Lapse in Appropriations
For workplace safety and health, please call 800-321-6742; for mine safety and health, please call 800-746-1553; for Job Corps, please call 800-733-5627 and for Wage and Hour, please call 866-487-9243 (866-4-US-WAGE). This website is currently not being updated due to the suspension of Federal government services. The last update to the site was 10/1/2025. Updates to the site will start again when the Federal government resumes operations.
TANTALUM, METAL & OXIDE †
| CAS # | 7440-25-7 |
|---|---|
| Formula |
Ta |
| Synonyms |
tantalum metal: Tantalum-181. Synonyms of other tantalum dusts (including oxide dusts) vary depending upon the specific compound. |
| Physical description | Steel-blue to gray solid or black, odorless powder. | ||
|---|---|---|---|
| Boiling point | 9797°F | Molecular weight | 180.9 |
| Freezing point/melting point | 5425°F | Vapor pressure | 0 mmHg (approx) |
| Flash point | Vapor density | ||
| Specific gravity | 16.65 (metal) 14.40 (powder) | 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 | |||
| Analyte code (IMIS no.) | 2325 (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)* | |
| Sampling flow rate (STEL/Peak/C)* | |
| Analytical method instruments | Gravimetric |
| Method reference | OSHA PV2121 (partially validated) |
| Notes | Samples are analyzed gravimetrically. Results will be qualified based on the assumption that the material sampled is as identified by the compliance officer using available documentation of materials and processes; no further work on the sample will be performed due to method limitations. |
| 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 Sampler/Sampling media | |
|---|---|
| Bulk Method |
| Device | |||||
|---|---|---|---|---|---|
| Model/Type | |||||
|
Sampling information (see manufacturer instructions) |
|
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 |
|||||
|---|---|---|---|---|---|---|---|
| PEL-TWA |
5 mg/m³ |
REL-TWA |
5 mg/m³ |
TLV-TWA |
Withdrawn in 2010 for insufficient data. |
PEL-TWA |
5 mg/m³ |
| PEL-STEL | REL-STEL |
10 mg/m³ |
TLV-STEL | PEL-STEL | |||
| PEL-C | REL-C | TLV-C | PEL-C | ||||
| Skin notation |
N |
Skin notation |
N |
Skin notation |
NA |
Skin notation |
N |
| Notes: | Notes: | Notes: | Notes: | ||||
| Health factors: See NIH-NLM PubChem. | IDLH |
2500 mg/m³ |
|||||
| Carcinogenic classifications: Not listed | Notes: | ||||||
| AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3: | |||||||
Additional Resources and Literature References
|
NOAA: CAMEO Chemicals - Tantalum (metal and oxide dust) NIOSH: Pocket Guide to Chemical Hazards - Tantalum (metal and oxide dust) Literature References
|
Last Updated Date : 01/22/2021