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Chemical Datasheet

PHOSPHORIC ACID

8 - Corrosive

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 7664-38-2
  • 1805 (solution)
  • 3453 (solid)
  • Corrosive
  • PAC
NIOSH Pocket Guide International Chem Safety Card
Phosphoric acid
  • PHOSPHORIC ACID
NFPA 704
Diamond Hazard Value Description
0
3 0
Blue Health 3 Can cause serious or permanent injury.
Red Flammability 0 Will not burn under typical fire conditions.
Yellow Instability 0 Normally stable, even under fire conditions.
White Special
(NFPA, 2010)
General Description
A clear colorless liquid or transparent crystalline solid. The pure solid melts at 42.35°C and has a density of 1.834 g / cm3. Liquid is usually an 85% aqueous solution. Shipped as both a solid and liquid. Corrosive to metals and tissue. Used in making fertilizers and detergents and in food processing.

Hazards

Reactivity Alerts
none
Air & Water Reactions
Soluble in water with small release of heat.
Fire Hazard
Excerpt from 154 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. For electric vehicles or equipment, 147 Polymerizable warning (lithium ion batteries) or 138 Polymerizable warning (sodium batteries) should also be consulted. (ERG, 2020)
Health Hazard
Burns on mouth and lips, sour acrid taste, severe gastrointestinal irritation, nausea, vomiting, bloody diarrhea, difficult swallowing, severe abdominal pains, thirst, acidemia, difficult breathing, convulsions, collapse, shock, death. (USCG, 1999)
Reactivity Profile
PHOSPHORIC ACID reacts exothermically with bases. May react with active metals, including such structural metals as aluminum and iron, to release hydrogen, a flammable gas. Can initiate the polymerization of certain classes of organic compounds. Reacts with cyanide compounds to release gaseous hydrogen cyanide. May generate flammable and/or toxic gases in contact with dithiocarbamates, isocyanates, mercaptans, nitrides, nitriles, sulfides, and strong reducing agents. Forms explosive mixture with nitromethane. Reacts violently with sodium tetrahydroborate. In the presence of chlorides can corrode stainless steel to form explosive hydrogen gas. Emits toxic and irritating fumes of oxides of phosphorus when heated to decomposition [Lewis, 3rd ed., 1993, p. 1029].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
Excerpt from 154 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible)]:

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: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

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 154 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. 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 154 Polymerizable warning [Substances - Toxic and/or Corrosive (Non-Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2020)
Protective Clothing
Excerpt from NIOSH Pocket Guide for Phosphoric 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: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

Provide:
• EYEWASH (>1.6%) - 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. (>1.6%)
• QUICK DRENCH (>1.6%) - 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.] (>1.6%) (NIOSH, 2023)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Phosphoric acid (85%) 7664-38-2 Liquid >480 >480 >480 >480 >480 >480 >480
> indicates greater than.

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 Phosphoric 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:
  • H3PO4
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: Not flammable (USCG, 1999)
Melting Point: 108°F (NIOSH, 2023)
Vapor Pressure: 0.03 mmHg (NIOSH, 2023)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 1.892 at 77°F (USCG, 1999) - Denser than water; will sink
Boiling Point: greater than 266°F at 760 mmHg (USCG, 1999)
Molecular Weight: 98 (USCG, 1999)
Water Solubility: Miscible (NIOSH, 2023)
Ionization Energy/Potential: data unavailable
IDLH: 1000 mg/m3 (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Phosphoric Acid (7664-38-2) 3 mg/m3 30 mg/m3 150 mg/m3
(AIHA, 2022)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Phosphoric acid (7664-38-2) 3 mg/m3 30 mg/m3 150 mg/m3
(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
Phosphoric acid 7664-38-2 5000 pounds

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names