PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mercurous oxide; (Mercury(I) oxide) | 15829-53-5 | 1641 |
15.01
11.01
15.02
4.05
7.01
11.00
4.09
4.07
7.10
3.09
|
|||||||||
| Formula | Synonyms | |||||||||||
| Hg2O | MERCURY OXIDE, MERCUROUS OXIDE, MERCUROUS OXIDE (HG2O), MERCURY METAL: COLLOIDAL MERCURY, MERCURY OXIDE BLACK, METALLIC MERCURY, OXIDO DE MERCURIO (DOT SPANISH), OXYDE DE MERCURE (DOT FRENCH), QUICKSILVER | |||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 417.18 | S | 9.8 |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.046 | 0.25 | 0.50 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.78 | 4.3 | 8.5 |
Technical Basis
A review of available sources did not identify acute toxicity data or exposure limits for mercurous oxide. Instead, exposure limits for aryl and inorganic mercury compounds (inorganic mercury, CASRN: 7439-97-6; ceiling limits, TWAs, ERPG-3/ERPG-2, and IDLH) were evaluated for TEEL development. Data sources were selected according to the hierarchy listed in Table 3.1. The mercury aryl and inorganic compounds ERPG-3 and ERPG-2 were selected as the TEEL-3 and TEEL-2, respectively. The mercury TLV-TWA was selected as the TEEL-1 basis and a compound adjustment factor was applied (Section 3.2.2).
• TEEL-1 = MW-adjusted TLV-TWA (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.025 mg/m3) x 3
• TEEL-2 = ERPG-2 (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.25 ppm)
• TEEL-3 = ERPG-3 (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.5 ppm)
This review generated TEEL-3 and TEEL-2 values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was the mercury 1990 IDLH (CASRN: 7439-97-6) and the Rev. 29A TEEL-2 basis was a mercury PEL-C; compound adjustment factors were applied to both limits. The current TEEL-3 and TEEL-2 are unadjusted ERPGs for mercury aryl and inorganic compounds (CASRN: 7439-97-6), a higher priority source (Section 1). The Rev. 29A and current TEEL-1 values, methodology, and source are consistent.
• TEEL-1 = MW-adjusted TLV-TWA (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.025 mg/m3) x 3
• TEEL-2 = ERPG-2 (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.25 ppm)
• TEEL-3 = ERPG-3 (mercury, aryl and inorganic compounds, CASRN: 7439-97-6, 0.5 ppm)
This review generated TEEL-3 and TEEL-2 values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was the mercury 1990 IDLH (CASRN: 7439-97-6) and the Rev. 29A TEEL-2 basis was a mercury PEL-C; compound adjustment factors were applied to both limits. The current TEEL-3 and TEEL-2 are unadjusted ERPGs for mercury aryl and inorganic compounds (CASRN: 7439-97-6), a higher priority source (Section 1). The Rev. 29A and current TEEL-1 values, methodology, and source are consistent.
References
Chemical information: https://pubchem.ncbi.nlm.nih.gov/compound/Mercury_I_-oxide.
Mercury, aryl and inorganic compounds exposure limits: https://www.osha.gov/chemicaldata/504
Mercury compounds [except (organo) alkyls], as Hg IDLH: https://www.cdc.gov/niosh/idlh/7439976.html