NITRIC ACID†

Chemical Identification
Chemical Identification
CAS # 7697-37-2
Formula

HNO₃

Synonyms
 

aqua fortis; spirit of niter; engravers acid; white fuming nitric acid (WFNA); red fuming nitric acid (RFNA); hydrogen nitrate

Physical Properties
Physical Properties
Physical description Colorless, yellow, or red, fuming liquid with an acrid, suffocating odor.
Boiling point 181°F Molecular weight 63
Freezing point/melting point -44°F Vapor pressure 48 mmHg
Flash point Vapor density
Specific gravity 1.5 Ionization potential 11.95 eV
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating 4 NFPA fire rating 0
NFPA reactivity rating 0, 1 (red fuming) NFPA special instruction OX: Possesses oxidizing properties
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 1860
Sampling group
Sampler/Sampling media ORBO™ 53 activated silica gel tube [Supelco 20265]
Sampling time*
 

480 min

Sampling volume (TWA)*
 

96 L

Sampling flow rate (TWA)*
 

0.2 L/min

Sampling volume (STEL/Peak/C)*
 

7.5 L

Sampling flow rate (STEL/Peak/C)*
 

0.5 L/min

Analytical method instruments IC
Method reference OSHA ID-165SG (partially validated)
Notes
 

Nitric and hydrobromic (HBr) acids may be submitted on the same sample (TWA only). For STEL samples, submit as a separate sample. Make sure that glass fiber filter plug is firmly in contact with silica gel before sampling and before sealing tube for shipment. Interferences: particulate acids and salts of an anion. Large quantities of any one of the analytes can result in masking of the peaks of other analytes.

Special requirements
 

 

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Wipe Method
Sampler/Sampling media
 

Wipe with Whatman smear tab. [WHA1450993]

Bulk Method
Bulk Method
 

 

On-Site Screening Techniques
On-Site Screening Techniques
Device Detector tube Detector tube Detector tube Detector tube
Model/Type Dräger - Nitric Acid 1/a, 6728311 Gastec 15L Gastec 80 Matheson-Kitagawa 8014-233S
Sampling information
(see manufacturer instructions)
10 or 20 strokes, approx 1-50 ppm range, uncertainty 16% 0.5-10 strokes, 0.05-40 ppm range, uncertainty 25% for 1 to 5 ppm, 16% for 5 to 20 ppm 2 strokes, 2.5-200 ppm range follow mfr instructions, approx 1-20 ppm range
Exposure Limits
Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA
 

2 ppm (5 mg/m³)

REL-TWA
 

2 ppm (5 mg/m³)

TLV-TWA
 

2 ppm [1992]

PEL-TWA
 

2 ppm (5 mg/m³)

PEL-STEL
 

 

REL-STEL
 

4 ppm (10 mg/m³)

TLV-STEL
 

4 ppm [1992]

PEL-STEL
 

4 ppm (10 mg/m³)

PEL-C
 

 

REL-C
 

 

TLV-C
 

 

PEL-C
 

 

Skin notation
 

N

Skin notation
 

N

Skin notation
 

N

Skin notation
 

N

Notes:
 

See 29 CFR 1910.1000 Table Z-1.

Notes:
 

 

Notes:
 

 

Notes:
 

 

Health factors:  See NIH-NLM PubChem. IDLH
 

25 ppm

Carcinogenic classifications: Not listed Notes:
 

 

AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
 

1 ppm/10 ppm/78 ppm

Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Nitric acid (other than red fuming)

NIOSH: Pocket Guide to Chemical Hazards - Nitric acid

Literature References

 
  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) – Nitric Acid. See annual publication for most recent information.
  • Litovitz, T.L. et al.: 2001 Annual Report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am. J. Emerg. Med. 20(5): 391-452, 2002.
  • Murphy, CM, Akbarnia, H, and Rose, SR: Fatal pulmonary edema after acute occupational exposure to nitric acid. J Emerg Med. 39(1): 39-43, 2010.
  • NIOSH: Occupational Health Guideline for Nitric Acid. September 1978.
  • NIOSH: Criteria for a Recommended Standard - Occupational Exposure to Nitric Acid. March 1976.

Last Updated Date : 01/05/2021