PHOSPHORIC ACID†

Chemical Identification
Chemical Identification
CAS # 7664-38-2
Formula
 

H₃PO₄

Synonyms
 

white phosphoric acid; orthophosphoric acid; metaphosphoric acid

Physical Properties
Physical Properties
Physical description Thick, colorless, odorless, crystalline solid.
Boiling point 415°F Molecular weight 98
Freezing point/melting point 108°F Vapor pressure 0.03 mmHg
Flash point Vapor density
Specific gravity 1.87 (pure) 1.33 (50% solution) Ionization potential
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating 3 NFPA fire rating 0
NFPA reactivity rating 0 NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 2085
Sampling group
Sampler/Sampling media Pre-assembled cassette with mixed cellulose ester filter (MCEF) 0.8 micron (37 mm) [MAWP037A0]
Sampling time*
 

480 min

Sampling volume (TWA)*
 

960 L

Sampling flow rate (TWA)*
 

2 L/min

Sampling volume (STEL/Peak/C)*
 

30 L

Sampling flow rate (STEL/Peak/C)*
 

2 L/min

Analytical method instruments IC
Method reference OSHA ID-111 (partially validated)
Notes
 

If the filter is not overloaded, samples may be collected up to an 8-hour period. Within 1 hour after sampling, transfer the filter to a clean screw cap vial. Phosphoric and sulfuric acid may be submitted on the same filter; otherwise, submit as a separate filter. 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 mixed cellulose ester filter (MCEF) 0.8 micron (37 mm). [AAWP03700]

Bulk Method
Bulk Method
 

 

On-Site Screening Techniques
On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
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
 

1 mg/m³

REL-TWA
 

1 mg/m³

TLV-TWA
 

1 mg/m³ [1992]

PEL-TWA
 

1 mg/m³

PEL-STEL
 

 

REL-STEL
 

3 mg/m³

TLV-STEL
 

3 mg/m³ [1992]

PEL-STEL
 

3 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
 

1000 mg/m³

Carcinogenic classifications: Not listed Notes:
 

 

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

3 mg/m³/30 mg/m³/150 mg/m³

Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Phosphoric acid

NIOSH: Pocket Guide to Chemical Hazards - Phosphoric acid

Literature References

 
  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Phosphoric acid. See annual publication for most recent information.
  • Amin, W.M., Al-Omoush, S.A. and Hattab, F.N.: Oral health status of workers exposed to acid fumes in phosphate and battery industries in Jordan. Int. Dent. J. 51(3): 169-174, 2001.
  • NIOSH: Occupational Health Guideline for Phosphoric Acid. September 1978.

Last Updated Date : 01/08/2021