Print
Chemical Datasheet

PLASTER OF PARIS

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 26499-65-0
 none data unavailable none
NIOSH Pocket Guide International Chem Safety Card
Plaster of Paris
  • PLASTER OF PARIS
NFPA 704
data unavailable
General Description
White or yellowish, finely divided, odorless powder consisting mostly or entirely of calcium sulfate hemihydrate, CaSO4*1/2H2O. Forms a paste when it is mixed with water that soon hardens into a solid. Used in making casts, molds, and sculpture. Generally non-toxic.

Hazards

Reactivity Alerts
none
Air & Water Reactions
No rapid reaction with air. No rapid reaction with water.
Fire Hazard
No information available.
Health Hazard
Excerpt from NIOSH Pocket Guide for Plaster of Paris:

Exposure Routes: Inhalation, ingestion, skin and/or eye contact

Symptoms: Irritation eyes, skin, mucous membrane, respiratory system; cough

Target Organs: Eyes, skin, respiratory system (NIOSH, 2023)
Reactivity Profile
PLASTER OF PARIS is non-flammable and non-combustible. Has generally low chemical reactivity but can act as an oxidizing agent under extreme conditions. Decomposes at high temperature to generate toxic oxides of sulfur. Reacts exothermically but slowly with moisture in the air or water to form gypsum CaSO4.2H2O.
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
No information available.
Firefighting
No information available.
Non-Fire Response
No information available.
Protective Clothing
Excerpt from NIOSH Pocket Guide for Plaster of Paris:

Skin: No recommendation is made specifying the need for personal protective equipment for the body.

Eyes: No recommendation is made specifying the need for eye protection.

Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).

Remove: No recommendation is made specifying the need for removing clothing that becomes wet or contaminated.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift. (NIOSH, 2023)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
Excerpt from NIOSH Pocket Guide for Plaster of Paris:

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.

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:
  • CaSO4 = 0.5H2O
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: 325°F (Loses H2O) (NIOSH, 2023)
Vapor Pressure: 0 mmHg (approx) (NIOSH, 2023)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 2.5 (NIOSH, 2023) - Denser than water; will sink
Boiling Point: data unavailable
Molecular Weight: 145.2 (NIOSH, 2023)
Water Solubility: 0.3 % at 77°F (NIOSH, 2023)
Ionization Energy/Potential: data unavailable
IDLH: data unavailable

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

No PAC information available.

Regulatory Information

EPA Consolidated List of Lists

No regulatory information available.

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