Label abbreviations descriptions

PLASTER OF PARIS†

Chemical Identification
CAS # 26499-65-0
Formula

2CaSO₄
Synonyms
 

calcium sulfate hemihydrate; dried calcium sulfate; gypsum hemihydrate; hemihydrate gypsum

Physical Properties
Physical description White or yellowish, finely divided, odorless powder.
Boiling point Molecular weight 145.2
Freezing point/melting point 325°F (loses H₂O) Vapor pressure 0 mmHg (approx)
Flash point Vapor density
Specific gravity 2.5 Ionization potential
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating NFPA fire rating
NFPA reactivity rating NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 2127 (total); request using analyte code 9135 P102 (resp); request using analyte code 9130
Sampling group
Sampler/Sampling media Tared low-ash 37 mm PVC filter, 5 microns [SLTC108] Tared low-ash 37 mm PVC filter, 5 microns, preceded by 10 mm nylon Dorr-Oliver cyclone for respirable samples. [SLTC108]
Sampling time*
 

240-480 min
 

240-480 min
Sampling volume (TWA)*
 

960 L
 

816 L
Sampling flow rate (TWA)*
 

2 L/min
 

1.7 L/min ±5%
Sampling volume (STEL/Peak/C)*
 

 
 

 
Sampling flow rate (STEL/Peak/C)*
 

 
 

 
Analytical method instruments Gravimetric Gravimetric
Method reference OSHA PV2121 (partially validated) OSHA PV2121 (partially validated)
Notes
 

If the net weight of the sample yields a concentration below the PEL after considering the associated SAE , the SLTC will perform no further work on the sample and the sample air concentration will be reported as the calculated gravimetric air concentration. If the net weight corresponds to an amount greater than the PEL value after considering the associated SAE, the sample may be analyzed for  the applicable component and appropriate results will be reported.
 

If the filter is not overloaded, samples can be collected up to an 8-hour period. If the net weight of the sample yields a concentration below the PEL after considering the associated SAE , the SLTC will perform no further work on the sample and the sample air concentration will be reported as the calculated gravimetric air concentration.

If the net weight corresponds to an amount greater than the PEL value after considering the associated SAE, the sample may be analyzed for  the applicable component and appropriate results will be reported.
Special requirements
 

FOR TOTAL DUST SAMPLES, DO NOT USE A CYCLONE!!
 

 

* 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.

Bulk/Wipe Method
Wipe Sampler/Sampling media
 

 
Bulk Method
 

 

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

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
 

15 mg/m³ (total dust), 5 mg/m³ (respirable fraction)

 REL-TWA
 

10 mg/m³ (total), 5 mg/m³ (resp)

 TLV-TWA
 

 

 PEL-TWA
 

10 mg/m³ (total dust), 5 mg/m³ (respirable fraction)
PEL-STEL
 

 

 REL-STEL
 

 

 TLV-STEL
 

 

 PEL-STEL
 

 
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:
 

No TLV established. It is recommended that airborne concentrations be kept below 3 mg/m³ (respirable particles) and 10 mg/m³ (inhalable particles) for insoluble particles of low toxicity for which no TLV has been established. See Appendix B of the TLV booklet for guidelines.

 Notes:
 

As Particulates not otherwise regulated. See footnote [n].
Health factors:  See NIH-NLM PubChem. IDLH
Carcinogenic classifications: Notes:
 

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

 

Additional Resources and Literature References

Last Updated Date : 01/08/2021