Safety data sheet reference · CAS 1305-62-0
Calcium hydroxide SDS
also: calcium hydroxide MSDS · safety data sheet · Ca(OH)2 · CAS 1305-62-0 · slaked lime · hydrated lime
Official PDF from supplier
This page is a reference, not the legal document.
CAS number
1305-62-0
Molecular formula
Ca(OH)2
No harmonised EU classification
Calcium hydroxide has no entry in CLP Annex VI — there is no harmonised EU-wide classification for it. That is not evidence of safety. Suppliers remain obliged to self-classify it under CLP, and workplace hazards (dust, asphyxiation, thermal) can exist without a harmonised entry. Always obtain the supplier's SDS for the product you actually use.
Published emergency-response data does exist for calcium hydroxide and is reproduced below — first aid, fire fighting and spill response come from US federal sources, not from a harmonised classification.
§ 03 · Composition and identifiers
Calcium hydroxide structure
Calcium hydroxide is an ionic compound — there is no discrete Ca(OH)2 molecule. The diagram shows the ions the crystal lattice is built from.
Ions of calcium hydroxide · Ca(OH)2
Identifiers from PubChem (NIH, public domain). Structure diagram drawn with RDKit from the SMILES string.
§ 04 · First-aid measures
Calcium hydroxide first aid measures
Call your national emergency number first. These are published first-aid measures, not medical advice, and they do not replace emergency services, a poison control centre or the supplier's safety data sheet.
§4–§6 below reproduce the CAMEO Chemicals entry CALCIUM HYDROXIDE. CAMEO publishes response data per product entry, so the entry can describe a solution, a refrigerated liquid or a molten form rather than the pure substance in §9 — check it matches what you are handling.
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.
Source: NIOSH, 2024 — via CAMEO Chemicals (NOAA), public domain.
§ 08 · Exposure controls
Calcium hydroxide exposure limits (IDLH)
IDLH
NIOSH lists calcium hydroxide in the Pocket Guide but has not established an IDLH value for it.
NIOSH Pocket Guide — Calcium hydroxide →
IDLH from the NIOSH Pocket Guide to Chemical Hazards (CDC, U.S. public domain), via CAMEO Chemicals. Occupational exposure limits — OSHA PEL, NIOSH REL and EU IOELV — are not published on this page yet.
MSDS vs SDS
Calcium hydroxide MSDS vs SDS: is there a difference?
MSDS (Material Safety Data Sheet) is the older name for the same document. In the US, OSHA's Hazard Communication Standard (2012) adopted the GHS-standardised 16-section Safety Data Sheet; in the EU the format is set by REACH Annex II. So a "calcium hydroxide MSDS" and a "calcium hydroxide SDS" refer to the same document — today it is issued as an SDS. Full breakdown of the differences →
Compliance hub
From classification to SDS
The classification above corresponds to Section 2 of a Safety Data Sheet. Learn how a compliant 16-section SDS is structured and authored →
GHS label maker
Build the label for calcium hydroxide
Pictograms, signal word and H-statements combined into a compliant label layout →
§ 16 · Sources
- Classification: Regulation (EC) No 1272/2008 (CLP), Annex VI
- Transport: UN ADR 2025 (UNECE), Table A
- Reactivity: NOAA CAMEO Chemicals reactive-group matrix (public domain)
- Physical properties: CAMEO Chemicals (NOAA, public domain) — per-value source references stored in the database
- Emergency response (§4–§6): ERG 2024 (PHMSA) · NIOSH Pocket Guide (CDC) · CHRIS (USCG) · NTP · EPA — via CAMEO Chemicals (NOAA), all US federal public domain, reproduced verbatim
- Substance data: PubChem · ECHA
Reference aid only. This page summarises the harmonised EU classification and computed storage guidance — it is not a Safety Data Sheet and does not replace one. Always verify hazards, handling and storage against the supplier's SDS (sections 7 and 10) and local regulations before use. Page updated 2026-08-11.
Frequently asked questions about calcium hydroxide
Is an MSDS the same as an SDS?
In practice, yes. MSDS (Material Safety Data Sheet) is the older name for the same document. In the US, OSHA's Hazard Communication Standard (2012) adopted the GHS-standardised 16-section Safety Data Sheet; in the EU the SDS format is set by REACH Annex II. A document you find labelled "calcium hydroxide MSDS" is today issued as an SDS.
Where can I download an official calcium hydroxide SDS PDF?
From your own supplier — an SDS is issued per product and supplier, so the correct PDF for an inspection is the one matching the product you actually purchased. The supplier links on this page lead to the official SDS libraries of major distributors.