Perchloric acid

  • Perchloric acid, 50 - 72%
  • Dioxonium perchlorate solution
  • Hydronium perchlorate
Formula
HClO4
Structure
Description
Colorless to yellowish, odorless liquid.
Uses
In analytical chemistry as an oxidizer & for separation of potassium from sodium.

Registry Numbers and Inventories.
CAS
7601-90-3
EC (EINECS/ELINCS)
231-512-4
EC Index Number
017-006-00-4
EC Class
Heating may cause an explosion; Oxidising; Corrosive
R 5 8 35
S 23 26 36 45
RTECS
SC7500000
RTECS class
Other
UN (DOT)
1802
Merck
12,7296
Beilstein/Gmelin
2137 (G)
Swiss Giftliste 1
G-3036
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
HClO4
Formula mass
100.46
Melting point, °C
-18
Boiling point, °C
203
Decomposition point, °C
92
Vapor pressure, mmHg
29 (25 C)
Vapor density (air=1)
3.5
Density
1.7722 g/cm3 (25 C)
Solubility in water
Very soluble
Viscosity
0.008 P (25 C)
Surface tension
69.0 erg/cm2 (25 C)
Refractive index
1.3 (20 C)8189
Thermal expansion
0.0011/K (20 C)
Heat of fusion
6.9 kJ/mol
Heat of vaporization
30.3 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
C E
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear rubber or neoprene gloves and additional protection including impervious boots, apron, or coveralls, as needed in areas of unusual exposure. Use chemical safety goggles and/or a full face shield where splashing is possible. Maintain eye wash fountain and quick-drench facilities in work area.
Respirators
For emergencies, or instances where the exposure levels are not known, use a full-facepiece positive-pressure, air-supplied respirator. WARNING: Air purifying respirators do not protect workers in oxygen-deficient atmospheres. If the exposure limit is exceeded and engineering controls are not feasible, wear a supplied air, full-facepiece respirator, airlined hood, or full-facepiece self-contained breathing apparatus. Breathing air quality must meet the requirements of the OSHA respiratory protection standard (29CFR1910.134).
Small spills/leaks
Ventilate area of leak or spill. Remove all sources of ignition. Wear appropriate personal protective equipment. Isolate hazard area. Keep unnecessary and unprotected personnel from entering. Contain and recover liquid when possible. Use non-sparking tools and equipment. Remove spilled perchloric acid by immediate and thorough washing with large amounts of water. Reduce with a weak reducung agent, (hypobisulfite or ferrous salt, plus sulfuric acid as an accelerator have been recommended), then neutralize with sodium carbonate or calcium oxide.
Stability
Unstable at ordinary temperature and pressure and can undergo explosive decomposition, especially at elevated temperatures or if allowed to dehydrate.
Incompatibilities
Incompatible with numerous materials, including combustible materials, organic chemicals, strong dehydrating agents, reducing and oxidizing agents. Reacts violently with benzene, calcium hydride, wood, acetic acid, charcoal, olefins, ethanol, sulfur and sulfuric acid.
Decomposition
May emit toxic chloride fumes when heated to decomposition.

Fire.
Fire fighting
Wear full protective clothing and NIOSH-approved self-contained breathing apparatus with full facepiece operated in the pressure demand or other positive pressure mode. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.
Fire potential
Not combustible, but substance is a strong oxidizer and its heat of reaction with reducing agents or combustibles may cause ignition.
Hazards
Can react with metals to release flammable hydrogen gas. Reactions may cause fire and explosion. In the event of a fire, assume that organic materials are involved and that an explosion may occur. May form sensitive powerful explosive mixtures with organic materials.
Combustion products
Poisonous gases may be produced in fire.
Health
3
 
Flammability
0
 
 
Reactivity
3
 
 
Special
O

Health.
Poison_Class
1
Exposure effects
Repeated exposure to dilute solutions may cause skin rash and possible sensitization.
   Ingestion
Corrosive. May cause burns of mouth, throat, and stomach, nausea, vomiting and diarrhea.
   Inhalation
Corrosive. Inhalation of vapors or mists will cause irritation with coughing, choking, and inflammation of the nose, throat, and upper respiratory tract.
   Skin
Corrosive. Can cause severe burns with discoloration and pain.
   Eyes
Corrosive. Permanent visual damage may occur. Highly corrosive to tissue.

First aid
 
   Ingestion
If swallowed, DO NOT INDUCE VOMITING. Give large quantities of water. Never give anything by mouth to an unconscious person. Get medical attention immediately.
   Inhalation
Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Call a physician.
   Skin
Immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Call a physician, immediately. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, lifting lower and upper eyelids occasionally. Get medical attention immediately.

Transport.
UN number
1802
Response guide
Hazard class
8
USCG CHRIS Code
PCL
 
Std. Transport #
4930215