or compare this substance across all supported market datasets.

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Source note for POTASSIUM SULFITE

This page combines the CosIng inventory entry for POTASSIUM SULFITE with 2 linked Annex II–VI records from the local dataset built from public European Commission cosmetic ingredient materials.

Use this inventory page to research POTASSIUM SULFITE and compare linked records, but verify restrictions and legal status against the current official source text and law before making regulatory decisions.

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