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Registry of Toxic Effects of Chemical Substances (RTECS)

Plaster of paris

RTECS #

TP0700000

CAS #

26499-65-0

Updated

March 2011

Molecular Weight

145.15

Molecular Formula

O4S·Ca·1/2H2O

Synonyms

Crystacal
Densite
Densite (gypsum)
FGR
Gypsum hemihydrate
Hemihydrate gypsum
Plaster of paris (ACGIH:OSHA)
Plaster of Paris (Ca(SO4).1/2H2O) (9CI)
TA 20

Standards and Regulations

OrganizationStandardReference
Occupational Exposure Limit-MEXICOtime-weighted average 10 mg/m3;short term exposure limit 20 mg/m3, 2004
Occupational Exposure Limit-UNITED KINGDOMtime-weighted average 10 mg/m3 (inhal. dust), OCT2007
Occupational Exposure Limit-UNITED KINGDOMtime-weighted average 4 mg/m3 (resp. dust), OCT2007
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Construction)8H time-weighted average 15 mg/m3, total dustCFRGBR 29,1926.55,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Construction)8H time-weighted average 5 mg/m3, respirable fractionCFRGBR 29,1926.55,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (General Industry)8H time-weighted average 15 mg/m3, total dustCFRGBR 29,1910.1000,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (General Industry)8H time-weighted average 5 mg/m3, respirable fractionCFRGBR 29,1910.1000,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Shipyards)8H time-weighted average 15 mg/m3, total dustCFRGBR 29,1915.1000,1993
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Shipyards)8H time-weighted average 5 mg/m3, respirable fractionCFRGBR 29,1915.1000,1993

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO PLASTER OF PARIS, resp. fraction-air10H time-weighted average 5 mg/m3NIOSH* DHHS #92-100,1992
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO PLASTER OF PARIS, total dust-air10H time-weighted average 10 mg/m3NIOSH* DHHS #92-100,1992
National Occupational Exposure Survey 1983Hazard Code 60122; Number of Industries 21; Total Number of Facilities 2201; Number of Occupations 28; Total Number of Employees Exposed 60066; Total Number of Female Employees Exposed 7948
National Occupational Hazard Survey 1974Hazard Code M4257; Number of Industries 68; Total Number of Facilities 11334; Number of Occupations 61; Total Number of Employees Exposed 192121

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