Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Phosphoric acid

Synonyms & Trade Names
Orthophosphoric acid, Phosphoric acid (aqueous), White phosphoric acid
CAS No.
7664-38-2
RTECS No.
TB6300000
DOT ID & Guide
1805 154(liquid or solution)
3453 154(solid)
Formula
H₃PO₄
Conversion
IDLH
1000 mg/m3
See: 7664382
Exposure Limits
NIOSH REL
TWA 1 mg/m3 ST 3 mg/m3
OSHA PEL
TWA 1 mg/m3 See Appendix G
Measurement Methods
NIOSH 7903;
OSHA ID165SG
See: NMAM or OSHA Methods
Physical Description
Thick, colorless, odorless, crystalline solid. [Note: Often used in an aqueous solution.]
Molecular Weight
98.0
Boiling Point
415°F
Melting Point
108°F
Solubility
Miscible
Vapor Pressure
0.03 mmHg
Ionization Potential
?
Specific Gravity
(77°F): 1.87 (pure) 1.33 (50% solution)
Flash Point
NA
Upper Exposive Limit
NA
Lower Explosive Limit
NA
Noncombustible Solid
Incompatibilities & Reactivities
Strong caustics, most metals [Note: Readily reacts with metals to form flammable hydrogen gas. DO NOT MIX WITH SOLUTIONS CONTAINING BLEACH OR AMMONIA.]
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
irritation eyes, skin, upper respiratory system; eye, skin, burns; dermatitis
Target Organs
Eyes, skin, respiratory system
Personal Protection/Sanitation
(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet or contaminated
Change:Daily
Provide:Eyewash (>1.6%), Quick drench (>1.6%)
First Aid
(See procedures)
Eye:Irrigate immediately
Skin:Water flush immediately
Breathing:Respiratory support
Swallow:Medical attention immediately
Respirator Recommendations

NIOSH/OSHA

Up to 25 mg/m3:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode*

Up to 50 mg/m3:
(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters.
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator with a full facepiece

Up to 1000 mg/m3:
(APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:
(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters.
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 1008

Follow NIOSH

NIOSH Homepage

TOP