Nitric acid

  • Aqua fortis
  • Hydrogen nitrate
Formula
HNO3
Structure
Description
Clear, colorless or yellowish liquid with an acrid, choking odor. Hygroscopic.
Uses
Manufacturing of pharmaceuticals, for photo-engraving in printing industry, in jewelry manufacturing and in engineering industry.

Registry Numbers and Inventories.
CAS
7697-37-2
EC (EINECS/ELINCS)
231-714-2
EC Index Number
007-004-00-1
EC Class
Oxidising; Corrosive
S 23.2 26 36 45
RTECS
QU5775000
RTECS class
Other
UN (DOT)
2031
Merck
12,6672
Beilstein/Gmelin
1576 (G)
EPA OPP
45951
Swiss Giftliste 1
G-9512
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
HNO3
Formula mass
63.01
Melting point, °C
-42
Boiling point, °C
87
Decomposition point, °C
240
Vapor pressure, mmHg
48 (20 C)
Vapor density (air=1)
2.5
Saturation Concentration
7200 ppm at 20 C; 9300 ppm at 20 C (calculated)
Evaporization number
Information not available
Odor Threshold Odor threshold 0.75 mg/m3
Density
3.382 g/cm3 (25 C)
Solubility in water
Miscible
Viscosity
0.0076 P (25 C)
Surface tension
60.7 erg/cm2 (20 C)
Refractive index
1.39717 (14 C)
Dipole moment
2.17 D
pKa/pKb
Strong acid
Thermal expansion
0.00033/K (-96 C)
Heat of fusion
2.5 kJ/mol
Heat of vaporization
39.1 kj/mol

Hazards and Protection.
Storage
Safeguard against mechanical injury of containers, isolate from turpentine, combustible materials, carbides, metallic powders, fulminates, picrates, or chlorates.
C 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 impervious protective clothing, including boots, gloves, lab coat, apron or coveralls, as appropriate, to prevent skin contact. 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
Wear a supplied air, full-facepiece respirator, airlined hood, or full-facepiece self-contained breathing apparatus. Nitric acid is an oxidizer and should not come in contact with cartridges and canisters that contain oxidizable materials, such as activated charcoal. Canister-type respirators using sorbents are ineffective.
Small spills/leaks
ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. A vapor suppressing foam may be used to reduce vapors. DO NOT GET WATER INSIDE CONTAINERS. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Prevent entry into waterways, sewers, basements or confined areas. SMALL SPILLS: Cover with DRY earth, DRY sand, or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean non-sparking tools to collect material and place it into loosley covered plastic containers for later disposal.
Stability
Stable under ordinary conditions of use and storage. Containers may burst when heated.
Incompatibilities
A dangerously powerful oxidizing agent, concentrated nitric acid is incompatible with most substances, especially strong bases, metallic powders, carbides, hydrogen sulfide, turpentine, and combustible organics.
Decomposition
When heated to decomposition, emits toxic nitrogen oxides fumes and hydrogen nitrate. Will react with water or steam to produce heat and toxic and corrosive fumes.

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. Note: Most foams will react with the material and release corrosive/toxic gases. SMALL FIRES: carbon dioxide, dry chemical, dry sand, alcohol-resistant foam. LARGE FIRES: Water spray, fog or alcohol-resistant foam. Move containers from fire area if you can do it without risk. Use water spray or fog; do not use straight streams. Dike fire control water for later disposal; do not scatter the material. FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire.
Fire potential
Not combustible, but substance is a strong oxidizer and its heat of reaction with reducing agents or combustibles may cause ignition. Can react with metals to release flammable hydrogen gas.
Hazards
Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases. Reaction with water may generate much heat which will increase the concentration of fumes in the air. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.
Combustion products
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Health
3
 
Flammability
0
 
 
Reactivity
1
 
 
Special
O

Health.
Exposure limit(s)
TLV: 2 ppm; 5.2 mg/m3 (as STEL: 4 ppm; 10 mg/m3) (ACGIH 1993-1994). OSHA PEL: TWA 2 ppm (5 mg/m3) NIOSH REL: TWA 2 ppm (5 mg/m3) ST 4 ppm 10 mg/m3) NIOSH IDLH: 25 ppm
Poison_Class
5
Exposure effects
Long-term exposure to concentrated vapors may cause erosion of teeth and lung damage. Long-term exposures seldom occur due to the corrosive properties of the acid.
   Ingestion
Corrosive! Swallowing nitric acid can cause immediate pain and burns of the mouth, throat, esophagus and gastrointestinal tract.
   Inhalation
Corrosive! Inhalation of vapors can cause breathing difficulties and lead to pneumonia and pulmonary edema, which may be fatal. Other symptoms may include coughing, choking, and irritation of the nose, throat, and respiratory tract.
   Skin
Corrosive! Can cause redness, pain, and severe skin burns. Concentrated solutions cause deep ulcers and stain skin a yellow or yellow-brown color.
   Eyes
Corrosive! Vapors are irritating and may cause damage to the eyes. Contact may cause severe burns and permanent eye damage.

First aid
 
   Ingestion
Do not induce emesis - dilution: following ingestion and/or prior to gastric evacuation, immediately dilute with 4 to 8 ounces (120 to 240 ml) of milk or water (not to exceed 15 ml/kg in a child). The possible benefit of early removal of some ingested material by cautious gastric lavage must be weighed against potential complications of bleeding or perforation.
   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.
   Skin
Remove and isolate contaminated clothing and shoes. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
2031
Response guide
Hazard class
8
Packing Group
I; II
 
USCG CHRIS Code
NAC
 
HS Code
2808 00 00
 
Std. Transport #
4931201
 
IMO Chemical Code
17
IMO Pollution Category
C
IMO Hazard code
S/P