CosIng Checker
CosIng Checker
EU cosmetic ingredients, restrictions and safety
Login
RestrictedBinding ruleGBOriginal is EnglishOfficial-source import checked

Calcium hydroxide

The consolidated GB Cosmetics Regulation lists this record in Annex III.

All Great Britain recordsOpen ingredient profileCompare all marketsOpen official source

Regulatory decision and full conditions

Status
Restricted
Legal role
Binding rule
Regulatory summary
The consolidated GB Cosmetics Regulation lists this record in Annex III.
Conditions and restrictions
(a) Hair straighteners containing two components: calcium hydroxide and a guanidine salt · (a) 7% (as calcium hydroxide) · (a) Contains alkali Avoid contact with eyes Keep out of reach of children Can cause blindness

Substance identity

Official source name
Calcium hydroxide
CAS
1305-62-0
EC
215-137-3
Identity mapping
cas_number
Linked ingredient
CALCIUM HYDROXIDE
Search this identity across the siteCAS 1305-62-0EC 215-137-3

Linked CosIng identity data

Names and aliases

CALCIUM HYDROXIDEcalcium hydroxidecalcii hydroxidum

CosIng description: Calcium dihydroxide

EU inventory restriction note: III/15c

Recorded cosmetic function: BUFFERING

Function pages:BUFFERING

View the complete ingredient profile

Cross-market snapshot for this identity

Exact linked records currently present in this site. An absent market means no imported exact match, not permission to use the substance.

7 market datasets
PubChem 2D chemical structure for CAS 1305-62-0
CAS 1305-62-0PubChem CID 6093208

Verified chemistry for CAS 1305-62-0

Calcium Hydroxide

Calcium dihydroxide is a calcium hydroxide. It has a role as an astringent. — ChEBI

IUPAC name
calcium dihydroxide
Molecular formula
CaH2O2
Molecular weight
74.09 g/mol
Exact mass
73.9680702 Da
Monoisotopic mass
73.9680702 Da
Topological polar surface area
2.0 Ų
Molecular complexity
0.0
Formal charge
0
Hydrogen-bond donors
2
Hydrogen-bond acceptors
2
Rotatable bonds
0
Heavy atoms
3
Covalent units
3

Names and synonyms reported to PubChem

Slaked limeHydrated limeLime hydrateCalcium hydrateLime waterCalcium hydroxide (Ca(OH)2)HydralimeSlaked-lime
16 more reported names
Lime milkCalcarea causticaINS NO.526PF5DZW74VNE-526CHEBI:31341Hydroxide, Calcium215-137-3O2 PatchRefChem:54625KO2, Ca(OH)2CHEBI:35150620-122-3Bell mineBiocalcCalbit
Open full PubChem recordSafety and hazards at PubChemPubChem annotationsChemical classifications3D structure image
External database identifiers
Advanced structure statistics
Defined atom stereocentres
0
Undefined atom stereocentres
0
Defined bond stereocentres
0
Undefined bond stereocentres
0
3D conformers
0
Machine-readable structure identifiers
SMILES
[OH-].[OH-].[Ca+2]
InChI
InChI=1S/Ca.2H2O/h;2*1H2/q+2;;/p-2
InChIKey
AXCZMVOFGPJBDE-UHFFFAOYSA-L

Evidence from additional scientific databases

NIH PubChem PUG-View
Exact identifier match6093208

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

  • Autoignition Temperature: Not flammable (USCG, 1999) Source: CAMEO Chemicals
  • First Aid: Excerpt from NIOSH Pocket Guide for Calcium hydroxide:; Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Skin: SOAP FLUSH IMMEDIATELY - If this chemical contacts the skin, immediately flush the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. If irritation persists after washing, get medical attention.; Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.; Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024) Source: CAMEO Chemicals
  • First Aid: (General first aid procedures); Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Skin: Soap flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. If irritation persists after washing, get medical attention.; Breathing: Respiratory support; Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. Source: The National Institute for Occupational Safety and Health (NIOSH)
  • Note: This chemical does not meet GHS hazard criteria for 0.4% (28 of 6644) of reports. Source: European Chemicals Agency (ECHA)
  • Signal: Danger Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H314 (22.4%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]; H315 (45.3%): Causes skin irritation [Warning Skin corrosion/irritation]; H318 (76.9%): Causes serious eye damage [Danger Serious eye damage/eye irritation]; H335 (38.9%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P260, P261, P264, P264+P265, P271, P280, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P319, P321, P332+P317, P362+P364, P363, 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 6644 reports by companies from 59 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 28 of 6644 reports by companies.; There are 56 notifications provided by 6616 of 6644 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)
  • GHS Hazard Statements: Not Classified; Reported as not meeting GHS hazard criteria by 1 of 1 companies. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
  • Signal: Danger Source: NITE-CMC
  • GHS Hazard Statements: H315: Causes skin irritation [Warning Skin corrosion/irritation]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure] Source: NITE-CMC
  • Precautionary Statement Codes: P260, P264, P264+P265, P270, P280, P302+P352, P305+P354+P338, P308+P316, P317, P321, P332+P317, P362+P364, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • GHS Hazard Statements: H315: Causes skin irritation [Warning Skin corrosion/irritation]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure] Source: NITE-CMC
  • Precautionary Statement Codes: P260, P264, P264+P265, P270, P280, P302+P352, P305+P354+P338, P308+P316, P317, P319, P321, P332+P317, P362+P364, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • Signal: Danger Source: Hazardous Chemical Information System (HCIS), Safe Work Australia
  • Cosmetic Ingredient Review Conclusion: The CIR Expert Panel concluded that ... Calcium Hydroxide is safe in hair straighteners and depilatories under conditions of recommended use; users should minimize skin contact. These ingredients are safe for all other present practices of use and concentration described in this safety assessment when formulated to be nonirritating. Source: Cosmetic Ingredient Review (CIR)
  • Cosmetic Ingredient Review Finding(s): Safe for use in cosmetics, with qualifications Source: Cosmetic Ingredient Review (CIR)
  • Environmental Fate: Aquatic Fate: Aquatic toxicity is the function of an alkalinity effect. Addition of lime to soft water lakes has increased biological activity, possibly by providing a carbon dioxide reservoir. Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: Calcium hydroxide does not degrade by photooxidation; it is neutralized by absorption of atmospheric carbon dioxide. Source: Hazardous Substances Data Bank (HSDB)
  • Consumer Uses: Chemical reaction regulator; pH regulating agent; Other; Lubricating agent; Adhesion/cohesion promoter; Flocculating agent; Heat stabilizer; Intermediate; Reducing agent; Soil amendments (fertilizers); Filler; Not Known or Reasonably Ascertainable; Absorbent Source: EPA Chemical Data Reporting (CDR)
  • Industry Uses: Other; Binder; Lubricating agent; Processing aids not otherwise specified; Chemical reaction regulator; Fuel agents; pH regulating agent; Fuel; Antioxidant; Flux agent; Absorbent; Dehydrating agent (desiccant); Sealant (barrier); Reducing agent; Stabilizing agent; Flow promoter; Catalyst; Filler; Diluent; Not Known or Reasonably Ascertainable; Corrosion inhibitor; Soil amendments (fertilizers); Solids separation (precipitating) agent, not otherwise specified; Hardener; Flocculating agent; Adhesion/cohesion promoter; Processing aids, specific to petroleum production; Intermediate; Softener and conditioner; Oxidizing agent; Adsorbent Source: EPA Chemical Data Reporting (CDR)
  • Cosmetic Ingredient Review Link: CIR ingredient: Calcium Hydroxide Source: Cosmetic Ingredient Review (CIR)
  • Sources/Uses: Used in mortar, plaster, cement, lubricants, drilling fluids, paper pulp, and water treatment; also used to dehair hides; [ACGIH] Used in pesticides, fireproofing coatings, water-based paints, SBR rubber vulcanization, binding and paving materials, soil treatments, brewing manufacture, dental cements, petrochemicals, as chemical intermediate, buffering agent for metals, pearls, and celluloid, disinfectant, food additive, for ammonia recovery in gas manufacture, purification of sugar juices, to preserve eggs and apples during storage, in cattle feeds, and veterinary medicine; [HSDB] Used as both an inert and active ingredient (microbiocide/microbiostat) in pesticide products; [EPA REDs] Used as a nutritional supplement, pH control agent, firming agent, and processing aid for foods; [FDA] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Industrial Processes with risk of exposure: Petroleum Production and Refining [Category: Industry]; Pulp and Paper Processing [Category: Industry]; Painting (Pigments, Binders, and Biocides) [Category: Paint]; Using Disinfectants or Biocides [Category: Clean]; Farming (Pesticides) [Category: Industry]; Sewer and Wastewater Treatment [Category: Industry]; Leather Tanning and Processing [Category: Industry]; Cement Producing [Category: Industry]; Farming (Feed Additives) [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Uses: For calcium hydroxide (USEPA/OPP Pesticide Code: 075601) ACTIVE products with label matches. /SRP: Registered for use in the USA but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./ Source: Hazardous Substances Data Bank (HSDB)
  • Uses: In mortar, plaster, cement and other binding and paving materials; in lubricants, drilling fluid, pesticides, fireproofing coatings, water paint; as egg preservative; manufacture of paper pulp; in SBR rubber vulcanization; in water treatment; as absorbant for carbon dioxide; dehairing hides. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: Chem int in chlorohydrin process for propylene oxide /former use/; chem int for calcium hypochlorite, bleaching powder, and the fungicide, lime-sulfur spray; flux in iron and steel mfr; soil treatment for acidic soils; water softening agent; stabilization of soils for road base; component of sand-lime bricks and blocks; component of masonary mortar; water correcting agent in brewing mfr; component of dental cement; buffering agent for metals, pearls and celluloid. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: Calcium salts, causticizing soda, depilatory, whitewash, soil conditioner, ammonia recovery in gas manufacturing, disinfectant, water softening, purification of sugar juices, petrochemicals, food additive as buffer and neutralizing agent, shell-forming agent (poultry) Source: Hazardous Substances Data Bank (HSDB)
  • Uses: For more Uses (Complete) data for CALCIUM HYDROXIDE (13 total), please visit the HSDB record page. 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
SourceResultChecked
NIH PubChem PUG-ViewExact match2026-08-31

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 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Official source and provenance

Registered source
Great Britain Cosmetics Regulation — consolidated Annexes II–VI and amendments
Source reference
GB Cosmetics Regulation, Annex III, entry 15c
Source record ID
III-15c
Source version
2026-08-15
Source language
English
Translation status
Original is English
Effective date
2026-08-15
Source updated
2026-08-19
Snapshot checked
2026-08-30 04:51 UTC
Validation method
legislation.gov.uk XML table parse; {'II': 1758, 'III': 326, 'IV': 154, 'V': 57, 'VI': 34}
SHA-256
e3a386d950f54c6e7a7f9e784d1bd46e52de725137e89d5630709824475215d8

Registered dataset notes

Dataset coverage
Complete consolidated GB Annexes II–VI, with later amendments versioned separately
Authority note
Binding GB schedules and versioned amendments to retained Regulation 1223/2009; applies to England, Wales and Scotland, not Northern Ireland
Source licence
Open Government Licence v3.0 / Crown copyright
Attribution
Contains public sector information licensed under the Open Government Licence v3.0.
Inspect the exact official sourceRegulator guidance

How this record fits the market dataset

2329
current Great Britain records
326
records marked Restricted
2329
records from this source version
2015
market records with CAS identity

Status distribution

Permitted list with conditions: 245Prohibited: 1758Restricted: 326

Condition text is present on 517 of 2329 current records. An empty condition field is interpreted according to the record type above; it is never converted into an unrestricted-use claim.

Great Britain market context

Complete consolidated annex dataset

Coverage version: GB retained Regulation 1223/2009 schedules, effective 15 August 2026

Current consolidated Annexes II–VI for England, Scotland and Wales.

Verification checklist

  1. Confirm INCI/CAS/EC identity.
  2. Review every current GB Annex II–VI match.
  3. Check commencement dates and later statutory instruments.
  4. Verify SCPN, responsible-person, safety-report and labelling duties.

Official market sources

Verification workflow and record completeness

Before using this result in a compliance decision

  1. Confirm that “Calcium hydroxide” and every CAS/EC identifier refer to the material in your supplier specification.
  2. Confirm INCI/CAS/EC identity.
  3. Review every current GB Annex II–VI match.
  4. Check commencement dates and later statutory instruments.
  5. Verify SCPN, responsible-person, safety-report and labelling duties.
  6. Document the source version and recheck the regulator before manufacture, notification or market placement.

Fields available in this record

  • Official substance nameAvailable
  • CASAvailable
  • ECAvailable
  • Separate condition textAvailable
  • Effective dateAvailable
  • Snapshot hash and methodAvailable

Questions this page answers

This substance is not unrestricted: cosmetic use is subject to the conditions in the cited official record. Check product type, body area, concentration, purity and warning requirements before deciding whether a formulation is compliant.

If this row does not reproduce conditions, open the cited official detail because omission does not mean unrestricted use. No annex match is not approval and does not cover Northern Ireland, which follows the applicable EU framework.

The record cites GB Cosmetics Regulation, Annex III, entry 15c, source version 2026-08-15. Open the official source.

No. CAS helps resolve identity, but jurisdictions can classify the same substance differently and can apply different product scopes, limits, warnings and transition dates.

Stable citation

Calcium hydroxide. GB Cosmetics Regulation, Annex III, entry 15c. Great Britain. Source version 2026-08-15. CosIng Checker regulatory record: https://cosingchecker.com/regulations/gb/records/6134/

Cite the regulator as the legal authority. This page is a structured evidence index and verification aid, not a substitute for the official text or professional legal assessment.

Interpretation and limits for Great Britain

This substance is not unrestricted: cosmetic use is subject to the conditions in the cited official record.

Check product type, body area, concentration, purity and warning requirements before deciding whether a formulation is compliant.

How to interpret the legal role

The cited row forms part of a binding rule or legally incorporated list for this market.

Evidence on this page

  • Recorded outcome: Restricted
  • Legal role: Binding rule
  • Source version: 2026-08-15
  • Effective date: 2026-08-15

What it does not prove

No annex match is not approval and does not cover Northern Ireland, which follows the applicable EU framework.

Further authoritative substance research

These sources can add identity, safety, exposure or hazard context. A link is not evidence that the database contains this exact substance, and none of these sources overrides the market decision above.

Cosmetic Ingredient Review safety assessments

Expert Panel conclusions, assessed ingredient groups, use conditions, dates and report documents

Independent expert review considered by FDA; not a government approval or binding market rule

Research this identity at the source

FDA Global Substance Registration System

UNII identifiers, preferred names, substance types, codes and public substance relationships

Identity registry only; UNII availability does not imply FDA review or approval

Research this identity at the source

ILO/WHO International Chemical Safety Cards

Hazards, symptoms, first aid, storage, incompatibilities and physical properties for covered chemicals

International occupational chemical-safety reference; not cosmetic-use approval

Research this identity at the source

Japan NITE-CHRIP

Chemical identity, Japanese and foreign legal lists, GHS hazards and exposure-related information

Chemical-management evidence; cosmetic status remains governed by the applicable MHLW standard and market rules

Research this identity at the source

NIOSH Pocket Guide to Chemical Hazards

REL, PEL, IDLH, properties, exposure routes, symptoms, target organs, first aid and measurement methods for covered workplace chemicals

US occupational-health guidance and limits; not a cosmetic ingredient decision

Research this identity at the source

OECD eChemPortal

Gateway to authority-owned physical-property, fate, ecotoxicity, toxicity, exposure and GHS records

Discovery gateway; each linked authority remains responsible for its data

Research this identity at the source

US EPA CompTox CTX APIs

API key required for import

DTXSID identity, experimental and predicted properties, toxicity, bioactivity, exposure and environmental data

Scientific and computational evidence; predictions must remain labelled and do not determine cosmetic legality

Research this identity at the source