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HYDROQUINONE (DIHYDROXYBENZENE)†
| CAS # | 123-31-9 |
|---|---|
| Formula |
C₆H₆O₂ |
| Synonyms |
p-benzenediol; 1,4-benzenediol; dihydroxybenzene; 1,4-dihydroxybenzene; quinol |
| Physical description | Light-tan, light-gray, or colorless crystals. | ||
|---|---|---|---|
| Boiling point | 545°F | Molecular weight | 110.11 |
| Freezing point/melting point | 338°F | Vapor pressure | 4 mmHg at 302°F |
| Flash point | 329°F | Vapor density | 3.81 |
| Specific gravity | 1.332 at 59°F | Ionization potential | 7.95 eV |
| Lower explosive limit (LEL) | Upper explosive limit (UEL) | ||
| NFPA health rating | 2 | NFPA fire rating | 1 |
| NFPA reactivity rating | 0 | NFPA special instruction | |
| Vapor hazard ratio (VHR) | |||
| Historical exceedance percentage | |||
| Target organs | |||
| Analyte code (IMIS no.) | 1490 |
|---|---|
| Sampling group | |
| Sampler/Sampling media | XAD-7 (80/40 mg sections, 20/60 mesh) coated with 10% phosphoric acid [SKC 226-98] |
| Sampling time* |
100 min |
| Sampling volume (TWA)* |
20 L |
| Sampling flow rate (TWA)* |
0.2 L/min |
| Sampling volume (STEL/Peak/C)* |
|
| Sampling flow rate (STEL/Peak/C)* |
|
| Analytical method instruments | HPLC |
| Method reference | OSHA PV2094 (partially validated) |
| Notes |
|
| 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 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 |
2 mg/m³ |
REL-TWA |
|
TLV-TWA |
1 mg/m³ [2007] |
PEL-TWA |
2 mg/m³ |
| PEL-STEL |
|
REL-STEL |
|
TLV-STEL |
|
PEL-STEL |
|
| PEL-C |
|
REL-C |
2 mg/m³ [15 minutes] |
TLV-C |
|
PEL-C |
|
| Skin notation |
N |
Skin notation |
N |
Skin notation |
N |
Skin notation |
N |
| Notes: |
Notes:
|
Notes:
dermal sensitizer (DSEN) |
Notes:
|
||||
| Health factors: See NIH-NLM PubChem. | IDLH |
50 mg/m³ |
|||||
| Carcinogenic classifications: IARC-3, TLV-A3 |
Notes:
|
||||||
|
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
|
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Additional Resources and Literature References
|
NOAA: CAMEO Chemicals - Hydroquinone NIOSH: Pocket Guide to Chemical Hazards - Hydroquinone Literature References
|
Last Updated Date : 12/31/2020