HAFNIUM & COMPOUNDS†

Chemical Identification
Chemical Identification
CAS # 7440-58-6
Formula

Hf

Synonyms

Celtium; elemental hafnium; hafnium metal

Physical Properties
Physical Properties
Physical description Highly lustrous, ductile, grayish solid.
Boiling point 8316°F Molecular weight 178.5
Freezing point/melting point 4041°F Vapor pressure 0 mmHg (approx)
Flash point Vapor density
Specific gravity 13.31 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.) 1368
Sampling group
Sampler/Sampling media Pre-assembled cassette with mixed cellulose ester filter (MCEF) 0.8 micron (37 mm) [MAWP037A0]
Sampling time*

480 min

Sampling volume (TWA)*

960 L

Sampling flow rate (TWA)*

2 L/min

Sampling volume (STEL/Peak/C)*
Sampling flow rate (STEL/Peak/C)*
Analytical method instruments AAS
Method reference OSHA ID-121 (fully validated)
Notes

OSHA staff to call the SLTC prior to sampling for detailed instructions.

Special requirements

* 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
Bulk Method
Bulk Method
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

0.5 mg/m³

REL-TWA

0.5 mg/m³

TLV-TWA

0.5 mg/m³ [1990]

PEL-TWA

0.5 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: Notes: Notes:
Health factors:  See NIH-NLM PubChem. IDLH

50 mg/m³

Carcinogenic classifications: Not listed 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 - Hafnium powder, dry

NIOSH: Pocket Guide to Chemical Hazards - Hafnium

Literature References

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Hafnium [7440-58-6] and compounds, as Hf. See annual publication for most recent information.

Last Updated Date : 12/29/2020