General Description
Odorless white granules. Sinks in water.
Reactivity Profile
The nitroparaffins, nitromethane, nitropropane, etc. form salts with inorganic bases such as CALCIUM HYDROXIDE(1305-62-0). The dry salts are explosive [Chem. Eng. news 30:2344 1952]. Bases are chemically similar to sodium hydroxide (NaOH) or sodium oxide (Na2O). They neutralize acids exothermically to form salts plus water. When soluble in water they give solutions having a pH greater than 7.0. Mixing these materials with water can generate troublesome amounts of heat as the base is dissolved or diluted. Bases react with certain metals (such as aluminum and zinc) to form oxides or hydroxides of the metal and generate gaseous hydrogen. Bases may initiate polymerization reactions in polymerizable organic compounds, especially epoxides). They may generate flammable and/or toxic gases with ammonium salts, nitrides, halogenated organics, various metals, peroxides, and hydroperoxides. Materials of this group often serve as catalysts. A strong base. Forms caustic solution in water [Merck 11th ed. 1989].
Air & Water Reactions
Water soluble. The amount of heat generated by hydrolysis may be large.
Hazard
Skin, eye, and upper respiratory tract irri-
tant, avoid inhalation.
Health Hazard
Dust irritates eyes, nose and throat.
Potential Exposure
Calcium hydroxide is used in agriculture and in fertilizer manufacture; it is used in the formulation of mortar, plasters, and cements; it is used as a
scrubbing and neutralizing agent in the chemical industry.
For making insecticides, acaricides, and products to control
arthropods
First aid
Move victim to fresh air. Call 911 or emergency
medical service. Give artificial respiration if victim is not
breathing. Do not use mouth-to-mouth method if victim
ingested or inhaled the substance; give artificial respiration
with the aid of a pocket mask equipped with a one-way valve
or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated
clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least
20 minutes. For minor skin contact, avoid spreading material
on unaffected skin. Keep victim warm and quiet. Effects of
exposure (inhalation, ingestion, or skin contact) to substance
may be delayed. Ensure that medical personnel are aware of
the material(s) involved and take precautions to protect themselves. Medical observation is recommended for 24 to
48 hours after breathing overexposure, as pulmonary edema
may be delayed. As first aid for pulmonary edema, a doctor
or authorized paramedic may consider administering a drug
or other inhalation therapy.
Shipping
UN3262 Corrosive solid, basic, inorganic, n.o.s.,
Hazard class: 8; Labels: 8-Corrosive material, Technical
Name required
Incompatibilities
May react violently with acids, maleic
anhydride, nitromethane, nitroethane, nitropropane, nitroparaffins, and phosphorus.
Description
Calcium Hydroxide is a colorless crystal or white powder,
obtained when CaO (called lime or quicklime) is mixed, or
“slaked” with water. It can also be precipitated by mixing
CaCl2 andNaOH.The nameof the natural,mineral formis
“portlandite”. It is a relatively rare mineral, known from
some volcanic, plutonic, and metamorphic rocks. It has
also been known to be formed in burning coal dumps.
Waste Disposal
Landfill or admixture with
acid industrial wastes prior to lagooning
Physical properties
Soft white crystalline powder; hexagonal; density 2.34 g/cm3; slightly bitter taste; loses water when heated at elevated temperatures (580°C); slightly soluble in water; Ksp 1.2x10-14; aqueous solution alkaline; soluble in glycerol and acids; insoluble in alcohol.
Definition
Lime water: A solution of calcium hydroxide
in water. If carbon dioxide is bubbled
through lime water a milky precipitate of
calcium carbonate forms. Prolonged bubbling
of carbon dioxide turns the solution
clear again as a result of the formation of
soluble calcium hydrogencarbonate
(Ca(HCO3)2).
Production Methods
Calcium hydroxide is manufactured by adding water to calcium
oxide, a process called slaking.
Flammability and Explosibility
Notclassified
Agricultural Uses
Calcium hydroxide, [Ca(OH)2], also called slaked lime
or hydrated lime, is a white solid that dissolves
sparingly in water. It is manufactured by adding water to
calcium oxide, a process that emits heat and is known as
slaking.
Calcium hydroxide is a cheap alkali, used for
neutralizing the acidity of acid soils and in the
manufacture of mortar, white wash, bleaching powder
and glass. It is an excellent absorbent for carbon dioxide
to produce insoluble calcium carbonate and has a
neutralizing value of 179%, compared to 100% of pure
calcium carbonate.
Pharmaceutical Applications
Calcium hydroxide is a strong alkali and is used as a pharmaceutical
pH adjuster/buffer and antacid in topical medicinal ointments,
creams, lotions, and suspensions, often as an aqueous solution (lime
water). It forms calcium soaps of fatty acids, which produce
water-in-oil emulsions (calamine liniment), and it is also used as a
topical astringent.
Calcium hydroxide is a common cosmetic ingredient in hairstraightening
and hair-removal products, and in shaving preparations.
1) In dentistry, it is used as a filling agent and in dental pastes
to encourage deposition of secondary dentine. Calcium hydroxide
was traditionally used as an escharotic in Vienna Paste.
Safety
Calcium hydroxide is used in oral and topical pharmaceutical
formulations. It is mildly toxic by ingestion. In the pure state,
calcium hydroxide is a severe skin, eye, and respiratory irritant, and
it is corrosive, causing burns. Typical exposure limits are TVL
5 mg/m3 in air.
LD50 (mouse, oral): 7.3 g/kg
LD50 (rat, oral): 7.34 g/kg
storage
Calcium hydroxide should be stored in an airtight container, in a
cool, dry, well-ventilated place. Calcium hydroxide powder may be
sterilized by heating for 1 hour at a temperature of at least 1608℃.
Purification Methods
Heat analytical grade calcium carbonate at 1000o during 1hour. Allow the resulting oxide to cool and add slowly to water. Heat the suspension to boiling, cool and filter through a sintered glass funnel of medium porosity (to remove soluble alkaline impurities). Dry the solid at 110o and crush it to a uniformly fine powder. [Ehrlich in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 934 1963.]
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe.
Included in the FDA Inactive Ingredients Database (intravenous and
subcutaneous injections; oral suspensions and tablets; topical
emulsions and creams). Included in parenteral preparations licensed
in the UK.
