CompoundList
Sign in
Hydroxides and bases

Calcium hydroxide

Also known as Slaked lime, Hydrated lime, Lime hydrate

CAS 1305-62-0Formula H2CaO2Molar mass 74.09 g/molEC 215-137-3
GHS signal word: Danger. Pictograms: Corrosive, Harmful or irritant 496 suppliers listed Drug substance
Get quotes Compare 496 suppliers
Calcium hydroxide chemical structure, H2CaO2, CAS 1305-62-0
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Crystals or soft granules or powder
Melting point
580 °C
Boiling point
Decomposes
Density
Approximately 2.2 g/cm³
Flash point
/Calcium Hydroxide is/ non flammable
HS code
282590
Category
Hydroxides and bases
Illustrative photo, closed blue fibre drums on a pallet in a warehouse
Typical packagingIllustrative packaging image, not the actual product

What is Calcium hydroxide?

Plain description, key identifiers and synonyms

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

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
calcium dihydroxide
CAS number
1305-62-0
EC numbers
215-137-3, 620-122-3
Molecular formula
H2CaO2
UNII
PF5DZW74VN
INCI name
CALCIUM HYDROXIDE
InChIKey
AXCZMVOFGPJBDE-UHFFFAOYSA-L
InChI
InChI=1S/Ca.2H2O/h;2*1H2/q+2;;/p-2
SMILES (canonical and isomeric)
[OH-].[OH-].[Ca+2]

Synonyms

  • Slaked lime
  • Hydrated lime
  • Lime hydrate
  • Calcium hydrate
  • Lime water
  • Calcium hydroxide (Ca(OH)2)
  • Hydralime
  • Slaked-lime
  • Lime milk
  • Calcarea caustica
  • INS NO.526
  • Hydroxide, Calcium
  • O2 Patch
  • KO2, Ca(OH)2
  • Bell mine
  • Biocalc
  • Calbit
  • Calcium dihydroxide
  • Caldic 1000
  • Calvit
  • Caustic lime
  • Kalkhydrate
  • Kemikal
  • Kentoku K 100
  • Limbux
Show all 38 synonyms
  • Milk of lime
  • NICC 3000
  • Rhenofit CF
  • Sa 074
  • Super Microstar
  • Yukijirushisakanyo
  • Ca(OH)2
  • Calcium dihydoxide
  • BTTE
  • calcium(II) hydroxide
  • Kalziumhydroxid
  • Loeschkalk
  • geloeschter Kalk

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Appearance
Crystals or soft granules or powderexp.
Odour
Odorlessexp.
Taste
Slightly bitter alkaline tasteexp.
Melting point
580 °Cexp.
Boiling point
Decomposesexp.
Density
Approximately 2.2 g/cm³exp.
Flash point
/Calcium Hydroxide is/ non flammableexp.
Autoignition temperature
Not flammableexp.
Solubility
Solubility in water is decreased by the presence of fixed alkali hydroxides.exp.
Vapour pressure
0 mmHg (approx)exp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
74.09 g/molcalc.
Exact mass
73.9681 Dacalc.
LogP (octanol/water)
-0.73calc.
Topological polar surface area
60 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
0calc.
Heavy atoms
3calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Components
3calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS05: Corrosive
Corrosive
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H314Causes severe skin burns and eye damage.
  • H315Causes skin irritation.
  • H318Causes serious eye damage.
  • H335May cause respiratory irritation.
Precautionary statements (21)
  • P260Do not breathe dust, fume, gas, mist, vapours or spray.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P330 + P331If swallowed: Rinse mouth. Do not induce vomiting.
  • P302 + P352If on skin: Wash with plenty of water.
  • P302 + P361 + P354If on skin: Take off immediately all contaminated clothing. Immediately rinse with water for several minutes.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P354 + P338If in eyes: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P316Get emergency medical help immediately.
  • P317Get medical help.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P332 + P317If skin irritation occurs: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P363Wash contaminated clothing before reuse.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Calcium hydroxide suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 496 suppliers
30 of 30 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

496 suppliers in 55 countries

Send one request to many suppliers

Choose up to 10 suppliers or let us match your request. Compare quotes side by side, free.

Choose suppliersPost a request

Calcium hydroxide price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

Get latest price

Uses and applications

What the substance is used for, by industry and function

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.

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.

Calcium salts, causticizing soda, depilatory, whitewash, soil conditioner, ammonia recovery in gas manufacturing, disinfectant, water soft

Read more

ening, purification of sugar juices, petrochemicals, food additive as buffer and neutralizing agent, shell-forming agent (poultry).

Industrial uses: Other, Binder, Lubricating agent, Processing aids not otherwise specified, Chemical reaction regulator, Fuel agents, pH regulating agent, Fuel.

Consumer uses: Chemical reaction regulator, pH regulating agent, Other, Lubricating agent, Adhesion/cohesion promoter, Flocculating agent, Heat stabilizer, Intermediate.

Use classes: Processing Aids and Additives, Safer Chemical Classes, Food additives, Cosmetics, Plastics.

Cosmetic ingredient, INCI name CALCIUM HYDROXIDE(buffering)

Pharmacological actions

  • Bone Cements

Roles

  • astringent
  • pharmaceutical

Cosmetic functions

  • Buffering

How it is made

Commercial preparation by hydration of lime.

Action of water on calcium oxide.

Commercial grade is produced by adding precise quant of water (between 2- and 3-times more) to calcium oxide in hydrators. Beds of calcium oxide up to 20 cm thick ... slaked manually by hosing, or lumps in wire baskets can be immersed in water.

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • EU cosmetic ingredient inventory
  • EU Cosmetics Regulation Annex III, restricted in cosmetics
    Name: CALCIUM HYDROXIDE, Ref no: 15c, Annex ref: III/15c
  • Active ingredient in FDA approved drug labels
  • Food additive

United States

  • Safer Choice ingredient list (USA)
  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Calcium hydroxide is traded under.

HS 2825.90Indicative HS code

Inorganic bases not elsewhere classified in heading 2825

World exports in 2024
$972M
+5.4% vs 2023, imports $3.4B
2019 to 2024
Top exporters
  1. China28.5%
  2. United States23.7%
  3. Brazil10.8%
Top importers
  1. South Korea77.2%
  2. Japan4.3%
  3. United States3.8%
Reported customs values in USD, not prices.Full trade data

The HS code shown for Calcium hydroxide is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Calcium hydroxide, based on the data on this page

What is Calcium hydroxide?

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

What is the CAS number of Calcium hydroxide?

The CAS registry number of Calcium hydroxide is 1305-62-0.

What is the molecular formula and weight of Calcium hydroxide?

The molecular formula of Calcium hydroxide is H2CaO2 and its molar mass is 74.09 g/mol.

What is Calcium hydroxide used for?

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.

Is Calcium hydroxide hazardous?

Calcium hydroxide carries the GHS signal word "Danger". Main hazards: causes severe skin burns and eye damage, causes skin irritation, causes serious eye damage. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Calcium hydroxide?

Calcium hydroxide is usually classified under HS code 282590 (Hydrazine and hydroxylamine and their inorganic salts, other inorganic bases, other…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Calcium hydroxide?

CompoundList lists 496 suppliers of Calcium hydroxide in India, United States, China, South Korea and 51 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Calcium hydroxide in India?

147 suppliers in India list Calcium hydroxide on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Calcium hydroxide?

Suppliers quote Calcium hydroxide on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Calcium hydroxide

Get quotes for Calcium hydroxide

Post one free request with your grade, quantity and destination. Matching suppliers send quotes you can compare side by side.
Post a request Sell Calcium hydroxide
Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
Embed this structure on your websiteShow code

Paste this code into your page to show the 2D structure of Calcium hydroxide with a 3D view, its CAS number where known and a link back to this page. Free to use with the link kept.

<iframe src="https://www.compoundlist.com/embed/structure/calcium-hydroxide-1305-62-0" title="Calcium hydroxide structure on CompoundList" width="360" height="420" style="border:1px solid #E7E2DA;border-radius:12px;max-width:100%" loading="lazy" referrerpolicy="strict-origin-when-cross-origin"></iframe>
Preview the embed

Explore more in Hydroxides and bases or HS code 282590

496 suppliers
Free quotes, contact stays private
Get quotes