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Chemical Datasheet

NITRIC ACID, RED FUMING

8 - Corrosive 5.1 - Oxidizer 6.1 - Poison Inhalation Hazard

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 7697-37-2   (NITRIC ACID, ANHYDROUS)
  • 2032
  • Corrosive
  • Oxidizer
  • Poison Inhalation Hazard
none
NIOSH Pocket Guide International Chem Safety Card
Nitric acid
  • NITRIC ACID
NFPA 704
Diamond Hazard Value Description
0
4 1
ox
Blue Health 4 Can be lethal.
Red Flammability 0 Will not burn under typical fire conditions.
Yellow Instability 1 Normally stable but can become unstable at elevated temperatures and pressures.
White Special OX Possesses oxidizing properties.
(NFPA, 2010)
General Description
A pale yellow to reddish brown liquid generating red-brown fumes and having a suffocating odor. Very toxic by inhalation. Corrosive to metals or tissue. Prolonged exposure to low concentrations or short term exposure to high concentrations may result in adverse health effects.

Rate of onset: Immediate

Persistence: Hours - days

Odor threshold: ~1 ppm

Source/use/other hazard: Used in many industries; Very corrosive to skin/mucous membranes as well as metals & other materials.

Hazards

Reactivity Alerts
Air & Water Reactions
Fumes in air. Soluble in all proportions with water. Dissolution in water produces heat, fumes, and spattering.
Fire Hazard
Excerpt from 157 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. UN1796, UN1802, UN1826, UN2032, UN3084, UN3085, and, at concentrations above 65%, UN2031 may act as oxidizers. Also consult 140 Polymerizable warning. Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.). Substance may react with water (some violently), releasing corrosive and/or toxic gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water. (ERG, 2020)
Health Hazard
Excerpt from 157 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Reaction with water or moist air may release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination. (ERG, 2020)
Reactivity Profile
NITRIC ACID, RED FUMING is a powerful oxidizing agent and nitrating agent. Accelerates the burning of combustible material and may cause charring and then ignition of combustible materials. May ignite alcohols, amines, ammonia, beryllium alkyls, boranes, dicyanogen, hydrazines, hydrocarbons, hydrogen, nitroalkanes, powdered metals, silanes, or thiols on contact [Bretherick 1979. p.174]. Can react violently with finely divided antimony [Pascal 10:504. 1931-34]. Reacts violently with bromine pentafluoride [Mellor 2, Supp. 1:172. 1956]. Reacts with hydrogen selenide and hydrogen sulfide with incandescence [Berichte 3:658]. Mixtures with finely divided magnesium are explosive [Pieters 1957 p. 28]. Oxidizes magnesium phosphide with incandescence [Mellor 8:842. 1946-47]. Mixtures with acetic anhydride containing over 50% nitric acid by mass may act as detonating explosives [BCISC 42:2. 1971]. An etching agent prepared with equal portions of acetone, nitric acid, and 75% aqueous acetic acid exploded four hours after it was prepared and placed in a closed bottle. The explosive material may have been tetranitromethane [Chem. Eng. News 38: 56. 1960]. Reacts violently with phosphine [Edin. Roy. Soc. 13:88. 1835]. Explodes in contact with phosphorus trichloride [Comp. Rend. 28:86]. Reacts exothermically with phthalic acid or phthalic anhydride in the presence of sulfuric acid to give potentially explosive phthaloyl nitrates or nitrites or nitro derivatives of these compounds [Chem. & Ind. 20:790. 1972]. Reacts energetically with sodium azide [Mellor 8, Supp 2:315. 1967]. Reacts with uranium with explosive violence [Katz and Rabinowitch 1951].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below.

Response Recommendations

Isolation and Evacuation
Excerpt from 157 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 2032 datasheet.

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)
Firefighting
Excerpt from 157 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

Note: Some foams will react with the material and release corrosive/toxic gases.

SMALL FIRE: CO2 (except for Cyanides), dry chemical, dry sand, alcohol-resistant foam.

LARGE FIRE: Water spray, fog or alcohol-resistant foam. If it can be done safely, move undamaged containers away from the area around the fire. Avoid aiming straight or solid streams directly onto the product. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned master stream devices 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. (ERG, 2020)
Non-Fire Response
Excerpt from 157 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible / Water-Sensitive)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from 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 SPILL: 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 loosely covered plastic containers for later disposal. (ERG, 2020)
Protective Clothing
Excerpt from NIOSH Pocket Guide for Nitric acid:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide:
• EYEWASH (PH<2.5) - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection. (pH<2.5)
• QUICK DRENCH (PH<2.5) - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (pH<2.5) (NIOSH, 2023)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Nitric acid (50%) 7697-37-2 Liquid >480
Nitric acid (70%) 7697-37-2 Liquid 203 >480 >480 >480 105*/140 >480 >480 >480
Nitric acid (90%) 7697-37-2 Liquid >480 >480 >480 >480
Nitric acid (>95%) 7697-37-2 Liquid 46 390
> indicates greater than.
* indicates based on lowest single value.

Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...

(DuPont, 2023)

First Aid
Excerpt from NIOSH Pocket Guide for Nitric acid:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: WATER FLUSH IMMEDIATELY - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2023)

Physical Properties

Chemical Formula:
  • HNO3
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: -44°F (NIOSH, 2023)
Vapor Pressure: 48 mmHg (NIOSH, 2023)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 1.5 at 77°F (NIOSH, 2023) - Denser than water; will sink
Boiling Point: 181°F at 760 mmHg (NIOSH, 2023)
Molecular Weight: 63 (NIOSH, 2023)
Water Solubility: Miscible (NIOSH, 2023)
Ionization Energy/Potential: 11.95 eV (NIOSH, 2023)
IDLH: 25 ppm (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for Nitric Acid (7697-37-2)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes 0.16 ppm 43 ppm 170 ppm
30 minutes 0.16 ppm 30 ppm 120 ppm
60 minutes 0.16 ppm 24 ppm 92 ppm
4 hours 0.16 ppm 6 ppm 23 ppm
8 hours 0.16 ppm 3 ppm 11 ppm
(NAC/NRC, 2023)

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Nitric Acid WFNA (7697-37-2) 1 ppm star-in-circle icon indicates that odor should be detectable near ERPG-1. 10 ppm 78 ppm
star-in-circle icon indicates that odor should be detectable near ERPG-1.
(AIHA, 2022)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Nitric acid (7697-37-2) 0.16 ppm 24 ppm 92 ppm
(DOE, 2018)

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Nitric acid 7697-37-2 1000 pounds 1000 pounds 1000 pounds 313
Nitric acid (conc 80% or greater) 7697-37-2 1000 pounds 1000 pounds 1000 pounds X 15000 pounds

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

RELEASE THEFT SABOTAGE
Chemical of Interest CAS Number Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Min Conc STQ Security
Issue
Nitric acid 7697-37-2 80.00 % 15000 pounds toxic 68.00 % 400 pounds EXP/IEDP

(CISA, 2007)

OSHA Process Safety Management (PSM) Standard List

Chemical Name CAS Number Threshold Quantity (TQ)
Nitric Acid (94.5% by weight or greater) 7697-37-2 500 pounds

(OSHA, 2019)

Alternate Chemical Names