Calcium hydroxide

CAS: 1305-62-0

Overview

Calcium hydroxide ( CAS 1305-62-0 ), commercially known as slaked lime or hydrated lime, is a strong inorganic base used across food processing, water treatment, construction, and agriculture.

As E526 , it functions primarily as a pH regulator, firming agent, and alkali source in both industrial and food-grade applications. In food processing, it is used to nixtamalize corn for tortilla production.

It is also utilized to firm fruit and vegetable textures in pickling and canning. Water treatment plants rely on it to adjust pH, precipitate heavy metals, and soften hard water through controlled coagulation and flocculation.

In construction, it is a core component of mortars, plasters, and soil stabilization projects where controlled alkalinity improves structural binding. Pulp and paper producers use it in causticizing processes.

This process helps to regenerate sodium hydroxide from green liquor, making it integral to the kraft pulping cycle. The material is supplied as a dry white powder, with bulk availability in bags and super sacks.

Standard grades include food-grade ( FCC , E526-compliant), USP , and technical or industrial grade. Purity levels and particle size distributions vary significantly depending on the specific grade required.

Food and pharmaceutical grades are held to tighter specifications than construction or agricultural material. This ensures compliance with global safety and quality standards for sensitive manufacturing applications.

Physical Properties

Melting Point	580 °C (decomp)
Boiling Point	2850 °C
Density	2.24 g/cm³
Appearance	Calcium hydroxide is a soft white crystalline, odorless powder with an alkaline, bitter taste.
Color	White
Odor	Odorless
Form	Solid
Water Solubility	1.65 g/L (20 ºC)
Refractive Index	1.574
pH	12.6 (H2O, 20℃)(saturated solution)

Safety & Handling

Danger GHS05 GHS07 GHS08 Hazard Statements H314 Causes severe skin burns and eye damage H315 Causes skin irritation H318 Causes serious eye damage H335 May cause respiratory irritation H370 Causes damage to organs H373 May causes damage to organs through prolonged or repeated exposure H402 Harmful to aquatic life Precautionary Statements P260 Do not breathe dust/fume/gas/mist/vapours/spray. P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P264 Wash … thoroughly after handling. P270 Do not eat, drink or smoke when using this product. P271 Use only outdoors or in a well-ventilated area. P273 Avoid release to the environment. P280 Wear protective gloves/protective clothing/eye protection/face protection. P316 Get emergency medical help immediately. P317 Get emergency medical help. P319 Get medical advice/attention if you feel unwell. P321 Specific treatment (see … on this label). P363 Wash contaminated clothing before reuse. P405 Store locked up. P501 Dispose of contents/container in accordance with local regulations. P264+P265 Wash … thoroughly after handling. P302+P352 IF ON SKIN: Wash with plenty of water. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P308+P316 Get emergency medical help immediately. P332+P317 Get emergency medical help. P362+P364 Take off contaminated clothing and wash it before reuse. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P301+P330+P331 Rinse mouth. Do NOT induce vomiting. P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower. P305+P354+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code	28259099
Storage Class	13 - Non Combustible Solids
WGK (Germany)	1

Other Names

Industries

Food & Nutrition Agriculture & Feed Pulp & Paper Water Treatment Building & Construction