1. OSHA Occupational Chemical Database
  2. MAGNESIUM OXIDE (FUME)
Label abbreviations descriptions

MAGNESIUM OXIDE (FUME)†

Chemical Identification
Chemical Identification
CAS # 1309-48-4
Formula

MgO
Synonyms

magnesia fume; maglite; magox
Physical Properties
Physical Properties
Physical description A white solid, often found as a powder.
Boiling point 6512°F Molecular weight 40.3
Freezing point/melting point 5072°F Vapor pressure 0 mmHg (approx)
Flash point Vapor density
Specific gravity 3.58 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
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 1610 (total); request using analyte code 9135
Sampling group
Sampler/Sampling media Tared low-ash 37 mm PVC filter, 5 microns [SLTC108]
Sampling time*

240-480 min
Sampling volume (TWA)*

960 L
Sampling flow rate (TWA)*

2 L/min 
Sampling volume (STEL/Peak/C)*

408-960 L
Sampling flow rate (STEL/Peak/C)*

2 L/min 
Analytical method instruments Gravimetric
Method reference OSHA PV2121 (partially validated)
Notes

Samples collected for this compound are first analyzed gravimetrically. If the gravimetric result of a sample yields a concentration below the permissible exposure limit (PEL), the SLTC will report the calculated air concentration for the requested compound solely from the gravimetric result, qualified as less than or equal to the gravimetric result; no further work on the sample will be performed.

If the gravimetric result indicates an air concentration greater than the PEL, the sample will proceed for elemental analysis. Results will be reported from the elemental analysis for the element only; the stated identity of the actual sample contents is based on the assumption that the material sampled is as identified by the compliance officer using available documentation of materials and processes. An elemental result provided may be converted to the desired compound by multiplying the result by the appropriate stoichiometric factor. A 91B report specific to the compound (including the stoichiometric conversion) may by be provided upon request by contacting the laboratory.

The stoichiometric factor for magnesium oxide fume from magnesium is 1.658. The physical form of a sample (dust, mist, or fume) is identified by the compliance officer using available documentation of materials and processes.
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.

Wipe Method
Wipe Method
Sampler/Sampling media

Ghost Wipe [SKC 225-2414]
Bulk Method
Bulk Method

This analysis is for the metal component of this analyte only. The conversion back to the analyte is a mathematical one assuming all metal present is from the analyte source. Request using analyte code M100.
On-Site Screening Techniques
On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
Exposure Limits
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 particulate)

 REL-TWA TLV-TWA

10 mg/m³ (inhalable particulate matter) [2000]

 PEL-TWA

10 mg/m³
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:

See Appendix D - Substances with No Established RELs.

 Notes: Notes:
 

 
Health factors:  See NIH-NLM PubChem. IDLH
 

750 mg/m³
Carcinogenic classifications: TLV-A4 Notes:
 

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

 
Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Magnesium oxide

NIOSH: Pocket Guide to Chemical Hazards - Magnesium oxide fume

Literature References

 
  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) Magnesium oxide. See annual publication for most recent information.
  • Kuschner, W.G., Wong, H., D'Alessandro, A., Quinlan, P. and Blanc, P.D.: Human pulmonary responses to experimental inhalation of high concentration fine and ultrafine magnesium oxide particles. Environ. Health Perspect. 105(11): 1234-1237, 1997.
  • Pohanish, R.P. (editor): Magnesium Oxide (Fume). In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1426-1428.

Last Updated Date : 01/04/2021