Hydrogen fluoride, anhydrous

Formula
HF
Structure
Description
Colorless fuming liquid with a sharp, penetrating odor.
Uses
Cleaning cast iron, copper, brass, removing efflorescence from brick & stone, or sand particle from metallic castings, working over too heavily weighted silks, frosting, etching glass and enamel, polishing crystal glass, decomp cellulose, enameling & galvanizing iron, incr porosity of ceramics in analytical work to determine silicon dioxide.

Registry Numbers and Inventories.
CAS
7664-39-3
EC (EINECS/ELINCS)
231-634-8
EC Index Number
009-003-00-1
EC Class
Very toxic; Corrosive
RTECS
MW7875000
RTECS class
Mutagen; Reproductive Effector; Human Data; Primary Irritant
UN (DOT)
1052
Merck
12,4837
Beilstein/Gmelin
166 (G)
RCRA
U134
EPA OPP
45601
Swiss Giftliste 1
G-4551
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
FH
Formula mass
20.00
Melting point, °C
-83
Boiling point, °C
19.5
Vapor pressure, mmHg
760 (20 C)
Vapor density (air=1)
0.714
Odor Threshold Odor threshold 0.5 To 3 ppm
Critical temperature
230.6
Critical pressure
74.8
Density
0.0061 g/cm3 (50 C)
Solubility in water
Miscible
Viscosity
0.012571 cp (20 C)
Surface tension
8.99 erg/cm2 (16 C)
Refractive index
1.00001 (25 C)
Dipole moment
1.91 D
Dielectric constant
110.6 (-27 C)
pKa/pKb
3.19 (pKa)
Heat of fusion
3.9 kJ/mol
Heat of vaporization
7.5 kJ/mol

Hazards and Protection.
Storage
Protect against physical damage. Store at in well-ventilated area, separated from other storage.
D1A E
Handling
Containers of this material may be hazardous when emptied. Since emptied containers retain product residues (vapor, liquid, and/or solid), all hazard precautions given in the data sheet must be observed. Addition to water releases heat which can result in violent boiling and spattering. Always add slowly and in small amounts. Never use hot water. Never add water to acids. Always add acids to water.
Protection
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Use water spray to knock-down vapors. Neutralize spilled material with crushed limestone, soda ash, or lime. Vapor knockdown water is corrosive or toxic and should be diked for containment. Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. Neutralize with agricultural lime (CaO), crushed limestone (CaCO3) or sodium bicarbonate (NaHCO3). Water spill: Neutralize with agricultural lime (CaO), crushed limestone (CaCO3), or sodium bicarbonate (NaHCO3). Add soda ash (Na2CO3). Adjust pH to neutral (pH=7). Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.
Stability
Stable.
Incompatibilities
Attacks glass and any other silica containing material May react with common metals (iron, steel) to generate flammable hydrogen gas if diluted below 65% with water Reacts exothermically with chemical bases (examples: amines, amides, inorganic hydroxides) Reacts with cyanide salts and compounds to release gaseous hydrogen cyanide Reacts explosively with cyanogen fluoride, methanesulfonic acid or glycerol mixed with nitric acid Reacts violently with arsenic trioxide, phosphorus pentachloride, acetic anhydride, alkali metals, ammonium hydroxide, chlorosulfonic acid, ethylenediamine, fluorine, potassium permanganate, oleum, propylene oxide, vinyl acetate, mercury(II) oxide.
Decomposition
When heated to decomposition it emits highly corrosive fumes of hydrogen fluoride.

Fire.
Fire fighting
Use water on fires in which hydrofluoric acid is involved.
Fire potential
Nonflammable hydrogen may be generated in piping or containers.
Hazards
When heated, it emits highly corrosive fumes of fluorides. Its corrosive action on metals can result in formation of hydrogen in containers and piping to create fire hazard. Toxic and irritating vapors are generated when heated. Will attack glass, concrete, and certain metals, especially those containing silica, such as cast iron. Will attack natural rubber, leather, and many organic materials. May generate flammable hydrogen gas in contact with some metals.
Combustion products
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Health
4
 
Flammability
0
 
 
Reactivity
1
 

Health.
Exposure limit(s)
OSHA PEL: TWA 3 ppm NIOSH REL: TWA 3 ppm (2.5 mg/m3) C 6 ppm (5 mg/m3) 15-minute NIOSH IDLH: 30 ppm
Poison_Class
2
Exposure effects
The toxological properties of this substance have not been fully investigated.
   Ingestion
Swallowing this material may be harmful or fatal. Symptoms may include severe stomach and intestinal irritation (nausea, vomiting, diarrhea), abdominal pain, and vomiting of blood. Swallowing this material may cause burns and destroy tissue in the mouth, throat, and digestive tract. Low blood pressure and shock may occur as a result of severe tissue injury.
   Inhalation
Dyspnea, bronchospasm (with abnormal pfts and hypoxia), chemical pneumonitis, pulmonary edema (can be hemorrhagic), tracheobronchitis, upper airway obstruction, chemical burns (larynx, trachea, bronchi) and ards may occur following inhalation.
   Skin
Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
   Eyes
Can cause permanent eye injury. Symptoms include stinging, tearing, redness, and swelling of eyes. Can injure the cornea and cause blindness.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce 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. Effects may be delayed.
   Skin
Remove all exposed clothing and jewelry taking necessary precautions to prevent secondary exposure to health care providers. Irrigate exposed areas promptly with copious amounts of water for at least 30 minutes. Wash the skin, including hair and nails, vigorously; do repeated soap washings. Discard contaminated clothing.
   Eyes
In case of contact with liquefied gas, thaw frosted parts with lukewarm water Immediately flush skin with running water for at least 20 minutes.

Transport.
UN number
1052
Response guide
Hazard class
8
PRTC
T
Packing Group
I
 
USCG CHRIS Code
HFX
 
1 Non-oxidizing mineral acids
Std. Transport #
4930024
 
IMO Pollution Category
B